Communication method and apparatus

Abstract

A communication method and apparatus, which are used for realizing a security solution in the process of establishing an MPQUIC between a terminal apparatus and a user plane function. In the present application, the method comprises: after the establishment of a first MA PDU session of a first terminal apparatus is completed, the first terminal apparatus negotiating with a first user plane function to establish a first MPQUIC, wherein the first MPQUIC is associated with the first MA PDU session; and on the basis of a pre-configured key, the first terminal apparatus deriving a key for protecting data of the first MPQUIC, wherein the data of the first MPQUIC is transmitted via a plurality of paths between the first terminal apparatus and the first user plane function, the pre-configured key is further used for establishing a second MPQUIC between the first terminal apparatus and a second user plane function, and the first user plane function and the second user plane function are located within the same public land mobile network.

Description

Communication method and device

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on November 27, 2023, with application number 202311603343.2 and application name “A Communication Method and Device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The embodiments of the present application relate to the field of wireless communications, and in particular to a communication method and apparatus. Background Art

[0004] When the terminal device uses the access traffic steering, switching, splitting (ATSSS) function, the terminal device establishes a multiple access protocol data unit (MA PDU) session with the user plane function (UPF). This session supports multiple access paths (for example, including paths accessed through 3GPP and paths accessed through non-3GPP), and data can be transmitted on different access paths. The ATSSS function further supports the multipath quick user datagram protocol internet connections (MPQUIC) function. That is, the terminal device supports establishing an MPQUIC connection associated with the MA PDU session with the user plane function.

[0005] In the process of establishing an MPQUIC connection between the terminal device and the user plane function, how to implement a security solution is currently an urgent problem to be solved. Summary of the Invention

[0006] The present application provides a communication method and apparatus for implementing a security solution during the process of establishing an MPQUIC connection between a terminal device and a user plane function.

[0007] In a first aspect, the present application provides a communication method, which is performed by a first terminal device. The first terminal device may be a terminal device or a module (such as a chip) in the terminal device.

[0008] The method includes: after a first MA PDU session is established on a first terminal device, the first terminal device negotiates with a first user plane function to establish a first MPQUIC connection, where the first MPQUIC connection is associated with the first MA PDU session. The first terminal device derives, based on a preconfigured key, a key for protecting data of the first MPQUIC connection, where the data of the first MPQUIC connection is transmitted over multiple paths between the first terminal device and the first user plane function. The preconfigured key is also used by the first terminal device to establish a second MPQUIC connection with a second user plane function, where the first user plane function and the second user plane function are located within the same public land mobile network.

[0009] In the above technical solution, after the first MA PDU session of the first terminal device is established, the first terminal device establishes a first MPQUIC connection based on the preconfigured key, thereby achieving security during the process of establishing the first MPQUIC connection between the first terminal device and the first user plane function. Furthermore, the preconfigured key is used not only to establish the first MPQUIC connection between the first terminal device and the first user plane function, but also to establish the second MPQUIC connection between the first terminal device and the second user plane function, where the first user plane function and the second user plane function are located in the same public land mobile network. In other words, the preconfigured key can be used by the first terminal device to establish MPQUIC connections with multiple user plane functions located in the same public land mobile network, thereby reducing the complexity of establishing the MPQUIC connection for the first terminal device.

[0010] In a possible implementation manner, the first terminal device negotiates with the first user plane function to establish a first MPQUIC connection. Specifically, the first terminal device sends an identifier of the preconfigured key to the first user plane function.

[0011] In the above technical solution, the first terminal device sends an identifier of a pre-configured key to the first user plane function to negotiate with the first user plane function to establish a first MPQUIC connection, which helps to be compatible with the way the client and the server establish a connection in the existing transport layer security (TLS) protocol. Here, the client is equivalent to the first terminal device, and the server is equivalent to the first user plane function.

[0012] In a possible implementation, messages transmitted during negotiation are protected based on 3GPP security.

[0013] In the above technical solution, before the first terminal device establishes an MPQUIC connection with the first user plane function, the first MA PDU session of the first terminal device has already been established. That is, 3GPP security protection has already been established. Messages transmitted between the first terminal device and the first user plane function can be protected based on 3GPP security protection. This helps to improve the security of message transmission.

[0014] In one possible implementation, a preconfigured key used by the first terminal device when negotiating with the first user plane function to establish a first MPQUIC connection is the same as a preconfigured key used by the second terminal device when negotiating with the first user plane function to establish a third MPQUIC connection, where the first terminal device and the second terminal device belong to the same home public land mobile network.

[0015] In the above technical solution, the pre-configured key can also be used for the second terminal device to establish a third MPQUIC connection with the first user plane function. That is, the pre-configured key can be used for the first user plane function to establish an MPQUIC connection with multiple terminal devices located in the same home public land mobile network, thereby reducing the complexity of the first user plane function in establishing the MPQUIC connection.

[0016] In one possible implementation, after the first MA PDU session of the first terminal device is established, the first terminal device further negotiates with the first user plane function to establish a fourth MPQUIC connection, where the fourth MPQUIC connection is associated with the first MA PDU session. The first terminal device derives, based on a preconfigured key, a key for protecting data of the fourth MPQUIC connection, where the key for protecting data of the first MPQUIC connection is different from the key for protecting data of the fourth MPQUIC connection.

[0017] In the above technical solution, the first MA PDU session can be associated with multiple MPQUIC connections, and the first terminal device can deduce the key used to protect the data of the MPQUIC connection for each MPQUIC connection, which helps to improve the security of data transmission.

[0018] In one possible implementation, after the second MA PDU session of the first terminal device is established, the first terminal device further negotiates with the second user plane function to establish a second MPQUIC connection, where the second MPQUIC connection is associated with the second MA PDU session. The first terminal device derives a key for protecting data of the second MPQUIC connection based on the preconfigured key.

[0019] In a second aspect, the present application provides a communication method, which is performed by a first user plane function. The first user plane function can be a network element in a hardware device, a software function running on dedicated hardware, or a virtualized function instantiated on a platform (e.g., a cloud platform). Optionally, the first user plane function can be implemented by a single device, can be implemented jointly by multiple devices, or can be a functional module within a single device.

[0020] The method includes: after a first MA PDU session of a first terminal device is established, a first user plane function negotiates with the first terminal device to establish a first MPQUIC connection, the first MPQUIC connection being associated with the first MA PDU session. The first user plane function derives, based on a preconfigured key, a key for protecting data of the first MPQUIC connection, the data of the first MPQUIC connection being transmitted over multiple paths between the first terminal device and the first user plane function. The preconfigured key is also used by the first terminal device to establish a second MPQUIC connection with a second user plane function, the first user plane function and the second user plane function being located within the same public land mobile network.

[0021] In a possible implementation manner, the first user plane function negotiates with the first terminal device to establish a first MPQUIC connection. Specifically, the first user plane function receives an identifier of a pre-configured key from the first terminal device.

[0022] In a possible implementation, messages transmitted during negotiation are protected based on 3GPP security.

[0023] In one possible implementation, a preconfigured key used by the first user plane function to negotiate with the first terminal device to establish the first MPQUIC connection is the same as a preconfigured key used by the first user plane function to negotiate with the second terminal device to establish a third MPQUIC connection. The first terminal device and the second terminal device belong to the same home public land mobile network.

[0024] In one possible implementation, after the first MA PDU session of the first terminal device is established, the first user plane function further negotiates with the first terminal device to establish a fourth MPQUIC connection, where the fourth MPQUIC connection is associated with the first MA PDU session. The first user plane function derives, based on a preconfigured key, a key for protecting data of the fourth MPQUIC connection, where the key for protecting data of the first MPQUIC connection is different from the key for protecting data of the fourth MPQUIC connection.

[0025] The technical effects that can be achieved in the second aspect can be referred to the description of the beneficial effects in the first aspect, and will not be repeated here.

[0026] In a third aspect, the present application provides a communication method applicable to the process of establishing an MA PDU session for a terminal device. The communication method is performed by a session management function, which can be a network element in a hardware device, a software function running on dedicated hardware, or a virtualized function instantiated on a platform (e.g., a cloud platform). Optionally, the session management function can be implemented by one device, or by multiple devices, or it can be a functional module within a device.

[0027] The method includes: a session management function obtaining a shared key from a first function. The session management function sends the shared key to a user plane function, the shared key being used to derive a key for protecting data in an MPQUIC connection between a terminal device and the user plane function, the MPQUIC connection being associated with an MA PDU session, the data for the MPQUIC connection being transmitted over multiple paths between the terminal device and the user plane function.

[0028] In the above technical solution, the session management function sends a shared key to the user plane function. The user plane function can establish an MPQUIC connection with the terminal device based on the shared key, thereby achieving security in the process of establishing the MPQUIC connection between the terminal device and the user plane function.

[0029] In one possible implementation, the session management function further sends a first indication to the terminal device, the first indication being used to instruct the terminal device to establish an MPQUIC connection using a shared key. Exemplarily, the first indication is used to instruct the terminal device to establish an MPQUIC connection with the user plane function using a shared key. In the above technical solution, the terminal device can obtain the shared key based on the first indication, and then establish an MPQUIC connection with the user plane function based on the shared key, thereby achieving security during the process of establishing the MPQUIC connection between the terminal device and the user plane function.

[0030] In one possible implementation, before obtaining the shared key from the first function, the session management function further determines whether to enable a function corresponding to the MPQUIC connection. In one possible implementation, the session management function determines whether to enable the function corresponding to the MPQUIC connection. Specifically, the session management function may receive capability information from the terminal device and determine, based on the capability information of the terminal device, that the terminal device supports establishing an MPQUIC connection; and / or the session management function determines whether to support the function corresponding to the MPQUIC connection.

[0031] In the above technical solution, the session management function can first determine the function corresponding to the MPQUIC connection enabled, and then obtain the shared key from the first function, providing the session management function with the judgment conditions for determining whether an MPQUIC connection can be established between the terminal device and the user plane function.

[0032] In one possible implementation, the session management function obtains the shared key from the first function. Specifically, the session management function may send a second instruction to the first function, where the second instruction is used to instruct the first function to derive the shared key, and the session management function receives the shared key from the first function. Exemplarily, the second instruction is used to instruct the first function to derive the shared key.

[0033] In one possible implementation, after obtaining the shared key from the first function, the session management function also sends an identifier of the shared key to the user plane function. In one example, the shared key identifier is determined by the session management function based on the identifier of the MA PDU session. Accordingly, the session management function also sends the shared key identifier to the first function, and / or the session management function sends the shared key identifier to the terminal device. In another example, the shared key identifier is determined by the first function based on the identifier of the MA PDU session. Accordingly, the session management function sends the identifier of the MA PDU session to the first function and also receives the shared key identifier from the first function.

[0034] In the above technical solution, a method is provided for the session management function to obtain the identifier of the shared key.

[0035] In a possible implementation, the identifier of the shared key is an identifier of the MA PDU session.

[0036] In the above technical solution, since the terminal device records the identifier of the MA PDU session, the session management function does not need to send the identifier of the shared key (ie, the identifier of the MA PDU session) to the terminal device, which helps to reduce signaling interaction.

[0037] In a possible implementation manner, the first function is an access management function, a security anchor function, or an authentication server function.

[0038] In a fourth aspect, the present application provides a communication method applicable to the process of establishing an MA PDU session for a terminal device. The communication method is performed by a user plane function, which can be a network element in a hardware device, a software function running on dedicated hardware, or a virtualized function instantiated on a platform (e.g., a cloud platform). Optionally, the user plane function can be implemented by one device, or by multiple devices, or it can be a functional module within a device.

[0039] The method includes: a user plane function receiving a shared key from a session management function. The user plane function derives, based on the shared key, a key for protecting data in an MPQUIC connection between a terminal device and the user plane function, the MPQUIC connection being associated with an MA PDU session, and data in the MPQUIC connection being transmitted over multiple paths between the terminal device and the user plane function.

[0040] In one possible implementation, the user plane function further receives an identifier of a shared key from a session management function. The identifier of the shared key is determined by the session management function or the first function based on the identifier of the MA PDU session. The user plane function stores the identifier of the shared key in correspondence with the shared key. In one possible implementation, the identifier of the shared key is the identifier of the MA PDU session. Exemplarily, the first function is an access management function, a security anchor function, or an authentication server function.

[0041] The technical effects that can be achieved in the fourth aspect can be referred to the description of the beneficial effects in the third aspect, and will not be repeated here.

[0042] In a fifth aspect, the present application provides a communication method, which is applicable to a process of establishing an MA PDU session for a terminal device. The communication method is executed by the terminal device, which may be a terminal device or a module (such as a chip) in the terminal device.

[0043] The method includes: a terminal device receiving a first indication from a session management function, the first indication being used to instruct a user plane function to establish an MPQUIC connection using a shared key, the MPQUIC connection being associated with an MA PDU session. The terminal device derives the shared key based on the first indication, and further derives a key for protecting data in the MPQUIC connection based on the shared key, the data of the MPQUIC connection being transmitted over multiple paths between the terminal device and the user plane function.

[0044] In a possible implementation, the terminal device further sends capability information of the terminal device to the session management function, where the capability information of the terminal device is used to indicate that the terminal device supports establishing an MPQUIC connection.

[0045] In one possible implementation, the terminal device derives a shared key based on the first indication. Specifically, the terminal device derives the shared key based on the first indication and one or more of the following parameters: an identifier of the terminal device, an identifier of the MA PDU session, and a superior key. Exemplarily, the superior key includes one or more of the following: a security anchor function key, a radio access node (RAN) key, an access management function key, and an authentication server function key.

[0046] In the above technical solution, a method for a terminal device to deduce a shared key is provided.

[0047] In a possible implementation, the identifier of the shared key is determined by the session management function according to the identifier of the MA PDU session, and the terminal device also receives the identifier of the shared key from the session management function.

[0048] In a possible implementation manner, the identifier of the shared key is determined by the terminal device according to the identifier of the MA PDU session, that is, the terminal device also determines the identifier of the shared key according to the identifier of the MA PDU session.

[0049] In a possible implementation, the terminal device further stores the correspondence between the identifier of the shared key and the shared key.

[0050] In a possible implementation, the identifier of the shared key is an identifier of the MA PDU session.

[0051] The technical effects that can be achieved in the fifth aspect can be referred to the description of the beneficial effects in the third aspect, and will not be repeated here.

[0052] In a sixth aspect, the present application provides a communication method, which is applicable to the process of establishing an MA PDU session for a terminal device. The communication method is performed by a first function, which can be a network element in a hardware device, a software function running on dedicated hardware, or a virtualized function instantiated on a platform (e.g., a cloud platform). Optionally, the first function can be implemented by one device, or by multiple devices, or it can be a functional module within a device.

[0053] The method includes: a first function receives a second indication from a session management function, the first function derives a shared key based on the second indication, and the first function sends the shared key to the session management function, wherein the shared key is used to derive a key for protecting data in an MPQUIC connection between a terminal device and a user plane function, the MPQUIC connection is associated with an MA PDU session, and data of the MPQUIC connection is transmitted by multiple paths between the terminal device and the user plane function.

[0054] In one possible implementation, the identifier of the shared key is determined by the session management function based on the identifier of the MA PDU session, and the first function further receives the identifier of the shared key from the session management function. In one possible implementation, the identifier of the shared key is determined by the first function based on the identifier of the MA PDU session, that is, the first function further receives the identifier of the MA PDU session from the session management function and determines the identifier of the shared key based on the identifier of the MA PDU session.

[0055] In one possible implementation, the first function derives a shared key based on the second indication. Specifically, the first function may derive the shared key based on the second indication and one or more of the following parameters: an identifier of the terminal device, an identifier of the MA PDU session, and a superior key. Exemplarily, when the first function is an access management function, the superior key may include one or more of the following: a wireless access node key and an access management function key; when the first function is a security anchor function, the superior key may be a security anchor function key; and when the first function is an authentication server function, the superior key may be an authentication server function key.

[0056] In the above technical solution, a method for deriving a shared key by a first function is provided.

[0057] The technical effects that can be achieved in the sixth aspect can be referred to the description of the beneficial effects in the third aspect, and will not be repeated here.

[0058] In a seventh aspect, the present application provides a communication method, which is performed by a session management function. The session management function can be a network element in a hardware device, a software function running on dedicated hardware, or a virtualized function instantiated on a platform (e.g., a cloud platform). Optionally, the session management function can be implemented by a single device, by multiple devices, or as a functional module within a single device.

[0059] The method includes: a session management function receiving a session establishment request from a terminal device, the session establishment request being used to request establishment of an MA PDU session for the terminal device. The session management function sending a certificate request instruction to a user plane function based on the session establishment request, the certificate request instruction being used to instruct a certificate authority to request a certificate for the user plane function. The certificate of the user plane function is used to: during establishment of an MPQUIC connection between the terminal device and the user plane function, enable the terminal device to authenticate the user plane function, associate the MPQUIC connection with the MA PDU session, and transmit data for the MPQUIC connection via multiple paths between the terminal device and the user plane function.

[0060] In the above technical solution, the session management function sends a certificate application indication to the user plane function. The certificate application indication is used to instruct the certificate certification authority to request a certificate for the user plane function. The certificate of the user plane function is used for: during the establishment of the MPQUIC connection between the terminal device and the user plane function, the terminal device authenticates the user plane function. In this way, security is achieved during the process of establishing the MPQUIC connection between the terminal device and the user plane function.

[0061] In one possible implementation, after the session management function sends the certificate request indication to the user plane function, the session management function also receives a confirmation indication from the user plane function, where the confirmation indication is used to indicate that the user plane function successfully requested the certificate from the user plane function. Exemplarily, the session management function determines, based on the confirmation indication, that the user plane function successfully requested the certificate from the user plane function.

[0062] In the above technical solution, after receiving the confirmation indication, the session management function continues to execute the subsequent MA PDU session establishment process, and then the terminal device can initiate the process of establishing an MPQUIC connection with the user plane function after the MA PDU session establishment process is completed. This avoids the problem of the terminal device initiating the process of establishing an MPQUIC connection with the user plane function before the user plane function has requested the user plane function's certificate, resulting in the terminal device and the user plane function failing to establish an MPQUIC connection.

[0063] In one possible implementation, the session management function further sends a first certificate request to a certificate authority. The first certificate request includes the public key of the terminal device. The public key of the terminal device is used to generate a certificate for the terminal device. Exemplarily, the public key of the terminal device is used by the certificate authority to generate the certificate for the terminal device. The session management function receives the certificate of the terminal device from the certificate authority and sends the certificate of the terminal device to the terminal device. The certificate of the terminal device is used to authenticate the terminal device during the establishment of the MPQUIC connection. The above technical solution provides an implementation of a two-way authentication method.

[0064] In one possible implementation, before the session management function sends the first certificate request to the certificate authority, it also sends a mutual authentication indication to the terminal device. The mutual authentication indication is used to indicate that the authentication method used during the MPQUIC connection establishment process is mutual authentication. Subsequently, the session management function receives the public key of the terminal device. Exemplarily, the mutual authentication indication may be carried in a radio resource control reconfiguration message.

[0065] In the above technical solution, the session management function sends a two-way authentication instruction to the terminal device, then receives the terminal device's public key and requests the terminal device's certificate from the certificate authority based on the terminal device's public key. This avoids the unnecessary data transmission caused by the terminal device also sending its public key to the session management function in a one-way authentication method.

[0066] In a possible implementation, the session establishment request includes the public key of the terminal device. Exemplarily, the certificate of the terminal device may be carried in a radio resource control reconfiguration message.

[0067] In the above technical solution, the terminal device can use the two-way authentication indication by default, and then carry the public key of the terminal device in the session establishment request, avoiding the session management function instructing the terminal device to generate the public key of the terminal device, which helps to improve the efficiency of establishing the MPQUIC connection.

[0068] In a possible implementation, the first certificate request also includes an MA PDU session identifier, which is used to determine the identifier of the certificate of the terminal device. Exemplarily, the MA PDU session identifier is used by the certificate certification authority to determine the identifier of the certificate of the terminal device.

[0069] In one possible implementation, the session management function also sends the identifier of the MA PDU session to the user plane function. The identifier of the MA PDU session is used to determine the identifier of the certificate of the user plane function. Exemplarily, the identifier of the MA PDU session is used by the certificate authentication authority to determine the identifier of the certificate of the user plane function.

[0070] In the above technical solution, the identifier of the MA PDU session is used to determine the identifier of the certificate, so that the certificate is specific to each MA PDU session, which helps to improve the security of the MPQUIC connection.

[0071] In one possible implementation, before sending the certificate request indication to the user plane function, the session management function further determines whether to enable the functionality corresponding to the MPQUIC connection. Exemplarily, the session management function determines whether to enable the functionality corresponding to the MPQUIC connection by, for example, receiving capability information from the terminal device and determining, based on the capability information of the terminal device, that the terminal device supports establishing an MPQUIC connection, and / or the session management function determines whether to support the functionality corresponding to the MPQUIC connection.

[0072] In the above technical solution, the session management function can first determine the function corresponding to the MPQUIC connection, and then send a certificate application instruction to the user plane function, providing the session management function with the judgment conditions for determining whether an MPQUIC connection can be established between the terminal device and the user plane function.

[0073] In an eighth aspect, the present application provides a communication method, which is executed by a terminal device, which may be a terminal equipment or a module (such as a chip) in the terminal equipment.

