Communication method and apparatus

Abstract

Disclosed in the embodiments of the present application are a communication method and apparatus. The method comprises: a terminal device acquiring a first non-access stratum (NAS) security algorithm; after establishing an NAS connection with a first network element, the terminal device performing encryption and / or integrity protection on first information on the basis of the first NAS security algorithm; and sending the first information that has been subjected to encryption and / or integrity protection, wherein the first information is used for establishing an NAS connection with a second network element. By means of the embodiments of the present application, after a terminal device establishes an NAS connection with a first network element, the terminal device performs encryption and / or integrity protection on first information on the basis of a first NAS security algorithm, and requests the establishment of an NAS connection with a second network element. Therefore, the terminal device establishes NAS connections with a plurality of NAS termination points, and the security of establishing the NAS connections is improved.

Description

A communication method and apparatus

[0001] This application claims priority to Chinese Patent Application No. 202411458861.4, filed with the State Intellectual Property Office of China on October 17, 2024, entitled "A Communication Method and Apparatus", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of communication technology, and in particular to a communication method and apparatus. Background Technology

[0003] With the development of wireless communication systems, the evolution of future communication network architectures has proposed a distributed non-access stratum (NAS) architecture. NAS handles the communication between the core network and terminal devices. A distributed NAS architecture means that the network is not limited to a single NAS endpoint. In existing communication systems, the NAS endpoint in 4th-generation (4G) mobile communication technology is the mobility management entity (MME) network element, while in 5th-generation (5G) mobile communication technology, the NAS endpoint is the access and mobility management function (AMF) network element. In other words, in existing communication systems, terminal devices only establish a NAS connection with one network element node.

[0004] In a distributed NAS architecture, terminal devices can establish NAS connections with multiple network element nodes. NAS endpoints are not limited to AMF or MME; new NAS endpoints can be introduced, such as session management function (SMF) network elements and policy control function (PCF) network elements. The advantages of introducing a distributed NAS architecture include reduced coupling between network elements and faster feature deployment. From a performance perspective, it reduces signaling hop counts, enabling rapid connection establishment.

[0005] In a distributed NAS architecture, terminal devices need to establish secure connections with multiple NAS endpoints. How to achieve secure connection establishment between terminal devices and multiple NAS endpoints is a problem that needs to be solved. Summary of the Invention

[0006] This application provides a communication method and apparatus to enable a terminal device to establish a NAS connection with multiple NAS endpoints, thereby improving the security of establishing the NAS connection.

[0007] In a first aspect, embodiments of this application provide a communication method that can be applied to the terminal side, such as a terminal device or a communication module in the terminal device, or a circuit or chip in the terminal device responsible for communication functions (such as a modem chip, also known as a baseband chip, or a system-on-chip (SoC) chip containing a modem core, or a system-in-package (SIP) chip). Taking the application of this method to a terminal device as an example, the method includes:

[0008] The terminal device acquires a first non-access stratum NAS security algorithm. After establishing a NAS connection with the first network element, the terminal device encrypts and / or protects the integrity of the first information based on the first NAS security algorithm. Alternatively, after establishing a NAS connection with the first network element, the terminal device acquires the first non-access stratum NAS security algorithm, encrypts and / or protects the integrity of the first information based on the first NAS security algorithm, and sends the encrypted and / or integrity-protected first information, which is used to establish a NAS connection with the second network element.

[0009] After the terminal device establishes a NAS connection with the first network element, the terminal device encrypts and / or protects the integrity of the first information based on the first NAS security algorithm, and then requests to establish a NAS connection with the second network element. This enables the terminal device to establish NAS connections with multiple NAS endpoints, improving the security of establishing NAS connections.

[0010] In one possible design, the terminal device receives second information from a second network element. The second information is encrypted and / or protected for integrity based on a first NAS security algorithm or a second NAS security algorithm. The second information is used to indicate that NAS security negotiation has been initiated or completed. The terminal device decrypts and / or verifies the integrity protection of the second information based on the first NAS security algorithm or the second NAS security algorithm.

[0011] The terminal device decrypts and / or verifies the integrity of the second information based on the first or second NAS security algorithm, establishes a NAS connection with the second network element, and realizes the establishment of NAS connections between the terminal device and multiple NAS endpoints, thereby improving the security of establishing NAS connections.

[0012] In one possible implementation, the second NAS security algorithm is the same as the first NAS security algorithm.

[0013] In one possible implementation, the second NAS security algorithm differs from the first NAS security algorithm. The second NAS security algorithm is selected based on the UE's security capabilities, and the second information carries the identifier of the second NAS security algorithm.

[0014] In one possible implementation, the second message is a NAS security mode command message, which is used to instruct the initiation of NAS security negotiation.

[0015] In one possible implementation, the second message is a NAS security mode completion message, which indicates that NAS security negotiation has been completed.

[0016] In one possible implementation, if the second information is a NAS security mode command message, the terminal device sends a third information to the second network element. The third information is used to indicate that NAS security negotiation has been completed, and the third information is for encryption and / or integrity protection based on the second NAS security algorithm.

[0017] In one possible design, the first NAS security algorithm is either negotiated between the terminal device and the first network element, or configured by the terminal device.

[0018] In one possible design, the configuration of the terminal device can be understood as: the configuration locally of the terminal device or the configuration issued by core network elements such as security network elements or NAS endpoint network elements during communication.

[0019] By using a first NAS security algorithm negotiated between the terminal device and the first network element, or by using a configured first NAS security algorithm to encrypt and / or protect the integrity of the first information, a NAS connection is requested to be established with the second network element. This enables the terminal device to establish NAS connections with multiple NAS endpoints, improving the security of establishing NAS connections.

[0020] In one possible design, the terminal device acquires at least one of the Public Land Mobile PLMN, slice information, and core network element type obtained by the terminal device or by the second network element itself; the terminal device selects the first NAS security algorithm from at least one NAS security algorithm based on at least one of the PLMN, slice information, and core network element type obtained by the terminal device or by the second network element itself, wherein each of the at least one NAS security algorithms corresponds to at least one of the PLMN, slice information, and core network element type supported by the terminal device.

[0021] In one possible design, the terminal device obtains the configured NAS security algorithm, and the initial messages used for establishing NAS security all use this configured NAS security algorithm.

[0022] The terminal device selects a first NAS security algorithm from at least one of the following: Public Land Mobile PLMN information, slice information, and core network element type, obtained from at least one NAS security algorithm. This algorithm encrypts and / or protects the integrity of the first information, and then requests the establishment of a NAS connection with the second network element. This enables the terminal device to establish NAS connections with multiple NAS endpoints, improving the security of establishing NAS connections.

[0023] In one possible design, the terminal device acquires its own security capabilities; based on these capabilities, the terminal device selects the first NAS security algorithm from at least one NAS security algorithm.

[0024] By leveraging the security capabilities of the terminal device, a first NAS security algorithm is selected from at least one NAS security algorithm to encrypt and / or protect the integrity of the first information, and a request is made to establish a NAS connection with the second network element. This enables the terminal device to establish NAS connections with multiple NAS endpoints, thereby improving the security of establishing NAS connections.

[0025] In one possible design, the terminal device receives the at least one NAS security algorithm from the first network element; or, the terminal device configures the at least one NAS security algorithm.

[0026] By receiving or configuring at least one NAS security algorithm, selecting a first NAS security algorithm from at least one NAS security algorithm to encrypt and / or protect the integrity of first information, and requesting to establish a NAS connection with a second network element, a NAS connection can be established between the terminal device and multiple NAS endpoints, thereby improving the security of establishing NAS connections.

[0027] In one possible design, the first information includes the type of core network element, which is used to indicate the core network element that the terminal device needs to access.

[0028] In one possible design, the first information includes a first identifier, which is used to obtain the NAS security algorithm corresponding to the terminal device.

[0029] In one possible design, the first information includes a first identifier, which has only integrity protection.

[0030] In one possible design, the first identifier is the identifier of the terminal device and / or the identifier of the first network element.

[0031] In one possible design, the first information includes an identifier of the first NAS security algorithm. By carrying the identifier of the first NAS security algorithm in the first information, the second network element can decrypt and / or perform integrity protection verification on the first information based on the first NAS security algorithm, thereby improving the security of establishing a NAS connection.