[0074] The method includes: a terminal device sending a session establishment request to a session management function, the session establishment request being used to request establishment of an MA PDU session for the terminal device; after the MA PDU session is established, the terminal device may establish an MPQUIC connection with a user plane function. Furthermore, during the process of establishing the MPQUIC connection between the terminal device and the user plane function, the terminal device receives a user plane function certificate from the user plane function and authenticates the user plane function based on the user plane function certificate; wherein the MPQUIC connection is associated with the MA PDU session, and data for the MPQUIC connection is transmitted via multiple paths between the terminal device and the user plane function.

[0075] In one possible implementation, the terminal device also receives a certificate of the terminal device from the session management function; during the establishment of the MPQUIC connection between the terminal device and the user plane function, the terminal device sends the certificate of the terminal device to the user plane function, and the certificate of the terminal device is used by the user plane function to authenticate the terminal device.

[0076] There are three ways for the terminal device to receive the terminal device certificate from the session management function:

[0077] Mode 1: The terminal device uses a two-way authentication mode by default. The terminal device first generates a public key of the terminal device, and then when sending a session establishment request, carries the public key of the terminal device in the session establishment request, wherein the public key of the terminal device is used to request the certificate of the terminal device from the certificate certification authority. Accordingly, the session management function can obtain the public key of the terminal device from the session establishment request, request the certificate of the terminal device from the certificate certification authority based on the public key of the terminal device, and send the certificate of the terminal device to the terminal device. Exemplarily, the PDU session establishment process further includes an access network specific resource establishment (AN-specific resource setup) process. In the AN-specific resource setup process, the terminal device receives the certificate of the terminal device. Optionally, the terminal device also receives an indication that the MA PDU session establishment is complete. For example, the terminal device receives a radio resource control reconfiguration message, and the radio resource control reconfiguration message includes the certificate of the terminal device. Optionally, the radio resource control reconfiguration message may also carry the indication information.

[0078] In mode 2, the terminal device does not carry the public key of the terminal device in the session establishment request, but generates the public key of the terminal device after receiving the two-way authentication indication from the session management function. That is, the two-way authentication indication is used to indicate that the authentication method in the process of establishing the MPQUIC connection is a two-way authentication method. Exemplarily, the PDU session establishment process further includes an AN-specific resource setup process, in which the terminal device receives the two-way authentication indication. Optionally, the terminal device also receives indication information that the MA PDU session establishment is completed. For example, the terminal device receives a radio resource control reconfiguration message, and the radio resource control reconfiguration message includes a two-way authentication indication. Optionally, the radio resource control reconfiguration message may also carry indication information. Further, the terminal device sends the public key of the terminal device to the session management function, and the public key of the terminal device is used to request the certificate of the terminal device from the certificate certification authority. Accordingly, the session management function may request the certificate of the terminal device from the certificate certification authority based on the certificate of the terminal device, and send the certificate of the terminal device to the terminal device.

[0079] Mode 3: The terminal device does not carry the public key of the terminal device in the session establishment request, but generates the public key of the terminal device after receiving the two-way authentication indication from the session management function. That is, the two-way authentication indication is used to indicate that the authentication method in the establishment process of the MPQUIC connection is a two-way authentication method. Exemplarily, the PDU session establishment process further includes an authentication method notification process, in which the terminal device receives a two-way authentication indication, for example, the terminal device receives a radio resource control reconfiguration message, and the radio resource control reconfiguration message includes a two-way authentication indication. Further, the terminal device sends the public key of the terminal device to the session management function, and the public key of the terminal device is used to request the certificate of the terminal device from the certificate certification authority. Accordingly, the session management function can request the certificate of the terminal device from the certificate certification authority based on the certificate of the terminal device, and send the certificate of the terminal device to the terminal device. Exemplarily, the PDU session establishment process further includes an AN-specific resource setup process, in which the terminal device receives the certificate of the terminal device. Optionally, the terminal device also receives indication information that the MA PDU session establishment is completed, for example, the terminal device receives a wireless resource control reconfiguration message, and the wireless resource control reconfiguration message includes the certificate of the terminal device. Optionally, the wireless resource control reconfiguration message may also carry indication information.

[0080] Exemplarily, the indication information indicating that the MA PDU session establishment is completed is, for example, PDU session establishment acceptance.

[0081] In a possible implementation, the terminal device further generates a private key of the terminal device, and the private key of the terminal device is used to sign the transmitted messages during the establishment of the MPQUIC connection.

[0082] In a possible implementation manner, the terminal device further receives an identifier of a certificate of the user plane function from the user plane function; the identifier of the certificate of the user plane function is determined according to the identifier of the MA PDU session.

[0083] In a possible implementation, the terminal device further sends capability information of the terminal device to the session management function, where the capability information of the terminal device is used to indicate that the terminal device supports establishing an MPQUIC connection.

[0084] The technical effects that can be achieved in the eighth aspect can be referred to the description of the beneficial effects in the seventh aspect, and will not be repeated here.

[0085] In a ninth aspect, the present application provides a communication method, which is performed by a user plane function. The user plane function can be a network element in a hardware device, a software function running on dedicated hardware, or a virtualized function instantiated on a platform (e.g., a cloud platform). Optionally, the user plane function can be implemented by a single device, can be implemented by multiple devices, or can be a functional module within a single device.

[0086] The method includes: during the process of establishing an MA PDU session of a terminal device, a user plane function receives a certificate application instruction from a session management function, and requests a certificate for the user plane function from a certificate certification authority according to the certificate application instruction. During the process of establishing an MPQUIC connection between the terminal device and the user plane function, the user plane function sends the certificate of the user plane function to the terminal device, and the certificate of the user plane function is used by the terminal device to authenticate the user plane function. That is, the certificate of the user plane function is used by the terminal device to authenticate the user plane function during the process of establishing the MPQUIC connection between the terminal device and the user plane function; wherein the MPQUIC connection is associated with the MA PDU session, and data of the MPQUIC connection is transmitted via multiple paths between the terminal device and the user plane function.

[0087] In one possible implementation, the user plane function requests a certificate of the user plane function from the certificate authentication authority. Specifically, the user plane function sends a second certificate request to the certificate authentication authority, and the second certificate request is used to request a certificate of the user plane function from the certificate authentication authority; the user plane function receives the certificate of the user plane function from the certificate authentication authority.

[0088] In a possible implementation, during the establishment of the MPQUIC connection between the terminal device and the user plane function, the user plane function further receives a certificate of the terminal device and authenticates the terminal device based on the certificate of the terminal device.

[0089] In a possible implementation, the second certificate request includes the public key of the user plane function, which is used to determine the certificate of the user plane function. Furthermore, the user plane function generates the public key of the user plane function before sending the second certificate request.

[0090] In a possible implementation, the user plane function also generates a private key of the user plane function, and the private key of the user plane function is used to sign the transmitted messages during the establishment of the MPQUIC connection.

[0091] In one possible implementation, the second certificate request also includes an MA PDU session identifier, which is used to determine the identifier of the user plane function's certificate. Furthermore, before sending the second certificate request, the user plane function also receives the MA PDU session identifier from the session management function.

[0092] In a possible implementation, after successfully obtaining the user plane function certificate from the certificate authority, the user plane function sends a confirmation indication to the session management function, where the confirmation indication is used to indicate that the user plane function successfully requested the user plane function certificate.

[0093] The technical effects that can be achieved in the above-mentioned ninth aspect can be referred to the description of the beneficial effects in the above-mentioned seventh aspect, and will not be repeated here.

[0094] In a tenth aspect, an embodiment of the present application provides a communication device,

[0095] The device may be the first terminal device in the above-mentioned first aspect or any possible implementation manner of the first aspect.

[0096] The device may be the first user plane function in the above-mentioned second aspect or any possible implementation manner of the second aspect.

[0097] The device may be the session management function in the third aspect or any possible implementation of the third aspect.

[0098] The device may be the user plane function in the fourth aspect or any possible implementation of the fourth aspect.

[0099] The device may be a terminal device in the fifth aspect or any possible implementation of the fifth aspect.

[0100] The device may be the first function in the sixth aspect or any possible implementation of the sixth aspect.

[0101] The device may be the session management function in the seventh aspect or any possible implementation of the seventh aspect.

[0102] The device may be a terminal device in the above-mentioned eighth aspect or any possible implementation of the eighth aspect.

[0103] The device may be the user plane function in the ninth aspect or any possible implementation of the ninth aspect.

[0104] The functions of the above-mentioned communication device can be implemented by hardware, or by hardware executing corresponding software. The hardware or software includes one or more modules, units or means corresponding to the above-mentioned functions.

[0105] In one possible implementation, the structure of the device includes a processing module and a transceiver module, wherein the processing module is configured to support the device to execute the method in any implementation of any aspect of the first aspect to the ninth aspect. The transceiver module is used to support communication between the device and other communication devices. For example, when the device is the first terminal device in the first aspect or any possible implementation of the first aspect, it can transmit data with the first user plane function. The communication device may also include a storage module, which is coupled to the processing module and stores program instructions and data necessary for the device. As an example, the processing module may be a processor, the communication module may be a transceiver, and the storage module may be a memory. The memory may be integrated with the processor or may be set separately from the processor.

[0106] In another possible implementation, the structure of the device includes a processor and may also include a memory. The processor is coupled to the memory and can be used to execute computer program instructions stored in the memory, so that the device performs the method in any implementation of any aspect of the first to ninth aspects above. Optionally, the device also includes a communication interface, and the processor is coupled to the communication interface. When the device is a network device or a terminal device, the communication interface can be a transceiver or an input / output interface; when the device is a chip included in the network device or a chip included in the terminal device, the communication interface can be the input / output interface of the chip. Optionally, the transceiver can be a transceiver circuit, and the input / output interface can be an input / output circuit.

[0107] In the eleventh aspect, an embodiment of the present application provides a chip system, comprising: a processor and a memory, the processor being coupled to the memory, the memory being used to store programs or instructions, and when the programs or instructions are executed by the processor, the chip system executes any method in any implementation of any aspect from the first to the ninth aspect above.

[0108] Optionally, the chip system further includes an interface circuit for transmitting interactive code instructions to the processor.

[0109] Optionally, there may be one or more processors in the chip system, and the processor may be implemented in hardware or software. When implemented in hardware, the processor may be a logic circuit, an integrated circuit, etc. When implemented in software, the processor may be a general-purpose processor implemented by reading software code stored in a memory.

[0110] Optionally, the chip system may include one or more memories. The memory may be integrated with the processor or provided separately from the processor. For example, the memory may be a non-transient processor, such as a read-only memory (ROM), which may be integrated with the processor on the same chip or provided on separate chips.

[0111] In the twelfth aspect, the present application provides a computer-readable storage medium, which stores a computer program or instruction. When the computer program or instruction is executed by a communication device, the communication device performs the functions of any implementation method of any aspect from the first to the ninth aspect.

[0112] In the thirteenth aspect, the present application provides a computer program product, which includes a computer program or instructions. When the computer program or instructions are executed by a communication device, it performs the functions of any implementation method of any aspect from the first to the ninth aspect.

[0113] In a fourteenth aspect, an embodiment of the present application provides a communication system,

[0114] The communication system includes: the first terminal device in the first aspect or any possible implementation of the first aspect; and the first user plane function in the second aspect or any possible implementation of the second aspect. Or,

[0115] The communication system includes: the session management function in the third aspect or any possible implementation of the third aspect; the user plane function in the fourth aspect or any possible implementation of the fourth aspect; the terminal device in the fifth aspect or any possible implementation of the fifth aspect; and the first function in the sixth aspect or any possible implementation of the sixth aspect. Or,

[0116] The communication system includes: the session management function in the above-mentioned seventh aspect or any possible implementation of the seventh aspect; the terminal device in the above-mentioned eighth aspect or any possible implementation of the eighth aspect; and the user plane function in the above-mentioned ninth aspect or any possible implementation of the ninth aspect.

[0117] The technical effects that can be achieved in any of the tenth to fourteenth aspects can be referred to the description of the beneficial effects in the first to ninth aspects, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0118] FIG1 is a schematic diagram of a communication system architecture;

[0119] Figure 2 shows the first 5G system architecture supported by ATSSS;

[0120] Figure 3 shows the second 5G system architecture supported by ATSSS;

[0121] Figure 4 shows the third 5G system architecture supported by ASSSS;

[0122] FIG5 is a diagram of a protocol stack architecture for an MPQUIC connection;

[0123] FIG6 is a flow chart of the first communication method provided by this application;

[0124] FIG7 is a schematic diagram of the algorithm suite provided by this application;

[0125] FIG8 is a flowchart of a specific implementation of the first communication method provided in this application;

[0126] FIG9 is a flow chart of a second communication method provided by the present application;

[0127] FIG10 is a schematic diagram of the direction of key deduction provided by this application;

[0128] FIG11 is a flow chart of a first specific implementation of the second communication method provided in this application;

[0129] FIG12 is a flow chart of a second specific implementation of the second communication method provided in this application;

[0130] FIG13 is a flow chart of a third communication method provided by this application;

[0131] FIG14 is a flow chart of a first specific implementation of the third communication method provided in this application;

[0132] FIG15 is a flow chart of a second specific implementation of the third communication method provided in this application;

[0133] FIG16 is a schematic structural diagram of a first communication device provided by this application;

[0134] FIG17 is a schematic structural diagram of the second communication device provided in this application. DETAILED DESCRIPTION

[0135] The following first explains the relevant technical features involved in the embodiments of the present application. It should be noted that these explanations are intended to make the embodiments of the present application easier to understand and should not be regarded as limiting the scope of protection claimed by the present application.

[0136] 1. Transport layer security (TLS)

[0137] The TLS protocol is a widely adopted security protocol designed to protect the privacy and data security of Internet communications.

[0138] The main purpose of the TLS protocol is to protect the communication between the client (also known as the web application) and the server (Server), and to encrypt and protect the integrity of the related communication data.

[0139] The TLS protocol mainly includes the handshake protocol and the record layer protocol. The handshake protocol mainly performs identity authentication and key negotiation between the two parties, and the record layer protocol uses the key negotiated by the handshake protocol to provide security protection for application layer data (including encryption protection and integrity protection).

[0140] In the handshake protocol, the client and server mainly include two rounds of interaction:

[0141] The first round of interaction: Both parties exchange keys.

[0142] The TLS protocol supports two key exchange modes:

[0143] (1) Pre-shared key exchange modes (PSK): The client sends a ClientHello to the server, which carries two extended options: psk_key_share_modes and pre-shared_key (PSK). psk_key_share_modes indicates the use of the pre-shared key exchange mode for key negotiation, and pre_shared_key indicates the pre-shared key that the client wishes to use. Similarly, the server sends a ServerHello to the client, which also carries the above two extended options. The client and server can then negotiate a pre-shared key to be used in the second round of interaction.

[0144] (2) Key sharing modes (key_share modes): The client generates its temporary private key and temporary public key, and sends a ClientHello to the server, which carries the client's temporary public key. The server generates its temporary private key and temporary public key, and sends a ServerHello to the client, which carries the server's temporary public key. Furthermore, the server obtains the client's temporary public key from the ClientHello, and generates a shared key based on the server's temporary private key and the client's temporary public key. The client obtains the server's temporary public key from the ServerHello, and generates a shared key based on the server's temporary public key and the client's temporary private key. It can be understood that the shared key generated by the client is the same as the shared key generated by the server, that is, the client and server negotiate a shared key to be used by both in the subsequent authentication phase.

[0145] Second round of interaction: Both parties perform identity authentication.

[0146] Identity authentication currently supports two methods:

[0147] (1) Pre-shared key authentication: corresponds to the pre-shared key exchange mode in the first round of interaction.

[0148] The client uses the handshake key derived from the pre-shared key to calculate the message authentication code (MAC) of the previous interactive information, forming Finished message 1 (it can be understood that Finished message 1 includes the MAC calculated by the client) and sends Finished message 1 to the server. In response, the server verifies the MAC in Finished message 1 based on the handshake key derived from its own pre-shared key. If the verification succeeds, it determines that the client and itself have the same pre-shared key.

[0149] Similarly, the server uses the handshake key derived from the pre-shared key to calculate the MAC of the previous interactive information, forming Finished message 2 (understandably, Finished message 2 includes the MAC calculated by the server) and sends Finished message 2 to the client. In return, the client verifies the MAC in Finished message 2 based on the handshake key derived from its own pre-shared key. If the verification succeeds, it determines that the server and itself have the same pre-shared key.

[0150] (2) Certificate authentication: Corresponding to the key sharing mode in the first round of interaction. Certificates are also called digital certificates.

[0151] Two-way authentication can include the server authenticating the client, and the client authenticating the server.

[0152] During the process of Server authenticating the Client: the Client uses the private key corresponding to its certificate to sign the previous interactive information to obtain the signature information (certificate verification), and uses the handshake key derived from the negotiated shared key to calculate the MAC of the previous interactive information to form Finished message 1. The Client sends the Client's certificate, signature information, and Finished message 1 to the Server. In response, the Server verifies the Client's identity based on the Client's certificate and signature information, and determines that the shared key derived by itself is the same as the shared key derived by the Client based on the MAC in Finished message 1.

[0153] During client authentication, the server signs the previous interaction message using the private key corresponding to its certificate, and uses the handshake key derived from the shared key to calculate the MAC of the previous interaction message, forming Finished message 2 (which includes the MAC calculated by the server). The server then sends its certificate, signature, and Finished message 2 to the client. The client then verifies the server's identity based on its certificate and signature, and confirms, based on the MAC in Finished message 2, that the shared key it derived is the same as the shared key derived by the server.

[0154] One-way authentication is specifically the client authenticating the server, which will not be explained in detail.

[0155] Here, previous interaction information refers to information transmitted during the previous interaction between the client and server. For example, if the client has already sent a ClientHello to the server and the server has already sent a ServerHello to the client before using the handshake key derived from the pre-shared key to calculate the MAC of the previous interaction information, then the previous interaction information includes both the ClientHello and the ServerHello.

[0156] After two rounds of interaction, both parties can derive a common protection key to protect subsequent application layer data.

[0157] 2. Security Mechanisms of the Quick User Datagram Protocol Internet Connection (QUIC) Protocol

[0158] The QUIC protocol uses the TLS handshake protocol to establish a protection key, which is used to subsequently protect QUIC data packets. The TLS handshake protocol operates on the premise that the client and server pre-share a key, and the client and server each authenticate each other's identity based on the pre-shared key; or, the client and server pre-configure their own certificates, and the client and server each authenticate each other's identity based on the other's certificate; or, the server unilaterally pre-configures the server's certificate, and the client authenticates the server's identity based on the server's certificate. In other words, it can be understood that before the server and client transmit data based on the QUIC protocol, they also need to negotiate a pre-shared key, or pre-configure certificates on both sides or one side to establish relevant security mechanisms.

[0159] 3. 5G Network Architecture

[0160] Figure 1 is a schematic diagram of a communication system architecture. The communication system architecture shown in Figure 1 includes three components: the terminal device component, the data network (DN), and the operator network component. The following briefly describes the functions of some of these network elements.

[0161] The operator network may include one or more of the following network elements:

[0162] Authentication server function (AUSF), network exposure function (NEF), policy control function (PCF), unified data management (UDM), unified data repository (UDR), network repository function (NRF), access and mobility management function (AMF), session management function (SMF), user plane function (UPF), security anchor function (SEAF), authentication repository and processing function (ARPF), and access network, etc.

[0163] The portion of the aforementioned carrier network, excluding the radio access network, can be referred to as the core network. In one possible implementation, the carrier network also includes an application function (AF). Alternatively, the AF may not belong to the carrier network but to a third party. The AF's primary function is to inform the PCF of the latest third-party service requirements for a particular application. Based on these requirements, the PCF generates corresponding quality of service (QoS) rules to ensure that the services provided by the network meet the requirements set by the third party.

[0164] A terminal device (UE), also known as user equipment (UE), is a device with wireless transceiver capabilities. It can be deployed on land, indoors or outdoors, handheld or in a vehicle; on water (such as ships); or in the air (such as on airplanes, balloons, and satellites). Terminal devices can be mobile phones, tablets, computers with wireless transceiver capabilities, virtual reality (VR) terminals, augmented reality (AR) terminals, wireless terminals used in industrial control, self-driving vehicles, remote medical devices, smart grids, transportation safety, smart cities, and smart homes. The terminal device stores long-term keys and related functions. During bidirectional authentication, the terminal device uses these long-term keys and related functions to verify the network's authenticity. For the convenience of description, the following description takes the terminal device as UE as an example. In this application, UE can be replaced by the terminal device.

[0165] The above-mentioned UE can establish a connection with the operator network through the interface provided by the operator network (such as N1, etc.), and use the data and / or voice services provided by the operator network. The UE can also access the DN through the operator network, use the operator services deployed on the DN, and / or services provided by a third party. Among them, the above-mentioned third party may be a service provider other than the operator network and the UE, and can provide data and / or voice services to the UE. Among them, the specific form of the above-mentioned third party can be determined according to the actual application scenario and is not limited here.

[0166] The core network part includes user plane functions and control plane functions.

[0167] The user plane function (UPF) is the interface with the data network, performing functions such as forwarding user plane data (such as packets), QoS control, session / flow-level billing and statistics, and bandwidth limiting.

[0168] The control plane functions mainly carry out user registration and authentication, mobility management, and delivery of data packet forwarding policies and QoS control policies to the user plane functions. The control plane functions can be further refined to include other network elements besides the UPF, such as the AMF, SMF, and SEAF.

[0169] The AMF primarily handles user registration, location management, and access authentication / authorization during user mobility. It is also responsible for delivering user policies between the UE and PCF.

[0170] SMF is mainly responsible for establishing corresponding session connections when users initiate services and providing specific services to users, such as sending data packet forwarding strategies and QoS strategies to UPF based on the NG4 interface between SMF and UPF.

[0171] SEAF is responsible for initiating authentication requests to AUSF and completing network-side authentication of the UE during the authentication and key agreement (AKA) process. Optionally, SEAF is part of AMF.

[0172] The AUSF is primarily responsible for authenticating users and determining the legitimacy of the UE to determine whether the UE is allowed to access the network. For example, the AUSF can be used to receive authentication requests from the SEAF; select an authentication method; complete network-side authentication of the UE when using the AKA process; request an authentication vector from the ARPF; return an authentication response to the SEAF, and generate an anchor key.

[0173] ARPF, stores long-term keys; receives authentication vector requests from AUSF; calculates authentication vectors using long-term keys; and sends authentication vectors to AUSF.

[0174] UDM is mainly responsible for storing UE subscription data, user access authorization and other functions.

[0175] UDR is mainly responsible for the storage and access of contract data, policy data, application data and other types of data.

[0176] PCF is mainly responsible for issuing business-related policies to AMF or SMF.

[0177] NEF is mainly used to support the opening of capabilities and events. For example, NEF is used to interact with third parties, allowing third parties to indirectly interact with network elements within certain 3GPP networks.

[0178] The AF primarily communicates application-side requirements for the network to the PCF, enabling the PCF to generate corresponding policies. The AF can be a third-party functional entity or an application service deployed by an operator, such as the Internet Protocol (IP) Multimedia Subsystem (IMS) voice call service.

[0179] NRF can be used to provide network element discovery capabilities, providing network element information corresponding to the network element type based on requests from other network elements. NRF also provides network element management services such as network element registration, update, and deregistration, as well as network element status subscription and push.

[0180] A DN is a network located outside of a carrier network. A carrier network can connect to multiple DNs, and a variety of services can be deployed on the DN, providing UEs with data and / or voice services. For example, a DN is the private network of a smart factory. Sensors installed in the workshop can be UEs. The DN houses a control server for these sensors, which can provide services to the sensors. The sensors can communicate with the control server, receive instructions from the control server, and transmit collected sensor data to the control server based on the instructions. Another example is a DN that is a company's internal office network. An employee's mobile phone or computer can be a UE, allowing them to access information and data resources on the company's internal office network.

[0181] In Figure 1, Nausf, Nnef, Nnrf, Npcf, Nudm, Naf, Namf, Nsmf, N1, N2, N3, N4, and N6 are interface sequence numbers. The meanings of these interface sequence numbers can be found in the 3GPP protocol and are not limited here.

[0182] It can be understood that the above-mentioned network elements or functions can be network elements in hardware devices, software functions running on dedicated hardware, or virtualized functions instantiated on a platform (e.g., a cloud platform). Optionally, the above-mentioned network elements or functions can be implemented by one device, or by multiple devices together, or can be a functional module within a device, and the embodiments of the present application are not limited to this. The functions in the present application can also be referred to as functional entities, entities, network elements, functional network elements, etc. For example, the session management function can be referred to as a session management entity, session management network element, etc. The access and mobility management function (also referred to as the access management function), user plane function, and session management function in the embodiments of the present application are respectively illustrated by taking the AMF, UPF, and SMF in Figure 1 as examples. Of course, they can also be network elements with the functions of the above-mentioned AMF, UPF, and SMF in future communications such as the sixth generation (6G) network, and the embodiments of the present application are not limited to this.

[0183] The access network is a subnetwork of the operator's network and serves as the implementation system between the service nodes and UEs within the operator's network. To access the operator's network, the UE first passes through the access network, and then connects to the service nodes of the operator's network through the access network.

[0184] The access network may include a 3GPP access network and / or a non-3GPP access network, that is, the UE may access the core network through the 3GPP access network and / or the non-3GPP access network. Non-3GPP access network refers to an access network other than 3GPP, such as wireless local area networks (WLAN), wireless fidelity (Wi-Fi) networks, worldwide interoperability for microwave access (WiMAX), fixed networks, etc. The access type of the UE in the 3GPP access network may be referred to as 3GPP access (3GPP access), and the access type of the UE in the non-3GPP access network may be referred to as non-3GPP access (non 3GPP access). For a schematic diagram of the UE accessing the core network through 3GPP access and non-3GPP access respectively, please refer to the following description of the ASSS function.

[0185] Access devices of the 3GPP access network may include, but are not limited to, the next-generation base station (gNB) in 5G, evolved node B (eNB), radio network controller (RNC), node B (NB), base station controller (BSC), base transceiver station (BTS), home base station (e.g., home evolved node B, or home node B, HNB), baseband unit (BBU), transmission point (TRP), transmitting point (TP), mobile switching center, etc. Messages transmitted between the UE and the access devices of the 3GPP access network may be radio resource control (RRC) messages, user plane (UP) messages, etc. For ease of description, the access devices of the 3GPP access network may be collectively referred to as radio access nodes (RAN).

[0186] The access equipment of the non-3GPP access network may include, but is not limited to, non-3GPP interworking function (N3IWF) equipment and next generation packet data gateway (ngPDG). N3IWF is similar to the evolved packet data gateway (ePDG) in long term evolution (LTE). In 5G, it is used to establish an Internet Protocol security (IPsec) tunnel with the UE when the UE accesses the core network through a non-3GPP access network. For example, the N3IWF device may include a router, etc.

[0187] 4. ATSSS

[0188] In the ATSSS scenario, the UE supports one or more steering functions, such as the multipath transmission control protocol (MPTCP) function, the multipath quick user datagram protocol internet connections (MPQUIC) function, the ATSSS lower layer (ATSSS-LL) function, etc. When the UE uses one of the above steering functions, it can specifically allow the UE to steer, switch, and divert service traffic across 3GPP access and non-3GPP access according to the ASSSS rules provided by the network.

[0189] The UPF can support the MPTCP proxy function, which communicates with the MPTCP function in the UE by using the MPTCP protocol. The UPF can support the MPQUIC proxy function, which communicates with the MPQUIC function in the UE by using the MPQUIC protocol. The UPF can also support the ASSSS-LL function, which is similar to the ASSSS-LL function defined for the UE. In addition, the UPF supports the performance measurement function (PMF), which the UE can use to measure the performance of the corresponding access in the user plane of the 3GPP access and / or the user plane of the non-3GPP access.

[0190] A multi-access protocol data unit (PDU) connection service is implemented in the ATSSS scenario, which can use a 3GPP access network and a non-3GPP access network at the same time to exchange PDUs between the UE and the DN. The multi-access PDU connection service is implemented by establishing an MA PDU session, that is, establishing a PDU session for user plane resources on two access networks. This assumes that the single network slice selection assistance information (S-NSSAI) of the PDU session allows both 3GPP access and non-3GPP access. In other words, the MA PDU session is a PDU session that provides a multi-access PDU connection service, which can use one access at a time or use a 3GPP access and a non-3GPP access at the same time.

[0191] A UE may request an MA PDU session when it is registered over a 3GPP access and a non-3GPP access, or when it is registered over only one access. After an MA PDU session is established, when user plane resources are available on both access networks, the UE applies network provided policies (such as ASSS rules) and considers local conditions (such as network interface availability, signal loss conditions, user preferences, etc.) to decide how to distribute uplink traffic across the two access networks. Similarly, the UPF anchor for the MA PDU session applies network provided policies (such as N4 rules) and feedback information received from the UE over the user plane (such as access network unavailability or availability) to decide how to distribute downlink traffic across the two N3 / N9 tunnels and the two access networks. When user plane resources are available on only one access network, the UE applies ASSS rules and considers local conditions that trigger the establishment or activation of user plane resources on the other access.

[0192] In the same MA PDU session of the UE, the MPTCP function can be used to steer TCP flows, the MPQUIC function can be used to steer User Datagram Protocol (UDP) flows, and the ATSSS-LL function can be used to steer all other flows. For the same packet flow, only one steering function should be used. All steering functions in the UE should use the same set of ATSSS rules to make ASSS decisions (i.e., decide how to steer, switch, and split traffic). Similarly, all ATSSS decisions in the UPF should be made by applying the same set of N4 rules that support ASSSS. When the MA PDU session is established, the ATSSS rules and the N4 rules that support ASSSS are provided to the UE and UPF, respectively. If the UE supports multiple steering functions, such as MPTCP function and ASSSS-LL function, or MPTCP function, MPQUIC function and ASSSS-LL function, it should use the provided ATSSS rules to decide the steering function to apply to a specific packet flow.

[0193] In conjunction with Figure 1, Figure 2 shows the 5G system architecture supported by ATSSS when the UE registers to the public land mobile network (PLMN) through 3GPP access and non-3GPP access in non-roaming and roaming with local breakout architecture.

[0194] In conjunction with Figure 1, Figure 3 shows the 5G system architecture supported by ATSSS when the UE registers to the same visited public land mobile network (V-PLMN) through 3GPP access and non-3GPP access in roaming. In this case, the MPTCP proxy function, MPQUIC proxy function, ASSSS-LL proxy function, and PMF are located in the home UPF (H-UPF).

[0195] In conjunction with Figure 1, Figure 4 shows a 5G system architecture that supports ATSSS in roaming scenarios when the UE is registered to the V-PLMN via 3GPP access and to the home public land mobile network (H-PLMN) via non-3GPP access (i.e., the UE is registered to different PLMNs). In this case, the MPTCP proxy function, MPQUIC proxy function, ASSSS-LL proxy function, and PMF are located in the H-UPF.

[0196] For the description of each network element, please refer to the description in the relevant embodiment of Figure 1.

[0197] 5. MPQUIC connection protocol stack

[0198] Referring to Figure 5, which illustrates an exemplary protocol stack architecture for an MPQUIC connection, the bold box portion represents a newly added protocol stack compared to the traditional 5G user plane protocol stack. Taking the case of a UE sending data (i.e., a PDU packet) to the UPF as an example, when the PDU packet passes through the MPQUIC layer, the MPQUIC layer performs TLS encryption on the PDU packet to obtain a TLS-encrypted PDU packet. Subsequently, the TLS-encrypted PDU packet is encapsulated into an IP packet via the UDP layer and the Internet Protocol (IP) layer. The UE transmits the IP packet to the RAN through air interface security protection. The RAN decrypts and decapsulates the packet layer by layer based on air interface security, obtaining a GTP-U packet at the GPRS tunneling protocol for user plane (GTP-U) layer. The GTP-U layer then encrypts the GTP-U packet with IPsec security protection and transmits the IPsec-encrypted GTP-U packet to the UPF via the IPsec tunnel. The UPF decrypts the IPsec-encrypted GTP-U packet to obtain the GTP-U packet, which is then decrypted at the MPQUIC layer using the TLS protocol to obtain the actual PDU packet. As can be seen, after the UE and UPF establish an MPQUIC connection, they undergo two layers of security protection: one layer is the MPQUIC layer's TLS-based security protection (or, what we call end-to-end security protection between the UE and UPF), and the other layer is 3GPP security protection, which specifically includes air interface security protection and IPsec security protection.

[0199] Based on the above explanation of the relevant technical features involved in the embodiments of the present application, the embodiments of the present application are described in detail as follows.

[0200] The UE and UPF can establish an MA PDU session, which supports multiple access paths (for example, including paths accessed through 3GPP and paths accessed through non-3GPP), and data can be transmitted on different access paths. The ATSSS function further supports the MPQUIC function. That is, for UEs that support the ATSSS function, the UE can support the establishment of an MPQUIC connection associated with the MA PDU session with the UPF. In the process of establishing an MPQUIC connection between the UE and the UPF, how to implement a security solution is a technical problem that needs to be solved urgently.

[0201] To this end, this application provides three communication methods for implementing a security solution during the process of establishing an MPQUIC connection between a UE and a UPF. The MPQUIC connection between a UE and a UPF is referred to as an MPQUIC connection below.

[0202] In the first communication method, the UE and UPF are each pre-configured with the same key (which may be referred to as a pre-configured key), and the UE and UPF can establish an MPQUIC connection based on the pre-configured key.

[0203] In the second communication method, the SMF instructs the first function and the UE to derive the same key (which may be referred to as a shared key). The SMF also sends the shared key derived by the first function to the UPF. In this way, both the UE and the UPF store the shared key, and the UE and the UPF can establish an MPQUIC connection based on the shared key. The first function can be an AMF, an AUSF, or a SEAF. In this application, the first function may also be referred to as a first entity, a first network element, a first functional entity, a first functional network element, etc.

[0204] In the third communication method, SMF instructs UPF to apply for UPF's certificate from CA, UPF sends UPF's certificate to UE, and UE can authenticate UPF based on UPF's certificate. In one-way authentication, UE can establish an MPQUIC connection with UPF based on the shared key negotiated by the two parties after determining that UPF has passed the authentication. In two-way authentication, SMF also applies for UE's certificate from CA, sends UE's certificate to UE, and UE sends UE's certificate to UPF, and UPF authenticates UE based on UE's certificate. After determining that UPF has passed the authentication, UE establishes an MPQUIC connection with UPF based on the shared key negotiated by the two parties; after determining that UE has passed the authentication, UPF establishes an MPQUIC connection with UE based on the shared key negotiated by the two parties.

[0205] The first to third communication methods are described in sequence as follows:

[0206] See FIG6 for a flow chart of a first communication method provided as an example:

[0207] Step 601: After the first MA PDU session of the first UE is established, the first UE negotiates with the first UPF to establish a first MPQUIC connection, and the first MPQUIC connection is associated with the first MA PDU session.

[0208] The process of establishing the first MA PDU session of the first UE may refer to the description in the 3GPP TS23.502 protocol.

[0209] The same preconfigured key is stored in both the first UE and the first UPF. Optionally, the identifier of the preconfigured key is also stored in the first UE and the first UPF. In one possible manner, when the first UE negotiates with the first UPF to establish the first MPQUIC connection, specifically, when the first UE wishes to use the preconfigured key to establish the first MPQUIC connection with the first UPF, it sends the identifier of the preconfigured key to the first UPF. Accordingly, the first UPF determines the preconfigured key based on the identifier of the preconfigured key, and then sends the identifier of the preconfigured key to the first UE when agreeing to use the preconfigured key to establish the first MPQUIC connection with the first UE. In this way, the two parties agree on the key (i.e., the preconfigured key) used when establishing the first MPQUIC connection.

[0210] Exemplarily, the first UE and the first UPF are respectively the Client and Server in the TLS protocol. When the first UE wishes to use the preconfigured key to establish the first MPQUIC connection with the first UPF, it sends a first message (e.g., ClientHello) to the first UPF, and the first message carries the identifier of the preconfigured key. Accordingly, the first UPF receives the first message from the first UE, determines the preconfigured key based on the identifier of the preconfigured key in the first message, that is, learns that the first UE wishes to use the preconfigured key to establish the first MPQUIC connection with the first UPF. Further, the first UPF sends a second message (e.g., ServerHello) to the first UE when agreeing to use the preconfigured key to establish the first MPQUIC connection with the first UE. The second message carries the identifier of the preconfigured key. It can be considered that the second message is sent by the first UPF in response to the first message. In this way, the first UE and the first UPF negotiate that they can use the preconfigured key to establish the first MPQUIC connection. This method helps to better compatibility with the method of establishing a connection between the Client and the Server in the existing TLS protocol.

[0211] The first MPQUIC connection is associated with the first MA PDU session. Specifically, the MPQUIC connection is a connection in the first MA PDU session, or the MPQUIC connection is used to transmit data in the first MA PDU session, etc.

[0212] In addition, the first UE and the first UPF may also negotiate the cipher suit to be used when transmitting data between the two parties. Exemplarily, the first UE sends the identifiers of one or more cipher suits it supports to the first UPF. The first UPF selects an cipher suit it supports from the one or more cipher suits and sends the identifier of the selected cipher suit to the first UE. In this way, the two parties negotiate an cipher suit that they both support and can be used for data transmission. Exemplarily, the cipher suit includes one or more of an encryption algorithm, an encryption mode, an integrity protection algorithm, and a hash algorithm.

[0213] As shown in Figure 7, multiple algorithm suites are provided as examples in this application. Take the algorithm suite TLS_CHACHA20_POLY1305_SHA256 as an example, where CHACHA20 is an encryption algorithm, POLY1305 is an integrity protection algorithm, and SHA256 is a hash algorithm. The identifier of this algorithm suite is {0x13, 0x03}. Take TLS_AES_128_GCM_SHA256 as an example, where AES_128 is an encryption algorithm, GCM is an encryption mode, and SHA256 is a hash algorithm. The identifier of this algorithm suite is {0x13, 0x01}. For example, if the algorithm suites supported by the first UE are TLS_CHACHA20_POLY1305_SHA256 and TLS_AES_128_GCM_SHA256, then the first UE can send the identifiers of the two algorithm suites, namely {0x13, 0x03} and {0x13, 0x01}, to the first UPF. Correspondingly, if the first UPF determines that it supports TLS_CHACHA20_POLY1305_SHA256, it sends {0x13, 0x03} to the first UE. In this way, the two parties have negotiated that they can use the algorithm suite TLS_CHACHA20_POLY1305_SHA256 for data transmission.

[0214] Exemplarily, when the first UE sends the identifier of the algorithm suite supported by the first UE to the first UPF, specifically, the first UE sends a first message to the first UPF, and the first message carries the identifier of the algorithm suite supported by the first UE, that is, the first message can carry not only the identifier of the preconfigured key, but also the identifier of the algorithm suite supported by the first UE. When the first UPF sends the identifier of the algorithm suite selected by the first UPF to the first UE, specifically, the first UPF sends a second message to the first UE, and the second message carries the identifier of the algorithm suite selected by the first UPF, that is, the second message can carry not only the identifier of the preconfigured key, but also the identifier of the algorithm suite selected by the first UPF.

[0215] In this application, the pre-configured key may also be referred to as a pre-shared key (PSK). Optionally, the first message may further include a psk_key_share_modes extension item, which is used to instruct the first UE to use the pre-shared key (ie, the pre-configured key) for authentication.

[0216] In step 602, the first UE derives a key (denoted as a first protection key) for protecting data of the first MPQUIC connection based on the preconfigured key. The data of the first MPQUIC connection is transmitted via multiple paths between the first UE and the first UPF.

[0217] Among them, the first protection key is used for the first UE to transmit data of the first MPQUIC connection with the first UPF. Specifically, the first protection key includes an uplink protection key and a downlink protection key. The uplink protection key in the first protection key can be used by the first UE to protect the uplink data sent by the first UE to the first UPF. The protection here includes encryption protection and / or integrity protection; the downlink protection key in the first protection key can be used by the first UE to decrypt and / or verify the downlink data received by the first UE from the first UPF. The first protection key is, for example, a 1-round-trip time (RTT) key.

[0218] Alternatively, multiple UPFs within the same PLMN may store the same preconfiguration key. In this manner, the preconfiguration key can be used not only to establish a first MPQUIC connection between a first UE and a first UPF, but also to establish a second MPQUIC connection between the first UE and a second UPF, where the first and second UPFs are within the same PLMN. Optionally, the multiple UPFs within the same PLMN may also store an identifier for the preconfiguration key.

[0219] In a specific example, after the first UE completes the establishment of the second MA PDU session, the first UE negotiates with the second UPF to establish a second MPQUIC connection, and the second MPQUIC connection is associated with the second MA PDU session. The first UE derives a key for protecting data on the second MPQUIC connection based on a preconfigured key. Similarly, the second UPF derives a key for protecting data on the second MPQUIC connection based on the preconfigured key. The data on the second MPQUIC connection is transmitted over multiple paths between the first UE and the second UPF.

[0220] In a specific example, during the establishment of the second MA PDU session of the first UE, the first UE sends a PDU session establishment request to the SMF. The PDU session establishment request includes the data network name (DNN) requested by the UE. The data network name is different from the data network name corresponding to the first MA PDU session. The SMF selects the UPF (i.e., the second UPF) that provides services for the data network name requested by the UE, and then establishes a second MA PDU session for the UE.

[0221] In step 603, the first UPF derives a key (denoted as a second protection key) for protecting data of the first MPQUIC connection based on the preconfigured key.

[0222] The second protection key is used by the first UPF to transmit data of the first MPQUIC connection with the first UE. Specifically, the second protection key includes an uplink protection key and a downlink protection key. The uplink protection key in the second protection key can be used by the first UPF to decrypt and / or verify uplink data received by the first UPF from the first UE; the downlink protection key in the first protection key can be used by the first UPF to protect downlink data sent by the first UPF to the first UE. The protection here includes encryption protection and / or integrity protection. The second protection key is, for example, a 1-RTT key.

[0223] Alternatively, it can be understood that multiple UEs located in the same HPLMN all store the same pre-configuration key. In this way, the pre-configuration key can be used not only by the first UPF to establish a first MPQUIC connection with the first UE, but also by the first UPF to establish a third MPQUIC connection with a second UE, where the first UE and the second UE are located in the same HPLMN. Optionally, the multiple UEs located in the same HPLMN also store an identifier for the pre-configuration key.

[0224] In a specific example, after the second UE completes establishment of its third MA PDU session, the first UPF negotiates with the second UE to establish a third MPQUIC connection, which is associated with the third MA PDU session. The first UPF derives a key for protecting data on the third MPQUIC connection based on a preconfigured key. Similarly, the second UE derives a key for protecting data on the third MPQUIC connection based on the preconfigured key. Data on the third MPQUIC connection is transmitted over multiple paths between the second UE and the first UPF.