[0032] In one possible design, the first information includes the identifier of the first NAS security algorithm, which is only protected for integrity.

[0033] In one possible design, the NAS security algorithm includes an integrity protection algorithm and / or an encryption algorithm.

[0034] Secondly, embodiments of this application provide a communication method that can be applied to the network side, such as a second network element or a communication module within the second network element, or a circuit or chip within the second network element responsible for communication functions. The method includes:

[0035] After the terminal device establishes a NAS connection with the first network element, the second network element receives first information, which is encrypted and / or protected for integrity. The first information is used to establish a non-access stratum NAS connection with the second network element. The second network element obtains the first NAS security algorithm. Based on the first NAS security algorithm, the second network element decrypts and / or verifies the integrity of the encrypted and / or protected first information.

[0036] After the terminal device establishes a NAS connection with the first network element, the second network element decrypts and / or verifies the integrity of the first information based on the first NAS security algorithm, and then establishes a NAS connection with the terminal device. This enables the terminal device to establish NAS connections with multiple NAS endpoints, improving the security of establishing NAS connections.

[0037] In one possible design, the second network element sends a second message to the terminal device. The second message is encrypted and / or protected for integrity based on a first NAS security algorithm or a second NAS security algorithm. The second message is used to indicate that NAS security negotiation has been completed.

[0038] In one possible implementation, the second NAS security algorithm is the same as the first NAS security algorithm.

[0039] In one possible implementation, the second NAS security algorithm differs from the first NAS security algorithm. The second NAS security algorithm is selected based on the UE's security capabilities, and the second information carries the identifier of the second NAS security algorithm.

[0040] In one possible implementation, the second message is a NAS security mode command message, which is used to instruct the initiation of NAS security negotiation.

[0041] In one possible implementation, the second message is a NAS security mode completion message, which indicates that NAS security negotiation has been completed.

[0042] In one possible implementation, if the second information is a NAS security mode command message, the second network element receives a third information from the terminal device, the third information being used to indicate that NAS security negotiation has been completed, and the third information being encryption and / or integrity protection based on a second NAS security algorithm.

[0043] In one possible design, the second network element sends a first request to the first network element or the third network element, the first request being used to request the first NAS security algorithm; the second network element receives a first response from the first network element or the third network element, the first response including the first NAS security algorithm.

[0044] The second network element requests the first NAS security algorithm from the first or third network element to decrypt and / or verify the integrity of the first information, thus establishing a NAS connection with the terminal device. This enables the terminal device to establish NAS connections with multiple NAS endpoints, improving the security of establishing NAS connections.

[0045] In one possible design, the second network element receives the first NAS security algorithm from the first network element or the third network element.

[0046] The first or third network element directly sends the first NAS security algorithm to the second network element. The second network element does not need to request the first or third network element to obtain the first NAS security algorithm, but instead decrypts and / or verifies the integrity of the first information, and establishes a NAS connection with the terminal device. This enables the terminal device to establish NAS connections with multiple NAS endpoints, improving the security of establishing NAS connections.

[0047] In one possible design, the second network element is configured with at least one NAS security algorithm, wherein each of the at least one NAS security algorithm corresponds to at least one of PLMN, slice information and core network element type; the second network element selects the first NAS security algorithm from the at least one NAS security algorithm based on at least one of PLMN, slice information and core network element type obtained by the terminal device or by the second network element itself.

[0048] The second network element selects a first NAS security algorithm from at least one configured NAS security algorithm based on at least one of the following: PLMN, slice information, and core network element type obtained from the terminal device or by the second network element itself. It then decrypts and / or verifies the integrity of the first information based on the first NAS security algorithm, and establishes a NAS connection with the terminal device. This enables the terminal device to establish NAS connections with multiple NAS endpoints, improving the security of establishing NAS connections.

[0049] In one possible design, the identifier of the first NAS security algorithm is carried in the first information.

[0050] The second network element obtains the first NAS security algorithm from the first information, decrypts and / or verifies the integrity of the first information, and establishes a NAS connection with the terminal device. This enables the terminal device to establish NAS connections with multiple NAS endpoints, thereby improving the security of establishing NAS connections.

[0051] In one possible design, the first NAS security algorithm is configured for the second network element.

[0052] The second network element uses the default first NAS security algorithm to decrypt and / or verify the integrity of the first information, establishing a NAS connection with the terminal device. This enables the terminal device to establish NAS connections with multiple NAS endpoints, improving the security of establishing NAS connections.

[0053] In one possible design, the second network element receives security capabilities from a terminal device of the access network device; the second network element selects a second NAS security algorithm from at least one NAS security algorithm based on the security capabilities of the terminal device; wherein, when the first NAS security algorithm and the second NAS security algorithm are the same, the second information carries the identifier of the first NAS security algorithm, and the second network element encrypts and / or protects the integrity of the second information based on the first NAS security algorithm; when the first NAS security algorithm and the second NAS security algorithm are different, the second information carries the identifier of the second NAS security algorithm, and the second network element encrypts and / or protects the integrity of the second information based on either the first NAS security algorithm or the second NAS security algorithm.

[0054] The second network element selects a second NAS security algorithm from at least one NAS security algorithm through the security capabilities of the terminal device, encrypts and / or protects the integrity of the second information based on the second NAS security algorithm, establishes a NAS connection with the terminal device, and realizes the establishment of NAS connections between the terminal device and multiple NAS endpoints, thereby improving the security of establishing NAS connections.

[0055] In one possible design, the first information includes the type of core network element, which is used to indicate the core network element that the terminal device needs to access.

[0056] In one possible design, the first information includes a first identifier, which is used to obtain the NAS security algorithm corresponding to the terminal device.

[0057] In one possible design, the first information includes an identifier of the first NAS security algorithm.

[0058] By carrying an identifier for the first NAS security algorithm, the second network element can decrypt and / or verify the integrity of the first information based on the first NAS security algorithm. This improves the security of the NAS connection.

[0059] Thirdly, embodiments of this application provide a communication method that can be applied to the network side, such as a first network element or a component (e.g., a circuit, chip, or chip system) within the first network element. The method includes:

[0060] The first network element receives a first request from the second network element, the first request being used to request a first NAS security algorithm; the first network element sends a first response to the second network element, the first response including the first NAS security algorithm, the first NAS security algorithm being used to encrypt and / or protect the integrity of NAS messages between the second network element and the terminal device.

[0061] The first network element receives a request from the second network element and returns a first NAS security algorithm to the second network element. This enables the second network element to decrypt and / or verify the integrity of the first information based on the first NAS security algorithm, thus establishing a NAS connection with the terminal device. This allows the terminal device to establish NAS connections with multiple NAS endpoints, improving the security of establishing NAS connections.

[0062] In one possible design, the first request includes a first identifier; the first network element obtains the first NAS security algorithm based on the first identifier.

[0063] The first network element obtains the first NAS security algorithm through the first identifier and returns the first NAS security algorithm to the second network element. This allows the second network element to decrypt and / or perform integrity protection verification on the first information based on the first NAS security algorithm, and establish a NAS connection with the terminal device. This enables the terminal device to establish NAS connections with multiple NAS endpoints, improving the security of establishing NAS connections.

[0064] In one possible design, the first request includes first indication information, which indicates the type of NAS security algorithm; the first network element obtains the first NAS security algorithm based on the first indication information.

[0065] The first network element obtains the first NAS security algorithm through the first instruction information and returns the first NAS security algorithm to the second network element. This allows the second network element to decrypt and / or perform integrity protection verification on the first information based on the first NAS security algorithm, and establish a NAS connection with the terminal device. This enables the terminal device to establish NAS connections with multiple NAS endpoints, improving the security of establishing NAS connections.

[0066] In one possible design, the first network element sends at least one NAS security algorithm to the terminal device.

[0067] The first network element sends at least one NAS security algorithm to the terminal device, enabling the terminal device to select a first NAS security algorithm from at least one of the following: PLMN, slice information obtained by the terminal device or by the second network element itself, and the type of the core network element. This algorithm encrypts and / or protects the integrity of the first information, establishing a NAS connection with the second network element. This enables the terminal device to establish NAS connections with multiple NAS endpoints, improving the security of establishing NAS connections.