[0225] It should be noted that the pre-configured key can also be used to establish an MPQUIC connection between a third UE and a third UPF, where the third UE and the first UE belong to the same H-PLMN and / or the third UPF and the first UPF belong to the same PLMN. The manner in which the third UE establishes an MPQUIC connection with the third UPF can be referred to the description in steps 601 to 603 above.

[0226] It should also be noted that the present application does not limit the order of step 602 and step 603, that is, the order in which the UE derives the first protection key and the UPF derives the second protection key is not limited. This description can also be applied to the following embodiments. For example, in the embodiment related to Figure 11 below, the order of step 1107 and step 1108 is not limited. For example, in the embodiment related to Figure 12 below, the order of step 1213 and step 1214 is not limited. In addition, there is no strict execution order between steps that have no timing dependency on each other in the present application.

[0227] Optionally, also include:

[0228] Step 604: The first UE and the first UPF transmit data of the first MPQUIC connection.

[0229] The first UE and the first UPF transmit data of the first MPQUIC connection, which may specifically include: the first UE uses the uplink key in the first protection key to protect the uplink data sent to the first UPF, and accordingly, the first UPF uses the uplink key in the second protection key to decrypt and / or verify the uplink data from the first UE; and / or, the first UPF uses the downlink key in the second protection key to protect the downlink data sent to the first UE, and accordingly, the first UE uses the downlink key in the first protection key to decrypt and / or verify the downlink data from the first UPF.

[0230] Furthermore, when the first UE negotiates an algorithm suite with the first UPF, the first UE and the first UPF can also use the negotiated algorithm suite to transmit data for the first MPQUIC connection. That is, the first UE can use the uplink key in the first protection key and the negotiated algorithm suite to protect the uplink data sent to the first UPF, and the first UPF can use the uplink key in the second protection key and the negotiated algorithm suite to decrypt and / or verify the uplink data from the first UE; and / or the first UPF can use the downlink key in the second protection key and the negotiated algorithm suite to protect the downlink data sent to the first UE, and the first UE can use the downlink key in the first protection key and the negotiated algorithm suite to decrypt and / or verify the downlink data from the first UPF.

[0231] For example, if the algorithm suite is TLS_CHACHA20_POLY1305_SHA256, when the first UE sends uplink data to the first UPF, the first UE encrypts the uplink data according to CHACHA20 and the uplink key in the first protection key, and hashes the uplink data according to POLY1305, SHA256, and the uplink key in the first protection key to obtain a MAC, and sends the encrypted uplink data and MAC to the first UPF. The first UPF decrypts the received uplink data according to CHACHA20 and the uplink key in the second protection key, and performs an integrity check on the received uplink data according to SHA256, POLY1305, and the uplink key in the second protection key.

[0232] Furthermore, the first MPQUIC connection may include multiple transmission paths, that is, the first MPQUIC connection may be used to transmit data between the first UE and the first UPF via multiple paths. Exemplarily, the first UE may simultaneously use multiple transmission paths to transmit data, or may select a single transmission path from the multiple transmission paths to transmit data.

[0233] For example, a first MPQUIC connection includes transmission path 1 and transmission path 2. Furthermore, transmission path 1 is a transmission path corresponding to 3GPP access, and transmission path 2 is a transmission path corresponding to non-3GPP access. The devices involved in transmission path 1 may include: a first UE, an access device of a 3GPP access network (such as a gNB or eNB), and a first UPF; the devices involved in transmission path 2 may include: the first UE, a non-3GPP access device (such as an N3IWF or ngPDG), and the first UPF. Alternatively, transmission path 1 is a transmission path corresponding to 3GPP access, and transmission path 2 is also a transmission path corresponding to 3GPP access. The devices involved in transmission path 1 may include: the first UE, access device 1 of the 3GPP access network, and the first UPF; the devices involved in transmission path 2 may include: the first UE, access device 2 of the 3GPP access network, and the first UPF. Furthermore, the first UE and the first UPF may simultaneously transmit data over transmission path 1 and transmission path 2, e.g., transmitting data 1 using transmission path 1 and transmitting data 2 using transmission path 2. Alternatively, the first UE and the first UPF may also select one of transmission path 1 and transmission path 2 to transmit data, such as selecting transmission path 1 to transmit data 3.

[0234] It should be noted that the first MA PDU session includes M QoS flows, each QoS flow can correspond to an MPQUIC connection, and M is an integer greater than or equal to 1. In a specific implementation, after the first MA PDU session of the first UE is established, the first UE establishes M MPQUIC connections, and each MPQUIC connection is used to carry data of UDP traffic in the corresponding QoS flow. For example, the first MA PDU session includes QoS flows 1 to QoS flows 3. After the first MA PDU session of the first UE is established, the first UE establishes MPQUIC connections 1 to MPQUIC connections 3, and the MPQUIC connections 1 to MPQUIC connections 3 correspond to QoS flows 1 to QoS flows 3, respectively, that is, MPQUIC connection 1 can be used to transmit UDP traffic of QoS flow 1, MPQUIC connection 2 can be used to transmit UDP traffic of QoS flow 2, and MPQUIC connection 3 can be used to transmit UDP traffic of QoS flow 3. As an optional method, the first UE establishes N MPQUIC connections, where N is greater than M. It can also be understood that the first MA PDU session is associated with M MPQUIC connections (or N MPQUIC connections), where the M MPQUIC connections (or N MPQUIC connections) include the first MPQUIC connection and the fourth MPQUIC connection. Subsequently, the first UE derives, based on the preconfigured key, keys for protecting the data of the first MPQUIC connection and the fourth MPQUIC connection, respectively, and the first UPF derives, based on the preconfigured key, keys for protecting the data of the first MPQUIC connection and the fourth MPQUIC connection, respectively. Furthermore, different MPQUIC connections have different protection keys corresponding to them, that is, the key for protecting the data of the first MPQUIC connection is different from the key for protecting the data of the fourth MPQUIC connection.

[0235] In conjunction with the description of the embodiment related to FIG6 , FIG8 illustrates a specific implementation of the first communication method exemplified in this application. In this specific implementation, the first UE and the first UPF may negotiate using the negotiation method in the TLS protocol, with the first UE and the first UPF acting as the client and server in the TLS protocol, respectively. Steps 801 to 806 below may be considered a specific implementation of step 601. After the first UE and the first UPF negotiate using the negotiation method in the TLS protocol, the first UE and the first UPF establish a first MPQUIC connection.

[0236] See the flow chart in Figure 8:

[0237] Step 801: After a first MA PDU session of a first UE is established, the first UE sends a first message to a first UPF. Correspondingly, the first UPF receives the first message from the first UE.

[0238] Exemplarily, the first message carries the identifier of the cipher suite supported by the first UE, the identifier of the pre-configured key, and psk_key_share_modes. The identifier of the pre-configured key is, for example, 0x00. The identifier of the cipher suite supported by the first UE is, for example, {0x13, 0x03}.

[0239] For the description of the first MA PDU session, the pre-configured key, and the identifier of the pre-configured key, refer to the description in the above step 601.

[0240] Step 802: The first UPF sends a second message to the first UE. Correspondingly, the first UE receives the second message from the first UPF.

[0241] In a specific implementation, the first UPF obtains the identifier of the algorithm suite supported by the first UE, the identifier of the preconfigured key, and psk_key_share_modes from the first message, wherein the identifier of the preconfigured key is 0x00 and the identifier of the algorithm suite is {0x13, 0x03}. Based on psk_key_share_modes and the identifier of the preconfigured key 0x00, the first UPF determines that the first UE wishes to establish a first MPQUIC connection with the first UPF using the preconfigured key, and the identifier of the preconfigured key used is 0x00. The first UPF also selects the algorithm suite supported by the first UPF from the identifiers of the algorithm suite supported by the first UE, for example, the identifier of the selected algorithm suite is {0x13, 0x03}. The first UPF sends a second message to the first UE, and the second message includes the identifier of the preconfigured key 0x00 and the identifier of the algorithm suite {0x13, 0x03}.

[0242] In steps 801 and 802, the first UE and the first UPF negotiate the preconfigured key and algorithm suite to be used when establishing the first MPQUIC connection. Furthermore, the first UE authenticates the first UPF (see steps 803 to 804) to determine whether the preconfigured key used by the first UPF is consistent with the preconfigured key used by itself; and the first UPF authenticates the first UE (see steps 805 to 806) to determine whether the preconfigured key used by the first UE is consistent with the preconfigured key used by itself.

[0243] In step 803, the first UPF sends a third message (eg, Finished message 2) to the first UE. Correspondingly, the first UE receives the third message from the first UPF, wherein the third message carries the second MAC.

[0244] Exemplarily, the first UPF derives the second handshake key based on the preconfigured key, and then determines the second MAC based on the second preceding interaction information and the second handshake key. The second preceding interaction information includes the first message and the second message, that is, the second preceding interaction information includes the identifier of the algorithm suite supported by the first UE, the identifier of the preconfigured key, psk_key_share_modes, the identifier of the algorithm suite selected by the first UPF, and the identifier of the preconfigured key.

[0245] In step 804, the first UE authenticates the first UPF according to the third message, the second previous interaction information, and the first handshake key. In this application, authenticating the first UPF may specifically be identity authentication of the first UPF.

[0246] In a specific implementation, the first UE derives the first handshake key based on the preconfigured key. The first UE obtains the second MAC from the third message, and then authenticates the second MAC based on the second previous interaction information and the first handshake key. When the second MAC authentication is successful, the first UE determines that the first UPF authentication is successful, that is, it is determined that the preconfigured key used by the first UPF is consistent with the preconfigured key used by itself. When the second MAC authentication fails, the first UE determines that the first UPF authentication is successful, that is, it is determined that the preconfigured key used by the first UPF is inconsistent with the preconfigured key used by itself.

[0247] In step 805, after determining that the first UPF has passed authentication, the first UE sends a fourth message (eg, Finished message 1) to the first UPF, where the fourth message carries the first MAC. Accordingly, the first UPF receives the fourth message from the first UE.

[0248] In a specific implementation, the first UE determines the first MAC based on the first preceding interaction information and the first handshake key. The first preceding interaction information includes the second message and the first message. That is, the first preceding interaction information includes the identifier of the algorithm suite supported by the first UE, the identifier of the preconfigured key, psk_key_share_modes, the identifier of the algorithm suite selected by the first UPF, and the identifier of the preconfigured key. In addition, the first preceding interaction information may also include a third message, namely, the second MAC.

[0249] In step 806, the first UPF authenticates the first UE according to the fourth message, the first previous interaction information, and the second handshake key. In this application, authenticating the first UE may specifically be identity authentication of the first UE.

[0250] In a specific implementation, the first UPF obtains the first MAC from the fourth message, and then authenticates the first MAC based on the first previous interaction information and the second handshake key. When the first MAC authentication passes, the first UPF determines that the first UE authentication passes, that is, it determines that the preconfigured key used by the first UE is consistent with the preconfigured key used by itself. When the first MAC authentication fails, the first UPF determines that the first UE authentication fails, that is, it determines that the preconfigured key used by the first UE is inconsistent with the preconfigured key used by itself.

[0251] Step 807: The first UE derives a first protection key based on the preconfigured key.

[0252] For specific implementation, please refer to the description in the above step 602.

[0253] Step 808: The first UPF derives a second protection key based on the pre-configured key.

[0254] For specific implementation, please refer to the description in the above step 603.

[0255] Step 809: The first UE and the first UPF transmit data of the first MPQUIC connection.

[0256] For specific implementation, please refer to the description in the above step 604.

[0257] It can be understood that the embodiment of the present application is explained by taking the example of the first UE first authenticating the first UPF and the first UPF then authenticating the first UE. Of course, it can also be that the first UPF first authenticates the first UE and the first UE then authenticates the first UPF. Exemplarily, the first UE determines the first MAC based on the first preceding interaction information and the first handshake key, and sends a fourth message to the first UPF, wherein the fourth message carries the first MAC. The first UPF obtains the first MAC from the fourth message, and authenticates the first MAC based on the first preceding interaction information and the second handshake key, that is, authenticates the first UE. Furthermore, after the first UPF determines that the first UE is authenticated, it determines the second MAC based on the second preceding interaction information and the second handshake key, and sends a third message to the first UE, wherein the third message carries the second MAC. Accordingly, the first UE obtains the second MAC from the third message, and authenticates the second MAC based on the second preceding interaction information and the first handshake key, that is, authenticates the first UPF. After the first UE determines that the first UPF is authenticated, the first UE and the first UPF establish a first MPQUIC connection.

[0258] It should be explained that after the above step 602 (or step 807), it can be considered that the first UE has established a first MPQUIC connection with the first UPF based on the preconfigured key; after the above step 603 (or step 808), it can be considered that the first UPF has established a first MPQUIC connection with the first UE based on the preconfigured key. Alternatively, in the above step 804, if the first UE determines that the first UPF has passed the authentication, it can be considered that the first UE has established a first MPQUIC connection with the first UPF based on the preconfigured key; in the above step 806, if the first UPF determines that the first UE has passed the authentication, it can be considered that the first UPF has established a first MPQUIC connection with the first UE based on the preconfigured key. This description can also be applied to the second communication method and the third communication method described below. The difference is that in the second communication method and the third communication method, the key used by the UE and the UPF when establishing the MPQUIC connection is a shared key, not a preconfigured key; and in the second communication method and the third communication method, there is no need to distinguish between the first UE, the second UE, and the third UE, and there is no need to distinguish between the first UPF, the second UPF, and the third UPF.

[0259] In the above-mentioned first communication method, after the first MA PDU session of the first UE is established, the first UE and the first UPF establish a first MPQUIC connection according to the pre-configured key, and security is achieved during the process of establishing the first MPQUIC connection between the first UE and the first UPF.

[0260] Furthermore, since the first MA PDU session has been established, if user plane security protection is enabled, the messages transmitted by the first UE and the first UPF during the negotiation process are already based on 3GPP security protection. Specifically, in step 601 above, the identifier of the pre-configured key sent by the first UE to the first UPF, or the identifier of the pre-configured key sent by the first UPF to the first UE, are all based on 3GPP security protection. Alternatively, in steps 801 to 805 above, the first message, the second message, the third message, and the fourth message are all based on 3GPP security protection. For specific details, please refer to the description in the relevant embodiment of Figure 5. This helps to improve the security of message transmission.

[0261] Since 3GPP security protection has already been established, the present embodiment configures the first UE and the first UPF to use a preconfigured key to establish an MPQUIC connection, thereby avoiding unnecessary interactions and calculations during the MPQUIC connection establishment process between the first UE and the first UPF. The preconfigured key is used not only to establish a first MPQUIC connection between the first UE and the first UPF, but also to establish a second MPQUIC connection between the first UE and the second UPF. The first and second UPFs are located in the same PLMN. In other words, the preconfigured key can be used by the UE to establish MPQUIC connections with multiple UPFs located in the same PLMN, thereby reducing the complexity of the UE establishing MPQUIC connections. In addition, the preconfigured key is used not only to establish a first MPQUIC connection between the first UPF and the first UE, but also to establish a third MPQUIC connection between the first UPF and the second UE. The first and second UEs are located in the same H-PLMN. In other words, the preconfigured key can be used by the UPF to establish MPQUIC connections with multiple UEs located in the same H-PLMN, thereby reducing the complexity of the UPF establishing MPQUIC connections.

[0262] 9 exemplifies a flow chart of a second communication method, which is specifically applicable to the process of establishing an MA PDU session for a UE. The process of establishing an MA PDU session can be described in 3GPP TS23.502.

[0263] Step 901: SMF obtains a shared key from the first function.

[0264] The shared key is used to derive the key used to protect the data in the MPQUIC connection between the UE and the UPF. The role of the shared key is similar to that of the pre-configured key in the first communication method and is not repeated here. The MPQUIC connection is associated with the MA PDU session. The data of the MPQUIC connection is transmitted by multiple paths between the UE and the UPF. For the relationship between the MPQUIC connection, MA PDU session, MPQUIC connection, and MA PDU session, please refer to the description of the relationship between the first MPQUIC connection, the first MA PDU session, the first MPQUIC connection, and the first MA PDU session in the first communication method.

[0265] The first function may be AMF, SEAF or AUSF.

[0266] In one possible implementation, the SMF obtains a shared key from the first function. Specifically, the SMF may send a second instruction to the first function. The first function receives the second instruction from the SMF, derives the shared key based on the second instruction, and sends the shared key to the SMF. Accordingly, the SMF receives the shared key from the first function. The second instruction is used to instruct the first function to derive the shared key. Exemplarily, the second instruction may be a key derivation instruction, an end-to-end key derivation instruction from UE to UPF, an MPQUIC key derivation instruction, a pre-shared key mode (PSK mode), etc. Exemplarily, the second instruction is included in a key derivation request.

[0267] In one possible implementation, the SMF sends a second indication and a first parameter to the first function. The first function determines that a shared key needs to be derived based on the second indication, and then derives the shared key based on the first parameter and the superior key. Exemplarily, the first parameter may be included in the key derivation request. The first parameter includes at least one or more of the following: a UE identifier, an MA PDU session identifier, and a shared key identifier.

[0268] Further, when the first function is AMF, the upper key includes at least one or more of the following: RAN key, AMF key, that is, AMF can derive the shared key from the AMF key, specifically refer to direction one in Figure 10, or AMF can also derive the shared key from the RAN key, specifically refer to direction two in Figure 10; when the first function is SEAF, the upper key can be the SEAF key, that is, SEAF can derive the shared key from the SEAF key, specifically refer to direction three in Figure 10; when the first function is AUSF, the upper key can be the AUSF key, that is, AUSF can derive the shared key from the AUSF key, specifically refer to direction four in Figure 10. As shown in Figure 10, K AUSF , K SEAF , K AMF , K gNB , K NASenc , K NASint They are AUSF key, SEAF key, AMF key, gNB key (i.e. RAN key), non-access stratum (NAS) encryption protection key, and NAS integrity protection key. The arrows indicate the direction of deduction.

[0269] In this application, the SMF can not only instruct the first function to derive a shared key, but also instruct the UE to derive a shared key. Exemplarily, the SMF sends a first instruction to the UE, and accordingly, the UE receives the first instruction from the SMF, and the UE derives the shared key according to the first instruction. Among them, the first instruction is used to instruct the UE to establish an MPQUIC connection with the UPF using a shared key, or it can be understood that the first instruction is used to instruct the UE to derive a shared key. Exemplarily, the first instruction can be a key derivation instruction, an end-to-end key derivation instruction from UE to UPF, an MPQUIC key derivation instruction, a pre-shared key mode, etc.

[0270] In one possible implementation, the SMF sends the first indication to the UE, specifically, during the MA PDU session establishment process of the UE, the SMF sends the first indication to the UE. In a possible example, the SMF sends an N1N2 message transfer to the AMF, and the N1N2 message transfer includes the first indication; the AMF responds to the N1N2 message transfer and sends an N2 PDU session request to the RAN, and the N2 PDU session request includes the first indication; the RAN responds to the N2 PDU session request and sends an RRC reconfiguration message to the UE, and the RRC reconfiguration message includes the first indication.

[0271] In one possible implementation, the UE determines that it needs to derive a shared key based on the first indication, and then derives the shared key based on the first parameter and the superior key. The first parameter includes at least one or more of the following: the UE identifier, the MA PDU session identifier, and the shared key identifier. Here, since the UE stores the UE identifier and the MA PDU session identifier, when the first parameter includes the UE's stored parameters, the SMF may not send the first parameter to the UE. The superior key includes at least one or more of the following: SEAF key, RAN key, AMF key. For the specific deduction method of the AUSF key, please refer to the method of deriving the shared key from the above-mentioned first function.

[0272] In one possible implementation, before the SMF obtains the shared key from the first function and / or before the SMF sends the first indication to the UE, the SMF may determine to enable the function corresponding to the MPQUIC connection.

[0273] Exemplarily, when the SMF determines to enable the function corresponding to the MPQUIC connection, it may be one of the following three examples:

[0274] Example 1: The UE sends its capability information to the SMF. The capability information indicates that the UE supports establishing an MPQUIC connection. The SMF receives the capability information from the UE and determines that the UE supports establishing an MPQUIC connection based on the capability information.

[0275] Among them, the UE capability information may specifically be the UE's ATSSS capability, and the ASSSS capability includes the MPQUIC capability.

[0276] Exemplarily, the UE sends a session establishment request to the SMF, and correspondingly, the SMF receives the session establishment request from the UE, and the session establishment request carries the capability information of the UE. Further, the UE sends a session establishment request to the SMF, and specifically, the UE sends a session establishment request to the AMF, the AMF selects the SMF, the AMF sends a session context request to the SMF, and correspondingly, the SMF receives the session context request from the AMF, wherein the session context request carries the session establishment request, that is, the session context request carries the capability information of the UE. The session establishment request is specifically a PDU session establishment request (PDU session establishment request), and the session context request is specifically a PDU session create SM context request (PDU session create SM context request), and this description is also applicable to other embodiments.

[0277] In Example 2, the SMF determines that it supports the function corresponding to the MPQUIC connection. Alternatively, the SMF enables the function corresponding to the MPQUIC connection, that is, the state of the function corresponding to the MPQUIC connection of the SMF is "enabled".

[0278] In Example 3, the UE sends its capability information to the SMF. The SMF receives the capability information from the UE and, based on the capability information, determines that the UE supports establishing an MPQUIC connection and supports the functions corresponding to the MPQUIC connection. For details, see Examples 1 and 2.

[0279] Step 902: SMF sends a shared key to UPF, and UPF receives the shared key from SMF.