[0068] In one possible design, each of the at least one NAS security algorithms corresponds to at least one of the types of PLMN, slice information, and core network elements supported by the terminal device.

[0069] In one possible design, the first network element obtains the subscription information of the terminal device; the first network element obtains the at least one NAS security algorithm from a configured algorithm list based on the subscription information, wherein the configured algorithm list includes multiple NAS security algorithms.

[0070] The first network element acquires at least one NAS security algorithm through the security capabilities of the terminal device and sends it to the terminal device. This allows the terminal device to select a first NAS security algorithm from the at least one algorithm based on at least one of the following: PLMN, slice information, and core network element type obtained by the terminal device or by the second network element itself. This algorithm encrypts and / or protects the integrity of the first information, establishing a NAS connection with the second network element. This enables the terminal device to establish NAS connections with multiple NAS endpoints, improving the security of establishing NAS connections.

[0071] In one possible design, when the first network element is a first NF network element and the third network element is a security network element, the third network element obtains the subscription information of the terminal device and, based on the subscription information, retrieves at least one NAS security algorithm from a configured algorithm list. The first network element receives at least one security algorithm from the third network element.

[0072] In one possible design, the plurality of NAS security algorithms may also include at least one of the following: the PLMN corresponding to each NAS security algorithm, slice information, and the type of core network element.

[0073] Fourthly, embodiments of this application provide a communication method that can be applied to the network side, such as a third network element or a component (e.g., a circuit, chip, or chip system) within the third network element. The method includes:

[0074] The third network element receives a second request from the first network element, the second request being for requesting at least one NAS security algorithm. The third network element then sends a second response to the first network element, the second response including at least one NAS security algorithm.

[0075] The third network element returns at least one NAS security algorithm to the first network element, which then distributes the at least one NAS security algorithm to the terminal device. The terminal device selects a first NAS security algorithm from the at least one algorithm to encrypt and / or protect the integrity of the first information, establishing a NAS connection with the second network element. This enables the terminal device to establish NAS connections with multiple NAS endpoints, improving the security of establishing NAS connections.

[0076] In one possible design, the at least one NAS security algorithm further includes at least one of the following: the PLMN, slice information, and core network element type supported by the terminal device for each NAS security algorithm.

[0077] In one possible design, the third network element obtains the subscription information of the terminal device, and based on the subscription information, obtains the at least one NAS security algorithm from a configured algorithm list, wherein the configured algorithm list includes multiple NAS security algorithms.

[0078] In one possible design, the plurality of NAS security algorithms may also include at least one of the following: the PLMN corresponding to each NAS security algorithm, slice information, and the type of core network element.

[0079] Fifthly, embodiments of this application provide a communication device that performs the functions described in the first aspect above. For example, the communication device includes modules, units, or means corresponding to the operations involved in the first aspect. These modules, units, or means can be implemented in software, hardware, or a combination of software and hardware. The device includes:

[0080] The processing module is used to obtain a first non-access stratum NAS security algorithm, and after establishing a NAS connection with the first network element, to encrypt and / or protect the first information based on the first NAS security algorithm; or, after establishing a NAS connection with the first network element, to obtain a first non-access stratum NAS security algorithm, and to encrypt and / or protect the first information based on the first NAS security algorithm.

[0081] The sending module is used to send encrypted and / or integrity-protected first information, which is used to establish a NAS connection with the second network element.

[0082] In one possible design, the receiving module is used to receive second information from the second network element, the second information being encrypted and / or protected for integrity based on a first NAS security algorithm or a second NAS security algorithm, and the second information being used to indicate that NAS security negotiation has been started or completed.

[0083] The processing module is used to decrypt and / or verify the integrity of the second information based on the first NAS security algorithm or the second NAS security algorithm.

[0084] In one possible design, the first NAS security algorithm is either negotiated between the terminal device and the first network element, or configured by the terminal device.

[0085] In one possible design, the processing module is further configured to acquire at least one of the Public Land Mobile PLMN, slice information, and core network element type obtained by the terminal device or by the second network element itself; and select the first NAS security algorithm from at least one NAS security algorithm based on at least one of the PLMN, slice information, and core network element type obtained by the terminal device or by the second network element itself, wherein each of the at least one NAS security algorithms corresponds to at least one of the PLMN, slice information, and core network element type supported by the terminal device.

[0086] In one possible design, the processing module is further configured to acquire the security capabilities of the terminal device; and select the first NAS security algorithm from at least one NAS security algorithm based on the security capabilities of the terminal device.

[0087] In one possible design, the receiving module is configured to receive the at least one NAS security algorithm from the first network element; or

[0088] The processing module is also used to configure the at least one NAS security algorithm.

[0089] In one possible design, the first information or the access network parameters sent together with the first information include the type of core network element, which is used to indicate the core network element that the terminal device needs to access.

[0090] In one possible design, the first information or the access network parameters sent together with the first information include a first identifier, which is used to obtain the NAS security algorithm corresponding to the terminal device.

[0091] In one possible design, the first information or the access network parameters sent together with the first information include the identifier of the first NAS security algorithm.

[0092] In one possible design, the NAS security algorithm includes an integrity protection algorithm and / or an encryption algorithm.

[0093] The operation and beneficial effects of this communication device can be found in the method and beneficial effects described in the first aspect above, and will not be repeated here.

[0094] Sixthly, embodiments of this application provide a communication device that performs the functions described in the second aspect above. For example, the communication device includes modules, units, or means corresponding to the operations involved in the second aspect. These modules, units, or means can be implemented in software, hardware, or a combination of software and hardware. The device includes:

[0095] The receiving module is used to receive first information after the terminal device establishes a NAS connection with the first network element. The first information is encrypted and / or protected for integrity. The first information is used to establish a non-access stratum NAS connection with the second network element.

[0096] The processing module is used to obtain the first NAS security algorithm; and based on the first NAS security algorithm, to decrypt and / or verify the integrity protection of the encrypted and / or integrity-protected first information.

[0097] In one possible design, the sending module is used to send second information to the terminal device, the second information being encrypted and / or protected for integrity based on a first NAS security algorithm or a second NAS security algorithm, and the second information being used to indicate that NAS security negotiation has been initiated or completed.

[0098] In one possible design, the sending module is used to send a first request to the first network element or the third network element, the first request being used to request the first NAS security algorithm;

[0099] The receiving module is configured to receive a first response from the first network element or the third network element, wherein the first response includes the first NAS security algorithm.

[0100] In one possible design, the receiving module is used to receive the first NAS security algorithm from the first network element or the third network element.

[0101] In one possible design, the processing module is further configured to configure at least one NAS security algorithm, wherein each of the at least one NAS security algorithm corresponds to at least one of PLMN, slice information, and core network element type; and to select the first NAS security algorithm from the at least one NAS security algorithm based on at least one of PLMN, slice information, and core network element type obtained by the terminal device or by the second network element itself.

[0102] In one possible design, the identifier of the first NAS security algorithm is carried in the first information.

[0103] In one possible design, the first NAS security algorithm is configured for the second network element.

[0104] In one possible design, the receiving module is also used to receive security capabilities from the terminal device of the access network device;

[0105] The processing module is further configured to select the second NAS security algorithm from at least one NAS security algorithm based on the security capabilities of the terminal device;

[0106] Wherein, when the first NAS security algorithm and the second NAS security algorithm are the same, the second information carries the identifier of the first NAS security algorithm, and the second network element encrypts and / or protects the integrity of the second information based on the first NAS security algorithm; when the first NAS security algorithm and the second NAS security algorithm are different, the second information carries the identifier of the second NAS security algorithm, and the second network element encrypts and / or protects the integrity of the second information based on the first NAS security algorithm or the second NAS security algorithm.

[0107] In one possible design, the first information or the access network parameters sent together with the first information include the type of core network element, which is used to indicate the core network element that the terminal device needs to access.

[0108] In one possible design, the first information or the access network parameters sent together with the first information include a first identifier, which is used to obtain the NAS security algorithm corresponding to the terminal device.

[0109] In one possible design, the first information or the access network parameters sent together with the first information include an identifier of the first NAS security algorithm.

[0110] The operation and beneficial effects of this communication device can be found in the method and beneficial effects described in the second aspect above, and will not be repeated here.

[0111] In a seventh aspect, embodiments of this application provide a communication device that performs the functions described in the third aspect above. For example, the communication device includes modules, units, or means corresponding to the operations involved in the third aspect. These modules, units, or means can be implemented in software, hardware, or a combination of software and hardware. The device includes:

[0112] The receiving module is used to receive a first request from the second network element, wherein the first request is used to request a first NAS security algorithm;

[0113] The sending module is used to send a first response to the second network element. The first response includes the first NAS security algorithm, which is used to encrypt and / or protect the integrity of NAS messages between the second network element and the terminal device.

[0114] In one possible design, the first request includes a first identifier; a processing module is configured to obtain the first NAS security algorithm based on the first identifier.

[0115] In one possible design, the first request includes first indication information, which indicates the type of NAS security algorithm; and a processing module, which obtains the first NAS security algorithm based on the first indication information.

[0116] In one possible design, a sending module is used to send at least one NAS security algorithm to the terminal device.

[0117] In one possible design, the at least one NAS security algorithm further includes at least one of the following: the PLMN, slice information, and core network element type supported by the terminal device for each NAS security algorithm.

[0118] In one possible design, a processing module is configured to obtain subscription information of the terminal device; and, based on the subscription information, obtain at least one NAS security algorithm from a configured algorithm list, wherein the configured algorithm list includes multiple NAS security algorithms.

[0119] In one possible design, the plurality of NAS security algorithms may also include at least one of the following: the PLMN corresponding to each NAS security algorithm, slice information, and the type of core network element.

[0120] The operation and beneficial effects of this communication device can be found in the method and beneficial effects described in the third aspect above, and will not be repeated here.

[0121] Eighthly, embodiments of this application provide a communication device that performs the functions described in the fourth aspect above. For example, the communication device includes modules, units, or means corresponding to the operations involved in the fourth aspect. These modules, units, or means can be implemented in software, hardware, or a combination of software and hardware. The device includes:

[0122] The receiving module is configured to receive a second request from the first network element, wherein the second request is for requesting at least one NAS security algorithm;

[0123] The sending module is used to send a second response to the first network element, the second response including at least one NAS security algorithm.

[0124] In one possible design, the at least one NAS security algorithm further includes at least one of the following: the PLMN, slice information, and core network element type supported by the terminal device for each NAS security algorithm.

[0125] In one possible design, a processing module is configured to obtain subscription information of the terminal device, and based on the subscription information, obtain at least one NAS security algorithm from a configured algorithm list, wherein the configured algorithm list includes multiple NAS security algorithms.

[0126] In one possible design, the plurality of NAS security algorithms may also include at least one of the following: the PLMN corresponding to each NAS security algorithm, slice information, and the type of core network element.

[0127] The operation and beneficial effects of this communication device can be found in the method and beneficial effects described in the fourth aspect above, and will not be repeated here.

[0128] Ninthly, embodiments of this application provide a communication device, the communication device including a memory and one or more processors. The memory is used to store part or all of the computer program or instructions necessary to implement the functions involved in the first aspect above. The one or more processors are capable of executing the computer program or instructions, and when the computer program or instructions are executed, they cause the communication device to implement the methods in any possible design or implementation of the first aspect above.

[0129] In one possible design, the communication device may further include an interface circuit, wherein the processor is used to communicate with other devices or components through the interface circuit.

[0130] In one possible design, the communication device may also include the memory.

[0131] The aforementioned communication device may be a terminal device, a communication module in a terminal device, or a chip in a terminal device that is responsible for communication functions, such as a modem chip (also known as a baseband chip) or a SoC or SIP chip that contains a modem module.

[0132] In a tenth aspect, embodiments of this application provide a communication device, the communication device including a memory and one or more processors. The memory is used to store part or all of the computer program or instructions necessary to implement the functions involved in the second aspect above. The one or more processors are capable of executing the computer program or instructions, such that when the computer program or instructions are executed, the communication device implements the methods in any possible design or implementation of the second aspect above.

[0133] In one possible design, the communication device may further include an interface circuit, wherein the processor is used to communicate with other devices or components through the interface circuit.

[0134] In one possible design, the communication device may also include the memory.

[0135] The aforementioned communication device may be a second network element, or a communication module in a second network element, or a chip in a second network element that is responsible for communication functions, such as a modem chip (also known as a baseband chip) or a SoC or SIP chip containing a modem module.

[0136] Eleventhly, embodiments of this application provide a communication device, the communication device including a memory and one or more processors. The memory is used to store part or all of the computer program or instructions necessary to implement the functions involved in the third aspect above. The one or more processors can execute the computer program or instructions, and when the computer program or instructions are executed, cause the communication device to implement the methods in any possible design or implementation of the third aspect above.

[0137] In one possible design, the communication device may further include an interface circuit, wherein the processor is used to communicate with other devices or components through the interface circuit.

[0138] In one possible design, the communication device may also include the memory.

[0139] The aforementioned communication device may be a first network element, or a communication module in the first network element, or a chip in the first network element responsible for communication functions, such as a modem chip (also known as a baseband chip) or a SoC or SIP chip containing a modem module.

[0140] In a twelfth aspect, embodiments of this application provide a communication device, the communication device including a memory and one or more processors. The memory is used to store part or all of the computer program or instructions necessary to implement the functions involved in the fourth aspect above. The one or more processors are capable of executing the computer program or instructions, such that when the computer program or instructions are executed, the communication device implements the methods in any possible design or implementation of the fourth aspect above.

[0141] In one possible design, the communication device may further include an interface circuit, wherein the processor is used to communicate with other devices or components through the interface circuit.

[0142] In one possible design, the communication device may also include the memory.

[0143] The aforementioned communication device may be a third network element, or a communication module in a third network element, or a chip in a third network element that is responsible for communication functions, such as a modem chip (also known as a baseband chip) or a SoC or SIP chip containing a modem module.

[0144] In a thirteenth aspect, this application provides a computer-readable storage medium for storing a computer program that, when executed, causes the method described in any one of the first to fourth aspects to be implemented.

[0145] In a fourteenth aspect, this application provides a computer program product including a computer program that, when executed, causes the method described in any one of the first to fourth aspects to be implemented.

[0146] In a fifteenth aspect, embodiments of this application provide a communication system comprising a terminal device, a second network element, a first network element, and a third network element. The terminal device is used to perform the steps in the first aspect described above, the second network element is used to perform the steps in the second aspect described above, the first network element is used to perform the steps in the third aspect described above, and the third network element is used to perform the steps in the fourth aspect described above.

[0147] In a sixteenth aspect, a chip is provided, the chip including a processor and a communication interface for communicating with external or internal devices, the processor for implementing the methods of the above aspects.

[0148] In one possible design, the chip may further include a memory storing computer programs or instructions, which the processor executes, either from the stored computer programs or instructions or derived from other programs or instructions. When the computer program or instructions are executed, the processor implements the methods described in the preceding aspects.

[0149] In one possible design, the chip can be integrated into a terminal device, a first network element, a second network element, or a third network element. Attached Figure Description

[0150] Figure 1 is a schematic diagram of a NAS architecture;

[0151] Figure 2 is a schematic diagram of the architecture of another NAS system;

[0152] Figure 3 is a schematic diagram of the process for establishing a secure NAS connection;

[0153] Figure 4 is a schematic diagram of the process for establishing a secure NAS connection based on a distributed NAS architecture.

[0154] Figure 5 is a schematic diagram of another process for establishing a secure NAS connection based on a distributed NAS architecture.