[0280] In one possible implementation, the SMF further sends an identifier of the shared key to the UPF. Accordingly, the UPF receives the identifier of the shared key from the SMF, and the UPF stores the identifier of the shared key in correspondence with the shared key. Exemplarily, the SMF sends the shared key and the identifier of the shared key to the UPF via a message, which may specifically be an N4 session establishment request.

[0281] The identifier of the shared key may be determined by the identifier of the MA PDU session, specifically as shown in the following example a and example b.

[0282] In example a, the identifier of the shared key is generated by the first function and the UE respectively.

[0283] For the first function, the SMF sends the identifier of the MA PDU session to the first function, where the identifier of the MA PDU session can be included in the first parameter or sent to the first function as a separate parameter. After deducing the shared key, the first function can also generate an identifier of the shared key based on the identifier of the MA PDU session and send the identifier of the shared key to the SMF. For the UE, after deducing the shared key, the UE can also generate an identifier of the shared key based on the identifier of the MA PDU session and store the shared key and the identifier of the shared key.

[0284] The first function and the UE use the same determination method to determine the shared key identifier, that is, the shared key identifiers determined by both are the same. Exemplarily, the first function and the UE determine the MA PDU session identifier as the shared key identifier.

[0285] In example b, the shared key identifier is generated by SMF.

[0286] The SMF generates a shared key identifier based on the identifier of the MA PDU session, and sends the shared key identifier to the first function and the UE respectively, wherein the shared key identifier can be included in the first parameter or sent as a separate parameter. Exemplarily, the SMF determines the identifier of the MA PDU session as the shared key identifier. It is worth noting that in this case, the SMF only needs to send the shared key identifier to the first function, and does not need to send the shared key identifier to the UE, which helps to reduce signaling interaction.

[0287] As mentioned above, both the UE and the UPF can obtain the shared key, or both can obtain the shared key and the identifier of the shared key. The UE and the UPF can negotiate to establish an MPQUIC connection based on the shared key or according to the shared key and the identifier of the shared key. For specific instructions, please refer to the description in step 601 above. The "pre-configured key" can be replaced with "shared key" for understanding.

[0288] In step 903, the UPF derives a key (i.e., a second protection key) for protecting data in the MPQUIC connection between the UE and the UPF based on the shared key. The MPQUIC connection is associated with the MA PDU session. For details, see the description in step 603.

[0289] Optionally, the UE further derives a key (ie, a first protection key) for protecting data in the MPQUIC connection based on the shared key. For details, see the description in step 602.

[0290] Optionally, the UE and UPF transmit data of the MPQUIC connection, for details, please refer to the description in step 604.

[0291] In combination with the description in the embodiment related to Figure 9, Figure 11 shows a first specific implementation of the second communication method exemplarily provided in this application. In this first specific implementation, an interaction mode between the SMF, UE, the first function and the UPF devices is provided.

[0292] See the flow chart in Figure 11:

[0293] Step 1101: The SMF sends a second instruction to the first function, and correspondingly, the first function receives the second instruction from the SMF.

[0294] Optionally, after determining to enable the function corresponding to the MPQUIC connection, the SMF sends a second indication to the first function.

[0295] In step 1102, the first function derives a shared key according to the second instruction.

[0296] Step 1103: The first function sends a shared key to the SMF. Correspondingly, the SMF receives the shared key from the first function.

[0297] Step 1104: SMF sends the shared key to UPF, and correspondingly, UPF receives the shared key from SMF.

[0298] Optionally, the SMF also sends an identifier of the shared key to the UPF, where the identifier of the shared key is determined based on the identifier of the MA PDU session. Optionally, the UPF stores the shared key and the identifier of the shared key.

[0299] Step 1105: The SMF sends a first indication to the UE, and correspondingly, the UE receives the first indication from the SMF.

[0300] Step 1106: The UE derives a shared key according to the first instruction.

[0301] Step 1107: The UE derives a first protection key based on the shared key.

[0302] In step 1108, the UPF derives a second protection key based on the shared key.

[0303] In step 1109, the UE and the UPF transmit data of the MPQUIC connection.

[0304] It is understood that any content not described in detail in FIG11 can be referred to the description of the relevant embodiment in FIG9 . Specifically, any content not described in detail in steps 1101 to 1103 can be referred to the description in step 901 . Any content not described in detail in step 1104 can be referred to the description in step 902 . Any content not described in detail in steps 1105 and 1106 can be referred to the description in step 901 . Any content not described in detail in steps 1107 to 1109 can be referred to the description in step 903 . The order of steps 1107 and 1108 is not limited, and the order of steps 1101 and 1105 is not limited.

[0305] In conjunction with the description in the relevant embodiments of Figures 9 and 11, Figure 12 shows a second specific implementation of the second communication method exemplarily provided in this application. In this second specific implementation, the first function is specifically AMF, which is explained in conjunction with the establishment process of the MA PDU session.

[0306] In step 1201, the UE sends a PDU session establishment request to the AMF. In response, the AMF receives the PDU session establishment request from the UE.

[0307] The PDU session establishment request is an example of a session establishment request.

[0308] The PDU session establishment request carries the PDU session identifier, request type and UE's ASSSS capability (an example of UE capability information). Among them, the request type is MA PDU request (MA PDU request), which indicates that the PDU session requested by the UE is an MA PDU session. Correspondingly, the PDU session identifier is the identifier of the MA PDU session. The UE's ASSSS capability includes MPQUIC capability to indicate that the UE supports the MPQUIC capability. Optionally, the UE's ASSSS capability also includes MPTCP capability and ASSSS-LL capability.

[0309] In step 1202, the AMF selects an SMF. Specifically, the AMF selects an SMF that supports the ATSSS capability.

[0310] In step 1203, the AMF sends a PDU session creation session management context request to the SMF. The PDU session creation session management context request carries a PDU session establishment request. Correspondingly, the SMF receives the PDU session creation session management context request from the AMF.

[0311] Among them, the PDU session creation session management context request is an example of a session context request.

[0312] In step 1204, the SMF creates a session management context request based on the PDU session and determines to enable the corresponding function of the MPQUIC connection.

[0313] Specifically, the SMF obtains the PDU session establishment request from the PDU session creation session management context request, and then obtains the request type and the UE's ATSSS capability from the PDU session establishment request. The SMF determines that the UE is requesting an MA PDU session based on the request type, and then queries the UDM for the UE's corresponding subscription information. Based on the UE's corresponding subscription information, the SMF determines that the UE has subscribed to the MA PDU session. Furthermore, based on the UE's ATSSS capability, the SMF determines that the UE supports establishing an MPQUIC connection, and determines that it enables the corresponding functions of the MPQUIC connection. Therefore, the SMF determines to enable the corresponding functions of the MPQUIC connection.

[0314] In step 1205, the SMF sends a key derivation request to the AMF. In response, the AMF receives the key derivation request from the SMF. The key derivation request carries a second indication and a first parameter. The first parameter includes the UE identifier and the MA PDU session identifier. The UE identifier and the MA PDU session identifier can be used by the AMF to derive a shared key. The MA PDU session identifier can be used as the shared key identifier.

[0315] In step 1206, the AMF sends the shared key and the shared key identifier to the SMF. Correspondingly, the SMF receives the shared key and the shared key identifier from the AMF.

[0316] Among them, when AMF sends the shared key and the identifier of the shared key to SMF, specifically, AMF obtains the second indication and the first parameter from the key derivation request, determines that the shared key needs to be deduced according to the second indication, and then obtains the UE identifier and the MA PDU session identifier from the first parameter, and deduces the shared key according to the UE identifier, the MA PDU session identifier, and the superior key. AMF also determines the MA PDU session identifier as the shared key identifier, and AMF sends the shared key and the MA PDU session identifier to SMF.

[0317] In step 1207, the SMF sends an N4 session establishment request to the UPF, where the N4 session establishment request includes a shared key and an identifier of the shared key. Accordingly, the UPF receives the N4 session establishment request from the SMF.

[0318] In step 1208, the UPF stores the shared key and the shared key identifier. In addition, the UPF also establishes an N4 session with the SMF.

[0319] Step 1209: SMF sends an N1N2 message transmission to AMF. Correspondingly, AMF receives the N1N2 message transmission from SMF, where the N1N2 message transmission includes the first indication.

[0320] Exemplarily, the N1N2 message transmission also includes ATSSS rules, which can be obtained by the SMF from the PCF. The ATSSS rules can be used by the UE to decide the steering function to be applied to a specific data packet flow (such as using the MPQUIC function after establishing the MPQUIC connection).

[0321] In step 1210, the AMF sends an N2 PDU session request to the RAN. Accordingly, the RAN receives the N2 PDU session request from the AMF, where the N2 PDU session request includes the first indication. Exemplarily, the N2 PDU session request also includes an ATSSS rule.

[0322] In step 1211, the RAN sends an RRC reconfiguration message to the UE. Correspondingly, the UE receives the RRC reconfiguration message from the RAN, where the RRC reconfiguration message includes the first indication. Exemplarily, the RRC reconfiguration message also includes ATSSS rules.

[0323] In a specific example, the MA PDU session establishment process further includes an AN-specific resource setup process. In the AN-specific resource setup process, the RAN sends an RRC reconfiguration message to the UE. The RRC reconfiguration message also includes indication information that the MA PDU session establishment is completed, such as PDU session establishment accept.

[0324] In step 1212, the UE determines that a shared key needs to be derived based on the first indication in the RRC reconfiguration message. The UE then obtains the UE identifier and the MA PDU session identifier, and derives the shared key based on the UE identifier, the MA PDU session identifier, and the superior key. Furthermore, the UE stores the shared key and the shared key identifier. It is understood that the key derivation method used by the UE is the same as that used by the AMF in step 1206.

[0325] In step 1213, the UE derives a first protection key based on the shared key.

[0326] In step 1214, the UPF derives a second protection key based on the shared key.

[0327] In step 1215, the UE and the UPF transmit data of the MPQUIC connection.

[0328] It is understood that any content not described in detail in FIG12 can be referred to the description of the related embodiment in FIG9 . For example, any content not described in detail in steps 1204 to 1206 can be referred to the description in step 901 . Any content not described in detail in steps 1207 to 1208 can be referred to the description in step 902 . Any content not described in detail in steps 1209 to 1212 can be referred to the description in step 901 . Any content not described in detail in steps 1213 to 1215 can be referred to the description in step 903 .

[0329] In the second communication method described above, the SMF instructs the first function and the UE to derive the same shared key. The SMF also sends the shared key derived by the first function to the UPF. In this way, the UPF and the UE both store the same shared key. The UPF and the UE can establish an MPQUIC connection based on this shared key, thereby ensuring security during the MPQUIC connection establishment process between the UE and the UPF.

[0330] 13 exemplarily provides a flow chart of a third communication method, which is specifically applicable to the process of establishing an MA PDU session for a UE. The process of establishing an MA PDU session can be described in 3GPP TS23.502.

[0331] Step 1301: The UE sends a session establishment request to the SMF. Correspondingly, the SMF receives the session establishment request from the UE. The session establishment request is used to request the establishment of the UE's MA PDU session.

[0332] The manner in which the UE sends a session establishment request to the SMF can be found in the description of step 901.

[0333] The session establishment request includes a request type of MA PDU request, indicating that the PDU session requested by the UE is an MA PDU session, or in other words, that the UE is requesting to establish an MA PDU session. The session establishment request is specifically a PDU session establishment request. For details about the PDU session establishment request, see the description in step 1201.

[0334] Step 1302: The SMF sends a certificate application instruction to the UPF according to the session establishment request. Correspondingly, the UPF receives the certificate application instruction from the SMF.

[0335] The certificate application instruction is used to instruct to request the certificate of the UPF. Specifically, the certificate application instruction is used to instruct to request the certificate of the UPF from the certificate certification authority.

[0336] In one possible approach, the SMF determines, based on the session establishment request, that the PDU session requested by the UE is an MA PDU session, and then sends a certificate request indication to the UPF. Exemplarily, the certificate request indication is sent to the UPF during the process of establishing an N4 session between the SMF and the UPF. Exemplarily, the certificate request indication is carried in the N4 session establishment request. Exemplarily, the N4 session establishment request includes an information element (IE), which is a certificate request indication, that is, the IE is used to indicate a request for a certificate from the UPF.

[0337] In one possible approach, before the SMF sends the certificate request indication to the UPF, it may also determine whether to enable the corresponding function of the MPQUIC connection. Exemplarily, when the SMF determines whether to enable the corresponding function of the MPQUIC connection, it may be one of the following three examples:

[0338] Example 1: The UE sends its capability information to the SMF. The capability information indicates that the UE supports establishing an MPQUIC connection. The SMF receives the capability information from the UE and determines that the UE supports establishing an MPQUIC connection based on the capability information.

[0339] Example 2: SMF determines whether to support the functions corresponding to the MPQUIC connection.

[0340] Example 3: The UE sends the UE capability information to the SMF. The SMF receives the capability information from the UE and determines, based on the UE capability information, that the UE supports establishing an MPQUIC connection and supports the functions corresponding to the MPQUIC connection.

[0341] For detailed descriptions of Examples 1 to 3, please refer to the descriptions of Examples 1 to 3 in step 901 .

[0342] In addition, the UE's capability information may be included in the session establishment request. In this case, after receiving the session establishment request, the SMF can not only determine that the PDU session requested by the UE is an MA PDU session, but also determine, based on the UE's capability information, that the UE supports establishing an MPQUIC connection (i.e., Example 1), and then send a certificate application indication to the UPF. Alternatively, after receiving the session establishment request, the SMF can not only determine that the PDU session requested by the UE is an MA PDU session, but also determine, based on the UE's capability information, that the UE supports establishing an MPQUIC connection and that it supports the functions corresponding to the MPQUIC connection (i.e., Example 3), and then send a certificate application indication to the UPF.

[0343] Step 1303: The UPF requests the CA for the UPF certificate according to the certificate application instruction.

[0344] Among them, the UPF certificate can be used for the UE to authenticate the UPF during the establishment of the MPQUIC connection between the UE and the UPF. For details, please refer to the following steps 1304 and 1305. It can be considered that steps 1304 and 1305 occur during the establishment of the MPQUIC connection between the UE and the UPF.

[0345] In one possible example, the UPF determines, based on the certificate request indication, that it needs to request the UPF's certificate from the CA. It then sends a second certificate request to the CA, where the second certificate request is used to request the UPF's certificate. Accordingly, the CA receives the second certificate request from the UPF, generates the UPF's certificate based on the second certificate request, and sends the UPF's certificate to the UPF. The UPF receives the UPF's certificate from the CA. Optionally, the CA further determines an identifier for the UPF's certificate, sends the identifier for the UPF's certificate to the UPF, and the UPF receives the identifier for the UPF's certificate from the CA. Alternatively, the CA may also include the identifier for the UPF's certificate in the UPF's certificate.

[0346] The second certificate request includes the public key (pk) of the UPF. Optionally, the second certificate request may also include one or more of the following parameters: an identifier of the MA PDU session, a third indication. The parameters are described below:

[0347] (1) UPF public key: used by the CA to generate a certificate for the UPF. That is, when the UPF determines that it needs to request a certificate from the CA for the UPF, it first generates the UPF public key and sends a second certificate request containing the UPF public key to the CA. For the CA, the CA can generate a certificate for the UPF based on the UPF public key. Optionally, the UPF can generate not only the UPF public key but also the UPF private key (secret key, sk). Alternatively, the UPF generates a public-private key pair (pk, sk) for the UPF, wherein the UPF private key is used by the UPF to sign the transmitted message during the establishment of the MPQUIC connection (see the description in step 1305 below).

[0348] (2) Identifier of MA PDU session: an identifier used by CA to generate the certificate of UPF. Specifically, CA can determine the identifier of UPF's certificate based on the identifier of MA PDU session. Exemplarily, CA can determine the identifier of UPF's certificate based on the identifier of MA PDU session and the type of UPF, such as using the identifier of MA PDU session + UPF type as the identifier of UPF's certificate. Another exemplary method is that CA can determine the identifier of MA PDU session as the identifier of UPF's certificate. In this way, UPF requests the CA for the certificate of UPF corresponding to each MA PDU session, and each MA PDU session corresponds to a certificate of UPF.

[0349] It should be added that the CA may not determine the identifier of the UPF certificate based on the identifier of the MA PDU session, but may generate a random string and use the random string as the identifier of the UPF certificate, or directly use the identifier of the UPF as the identifier of the UPF certificate. In this way, the UPF requests a UPF certificate from the CA, and the certificate of the UPF can be used by the UPF to establish MPQUIC connections associated with multiple MA PDU sessions. In this way, the UPF does not need to request the UPF certificate from the CA multiple times, reducing the complexity of the process. Accordingly, the identifier of the MA PDU session may not be included in the second certificate request. Optionally, after receiving the second certificate request from the SMF, the UPF first determines whether it has requested the UPF certificate from the CA. If so, there is no need to request the UPF certificate from the CA; otherwise, the UPF certificate is requested from the CA.

[0350] It can be understood that in the method of using a random string as the identifier of the UPF certificate, the UE can obtain the random strings corresponding to the certificates of the multiple UPFs by establishing MPQUIC connections with multiple UPFs, that is, it can know the number of UPFs included in the core network; in the method of using the UPF identifier as the identifier of the UPF certificate, the UE can obtain the identifiers of the multiple UPFs by establishing MPQUIC connections with multiple UPFs, that is, it can know the number of UPFs included in the core network and the identifier of the UPF. In this way, the UE can infer the network topology of the core network, which is not conducive to security protection. In the scheme of using the identifier of the MA PDU session as the identifier of the UPF certificate, the UE cannot know the number of UPFs included in the core network, that is, it cannot infer the network topology of the core network, which helps to achieve security protection of the core network.

[0351] (3) The third indication: used to indicate that the certificate requested by the second certificate request is for the UPF to establish an MPQUIC connection with the UE, or used to indicate that the CA does not need to authenticate a device (here, the UPF) before generating a certificate for the device. It can be understood that the third communication method is applicable to the PDU session establishment process, and before the PDU session is established, the AKA process has been completed, that is, the CA has authenticated the UPF and determined that the UPF authentication has passed. Therefore, when the UPF sends the second certificate request to the CA, the CA does not need to authenticate the UPF again, avoiding unnecessary authentication processes. For the CA, after obtaining the third indication from the second certificate request, the CA does not need to authenticate the UPF, but directly generates a UPF certificate for the UPF.

[0352] In one possible example, after the UPF obtains the UPF certificate from the CA, it may also send a confirmation indication to the SMF, which is used to indicate that the UPF has successfully requested the certificate from the UPF. Accordingly, after the SMF receives the confirmation indication from the UPF, it determines that the UPF has successfully requested the certificate from the UPF, and then executes the subsequent MA PDU session establishment process. After determining that the MA PDU session establishment process is completed, the UE initiates the process of establishing an MPQUIC connection with the UPF. Among them, the confirmation indication is, for example, an affirmative response (ACK). Exemplarily, the confirmation indication is carried in the N4 session establishment response. Exemplarily, the N4 session establishment response includes an IE, which is a confirmation indication, that is, the IE is used to indicate that the UPF has successfully requested the certificate from the UPF. In this way, the problem of the UE initiating the process of establishing an MPQUIC connection with the UPF when the UPF has not yet requested the certificate from the UPF is avoided, resulting in the failure of the UE to establish an MPQUIC connection with the UPF.

[0353] In step 1304, the UPF sends the UPF certificate to the UE, and accordingly, the UE receives the UPF certificate.

[0354] Step 1305: The UE authenticates the UPF based on the UPF certificate.

[0355] In one possible example, the UPF uses the private key of the UPF to sign the previous interaction information to obtain the signature information of the UPF, and sends the signature information of the UPF and the certificate of the UPF to the UE. Correspondingly, the UE receives the signature information of the UPF and the certificate of the UPF, and authenticates the UPF based on the signature information of the UPF and the certificate of the UPF. Here, the previous interaction information includes the information exchanged between the UPF and the UE before the UPF sends the signature information of the UPF and the certificate of the UPF to the UE. For details, please refer to the two-round interaction content of the key exchange and identity authentication between the two parties in the TLS protocol. The UPF can be considered as the server and the UE can be considered as the client.

[0356] In one possible example, when the identifier of the UPF certificate is determined by the CA based on the identifier of the MA PDU session, the UPF can also send the identifier of the UPF certificate to the UE. Accordingly, the UE can also receive the identifier of the UPF certificate to determine that the identifier of the UPF certificate is determined based on the identifier of the MA PDU session, that is, to determine that the UPF certificate is used for the MA PDU session, thereby avoiding abuse of the UPF certificate.

[0357] The UPF may send the UPF certificate identifier, UPF signature information, and UPF certificate to the UE via a verification message.

[0358] Optionally, also include:

[0359] In step 1306, the UE derives a key (i.e., a first protection key) for protecting data of the MPQUIC connection based on the shared key. The shared key is determined by the UE based on the UE's temporary private key and the UPF's temporary public key.

[0360] Please refer to the description in step 602 for details, and the pre-configured key may be replaced with the shared key for understanding.

[0361] In step 1307, the UPF derives a key (i.e., a second protection key) for protecting the data of the MPQUIC connection based on the shared key. The shared key is determined by the UPF based on the temporary public key of the UE and the temporary private key of the UPF.

[0362] Please refer to the description in step 603 for details, and it can be understood that the pre-configured key can be replaced with the shared key.

[0363] The UE's temporary public key is sent to the UPF during the first round of TLS protocol interaction, and the UPF's temporary public key is sent to the UE during the first round of TLS protocol interaction. That is, the UE and UPF can exchange their respective temporary public keys during the first round of TLS protocol interaction. Subsequently, each can derive a shared key based on its own temporary private key and the other party's temporary public key.