[0155] Figure 6 is a flowchart illustrating a communication method provided in an embodiment of this application;

[0156] Figure 7 is a flowchart illustrating another communication method provided in an embodiment of this application;

[0157] Figure 8 is a flowchart illustrating another communication method provided in an embodiment of this application;

[0158] Figure 9 is a flowchart illustrating another communication method provided in an embodiment of this application;

[0159] Figure 10 is a flowchart illustrating another communication method provided in an embodiment of this application;

[0160] Figure 11 is a flowchart illustrating another communication method provided in an embodiment of this application;

[0161] Figure 12 is a flowchart illustrating another communication method provided in an embodiment of this application;

[0162] Figure 13 is a schematic diagram of the structure of a communication device provided in an embodiment of this application;

[0163] Figure 14 is a schematic diagram of another communication device provided in an embodiment of this application;

[0164] Figure 15 is a schematic diagram of another communication device provided in an embodiment of this application;

[0165] Figure 16 is a schematic diagram of another communication device provided in an embodiment of this application;

[0166] Figure 17 is a structural schematic diagram of a terminal device provided in an embodiment of this application;

[0167] Figure 18 is a schematic diagram of the structure of a network device provided in an embodiment of this application. Detailed Implementation

[0168] The embodiments of this application are described below with reference to the accompanying drawings.

[0169] It should be understood that in the description of this application, "at least one" means one or more, and "multiple" means two or more. In addition, the words "first," "second," etc., unless otherwise stated, are used only for the purpose of distinguishing descriptions and should not be construed as indicating or implying relative importance or order.

[0170] It should be understood that in the description of this application, the indication includes direct indication (also known as explicit indication) and implicit indication. Direct indication information A refers to information A being included; implicit indication information A refers to information A being indicated through the correspondence between information A and information B, and the direct indication information B. The correspondence between information A and information B can be predefined, pre-stored, pre-burned, or pre-configured.

[0171] It should be understood that, in the description of this application, information C is used to determine information D, including both situations where information D is determined solely based on information C and situations where it is determined based on information C and other information. Furthermore, information C can also be used to determine information D indirectly, for example, where information D is determined based on information E, and information E is determined based on information C.

[0172] Furthermore, in this application, "network element A sends message A to network element B" can be understood as network element B being the destination of message A or an intermediate network element in the transmission path between the destination and network element B, which may include sending the message directly or indirectly to network element B. Similarly, "network element B receives message A from network element A" can be understood as network element A being the source of message A or an intermediate network element in the transmission path between the source and network element A, which may include receiving the message directly or indirectly from network element A. The message may undergo necessary processing between the source and destination, such as format changes, but the destination can understand a valid message from the source. Similar expressions in this application can be interpreted in a similar way and will not be elaborated further here.

[0173] The typical system architecture used in this application is a distributed NAS architecture, where terminal devices establish NAS connections with multiple different network function (NF) elements. Depending on whether the security element is a NAS endpoint, the distributed NAS architecture includes two types, as shown in Figure 1. Figure 1 is a schematic diagram of one NAS architecture, where the security element is a NAS endpoint. Figure 2 shows a schematic diagram of another NAS system architecture, where the security element is not a NAS endpoint, but rather establishes a connection with an NF element, and the NF element establishes a NAS connection with the terminal device.

[0174] It is worth noting that the typical architecture used in this application is a distributed NAS architecture, which is unrelated to the specific function of the distributed NAS endpoint, and can also be applied to other evolved architectures based on the distributed NAS architecture.

[0175] The NAS architecture in this application embodiment may include terminal devices, radio access network (RAN) devices, and core network elements. The core network elements may include NF (NF1, NF2, NF3, ..., NFx) network elements and security network elements. NF network elements may be access and mobility management function (AMF) network elements, session management function (SMF) network elements, policy control function (PCF) network elements, application function (AF) network elements, network slice selection function (NSSF) network elements, authentication server function (AUSF) network elements, etc.

[0176] The following describes the functions of the main entities or network elements included in the communication system:

[0177] Terminal devices can be devices or modules that access the aforementioned communication systems and possess corresponding communication functions. Terminal devices typically contain communication modules, circuits, or chips that perform the corresponding communication functions. They also contain program instructions configured to perform these functions. A terminal, also known as user equipment (UE), mobile station (MS), or mobile terminal (MT), refers to a device that provides voice and / or data connectivity to a user. Examples include handheld devices and in-vehicle devices with wireless connectivity. Currently, some examples of terminals include: mobile phones, tablets, laptops, PDAs, mobile internet devices, wearable devices, virtual reality (VR) devices, augmented reality (AR) devices, and wireless terminals used in industrial control, autonomous driving, remote surgery, smart grids, transportation safety, smart cities, and smart homes.

[0178] RAN equipment: refers to the Radio Access Network (RAN) node that connects terminal equipment to the wireless network; it can also be called a base station. It is primarily responsible for functions such as radio resource management, quality of service management, data compression, and encryption on the air interface side. The access network equipment can include various forms of base stations, such as macro base stations, micro base stations, relay stations, and access points. In systems employing different radio access technologies, the name of the equipment with base station functionality may differ; for example, in 5G systems, it is called a gNB.

[0179] Security network element: The network element responsible for UE security, with functions such as authentication and key derivation.

[0180] AMF network elements are core network elements primarily responsible for signaling processing, such as access control, mobility management, attach and detach, and gateway selection. When an AMF network element provides services to a session in a terminal device, it provides control plane storage resources for that session to store the session identifier and the SMF network element identifier associated with the session identifier.

[0181] SMF network elements are responsible for user plane network element selection, user plane network element redirection, Internet Protocol (IP) address allocation, bearer establishment, modification and release, and quality of service (QoS) control.

[0182] PCF network element: Responsible for policy control decisions, providing policy rules for control plane functions, and traffic-based billing control functions.

[0183] NSSF network element: mainly responsible for network slice selection, determining the network slice instance that the UE is allowed to access based on the UE's slice selection auxiliary information, subscription information, etc.

[0184] AUSF network element: Supports 3GPP and non-3GPP access authentication.

[0185] The embodiments of this application can be applied to various communication systems, such as Universal Mobile Telecommunications System (UMTS), Wireless Local Area Network (WLAN), Wireless Fidelity (Wi-Fi) system, 4th generation (4G) mobile communication system, such as Long Term Evolution (LTE) system, 5th generation (5G) mobile communication system, such as New Radio (NR) system, and future evolution communication systems, such as 6th generation (6G) mobile communication system, etc.

[0186] Figure 3 illustrates a flowchart of establishing a secure NAS connection. The UE sends an initial NAS message to the AMF network element. This initial NAS message is sent in plaintext and contains parameters for establishing the UE's security context, such as the subscription concealed identifier (SUCI) or globally unique temporary identity (GUTI), the UE's security capabilities, and single network slice selection assistance information (S-NSSAI). The UE's security capabilities carry the security algorithms supported by the UE, including integrity protection algorithms and encryption algorithms. The AMF network element configures algorithm lists through network management: one list for NAS integrity protection and another for NAS encryption. The configured algorithm lists are arranged by priority, determined by the operator. The AMF network element selects the appropriate algorithm for establishing the secure NAS connection based on the UE's security capabilities and its own configured security algorithm priorities.

[0187] The AMF network element sends a NAS security mode command to the UE. This command includes information such as the UE's security capabilities, the selected NAS security algorithm (encryption algorithm, integrity protection algorithm), and the NAS key set identifier (ngKSI). The ngKSI is used to identify the key K. AMF The message only had integrity protection enabled, not encryption.

[0188] After receiving the NAS security mode command, the UE verifies the integrity of the NAS message. If the verification is successful, the UE enables integrity protection and encryption / decryption of the NAS message. The UE sends a NAS security mode complete message to the AMF network element. This message contains the complete NAS initial message, which is both integrity-protected and encrypted. The AMF network element decrypts and / or verifies the integrity protection of this message. If successful, it enables downlink encryption. However, the above applies to single NAS endpoint architectures and not to distributed NAS architectures.

[0189] In a distributed NAS architecture, the UE can establish NAS connections with multiple network element nodes. NAS endpoints are not limited to AMF or MME network elements; new NAS endpoints, such as SMF and PCF network elements, can be introduced. A distributed NAS architecture can include the UE, RAN equipment, multiple NF network elements, and a security key management function (SKMF) network element.

[0190] Figure 4 illustrates a flowchart of establishing a secure NAS connection based on a distributed NAS architecture. The SKMF network element is used for security key management and is a NAS endpoint. Messages sent by the UE are directly sent to the SKMF network element via the RAN device, without needing to be forwarded through an NF network element. Figure 5 illustrates another flowchart of establishing a secure NAS connection based on a distributed NAS architecture. The SKMF network element is not a NAS endpoint. Messages sent by the UE are sent to a NAS endpoint NF 1 via the RAN device, and then sent to the SKMF network element. As can be seen from Figures 4 and 5, the UE needs to establish secure connections with different NAS endpoints, that is, complete the NAS secure connection establishment with different NF network elements.