[0364] Step 1308: The UE and UPF transmit data of the MPQUIC connection.

[0365] Among them, the MPQUIC connection is associated with the MA PDU session, and the data of the MPQUIC connection is transmitted by multiple paths between the UE and the UPF. The relationship between the MPQUIC connection, MA PDU session, MPQUIC connection and MA PDU session can be found in the description in step 601; the way in which the UE and UPF transmit the data of the MPQUIC connection can be found in the description in step 604.

[0366] It should be added that the embodiment related to Figure 13 is only that the UE authenticates the UPF based on the UPF's certificate, that is, one-way authentication. In this scenario, the SMF can determine that the UE and UPF use one-way authentication when establishing the MPQUIC connection, and then instruct the UPF to request the UPF's certificate from the CA. In one example, the UE uses one-way authentication by default. After receiving the certificate from the UPF, the UE can authenticate the UPF based on the UPF's certificate. In another example, the SMF can also send a one-way authentication indication to the UE. The one-way authentication indication is used to instruct the UE and UPF to use one-way authentication when establishing the MPQUIC connection. Subsequently, the UE can authenticate the UPF based on the UPF's certificate after receiving the certificate from the UPF.

[0367] In addition, this application also supports two-way authentication. Compared with one-way authentication, two-way authentication can add the following steps a to d.

[0368] The timing sequence of steps a to d can be found in the description of the embodiment related to FIG15 below. Of course, the timing sequence in the embodiment related to FIG15 is merely an example of the present application and does not constitute a limitation of the present application. For example, the SMF may first instruct the UPF to request the UPF certificate from the CA, then request the UE's certificate from the CA, and send the UE's certificate to the UE; or, the SMF may first request the UE's certificate from the CA, send the UE's certificate to the UE, and then instruct the UPF to request the UPF certificate from the CA.

[0369] Step a: SMF requests the UE's certificate from the CA.

[0370] Optionally, the SMF determines that the UE and UPF use two-way authentication when establishing the MPQUIC connection, and then requests the UE's certificate from the CA.

[0371] In the process of the SMF requesting the UE's certificate from the CA, specifically, the UE may generate the UE's public key and send the UE's public key to the SMF. The SMF sends a first certificate request to the CA, which includes the UE's public key. Correspondingly, the CA receives the first certificate request from the SMF, generates the UE's certificate based on the UE's public key in the first certificate request, and sends the UE's certificate to the SMF. Optionally, the CA also determines an identifier for the UE's certificate and sends the identifier for the UE's certificate to the SMF. Alternatively, the identifier for the UE's certificate may be carried in the UE's certificate.

[0372] Exemplarily, before generating the UE's public key, the UE may determine, based on the UE's capability information, that the UE supports establishing an MPQUIC connection and / or determines to use bidirectional authentication. The UE's capability information may refer to the description of the UE's capability information in step 901.

[0373] Exemplarily, the UE may also generate a private key for the UE. Exemplarily, the UE may simultaneously generate a public key and a private key for the UE (i.e., a public-private key pair (pk, sk) of the UE). The private key of the UE is used by the UE to sign messages transmitted during the establishment of the MPQUIC connection. For details, see step d below.

[0374] Exemplarily, the UE sends the UE's public key to the SMF. Specifically, the UE sends a PDU session establishment request to the AMF, and the PDU session establishment request carries the UE's public key. The AMF then sends a PDU session create session management context request to the SMF, and the PDU session create session management context request carries the PDU session establishment request, that is, the create session management context request carries the UE's public key. For the SMF, the SMF receives the create session management context request and obtains the UE's public key from the create session management context request.

[0375] The first certificate request may also include one or more of the following parameters: an identifier of the MA PDU session and a third indication. The identifier of the MA PDU session and the third indication are explained below:

[0376] (1) MA PDU session identifier: an identifier used by the CA to generate the UE's certificate. For the CA, the CA can determine the UE's certificate identifier based on the MA PDU session identifier. Exemplarily, the CA can determine the UE's certificate identifier based on the MA PDU session identifier and the UE type, such as using the MA PDU session identifier + UE type as the UE's certificate identifier. In this manner, the UE requests the CA for the UE's certificate corresponding to each MA PDU session, and each MA PDU session corresponds to a UE's certificate.

[0377] It is worth noting that in two-way authentication, the CA needs to generate the identifier of the UPF certificate and the identifier of the UE certificate respectively. In order to distinguish the identifier of the UPF certificate and the identifier of the UE certificate, the CA can use the identifier of the MA PDU session + UPF type as the identifier of the UPF certificate, and use the identifier of the MA PDU session + UE type as the identifier of the UE certificate.

[0378] Optionally, the CA may not determine the identifier of the UE's certificate based on the identifier of the MA PDU session, but may generate a random string and use the random string as the identifier of the UE's certificate, or directly use the UE's identifier as the identifier of the UE's certificate. In this way, the SMF requests a UE's certificate from the CA and sends the certificate of the UE to the UE. The certificate of the UE can be used for the UE to establish multiple MPQUIC connections, and the multiple MPQUIC connections can correspond to multiple MA PDU sessions. In this way, the SMF does not need to request the UE's certificate from the CA multiple times, reducing the complexity of the process. Accordingly, the identifier of the MA PDU session may not be included in the first certificate request. Optionally, after receiving the session establishment request from the UE, the SMF may determine whether the UE's certificate is requested from the CA. If so, it is determined that there is no need to send the first certificate request to the CA. Otherwise, the first certificate request is sent to the CA.

[0379] (2) The third indication: used to indicate that the certificate requested by the first certificate request is for the UE to establish an MPQUIC connection with the UPF, or used to indicate that the CA does not need to authenticate the device before generating a certificate for a certain device (here is the UE). It can be understood that the third communication method is applicable to the PDU session establishment process, and before the PDU session is established, the AKA process has been completed, that is, the CA has authenticated the UE and determined that the UE authentication is successful. Therefore, when the SMF sends the first certificate request to the CA, the CA does not need to authenticate the UE again, avoiding unnecessary authentication processes. For the CA, after obtaining the third indication from the first certificate request, the CA does not need to authenticate the UE, but directly generates a UE certificate for the UE.

[0380] Step b, SMF sends the UE's certificate to the UE.

[0381] Exemplarily, the SMF transmits an N1N2 message to the AMF, including the UE's certificate. The AMF transmits an N2 PDU session request to the RAN, including the UE's certificate. The RAN transmits an RRC reconfiguration message to the UE, including the UE's certificate. The UE receives the RRC reconfiguration message and obtains the UE's certificate from it. This RRC reconfiguration message can be considered the RRC reconfiguration message in the AN-specific resource setup process.

[0382] Optionally, the SMF also sends the UE's certificate identifier to the UE, and the UE's certificate and the UE's certificate identifier are carried in one message. Alternatively, the UE's certificate identifier is carried in the UE's certificate.

[0383] Step c: During the establishment of the MPQUIC connection between the UE and the UPF, the UE sends the UE certificate to the UPF.

[0384] In one example, the UE uses a two-way authentication method by default. After receiving the UE's certificate from the SMF, the UE may send the UE's certificate to the UPF for the UPF to authenticate the UE. In another example, the SMF may also send a two-way authentication indication to the UE. The two-way authentication indication is used to instruct the UE and the UPF to use two-way authentication when establishing an MPQUIC connection. Subsequently, the UE may send the UE's certificate to the UPF after receiving the UE's certificate from the SMF for the UPF to authenticate the UE. The sending method of the two-way authentication indication may be similar to the above-mentioned UE certificate method, that is, the SMF may send the two-way authentication indication and the UE's certificate to the UE through one message, for example, the two-way authentication indication and the UE's certificate are included in the RRC reconfiguration message.

[0385] In addition, when the UE sends a session establishment request, the session establishment request does not carry the UE's public key, but after receiving a two-way authentication indication from the SMF, the UE sends the UE's public key to the SMF.

[0386] In a specific implementation, the SMF sends a mutual authentication indication to the UE. The manner in which the mutual authentication indication is sent may be similar to the manner in which the UE certificate is sent. For example, the mutual authentication indication is included in the RRC reconfiguration message of the AN-specific resource setup process (in this case, the RRC configuration message does not include the UE certificate). Subsequently, in response to the mutual authentication indication, the UE generates a public key for the UE and sends the public key to the SMF. The SMF sends a first certificate request to the CA based on the public key of the UE to request the UE certificate. Subsequently, the SMF sends the UE certificate to the UE. Exemplarily, when the UE sends the public key of the UE to the SMF, the UE may send a first NAS message to the AMF, where the first NAS message carries the public key of the UE. Subsequently, the AMF obtains the public key of the UE in the first NAS message and forwards the public key of the UE to the SMF. Exemplarily, when the SMF sends the certificate of the UE to the UE, the SMF may send the certificate of the UE to the AMF, where the AMF carries the certificate of the UE in a second NAS message, and sends the second NAS message to the UE.

[0387] In another specific implementation, the MA PDU session process further includes an authentication mode notification process. In the authentication mode notification process, the SMF sends a bidirectional authentication indication to the UE. For example, the bidirectional authentication indication is included in the RRC reconfiguration message of the authentication mode notification process. Subsequently, the UE generates a public key of the UE in response to the bidirectional authentication indication and sends the public key of the UE to the SMF. The SMF sends a first certificate request to the CA based on the public key of the UE to request the certificate of the UE. Subsequently, the SMF sends the certificate of the UE to the UE. Exemplarily, when the UE sends the UE's public key to the SMF, specifically, the UE sends a first NAS message to the AMF, and the first NAS message carries the UE's public key. Subsequently, the AMF obtains the UE's public key in the first NAS message and forwards the UE's public key to the SMF. Exemplarily, when the SMF sends the UE's certificate to the UE, specifically, the SMF sends the UE's certificate to the AMF via an N1N2 message, the AMF sends the UE's certificate to the RAN via an N2 PDU session request, and the RAN sends an RRC reconfiguration message to the UE via an RRC reconfiguration message. That is, the UE's certificate is included in the RRC reconfiguration message of the AN-specific resource setup process. It can be understood that the authentication method notification process occurs before the AN-specific resource setup process and after the UE sends the session establishment request.

[0388] In one possible example, the UE uses its private key to sign the previous interaction information to obtain the UE's signature information, and sends the UE's signature information and the UE's certificate to the UPF. Exemplarily, the UE's signature information and the UE's certificate are carried in one message. Here, the previous interaction information includes the information exchanged between the UE and the UPF before the UE sends the signature information and certificate to the UPF. For details, please refer to the two-round interaction content of the TLS protocol regarding the key exchange and identity authentication between the two parties. The UPF can be considered as the server and the UE can be considered as the client.

[0389] In step d, the UPF authenticates the UE based on the UE's certificate.

[0390] In one possible example, the UPF authenticates the UE based on the UE's signature information and the UE's certificate.

[0391] In conjunction with the description of the embodiment related to Figure 13, Figure 14 shows a first specific implementation of the third communication method exemplarily provided in this application. This first specific implementation is for one-way authentication, and the UE uses the one-way authentication mode by default.

[0392] In step 1401, the UE sends a PDU session establishment request to the AMF. In response, the AMF receives the PDU session establishment request from the UE.

[0393] For details, please refer to the description in the above step 1201.

[0394] In step 1402, the AMF selects an SMF. Specifically, the AMF selects an SMF that supports the ATSSS capability.

[0395] In step 1403, the AMF sends a PDU session creation session management context request to the SMF. The PDU session creation session management context request carries a PDU session establishment request. Correspondingly, the SMF receives the PDU session creation session management context request from the AMF.

[0396] Step 1404: The SMF creates a session management context request based on the PDU session and determines to enable the corresponding function of the MPQUIC connection.

[0397] For details, please refer to the description in the above step 1204.

[0398] In step 1405, the SMF sends an N4 session establishment request to the UPF. In response, the UPF receives the N4 session establishment request from the SMF. The N4 session establishment request includes a certificate request instruction. Optionally, the N4 session establishment request also includes an N4 session identifier and an MA PDU session identifier. The SMF locally stores the correspondence between the N4 session identifier and the MA PDU session identifier.

[0399] In step 1406, the UPF generates a public key and a private key of the UPF.

[0400] Optionally, UPF also establishes an N4 session with SMF based on the N4 session establishment request.

[0401] In step 1407, the UPF sends a second certificate request to the CA. In response, the CA receives the second certificate request from the UPF, wherein the second certificate request includes the public key of the UPF. Optionally, the second certificate request also includes the identifier of the MA PDU session and / or the third indication.

[0402] In step 1408, the CA generates a certificate for the UPF based on the public key of the UPF.

[0403] When the second certificate request also includes the identifier of the MA PDU session, the CA can also determine the identifier of the UPF certificate based on the identifier of the MA PDU session; when the second certificate request also includes a third indication, the CA can also determine that there is no need to verify the UPF based on the third indication.

[0404] In step 1409, the CA sends the UPF certificate to the UPF. Accordingly, the UPF receives the UPF certificate from the CA.

[0405] In step 1410, the UPF sends an ACK (ie, an example of an acknowledgment indication) to the SMF, and correspondingly, the SMF receives the ACK from the UPF.

[0406] In step 1411, SMF sends an N1N2 message transmission to AMF, and accordingly, AMF receives the N1N2 message transmission from SMF.

[0407] Among them, the N1N2 message transmission includes ATSSS rules, and the ASSSS rules can be specifically obtained by the SMF from the PCF. The ASSSS rules can be used by the UE to decide the steering function applied to a specific data packet flow (such as using the MPQUIC function after establishing the MPQUIC connection).

[0408] In step 1412, the AMF sends an N2 PDU session request to the RAN. In response, the RAN receives the N2 PDU session request from the AMF, where the N2 PDU session request includes the ATSSS rules.

[0409] In step 1413, the RAN sends an RRC reconfiguration message to the UE. Correspondingly, the UE receives the RRC reconfiguration message from the RAN, where the RRC reconfiguration message includes the ATSSS rules.

[0410] In a specific example, in the AN-specific resource setup process, the RAN sends an RRC reconfiguration message to the UE. The RRC reconfiguration message also includes indication information of the completion of the MA PDU session establishment, such as PDU session establishment acceptance.

[0411] In step 1414, the UPF sends the UPF certificate to the UE, and accordingly, the UE receives the UPF certificate.

[0412] Step 1415: The UE authenticates the UPF based on the UPF certificate.

[0413] Step 1416: The UE derives a first protection key based on the shared key.

[0414] In step 1417, the UPF derives a second protection key based on the shared key.

[0415] In step 1418, the UE and the UPF transmit data of the MPQUIC connection.

[0416] It can be understood that for the contents not described in detail in FIG14 , reference can be made to the description in the related embodiment of FIG13 .

[0417] For example, for any unspecified content in steps 1401 to 1404, refer to the description in step 1301. For any unspecified content in step 1405, refer to the description in step 1302. For any unspecified content in steps 1406 to 1410, refer to the description in step 1303. For any unspecified content in steps 1414 and 1415, refer to the description in steps 1304 and 1305. For any unspecified content in step 1416, refer to the description in step 1306. For any unspecified content in step 1417, refer to the description in step 1307. For any unspecified content in step 1418, refer to the description in step 1308.

[0418] In addition, when the UE does not use the one-way authentication mode by default, that is, when the SMF needs to send a one-way authentication indication to the UE, the one-way authentication indication can be carried in the N1N2 message transmission, N2 PDU session request and RRC reconfiguration message respectively. Accordingly, the UE determines to use the one-way authentication mode when establishing the MPQUIC connection with the UPF based on the one-way authentication indication.

[0419] In conjunction with the description of the embodiments in Figures 13 and 14, Figure 15 shows a second specific implementation of the third communication method exemplarily provided in this application. The second specific implementation is for two-way authentication, and the UE uses the two-way authentication mode by default.

[0420] Step 1501: The UE generates a public key and a private key for the UE. Specifically, the UE generates the public key and the private key for the UE when determining, based on the UE capability information, that the UE supports establishing an MPQUIC connection and / or when determining that the UE and the UPF use mutual authentication when establishing the MPQUIC connection.

[0421] In step 1502, the UE sends a PDU session establishment request to the AMF. In response, the AMF receives the PDU session establishment request from the UE.

[0422] For details, please refer to the description in the above step 1201.

[0423] In step 1503, the AMF selects an SMF. Specifically, the AMF selects an SMF that supports the ATSSS capability.

[0424] In step 1504, the AMF sends a PDU session creation session management context request to the SMF. The PDU session creation session management context request carries the PDU session establishment request. Correspondingly, the SMF receives the PDU session creation session management context request from the AMF.

[0425] Step 1505: SMF creates a session management context request based on the PDU session and determines to enable the corresponding function of the MPQUIC connection.

[0426] For details, please refer to the description in the above step 1204.

[0427] In step 1506, the SMF sends an N4 session establishment request to the UPF. In response, the UPF receives the N4 session establishment request from the SMF, which includes a certificate application instruction. For details, please refer to the description of step 1405 above.

[0428] In step 1507, the UPF generates a public key and a private key of the UPF. For details, please refer to the description in step 1406 above.

[0429] In step 1508, the UPF sends a second certificate request to the CA. Correspondingly, the CA receives the second certificate request from the UPF. For details, please refer to the description in the above step 1407.

[0430] In step 1509, the CA generates a certificate for the UPF based on the public key of the UPF. For details, please refer to the description in step 1408 above.

[0431] In step 1510, the CA sends the UPF certificate to the UPF. Accordingly, the UPF receives the UPF certificate from the CA.

[0432] In step 1511, the UPF sends an ACK (ie, an example of an acknowledgment indication) to the SMF, and correspondingly, the SMF receives the ACK from the UPF.

[0433] Step 1512: The SMF sends a first certificate request to the CA. Correspondingly, the CA receives the first certificate request from the SMF, wherein the first certificate request includes the public key of the UE. Optionally, the first certificate request also includes an identifier of the MA PDU session and / or a third indication.

[0434] Step 1513: The CA generates a certificate for the UE based on the public key of the UE.

[0435] When the first certificate request also includes the identifier of the MA PDU session, the CA can also determine the identifier of the UE's public key based on the identifier of the MA PDU session; when the first certificate request also includes a third indication, the CA can also determine that there is no need to verify the UE based on the third indication.

[0436] Step 1514: CA sends the UE's certificate to SMF. Correspondingly, SMF receives the UE's certificate from CA.

[0437] In step 1515, the SMF sends an N1N2 message transmission to the AMF. Correspondingly, the AMF receives the N1N2 message transmission from the SMF, where the N1N2 message transmission includes the UE's certificate.

[0438] The N1N2 message transmission also includes ATSSS rules, which can be obtained by the SMF from the PCF. The ATSSS rules can be used by the UE to decide the steering function applied to a specific data packet flow (such as using the MPQUIC function after establishing an MPQUIC connection).

[0439] In step 1516, the AMF sends an N2 PDU session request to the RAN. In response, the RAN receives the N2 PDU session request from the AMF. The N2 PDU session request includes the UE's certificate and the ATSSS rules.

[0440] In step 1517, the RAN sends an RRC reconfiguration message to the UE. In response, the UE receives the RRC reconfiguration message from the RAN, which includes the UE's certificate. The RRC reconfiguration message also includes the ATSSS rules. In a specific example, during the AN-specific resource setup process, the RAN sends an RRC reconfiguration message to the UE. The RRC reconfiguration message also includes an indication that the MA PDU session establishment is complete, such as a PDU session establishment acceptance.

[0441] In step 1518, the UE sends the UE certificate to the UPF, and accordingly, the UPF receives the UE certificate.

[0442] In step 1519, the UPF authenticates the UE based on the UE's certificate.

[0443] In step 1520, the UPF sends the UPF certificate to the UE, and accordingly, the UE receives the UPF certificate.

[0444] Step 1521: The UE authenticates the UPF based on the UPF certificate.

[0445] In step 1522, the UE derives a first protection key based on the shared key.

[0446] In step 1523, the UPF derives a second protection key based on the shared key.

[0447] Step 1524: The UE and UPF transmit data of the MPQUIC connection.

[0448] It should be understood that for any details not fully described in FIG15 , reference may be made to the description of the related embodiment in FIG13 . For example, for any details not fully described in step 1501 , reference may be made to the description in step a. For any details not fully described in steps 1502 to 1505 , reference may be made to the description in step 1301 . For any details not fully described in step 1506 , reference may be made to the description in step 1302 . For any details not fully described in steps 1507 to 1511 , reference may be made to the description in step 1303 . For any details not fully described in steps 1512 to 1514 , reference may be made to the description in step a . For any details not fully described in steps 1515 to 1517 , reference may be made to the description in step b . For any details not fully described in steps 1518 and 1519 , reference may be made to the description in steps c and d . For any details not fully described in steps 1520 and 1521 , reference may be made to the description in steps 1304 and 1305 . For details not described in detail in step 1522, please refer to the description in step 1306. For details not described in detail in step 1523, please refer to the description in step 1307. For details not described in detail in step 1524, please refer to the description in step 1308.

[0449] In addition, when the UE does not use the mutual authentication mode by default, that is, when the SMF needs to send a mutual authentication indication to the UE, the N1N2 message transmission, N2 PDU session request and RRC reconfiguration message do not carry the UE's certificate, but carry a mutual authentication indication. Accordingly, the UE determines to use the mutual authentication mode when establishing an MPQUIC connection with the UPF based on the mutual authentication indication. Furthermore, steps 1501 and 1512 to 1514 occur after step 1517 and before step 1518.

[0450] In the one-way authentication of the third communication method described above, the SMF sends a certificate request instruction to the UPF. The UPF requests the UPF's certificate from the CA based on the certificate request instruction. During the establishment of the MPQUIC connection between the UE and the UPF, the UPF sends the UPF's certificate to the UE, and the UE can authenticate the UPF using the UPF's certificate. In this way, security is achieved during the establishment of the MPQUIC connection between the UE and the UPF.

[0451] In the two-way authentication of the third communication method described above, the SMF sends a certificate request instruction to the UPF. The UPF requests the UPF's certificate from the CA based on the certificate request instruction. During the establishment of the MPQUIC connection between the UE and the UPF, the UPF sends the UPF's certificate to the UE, and the UE can use the UPF's certificate to authenticate the UPF. The SMF also requests the UE's certificate from the CA and sends the UE's certificate to the UE. During the establishment of the MPQUIC connection between the UE and the UPF, the UE sends the UE's certificate to the UPF, and the UPF can use the UE's certificate to authenticate the UE. In this way, security is achieved during the process of establishing the MPQUIC connection between the UE and the UPF.

[0452] It should be noted that the step numbers in the flowcharts described in the first to third communication methods are merely examples of the execution process and do not limit the order in which the steps are executed. In the embodiments of the present application, there is no strict execution order between steps that have no temporal dependencies. Not all steps shown in the flowcharts are mandatory, and some steps may be deleted or added to each flowchart as needed.

[0453] The above description focuses on the differences between different embodiments of the first to third communication methods. Except for the differences, the first to third communication methods can refer to each other. In addition, in the same communication method, different implementation methods or different examples can also refer to each other.

[0454] It is understood that in the above-mentioned various method embodiments, the methods and operations implemented by the terminal device (i.e., UE) can also be implemented by a module (e.g., a chip or circuit) of the terminal device, and the terminal device and the modules of the terminal device can be collectively referred to as a terminal device. In other words, "UE" in the above-mentioned communication method can be replaced with "terminal device." In the following device embodiments, the UE is still used as an example.

[0455] Based on the above content and the same concept, Figures 16 and 17 are schematic diagrams of the structures of possible communication devices provided in this application. These communication devices can be used to implement the functions of the UE, the first function (such as AMF), the SMF, or the UPF in the above method embodiment, and thus can also achieve the beneficial effects of the above method embodiment.

[0456] As shown in FIG. 16 , the communication device 1600 may include a transceiver module 1601 and a processing module 1602 .

[0457] When the communication device 1600 is used to execute the method of the first UE in the first communication method:

[0458] The communication device 1600 may be the UE in FIG. 1 to FIG. 4 .

[0459] The processing module 1602 is used to: after the first MA PDU session of the first UE is established, control the transceiver module 1601 to negotiate with the first UPF to establish a first MPQUIC connection, and the first MPQUIC connection is associated with the first MA PDU session.

[0460] The processing module 1602 is configured to derive, based on a preconfigured key, a key for protecting data of a first MPQUIC connection, where the data of the first MPQUIC connection is transmitted over multiple paths between the first UE and the first UPF. The preconfigured key is further used by the first UE to establish a second MPQUIC connection with a second UPF, where the first UPF and the second UPF are located in the same PLMN.

[0461] In a possible implementation, when controlling the transceiver module 1601 to negotiate with the first UPF to establish the first MPQUIC connection, the processing module 1602 is specifically configured to: control the transceiver module 1601 to send an identifier of the pre-configured key to the first UPF.

[0462] In a possible implementation, messages transmitted during negotiation are protected based on 3GPP security.

[0463] In one possible implementation, the preconfigured key used by the first UE when negotiating with the first UPF to establish the first MPQUIC connection is the same as the preconfigured key used by the second UE when negotiating with the first UPF to establish the third MPQUIC connection. The first UE and the second UE belong to the same H-PLMN.

[0464] In one possible implementation, after the first MA PDU session of the first UE is established, the processing module 1602 is further used to: control the transceiver module 1601 to negotiate with the first UPF to establish a fourth MPQUIC connection, the fourth MPQUIC connection is associated with the first MA PDU session, and, based on the pre-configured key, derive a key for protecting data of the fourth MPQUIC connection, wherein the key used to protect the data of the first MPQUIC connection is different from the key used to protect the data of the fourth MPQUIC connection.

[0465] In one possible implementation, after the second MA PDU session of the first UE is established, the processing module 1602 is further configured to control the transceiver module 1601 to negotiate with the second UPF to establish a second MPQUIC connection, where the second MPQUIC connection is associated with the second MA PDU session. The processing module 1602 is further configured to derive, based on a preconfigured key, a key for protecting data of the second MPQUIC connection.

[0466] When the communication device 1600 is used to execute the method of the first UPF in the first communication method:

[0467] The communication device 1600 may be the UPF in FIG. 1 or 2 , or the H-UPF in FIG. 3 or 4 .

[0468] The processing module 1602 is configured to: after the first MA PDU session of the first UE is established, control the transceiver module 1601 to negotiate with the first UE to establish a first MPQUIC connection, where the first MPQUIC connection is associated with the first MA PDU session.

[0469] The processing module 1602 is further configured to derive, based on the preconfigured key, a key for protecting data of a first MPQUIC connection, where the data of the first MPQUIC connection is transmitted over multiple paths between the first UE and the first UPF. The preconfigured key is further used by the first UE to establish a second MPQUIC connection with a second UPF, where the first UPF and the second UPF are located in the same PLMN.

[0470] In a possible implementation, when the processing module 1602 controls the transceiver module 1601 to negotiate with the first UE to establish the first MPQUIC connection, the processing module 1602 is specifically configured to: control the transceiver module 1601 to receive an identifier of the pre-configured key from the first UE.

[0471] In a possible implementation, messages transmitted during negotiation are protected based on 3GPP security.

[0472] In one possible implementation, the preconfigured key used when the first UPF negotiates with the first UE to establish the first MPQUIC connection is the same as the preconfigured key used when the first UPF negotiates with the second UE to establish the third MPQUIC connection. The first UE and the second UE belong to the same H-PLMN.

[0473] In one possible implementation, after the first MA PDU session of the first UE is established, the processing module 1602 is further configured to: control the transceiver module 1601 to negotiate with the first UE to establish a fourth MPQUIC connection, where the fourth MPQUIC connection is associated with the first MA PDU session; and derive, based on a preconfigured key, a key for protecting data of the fourth MPQUIC connection, where the key for protecting data of the first MPQUIC connection is different from the key for protecting data of the fourth MPQUIC connection.

[0474] When the communication device 1600 is used to execute the SMF method in the second communication method:

[0475] The communication device 1600 may be the SMF in FIG. 1 or FIG. 2 , or the H-SMF in FIG. 3 or FIG. 4 .

[0476] In the process of establishing an MA PDU session for the UE, the processing module 1602 is used to: obtain a shared key from the first function, send the shared key to the UPF, and use the shared key to derive the key used by the UPF to protect the data in the MPQUIC connection between the UE and the UPF. The MPQUIC connection is associated with the MA PDU session, and the data of the MPQUIC connection is transmitted by multiple paths between the UE and the UPF.

[0477] In a possible implementation, the processing module 1602 is further used to: control the transceiver module 1601 to send a first indication to the UE, where the first indication is used to instruct the UE to establish an MPQUIC connection with the UPF using a shared key.

[0478] In one possible implementation, before obtaining the shared key from the first function, the processing module 1602 is further configured to: determine whether to enable the function corresponding to the MPQUIC connection. In one possible implementation, when the processing module 1602 determines whether to enable the function corresponding to the MPQUIC connection, it is specifically configured to: control the transceiver module 1601 to receive capability information from the UE, and determine, based on the UE capability information, that the UE supports establishing an MPQUIC connection; and / or determine whether to support the function corresponding to the MPQUIC connection.

[0479] In one possible implementation, when the processing module 1602 obtains the shared key from the first function, it is specifically used to control the transceiver module 1601 to send a second indication to the first function, where the second indication is used to instruct the first function to deduce the shared key; and control the transceiver module 1601 to receive the shared key from the first function.

[0480] In one possible implementation, after obtaining the shared key from the first function, the processing module 1602 is further used to: control the transceiver module 1601 to send an identifier of the shared key to the UPF. In one example, the identifier of the shared key is determined by the processing module 1602 according to the identifier of the MA PDU session. Accordingly, the processing module 1602 is further used to control the transceiver module 1601 to send the identifier of the shared key to the first function, and / or control the transceiver module 1601 to send the identifier of the shared key to the UE. In another example, the identifier of the shared key is determined by the first function according to the identifier of the MA PDU session. Accordingly, the processing module 1602 is further used to control the transceiver module 1601 to send the identifier of the MA PDU session to the first function, and receive the identifier of the shared key from the first function.

[0481] In a possible implementation, the identifier of the shared key is an identifier of the MA PDU session.

[0482] When the communication device 1600 is used to execute the UPF method in the second communication method:

[0483] The communication device 1600 may be the UPF in FIG. 1 or 2 , or the H-UPF in FIG. 3 or 4 .

[0484] In the process of establishing an MA PDU session for the UE, the transceiver module 1601 is used to: receive a shared key from the SMF; the processing module 1602 is used to: deduce, based on the shared key, the key used to protect the data in the MPQUIC connection between the UE and the UPF. The MPQUIC connection is associated with the MA PDU session, and the data of the MPQUIC connection is transmitted by multiple paths between the UE and the UPF.

[0485] In one possible implementation, the transceiver module 1601 is further configured to receive a shared key identifier from the SMF, where the shared key identifier is determined by the SMF or the first function based on the MA PDU session identifier; and the processing module 1602 is further configured to store the shared key identifier in correspondence with the shared key. In one possible implementation, the shared key identifier is the MA PDU session identifier.

[0486] When the communication device 1600 is used to execute the UE method in the second communication method:

[0487] The communication device 1600 may be the UE in FIG. 1 to FIG. 4 .

[0488] In the process of establishing an MA PDU session for the UE, the transceiver module 1601 is used to: receive a first indication from the SMF, where the first indication is used to instruct the UE to establish an MPQUIC connection with the UPF using a shared key, and the MPQUIC connection is associated with the MA PDU session; the processing module 1602 is used to: deduce the shared key based on the first indication, and, based on the shared key, deduce the key used to protect the data in the MPQUIC connection, and the data of the MPQUIC connection is transmitted by multiple paths between the UE and the UPF.

[0489] In a possible implementation, the transceiver module 1601 is further used to send the UE capability information to the SMF, where the UE capability information is used to indicate that the UE supports establishing an MPQUIC connection.

[0490] In one possible implementation, when the processing module 1602 derives the shared key according to the first indication, it is specifically configured to: derive the shared key according to the first indication and one or more of the following parameters: an identifier of the UE, an identifier of the MA PDU session, and a superior key. Exemplarily, the superior key includes one or more of the following: an AUSF key, a SEAF key, a RAN key, and an AMF key.

[0491] In a possible implementation, the identifier of the shared key is determined by the SMF according to the identifier of the MA PDU session, and the transceiver module 1601 is further configured to receive the identifier of the shared key from the SMF.

[0492] In a possible implementation, the identifier of the shared key is determined by the UE according to the identifier of the MA PDU session. That is, the processing module 1602 is further configured to determine the identifier of the shared key according to the identifier of the MA PDU session.

[0493] In a possible implementation, the processing module 1602 is further configured to: store the corresponding identifier of the shared key and the shared key.

[0494] In a possible implementation, the identifier of the shared key is an identifier of the MA PDU session.

[0495] When the communication device 1600 is used to perform the first function in the second communication method:

[0496] Exemplarily, the communication device 1600 is an AMF, SEAF, or AUSF. Exemplarily, when the communication device 1600 is an AMF, the communication device 1600 may specifically be the AMF in FIG. 1 or FIG. 2 , or the V-AMF in FIG. 3 , or the H-AMF or V-AMF in FIG. 4 . In the scenario of FIG. 4 , the communication device may specifically be the AMF corresponding to 3GPP access.

[0497] In the process of establishing an MA PDU session for the UE, the transceiver module 1601 is used to: receive a second indication from the SMF; the processing module 1602 is used to: deduce a shared key based on the second indication; the transceiver module 1601 is also used to: send a shared key to the SMF, wherein the shared key is used to deduce a key for protecting data in the MPQUIC connection between the UE and the UPF, the MPQUIC connection is associated with the MA PDU session, and the data of the MPQUIC connection is transmitted by multiple paths between the UE and the UPF.

[0498] In one possible implementation, the shared key identifier is determined by the SMF based on the identifier of the MA PDU session, and the transceiver module 1601 is further used to receive the shared key identifier from the SMF. In one possible implementation, the shared key identifier is determined by the AMF based on the identifier of the MA PDU session, that is, the transceiver module 1601 is further used to receive the MA PDU session identifier from the SMF, and the processing module 1602 is further used to determine the shared key identifier based on the MA PDU session identifier.

[0499] In one possible implementation, when the processing module 1602 derives the shared key according to the second indication, it is specifically configured to: derive the shared key according to the second indication and one or more of the following parameters: an identifier of the UE, an identifier of the MA PDU session, and a superior key. Exemplarily, when the first function is AMF, the superior key includes one or more of the following: a RAN key and an AMF key; when the first function is SEAF, the superior key may be a SEAF key; when the first function is AUSF, the superior key may be an AUSF key.

[0500] When the communication device 1600 is used to execute the SMF method in the third communication method:

[0501] The communication device 1600 may be the SMF in FIG. 1 or FIG. 2 , or the H-SMF in FIG. 3 or FIG. 4 .

[0502] During the process of establishing an MA PDU session for a UE, the transceiver module 1601 is configured to receive a session establishment request from the UE, where the session establishment request is used to request establishment of an MA PDU session for the UE. The processing module 1602 is configured to control the transceiver module 1601 to send a certificate request indication to the UPF based on the session establishment request, where the certificate request indication is used to request a certificate from the CA for the UPF. During the process of establishing an MPQUIC connection between the UE and the UPF, the UPF certificate is used by the UE to authenticate the UPF. The MPQUIC connection is associated with the MA PDU session, and data for the MPQUIC connection is transmitted over multiple paths between the UE and the UPF.

[0503] In one possible implementation, after controlling the transceiver module 1601 to send a certificate request instruction to the UPF, the processing module 1602 is further configured to control the transceiver module 1601 to receive a confirmation instruction from the UPF, where the confirmation instruction is used to indicate that the UPF has successfully requested the certificate from the UPF. Exemplarily, the processing module 1602 is further configured to determine, based on the confirmation instruction, that the UPF has successfully requested the certificate from the UPF.

[0504] In one possible implementation, the transceiver module 1601 is further configured to send a first certificate request to the CA, where the first certificate request includes the UE's public key, and the UE's public key is used by the CA to generate a certificate for the UE. The transceiver module 1601 is further configured to receive the UE's certificate from the CA and send the UE's certificate to the UE, where the UPF authenticates the UE during MPQUIC connection establishment.

[0505] In one possible implementation, before sending the first certificate request to the CA, transceiver module 1601 is further configured to send a mutual authentication indication to the UE, where the mutual authentication indication is used to indicate that the authentication method used during MPQUIC connection establishment is mutual authentication. Transceiver module 1601 is further configured to receive the UE's public key. Exemplarily, the mutual authentication indication may be carried in a radio resource control reconfiguration message.

[0506] In a possible implementation, the session establishment request includes the UE's public key. Exemplarily, the UE's certificate may be carried in a radio resource control reconfiguration message.

[0507] In one possible implementation, the first certificate request also includes an MA PDU session identifier, which is used to determine the identifier of the UE's certificate. In one possible implementation, the transceiver module 1601 is further used to send the MA PDU session identifier to the UPF, which is used to determine the identifier of the UPF's certificate.

[0508] In one possible implementation, before controlling the transceiver module 1601 to send a certificate request indication to the UPF, the processing module 1602 is further configured to: determine whether to enable a function corresponding to an MPQUIC connection. Exemplarily, when determining whether to enable a function corresponding to an MPQUIC connection, the processing module 1602 is specifically configured to: control the transceiver module 1601 to receive capability information from the UE, and determine, based on the UE capability information, whether the UE supports establishing an MPQUIC connection and / or determine whether to support a function corresponding to an MPQUIC connection.

[0509] When the communication device 1600 is used to execute the UE method in the third communication method:

[0510] The communication device 1600 may be the UE in FIG. 1 to FIG. 4 .

[0511] In the process of establishing an MA PDU session for the UE, the transceiver module 1601 is used to send a session establishment request to the SMF, and the session establishment request is used to request the establishment of the UE's MA PDU session; in the process of establishing the MPQUIC connection between the UE and the UPF, the transceiver module 1601 is used to receive the UPF certificate from the UPF, and the processing module 1602 is used to authenticate the UPF based on the UPF certificate; wherein, the MPQUIC connection is associated with the MA PDU session, and the data of the MPQUIC connection is transmitted by multiple paths between the UE and the UPF.

[0512] In one possible implementation, during the establishment of the MPQUIC connection between the UE and the UPF, the transceiver module 1601 is also used to receive the UE's certificate from the SMF, and to send the UE's certificate to the UPF. The UE's certificate is used by the UPF to authenticate the UE.

[0513] In one possible implementation, the session establishment request includes the UE's public key, which is used by the SMF to request the UE's certificate from the CA. Before the transceiver module 1601 sends the session establishment request to the SMF, the processing module 1602 is further configured to generate the UE's public key. Exemplarily, the UE's certificate is carried in an RRC reconfiguration message.

[0514] In one possible implementation, the transceiver module 1601 is further configured to: receive a bidirectional authentication indication from the SMF, where the bidirectional authentication indication is used to indicate that bidirectional authentication is used during the MPQUIC connection establishment process; the processing module 1602 is further configured to: generate a public key of the UE based on the bidirectional authentication indication; and the transceiver module 1601 is further configured to: send the UE public key to the SMF, where the UE public key is used by the SMF to request the CA for the UE certificate. Exemplarily, the bidirectional authentication indication is carried in an RRC reconfiguration message.

[0515] In one possible implementation, the processing module 1602 is further used to: generate a private key of the UE, where the private key of the UE is used by the UE to sign transmitted messages during the establishment of the MPQUIC connection.

[0516] In a possible implementation, the transceiver module 1601 is further used to: receive the identifier of the UPF certificate from the UPF; the processing module 1602 is further used to: determine whether the identifier of the UPF certificate is determined based on the identifier of the MA PDU session.

[0517] In a possible implementation, the transceiver module 1601 is further used to send the UE capability information to the SMF, where the UE capability information is used to indicate that the UE supports establishing an MPQUIC connection.

[0518] When the communication device 1600 is used to execute the UPF method in the third communication method:

[0519] The communication device 1600 may be the UPF in FIG. 1 or 2 , or the H-UPF in FIG. 3 or 4 .

[0520] During the establishment of the UE's MA PDU session, the transceiver module 1601 is used to: receive a certificate application indication from the SMF; the processing module 1602 is also used to: control the transceiver module 1601 to request the UPF certificate from the CA according to the certificate application indication; during the establishment of the MPQUIC connection between the UE and the UPF, the transceiver module 1601 is also used to send the UPF certificate to the UE, and the UPF certificate is used by the UE to authenticate the UPF; wherein, the MPQUIC connection is associated with the MA PDU session, and the data of the MPQUIC connection is transmitted by multiple paths between the UE and the UPF.

[0521] In a possible implementation, when the transceiver module 1601 requests the UPF certificate from the CA, it is specifically used to: send a second certificate request to the CA, where the second certificate request is used to request the UPF certificate from the CA; and receive the UPF certificate from the CA.

[0522] In one possible implementation, during the establishment of the MPQUIC connection between the UE and the UPF, the transceiver module 1601 is further used to: receive the UE's certificate; the processing module 1602 is further used to: authenticate the UE based on the UE's certificate.

[0523] In one possible implementation, the second certificate request includes the public key of the UPF, which is used by the CA to determine the UPF's certificate. That is, before the transceiver module 1601 sends the second certificate request, the processing module 1602 is further configured to generate the public key of the UPF.

[0524] In one possible implementation, the processing module 1602 is further used to generate a private key of the UPF, and the private key of the UPF is used by the UPF to sign the transmitted message during the establishment of the MPQUIC connection.

[0525] In one possible implementation, the second certificate request also includes an MA PDU session identifier, which is used to determine the UPF certificate identifier. That is, before sending the second certificate request, the transceiver module 1601 is also used to receive the MA PDU session identifier from the SMF.

[0526] In a possible implementation, after successfully obtaining the UPF certificate from the CA, the transceiver module 1601 is further used to send a confirmation indication to the SMF, where the confirmation indication is used to indicate that the UPF has successfully requested the UPF certificate.

[0527] FIG17 shows an apparatus 1700 provided in an embodiment of the present application. The apparatus shown in FIG17 may be a hardware circuit implementation of the apparatus shown in FIG16 . The apparatus may be applicable to the flowchart shown above to perform the functions of the UE, the first function (e.g., AMF), the SMF, or the UPF in the above-described method embodiment. For ease of explanation, FIG17 only shows the main components of the apparatus.

[0528] The device 1700 shown in FIG17 includes a communication interface 1710, a processor 1720, and a memory 1730, wherein the memory 1730 is used to store program instructions and / or data. The processor 1720 may operate in conjunction with the memory 1730. The processor 1720 may execute program instructions stored in the memory 1730. When the instructions or program stored in the memory 1730 are executed, the processor 1720 is used to perform the operations performed by the processing module 1602 in the above embodiment, and the communication interface 1710 is used to perform the operations performed by the transceiver module 1601 in the above embodiment.