[0191] It is worth noting that during the establishment of a NAS secure connection, the initial messages for establishing a NAS secure connection between the UE and each NAS endpoint are transmitted in plaintext, as shown in NAS connection request #1 and NAS connection request #2 in Figure 4, and the initial NAS request in Figure 5.

[0192] It can be seen that after the UE has established a secure NAS connection, the initial messages for the subsequent establishment of NAS connections between the UE and other NFs are transmitted in plaintext, which affects communication security.

[0193] To address the aforementioned technical problems, the embodiments of this application provide the following solutions.

[0194] As shown in Figure 6, Figure 6 is a flowchart illustrating a communication method provided in an embodiment of this application. The method mainly includes the following steps:

[0195] S601, the terminal device obtains the first non-access tier NAS security algorithm.

[0196] The first NAS security algorithm may include encryption algorithms and / or integrity protection algorithms.

[0197] In the first implementation, the first NAS security algorithm is either negotiated between the terminal device and the first network element, or configured by the terminal device.

[0198] Specifically, after the terminal device establishes a NAS connection with the first network element, a first NAS security algorithm has been negotiated. When the terminal device establishes a NAS connection with the second network element, the first NAS security algorithm negotiated during the establishment of the NAS connection can be used. Alternatively, the first NAS security algorithm is pre-configured, and it is used by default when the terminal device establishes a NAS connection with the second network element.

[0199] The first network element can be a security network element, responsible for UE security and possessing security functions. Alternatively, the first network element can also be an NF network element. For example, an NF network element can be an AMF network element, possessing access and mobility management functions; an NF network element can also be an SMF network element, possessing session management functions; or an NF network element can also be a PCF network element, possessing policy management functions. The second network element can also be a security network element or an NF network element. The second network element and the first network element belong to the same type of network element or belong to the same public land mobile network (PLMN).

[0200] In the second implementation, the terminal device obtains at least one of the PLMN, slice information, and core network element type obtained by the terminal device or by the second network element itself; based on at least one of the PLMN, slice information, and core network element type obtained by the terminal device or by the second network element itself, the first NAS security algorithm is selected from at least one NAS security algorithm, wherein each of the at least one NAS security algorithms corresponds to at least one of the PLMN, slice information, and core network element type supported by the terminal device.

[0201] The PLMN obtained by the terminal device or by the second network element itself can be the PLMN stored when the terminal device establishes a NAS connection with the first network element. Alternatively, the PLMN obtained by the terminal device or by the second network element itself can also be the PLMN obtained when establishing a NAS connection with the second network element. The terminal device can obtain the PLMN of the currently accessed network based on broadcast messages. In addition, the terminal device can obtain slice information and the type of core network element (e.g., NF type) based on the message type and slice information it needs to send.

[0202] Optionally, the first network element can obtain the subscription data of the terminal device, such as the PLMN, slice information, or NF type supported by the terminal device; based on the subscription information, it obtains the at least one NAS security algorithm from a configured algorithm list, wherein the configured algorithm list includes multiple NAS security algorithms, and each of the multiple NAS security algorithms corresponds to at least one of the PLMN, slice information, and core network element type. Then, the first network element sends the at least one NAS security algorithm to the terminal device, and the terminal device receives the at least one NAS security algorithm from the first network element, and selects the first NAS security algorithm from the at least one NAS security algorithm based on at least one of the PLMN, slice information, and core network element type obtained by the terminal device or by the second network element itself.

[0203] For example, as shown in Table 1, which is a list of configured algorithms, the first network element can configure PLMN and slice information locally, along with their correspondence with multiple NAS security algorithms. Specifically, PLMN1 and slice 1 correspond to NAS security algorithm 1 (Encryption Alg11 and / or Integrity Alg11); PLMN1 and slice 2 correspond to NAS security algorithm 2 (Cipher Alg12 and / or Integrity Alg12); and PLMN2 and slice 3 correspond to NAS security algorithm 3 (Encryption Alg2 and / or Integrity Alg2). Since the terminal device supports PLMN1, slice 1, and slice 2, the first network element can send NAS security algorithm 1 (Encryption Alg11 and / or Integrity Alg11) and NAS security algorithm 2 (Encryption Alg12 and / or Integrity Alg12) to the terminal device. NAS security algorithm 1 corresponds to PLMN1 and slice 1, and NAS security algorithm 2 corresponds to PLMN1 and slice 2. After receiving NAS security algorithm 1 and NAS security algorithm 2, the terminal device determines that PLMN1 and slice 1 are currently in use, and therefore selects NAS security algorithm 1 (Encryption Alg11 and / or Integrity Alg11).

[0204] Table 1

[0205] For example, as shown in Table 2, which is a list of algorithms for another configuration, the first network element can configure the correspondence between NF types and multiple NAS security algorithms locally. Specifically, the security network element corresponds to NAS security algorithm 1 (Encryption Alg1 and / or Integrity Alg1); the AMF network element corresponds to NAS security algorithm 2 (Encryption Alg2 and / or Integrity Alg2); ...; the NFi network element corresponds to NAS security algorithm i (Encryption Algi and / or Integrity Algi). Since the NF types supported by the terminal device include both security network elements and AMF network elements, the first network element can send NAS security algorithm 1 (Encryption Alg1 and / or Integrity Alg1) and NAS security algorithm 2 (Encryption Alg2 and / or Integrity Alg2) to the terminal device, where NAS security algorithm 1 corresponds to the security network element and NAS security algorithm 2 corresponds to the AMF network element. After receiving NAS security algorithm 1 and NAS security algorithm 2, the terminal device determines that it needs to access the AMF network element and therefore selects NAS security algorithm 2 (Encryption Alg2 and / or Integrity Alg2).

[0206] Table 2

[0207] For example, as shown in Table 3, which is a list of algorithms for another configuration, the first network element can configure the PLMN and slice information locally, as well as the correspondence between them and multiple NAS security algorithms. These NAS security algorithms are sorted by priority. Specifically, PLMN1 and slice 1 correspond to three encryption algorithms (Encryption Alg11_1, Alg11_2, Alg11_3) and three integrity protection algorithms (Integrity Alg11_1, Alg11_2, Alg11_3). Alg11_1 has a higher priority than Alg11_2, and Alg11_2 has a higher priority than Alg11_3. PLMN1 and Slice 2 support three encryption algorithms (Encryption Alg12_1, Alg12_2, Alg12_3) and three integrity protection algorithms (Integrity Alg12_1, Alg12_2, Alg12_3). Alg12_1 has a higher priority than Alg12_2, and Alg12_2 has a higher priority than Alg12_3. Similarly, PLMN2 and Slice 2 support three encryption algorithms (Encryption Alg2_1, Alg2_2, Alg2_3) and three integrity protection algorithms (Integrity Alg2_1, Alg2_2, Alg2_3). Alg2_1 has a higher priority than Alg2_2, and Alg2_2 has a higher priority than Alg2_3. Since the terminal device supports PLMN1, Slice 1, and Slice 2... Therefore, the first network element can send Encryption Alg11_1, Alg11_2, Alg11_3 and Integrity Alg11_1, Alg11_2, Alg11_3, as well as Encryption Alg12_1, Alg12_2, Alg12_3 and Integrity Alg12_1, Alg12_2, Alg12_3 to the terminal device. The terminal device can then select the NAS security algorithm according to priority based on the acquired PLMN and slice information.

[0208] Table 3

[0209] Optionally, the terminal device can configure the at least one NAS security algorithm locally, and then select the first NAS security algorithm from the at least one NAS security algorithm based on at least one of the PLMN, slice information, and core network element type obtained by the terminal device or by the second network element itself. The methods for configuring the at least one NAS security algorithm by the terminal device and the methods for configuring the algorithm list by the first network element can be found in Tables 1, 2, and 3 above, and will not be elaborated further here.

[0210] Optionally, the terminal device can be configured with a general NAS security algorithm locally, without distinguishing between at least one of the following: PLMN, slice, and core network element type.

[0211] In the third implementation, the terminal device obtains the security capabilities of the terminal device; based on the security capabilities of the terminal device, the first NAS security algorithm is selected from at least one NAS security algorithm.

[0212] Specifically, after receiving at least one NAS security algorithm sent by the first network element, or configuring the at least one NAS security algorithm locally, the terminal device can select one NAS security algorithm from the at least one NAS security algorithm according to priority and based on the UE's security capabilities.

[0213] S602, after the terminal device establishes a NAS connection with the first network element, it encrypts and / or protects the integrity of the first information based on the first NAS security algorithm.

[0214] Specifically, the terminal device can use the ID of the first NAS security algorithm as input parameter to generate a NAS key, and use the generated key to encrypt and / or protect the integrity of the first information.

[0215] It should be noted that the terminal device can obtain the first non-access stratum NAS security algorithm either after the terminal device establishes a NAS connection with the first network element or before the terminal device establishes a NAS connection with the first network element; this application does not limit this.

[0216] S603, the terminal device sends encrypted and / or integrity-protected first information, and the second network element receives the encrypted and / or integrity-protected first information.

[0217] Specifically, the terminal device can send an access network message (AN message) to the access network device. This AN message may include encrypted and / or integrity-protected first information. Upon receiving the AN message, the access network device can send the encrypted and / or integrity-protected first information to the second network element. The first information may be a NAS connection request. This first information is used to establish a NAS connection with the second network element.

[0218] The first information may include the type of the core network element, which indicates the core network element that the terminal device needs to access. After receiving the AN message, the access network can determine the second network element based on the type of the core network element and send the encrypted and / or integrity-protected first information to the second network element.

[0219] The first information may include a first identifier, which is used to obtain the NAS security algorithm corresponding to the terminal device. The first identifier may be the identifier of the terminal device, the identifier of the first network element, or both. After receiving the first information, the second network element can obtain the NAS security algorithm corresponding to the terminal device based on the first identifier.

[0220] The first information may include the identifier of the first NAS security algorithm. After receiving the first information, the second network element can use the identifier of the first NAS security algorithm as input to generate an encryption key and / or an integrity protection key, and based on the generated encryption key and / or integrity protection key, decrypt and / or verify the integrity protection of the encrypted and / or integrity-protected first information.

[0221] Optionally, the AN message may include access network parameters and first information. The access network parameters may include at least one of the following: the type of the core network element, a first identifier, and an identifier of the first NAS security algorithm. For example, the access network parameters may include the type of the core network element, and the first information may include the first identifier and the identifier of the first NAS security algorithm. Alternatively, the access network parameters may include the type of the core network element and the identifier of the first NAS security algorithm, and the first information may include the first identifier. There are no restrictions on the information contained in the access network parameters and the first information.

[0222] It should be noted that the AN message has access stratum (AS) encryption and / or integrity protection, and the first information is encrypted and / or protected for integrity based on the first NAS security algorithm. If the first information contains an identifier of the first NAS security algorithm, the identifier of the first NAS security algorithm can be carried in the header of the first information, with only integrity protection and no encryption. Optionally, the identifier of the first NAS security algorithm can also be a newly added parameter in the access network parameters, with AS encryption and / or integrity protection, and subsequently sent to the second network element along with the first information. Optionally, if the terminal device does not report the identifier of the first NAS security algorithm, the second network element can determine the first network element based on the first identifier, and the first network element can obtain the first NAS security algorithm based on the first identifier.

[0223] S604, the second network element acquires the first NAS security algorithm.

[0224] In the first implementation, the second network element sends a first request to the first network element or the third network element, the first request being used to request the first NAS security algorithm; the second network element receives a first response from the first network element or the third network element, the first response including the first NAS security algorithm. The first network element can be an NF network element or a security network element, or, if the first network element is an NF network element, the third network element can be a security network element.

[0225] Specifically, if a NAS connection has been established between the terminal device and the first network element, and the first network element is an NF network element, the second network element can send a first request to the first network element or the third network element. Alternatively, if the first network element is a security network element, and a NAS connection has been established between the terminal device and the first network element, the second network element can send a first request to the first network element. After receiving the first request, the first network element or the third network element can obtain the first NAS security algorithm based on the first identifier. Alternatively, the first request includes first indication information, which indicates the type of NAS security algorithm. The first network element or the third network element can obtain the first NAS security algorithm based on the first indication information. Finally, the first network element or the third network element sends the first NAS security algorithm to the second network element.

[0226] In the second implementation, the second network element receives the first NAS security algorithm from the first network element or the third network element. After the first network element and the terminal device have established a NAS connection, the first network element or the third network element can proactively send the first NAS security algorithm to the second network element, without the second network element needing to request the first NAS security algorithm from the first network element or the third network element. The second network element and the first or third network element can be located in the same PLMN.

[0227] The third implementation involves configuring at least one NAS security algorithm on the second network element. Each of these NAS security algorithms corresponds to at least one of the following: PLMN, slice information, and core network element type. The first NAS security algorithm is selected from the at least one NAS security algorithm based on at least one of the PLMN, slice information, and core network element type obtained by the terminal device or by the second network element itself. The method for configuring at least one NAS security algorithm on the second network element can be referred to Tables 1, 2, and 3 above, and will not be elaborated further here.

[0228] In a fourth implementation, the identifier of the first NAS security algorithm is carried within the first information. Further, the first NAS security algorithm can be carried in the header of the first information, featuring AS layer encryption and integrity protection, as well as NAS integrity protection and no encryption. Optionally, the first NAS security algorithm can also be a newly added information element (IE), carried in the access network parameters of the access network message, featuring AS layer encryption and / or integrity protection. If the terminal device reports the first NAS security algorithm, the second network element does not need to request the first NAS security algorithm from the first or third network element.

[0229] In the fifth implementation, the first NAS security algorithm is configured by the second network element. When the terminal device and the second network element request to establish a NAS connection, the first NAS security algorithm is used by default.

[0230] Optionally, when the second network element requests the first NAS security algorithm from the security network element, it may forward encrypted and / or integrity-protected first information to the security network element. The first information carries a first identifier or first indication information, which indicates the type of NAS security algorithm. The security network element can obtain the first NAS security algorithm based on the first identifier or first indication information, generate a key based on the first NAS security algorithm, and use the generated key to perform integrity protection verification on the first information forwarded by the second network element. After the integrity protection verification passes, the security network element sends the first NAS security algorithm to the second network element.

[0231] S605, the second network element decrypts and / or verifies the integrity protection of the encrypted and / or integrity-protected first information based on the first NAS security algorithm.

[0232] Specifically, the second network element can use the ID of the first NAS security algorithm as input to generate a NAS key. Alternatively, the second network element can use the ID of the first NAS security algorithm and the NAS key of the second network element as input to generate a NAS key. The NAS key of the second network element can be requested from the security network element, configured by the second network element, or directly issued to the second network element by the security network element. Then, the second network element can use the generated NAS key to decrypt and / or verify the integrity of the encrypted and / or integrity-protected first information.

[0233] Optionally, the second network element can receive security capabilities from the terminal device of the access network equipment, and select a second NAS security algorithm from at least one NAS security algorithm based on the security capabilities of the terminal device. The at least one NAS security algorithm can be locally configured by the second network element. The second network element can select one NAS security algorithm from the at least one NAS security algorithm according to priority, based on the UE's security capabilities.

[0234] Then, the second network element can determine whether the second NAS security algorithm and the first NAS security algorithm are consistent. If they are consistent, the first NAS security algorithm is continued to be used; if they are inconsistent, the existing NAS security negotiation process can be reused. For example, the second network element sends a NAS security mode command to the terminal device. The NAS security mode command carries the identifier of the second NAS security algorithm. The NAS security mode command is encrypted and / or its integrity is protected based on the second NAS security algorithm. The terminal device decrypts and / or verifies the integrity of the NAS message based on the second NAS security algorithm and returns a NAS security mode complete message to the second network element. If they are inconsistent, another possible implementation is that the second network element sends a NAS security mode command to the terminal device. The NAS security mode command carries the identifier of the second NAS security algorithm. The NAS security mode command is encrypted and / or its integrity is protected based on the first NAS security algorithm. The terminal device decrypts and / or verifies the integrity of the NAS message based on the first NAS security algorithm and returns a NAS security mode complete message to the second network element.