[0529] Memory 1730 is coupled to processor 1720. In the embodiments of the present application, coupling refers to an indirect coupling or communication connection between devices, units, or modules, and can be electrical, mechanical, or other forms, for information exchange between the devices, units, or modules. At least one of memory 1730 may be included in processor 1720.

[0530] In the embodiments of the present application, the communication interface may be a transceiver, circuit, bus, module, or other type of communication interface. In the embodiments of the present application, when the communication interface is a transceiver, the transceiver may include an independent receiver or an independent transmitter; or a transceiver or communication interface that integrates transceiver functions.

[0531] Device 1700 may also include a communication line 1740. Communication interface 1710, processor 1720, and memory 1730 may be interconnected via communication line 1740; communication line 1740 may be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, for example. Communication line 1740 may be classified as an address bus, a data bus, a control bus, and the like. For ease of illustration, FIG17 shows only one thick line, but this does not imply that there is only one bus or only one type of bus.

[0532] It is understood that the processor in the embodiments of the present application may be a central processing unit (CPU), or may be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. The general-purpose processor may be a microprocessor or any conventional processor.

[0533] The method steps in the embodiments of the present application can be implemented by hardware or by a processor executing software instructions. The software instructions can be composed of corresponding software modules, and the software modules can be stored in a random access memory, a flash memory, a read-only memory, a programmable read-only memory, an erasable programmable read-only memory, an electrically erasable programmable read-only memory, a register, a hard disk, a mobile hard disk, a CD-ROM or any other form of storage medium well known in the art. An exemplary storage medium is coupled to the processor so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium can also be an integral part of the processor. The processor and the storage medium can be located in an ASIC. In addition, the ASIC can be located in a base station or a terminal. Of course, the processor and the storage medium can also exist in a base station or a terminal as discrete components.

[0534] In the above embodiments, all or part of the embodiments may be implemented using software, hardware, firmware, or any combination thereof. When implemented using software, all or part of the embodiments may be implemented in the form of a computer program product. A computer program product includes one or more computer programs or instructions. When the computer program or instructions are loaded and executed on a computer, all or part of the processes or functions of the embodiments of the present application are performed. The computer may be a general-purpose computer, a special-purpose computer, a computer network, a network device, a user device, or other programmable device. The computer program or instructions may be stored in a computer-readable storage medium or transferred from one computer-readable storage medium to another. For example, the computer program or instructions may be transferred from one website, computer, server, or data center to another website, computer, server, or data center via wired or wireless means. The computer-readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server or data center that integrates one or more available media. The available media may be magnetic media, such as floppy disks, hard disks, or magnetic tapes; optical media, such as digital video disks; or semiconductor media, such as solid-state drives. The computer-readable storage medium may be a volatile or nonvolatile storage medium, or may include both volatile and nonvolatile types of storage media.

[0535] In the various embodiments of the present application, unless otherwise specified or there is a logical conflict, the terms and / or descriptions between different embodiments are consistent and can be referenced by each other. The technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationships.

[0536] In the present application, "at least one" means one or more, and "more" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. In the text description of the present application, the character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "Including at least one of A, B and C" can mean: including A; including B; including C; including A and B; including A and C; including B and C; including A, B and C. It can be understood that the various digital numbers involved in the embodiments of the present application are only distinguished for the convenience of description, and are not used to limit the scope of the embodiments of the present application. The size of the serial number of each of the above processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic.

Claims

1. A communication method, characterized in that: include: After the first multi-access protocol data unit MA PDU session of the first terminal device is established, the first terminal device negotiates with the first user plane function to establish a first multipath fast user datagram protocol internet connection MPQUIC connection, the first MPQUIC connection being associated with the first MA PDU session; The first terminal device derives, based on a preconfigured key, a key for protecting data of the first MPQUIC connection, where the data of the first MPQUIC connection is transmitted over a plurality of paths between the first terminal device and the first user plane function; The pre-configured key is also used for the first terminal device to establish a second MPQUIC connection with a second user plane function.

2. The method according to claim 1, characterized in that The first terminal device negotiates with the first user plane function to establish a first MPQUIC connection, including: The first terminal device sends an identifier of the pre-configured key to a first user plane function.

3. The method according to claim 1 or 2, characterized in that The messages transmitted in the negotiation are protected based on 3GPP security.

4. The method according to any one of claims 1 to 3, characterized in that The preconfiguration key used by the first terminal device when negotiating with the first user plane function to establish the first MPQUIC connection is the same as the preconfiguration key used by the second terminal device when negotiating with the first user plane function to establish a third MPQUIC connection.

5. The method according to any one of claims 1 to 4, characterized in that After the first MA PDU session of the first terminal device is established, the method further includes: The first terminal device negotiates with the first user plane function to establish a fourth MPQUIC connection, the fourth MPQUIC connection being associated with the first MA PDU session; The first terminal device derives, based on the preconfigured key, a key for protecting data of the fourth MPQUIC connection, wherein the key for protecting data of the first MPQUIC connection is different from the key for protecting data of the fourth MPQUIC connection.

6. The method according to any one of claims 1 to 5, characterized in that Also includes: After the second MA PDU session of the first terminal device is established, the first terminal device negotiates with the second user plane function to establish the second MPQUIC connection, and the second MPQUIC connection is associated with the second MA PDU session; The first terminal device derives, based on the preconfigured key, a key for protecting data of the second MPQUIC connection.

7. A communication method, characterized in that: include: After the first multi-access protocol data unit MA PDU session of the first terminal device is established, the first user plane function negotiates with the first terminal device to establish a first multipath fast user datagram protocol internet connection MPQUIC connection, the first MPQUIC connection being associated with the first MA PDU session; The first user plane function derives, based on a preconfigured key, a key for protecting data of the first MPQUIC connection, where the data of the first MPQUIC connection is transmitted over a plurality of paths between the first terminal device and the first user plane function; The pre-configured key is also used for the first terminal device to establish a second MPQUIC connection with a second user plane function.

8. The method according to claim 7, characterized in that The first user plane function negotiates with the first terminal device to establish a first MPQUIC connection, including: The first user plane function receives an identification of the pre-configuration key from the first terminal device.

9. The method according to claim 7 or 8, characterized in that The messages transmitted in the negotiation are protected based on 3GPP security.

10. The method according to any one of claims 7 to 9, characterized in that The preconfigured key used by the first user plane function to negotiate with the first terminal device to establish the first MPQUIC connection is the same as the preconfigured key used by the first user plane function to negotiate with the second terminal device to establish a third MPQUIC connection.

11. The method according to any one of claims 7 to 10, characterized in that: After the first MA PDU session of the first terminal device is established, the method further includes: The first user plane function negotiates with the first terminal device to establish a fourth MPQUIC connection, the fourth MPQUIC connection being associated with the first MA PDU session; The first user plane function derives, based on the preconfigured key, a key for protecting data of the fourth MPQUIC connection, wherein the key for protecting data of the first MPQUIC connection is different from the key for protecting data of the fourth MPQUIC connection.

12. A communication method, characterized in that: Applicable to the process of establishing a multi-access protocol data unit (MA PDU) session for a terminal device, the method comprising: The session management function obtains the shared key from the first function; The session management function sends the shared key to the user plane function, and the shared key is used to derive a key for protecting data in a multi-path fast user datagram protocol internet connection MPQUIC connection between the terminal device and the user plane function, the MPQUIC connection is associated with the MA PDU session, and the data of the MPQUIC connection is transmitted by multiple paths between the terminal device and the user plane function.

13. The method according to claim 12, characterized in that Also includes: The session management function sends a first indication to the terminal device, where the first indication is used to instruct the terminal device to establish the MPQUIC connection with the user plane function using a shared key.

14. The method according to claim 12 or 13, characterized in that Before the session management function obtains the shared key from the first function, the session management function further includes: The session management function determines to enable the function corresponding to the MPQUIC connection.

15. The method according to claim 14, characterized in that The session management function determines to enable the function corresponding to the MPQUIC connection, including: The session management function receives capability information from the terminal device, and determines, based on the capability information of the terminal device, that the terminal device supports establishing the MPQUIC connection; and / or, The session management function supports the functions corresponding to the MPQUIC connection.

16. The method according to any one of claims 12 to 15, characterized in that: The session management function obtains a shared key from the first function, comprising: The session management function sends a second instruction to the first function, where the second instruction is used to instruct the derivation of the shared key; The session management function receives the shared key from the first function.

17. The method according to any one of claims 12 to 16, characterized in that: Also includes: The session management function sends an identification of the shared key to the user plane function.

18. The method according to any one of claims 12 to 17, characterized in that: The identifier of the shared key is determined by the session management function according to the identifier of the MA PDU session, and the method further includes: The session management function sends an identification of the shared key to the first function; and / or, The session management function sends an identification of the shared key to the terminal device.

19. The method according to any one of claims 12 to 17, characterized in that: The identifier of the shared key is determined by the first function according to the identifier of the MA PDU session, and the method further includes: The session management function sends an identifier of the MA PDU session to the first function; The session management function receives an identification of the shared key from the first function.

20. The method according to any one of claims 12 to 19, characterized in that: The identifier of the shared key is the identifier of the MA PDU session.

21. The method according to any one of claims 12 to 20, characterized in that: The first function is an access management function, a security anchor function or an authentication server function.

22. A communication method, characterized in that: Applicable to a process of establishing an MA PDU session for a terminal device, the method comprising: The user plane function receives a shared key from the session management function; The user plane function derives a key for protecting data in an MPQUIC connection between the terminal device and the user plane function based on the shared key, the MPQUIC connection being associated with the MA PDU session, and the data of the MPQUIC connection being transmitted via multiple paths between the terminal device and the user plane function.

23. The method of claim 22, wherein: Also includes: The user plane function receives the identifier of the shared key from the session management function, where the identifier of the shared key is determined by the session management function or the access management function according to the identifier of the MA PDU session; The user plane function stores the identifier of the shared key in correspondence with the shared key.

24. The method according to claim 22 or 23, characterized in that The identifier of the shared key is the identifier of the MA PDU session.

25. A communication method, characterized in that: Applicable to a process of establishing an MA PDU session for a terminal device, the method comprising: The terminal device receives a first indication from a session management function, the first indication being used to instruct the terminal device to establish an MPQUIC connection with a user plane function using a shared key, the MPQUIC connection being associated with the MA PDU session; The terminal device derives a shared key according to the first instruction; The terminal device derives a key for protecting data in the MPQUIC connection based on the shared key, and the data of the MPQUIC connection is transmitted via multiple paths between the terminal device and the user plane function.

26. The method of claim 25, wherein: Also includes: The terminal device sends capability information of the terminal device to the session management function, where the capability information of the terminal device is used to indicate that the terminal device supports establishing the MPQUIC connection.

27. The method according to claim 25 or 26, characterized in that The terminal device derives a shared key according to the first instruction, including: The terminal device derives the shared key according to the first indication and one or more of the following parameters: The identifier of the terminal device, the identifier of the MA PDU session, and the superior key.

28. The method of claim 27, wherein: The upper-level key includes one or more of the following: a security anchor function key, a base station key, and an access management function key.

29. The method according to any one of claims 25 to 28, characterized in that The identifier of the shared key is determined by the session management function according to the identifier of the MA PDU session, and the method further includes: The terminal device receives an identification of the shared key from the session management function.

30. The method according to any one of claims 25 to 29, characterized in that Also includes: The terminal device determines the identifier of the shared key according to the identifier of the MA PDU session.

31. The method according to any one of claims 25 to 30, characterized in that Also includes: The terminal device stores the correspondence between the identifier of the shared key and the shared key.

32. The method according to any one of claims 25 to 31, characterized in that The identifier of the shared key is the identifier of the MA PDU session.

33. A communication method, characterized in that: Applicable to a process of establishing an MA PDU session for a terminal device, the method comprising: The first function receives a second indication from the session management function; The first function derives the shared key according to the second indication; The first function sends the shared key to the session management function; The shared key is used to derive a key for protecting data in an MPQUIC connection between the terminal device and the user plane function, the MPQUIC connection is associated with the MA PDU session, and the data of the MPQUIC connection is transmitted via multiple paths between the terminal device and the user plane function.

34. The method of claim 33, wherein: The identifier of the shared key is determined by the session management function according to the identifier of the MA PDU session, and the method further includes: The first function receives an identification of the shared key from the session management function.

35. The method of claim 33, wherein: Also includes: The first function receives an identification of the MA PDU session from the session management function; The first function determines the identifier of the shared key according to the identifier of the MA PDU session.

36. The method according to any one of claims 33 to 35, characterized in that The first function derives the shared key according to the second indication, including: The first function derives the shared key according to the second indication and one or more of the following parameters: The identifier of the terminal device, the identifier of the MA PDU session, and the superior key.

37. The method of claim 36, wherein: The upper-level key includes one or more of the following: a security anchor function key, a base station key, and an access management function key.

38. A communication method, characterized in that: include: The session management function receives a session establishment request from a terminal device, wherein the session establishment request is used to request to establish a multi-access protocol data unit MA PDU session of the terminal device; The session management function sends a certificate application indication to the user plane function according to the session establishment request, and the certificate application indication is used to indicate a request for a certificate of the user plane function from a certificate certification authority; wherein the certificate of the user plane function is used for: during the process of establishing a multi-path fast user datagram protocol internet connection MPQUIC connection between the terminal device and the user plane function, the terminal device authenticates the user plane function; the MPQUIC connection is associated with the MA PDU session, and the data of the MPQUIC connection is transmitted via multiple paths between the terminal device and the user plane function.

39. The method of claim 38, wherein: After the session management function sends the certificate application indication to the user plane function, it also includes: The session management function receives a confirmation indication from the user plane function, where the confirmation indication is used to indicate that the user plane function successfully requested the certificate of the user plane function.

40. The method according to claim 38 or 39, characterized in that Also includes: The session management function sends the first certificate request to the certificate certification authority, wherein the first certificate request includes the public key of the terminal device, and the public key of the terminal device is used to generate a certificate of the terminal device; The session management function receives the certificate of the terminal device from the certificate certification authority, and sends the certificate of the terminal device to the terminal device, where the certificate of the terminal device is used by the user plane function to authenticate the terminal device during the establishment of the MPQUIC connection.

41. The method of claim 40, wherein: Before the session management function sends the first certificate request to the certificate authentication authority, the further step includes: The session management function sends a two-way authentication indication to the terminal device, wherein the two-way authentication indication is used to indicate that the authentication method in the process of establishing the MPQUIC connection is a two-way authentication method; The session management function receives a public key of the terminal device from the terminal device.

42. The method of claim 40, wherein: The session establishment request includes the public key of the terminal device.

43. The method according to any one of claims 40 to 42, characterized in that The first certificate request also includes an identifier of the MA PDU session, and the identifier of the MA PDU session is used to determine an identifier of the certificate of the terminal device.

44. The method according to any one of claims 38 to 43, characterized in that Also includes: The session management function sends the identifier of the MA PDU session to the user plane function, and the identifier of the MA PDU session is used to determine the identifier of the certificate of the user plane function.

45. The method according to any one of claims 38 to 44, characterized in that Before the session management function sends the certificate application instruction to the user plane function, it also includes: The session management function determines to enable the function corresponding to the MPQUIC connection.

46. ​​The method of claim 45, wherein: The session management function determines to enable the function corresponding to the MPQUIC connection, including: The session management function receives capability information from the terminal device, and determines, based on the capability information of the terminal device, that the terminal device supports establishing the MPQUIC connection; and / or, The session management function supports the functions corresponding to the MPQUIC connection.

47. A communication method, characterized in that: include: The terminal device sends a session establishment request to the session management function, wherein the session establishment request is used to request to establish an MA PDU session of the terminal device; During establishment of the MPQUIC connection between the terminal device and the user plane function, the terminal device receives a certificate of the user plane function from the user plane function, and authenticates the user plane function based on the certificate of the user plane function; The MPQUIC connection is associated with the MA PDU session, and data of the MPQUIC connection is transmitted through multiple paths between the terminal device and the user plane function.

48. The method of claim 47, wherein: The process of establishing the MPQUIC connection between the terminal device and the user plane function further includes: the terminal device receiving a certificate of the terminal device from the session management function; The terminal device sends a certificate of the terminal device to the user plane function, and the certificate of the terminal device is used by the user plane function to authenticate the terminal device.

49. The method according to claim 47 or 48, characterized in that The session establishment request includes the public key of the terminal device, and the public key of the terminal device is used by the session management function to request the certificate of the terminal device from the certificate certification authority; Before the terminal device sends a session establishment request to the session management function, the terminal device also includes: The terminal device generates a public key of the terminal device.

50. The method of claim 49, wherein: The certificate of the terminal device is carried in a radio resource control reconfiguration message.

51. The method of claim 47 or 48, wherein: The method further comprises: The terminal device receives a bidirectional authentication indication from the session management function, wherein the bidirectional authentication indication is used to indicate that the authentication method in the process of establishing the MPQUIC connection is a bidirectional authentication method; The terminal device generates a public key of the terminal device according to the two-way authentication instruction; The terminal device sends a public key of the terminal device to the session management function, and the public key of the terminal device is used by the session management function to request a certificate of the terminal device from a certificate authority.

52. The method of claim 51, wherein: The two-way authentication indication is carried in a radio resource control reconfiguration message.

53. The method of claim 51, wherein: The method also includes: the terminal device generating a private key of the terminal device, and the private key of the terminal device is used by the terminal device to sign a message transmitted during the establishment of the MPQUIC connection.

54. The method according to any one of claims 47 to 53, characterized in that Also includes: The terminal device receives an identification of a certificate of the user plane function from the user plane function; The terminal device determines the identifier of the certificate of the user plane function based on the identifier of the MA PDU session.

55. The method of claim 54, wherein: Also includes: The terminal device sends capability information of the terminal device to the session management function, where the capability information of the terminal device is used to indicate that the terminal device supports establishing the MPQUIC connection.

56. A communication method, characterized in that: include: During the establishment of a multi-access protocol data unit MA PDU session of a terminal device, a user plane function receives a certificate application instruction from a session management function, and requests a certificate of the user plane function from a certificate certification authority according to the certificate application instruction; During establishment of the MPQUIC connection between the terminal device and the user plane function, the user plane function sends a certificate of the user plane function to the terminal device, the certificate of the user plane function being used by the terminal device to authenticate the user plane function; The MPQUIC connection is associated with the MA PDU session, and data of the MPQUIC connection is transmitted through multiple paths between the terminal device and the user plane function.

57. The method of claim 56, wherein: The user plane function requests a certificate of the user plane function from a certificate authentication authority, including: The user plane function sends a second certificate request to the certificate authentication authority, where the second certificate request is used to request a certificate for the user plane function; The user plane function receives a certificate of the user plane function from the certificate authority.

58. The method of claim 56 or 57, wherein: During establishment of the MPQUIC connection between the terminal device and the user plane function, the method further comprises: The user plane function receives a certificate of the terminal device from the terminal device; The user plane function authenticates the terminal device based on the certificate of the terminal device.

59. The method according to any one of claims 56 to 58, characterized in that The second certificate request includes a public key of the user plane function, where the public key of the user plane function is used to determine the certificate of the user plane function; The method further comprises: The user plane function generates a public key of the user plane function.

60. The method according to any one of claims 56 to 59, characterized in that The second certificate request also includes an identifier of the MA PDU session, where the identifier of the MA PDU session is used to determine an identifier of the certificate of the user plane function; The method further comprises: The user plane function receives an identification of the MA PDU session from the session management function.

61. The method according to any one of claims 56 to 60, characterized in that Also includes: The user plane function sends a confirmation indication to the session management function, where the confirmation indication is used to indicate that the user plane function successfully requested the certificate of the user plane function.

62. A communication device, characterized in that: Comprising modules for performing the method as claimed in any one of claims 1 to 61.

63. A communication device, characterized in that: It includes a processor and an interface circuit, wherein the interface circuit is used to receive signals from other communication devices outside the communication device and transmit them to the processor or send signals from the processor to other communication devices outside the communication device, and the processor is used to implement the method as described in any one of claims 1 to 61 through logic circuits or execution code instructions.

64. A computer-readable storage medium, characterized in that The storage medium stores a computer program or instructions, and when the computer program or instructions are executed by the communication device, the method as described in any one of claims 1 to 61 is implemented.

65. A computer program product, characterized in that The computer program product comprises a computer program or instructions, and when the computer program or instructions are executed by a communication device, the method according to any one of claims 1 to 61 is implemented.

66. A communication system, characterized in that: It comprises a first terminal device and a first user plane function, wherein the first terminal device is used to implement the method according to any one of claims 1 to 6, and the first user plane function is used to implement the method according to any one of claims 7 to 11.

67. A communication system, characterized in that: Includes at least two of the following devices: a session management function, a user plane function, a terminal device, or a first function; The session management function is used to implement the method as described in any one of claims 12 to 21, the user plane function is used to implement the method as described in any one of claims 22 to 24, the terminal device is used to implement the method as described in any one of claims 25 to 32, and the first function is used to implement the method as described in any one of claims 33 to 37.

68. A communication system, characterized in that: Includes at least two of the following devices: session management function, terminal device, or user plane function; The session management function is used to implement the method as described in any one of claims 38 to 46, the terminal device is used to implement the method as described in any one of claims 47 to 55, and the user plane function is used to implement the method as described in any one of claims 56 to 61.

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