[0235] S606, the second network element sends second information to the terminal device. The second information is for encryption and / or integrity protection based on the first NAS security algorithm or the second NAS security algorithm. The second information is used to indicate that NAS security negotiation has been started or completed.

[0236] The second piece of information can be a NAS security mode complete message, which indicates that NAS security negotiation has been completed; or, the second piece of information can be a NAS security mode command message, which indicates that NAS security negotiation has been started.

[0237] Optionally, when the first NAS security algorithm and the second NAS security algorithm are the same, the second information carries the identifier of the first NAS security algorithm, and the second network element encrypts and / or protects the integrity of the second information based on the first NAS security algorithm; when the first NAS security algorithm and the second NAS security algorithm are different, the second information carries the identifier of the second NAS security algorithm, and the second network element encrypts and / or protects the integrity of the second information based on the first NAS security algorithm or the second NAS security algorithm.

[0238] Optionally, after receiving the second information, the terminal device uses a NAS key generated based on the first or second NAS security algorithm to decrypt and / or verify the integrity of the second information. If the decryption and / or integrity verification passes, the terminal device completes NAS security negotiation with the second network element and establishes a NAS connection. The NAS security algorithm used by the terminal device depends on the NAS security algorithm used by S606.

[0239] S607, the terminal device sends third information to the second network element.

[0240] S607 is an optional step. If the second information is a NAS security mode command message, the terminal device can send a third information to the second network element. The third information can be a NAS security mode completion message. The third information is used to indicate that NAS security negotiation has been completed. The third information is based on the second NAS security algorithm for encryption and / or integrity protection.

[0241] In this embodiment, after the terminal device establishes a NAS connection with the first network element, the terminal device encrypts and / or protects the integrity of the first information based on a first NAS security algorithm, and then requests to establish a NAS connection with the second network element through the encrypted and / or integrity-protected first information. This enables the terminal device to establish NAS connections with multiple NAS endpoints, improving the security of establishing NAS connections.

[0242] The following explanation uses the terminal device as UE, the first network element as the first NF network element or security network element (the security network element is a NAS endpoint), the second network element as the second NF network element, and the third network element as a security network element (the security network element is a non-NAS endpoint) as examples.

[0243] As shown in Figure 7, Figure 7 is a flowchart illustrating another communication method provided in an embodiment of this application. The security network element is the NAS endpoint. The method mainly includes the following steps:

[0244] S701, the UE sends an access network message (AN message) to the RAN device.

[0245] Among them, the access network message is used to complete the access to the network.

[0246] S702, the RAN device sends an initial NAS message to the security network element.

[0247] S703, UE and security network element complete authentication and key derivation process.

[0248] S704, UE and security network element establish NAS connection.

[0249] NAS connection can also be called NAS secure connection.

[0250] S705, UE and security network element have negotiated the first NAS security algorithm.

[0251] After the UE establishes a NAS connection with the security network element, a first NAS security algorithm has been negotiated. The first NAS security algorithm may include encryption algorithms and / or integrity protection algorithms.

[0252] S706, UE and RAN equipment establish AS connection, AS security protection is enabled.

[0253] S707, the security network element sends a registration request response message (registration accept) to the UE.

[0254] The registration request response message carries a first identifier, which can be used to identify the UE and / or security network element.

[0255] S708, the UE generates a key based on the first NAS security algorithm.

[0256] Specifically, the UE determines whether the newly accessed second NF network element and the security network element with the established NAS connection belong to the same PLMN. If they belong to the same PLMN, the UE uses the negotiated first NAS security algorithm, takes the ID of the first NAS security algorithm as the input parameter, and generates the NAS encryption key and / or integrity protection key.

[0257] S709, the UE sends an AN message to the RAN device.

[0258] The AN message may include AN parameters and first information. The first information is encrypted and / or protected for integrity based on a first NAS security algorithm, and may be a NAS connection request. AN parameters may include the type of core network element, and the first information may include a first identifier and a service ID. Alternatively, AN parameters may include the type of core network element and a first identifier. There are no restrictions on the messages contained in the AN parameters and the first information.

[0259] The first identifier can be used by the second NF network element to determine the security network element, and the first identifier can also be used by the security network element to obtain the first NAS security algorithm.

[0260] It should be noted that the AN message has access stratum (AS) encryption and / or integrity protection, and the first information is encrypted and / or protected for integrity based on the first NAS security algorithm. If the first information contains an identifier of the first NAS security algorithm, the identifier of the first NAS security algorithm can be carried in the header of the first information, with only integrity protection and no encryption. Optionally, the identifier of the first NAS security algorithm can also be a newly added parameter in the access network parameters, with AS encryption and / or integrity protection, and subsequently sent to the second NF network element along with the first information. Optionally, if the UE does not report the identifier of the first NAS security algorithm, the second NF network element can determine the security network element based on the first identifier, and the security network element can obtain the first NAS security algorithm based on the first identifier.

[0261] S710, the RAN device sends the first information to the second NF network element.

[0262] The first piece of information is encrypted and / or protected for integrity based on the first NAS security algorithm.

[0263] Specifically, the RAN device determines whether the second NF network element meets the requirements. If it does, it selects the second NF network element and forwards the first information to the second NF network element.

[0264] S711, the second NF network element sends the first request to the security network element.

[0265] Specifically, the second NF network element can identify the security network element based on the first identifier. Then, it sends a first request to the security network element. This first request can be used to request the first NAS security algorithm, or it can be used to request the NAS key of the second NF network element. The first request can carry the first identifier.

[0266] Optionally, the second NF network element may also forward the first information to the security network element. The first information is encrypted and / or protected for integrity based on the first NAS security algorithm.

[0267] S712, the security network element obtains the first NAS security algorithm based on the first identifier or the identifier of the first NAS security algorithm contained in the first request.

[0268] S713, the security network element generates a key based on the first NAS security algorithm to decrypt and / or verify the integrity of the first information.

[0269] If the decryption and / or integrity protection verification passes, then execute S714.

[0270] S714, the security network element sends the first response to the second NF network element.

[0271] The first response may include the NAS key of the second NF network element and / or the first NAS security algorithm.

[0272] The above sections S711-S714 mainly describe how the second NF network element requests the first NAS security algorithm from the security network element. The second NF network element can also obtain the first NAS security algorithm in the following ways:

[0273] In another implementation, the identifier of the first NAS security algorithm is carried in the first information sent by the UE. Further, the first NAS security algorithm can be carried in the header of the first information, featuring AS layer encryption and integrity protection, as well as NAS integrity protection and no encryption. Optionally, the first NAS security algorithm can also be carried as a new information element (IE) in the access network parameters of the access network message, featuring AS layer encryption and / or integrity protection. If the UE reports the first NAS security algorithm, the second NF network element does not need to request the first NAS security algorithm from the security network element.

[0274] In another implementation, the second NF network element can receive the first NAS security algorithm from the security network element. After the security network element and the UE have established a NAS connection, the security network element can proactively send the first NAS security algorithm to the second NF network element within the same PLMN, without the second NF network element needing to request the first NAS security algorithm from the security network element.

[0275] S715, the second NF network element decrypts and / or verifies the integrity of the first information based on the first NAS security algorithm.

[0276] Specifically, the second NF network element can use the ID of the first NAS security algorithm as input to generate a NAS key. Alternatively, the second NF network element can use the ID of the first NAS security algorithm and the NAS key of the second NF network element as input to generate a NAS key. The NAS key of the second NF network element can be requested from the security network element, configured by the second NF network element, or directly issued to the second NF network element by the security network element. Then, the second NF network element can use the generated NAS key to decrypt and / or verify the integrity of the encrypted and / or integrity-protected first information.

[0277] Optionally, the second NF network element can receive the security capabilities of the UE from the RAN equipment, and select a second NAS security algorithm from at least one NAS security algorithm based on the UE's security capabilities. The at least one NAS security algorithm can be configured for the second NF network element. The second NF network element can select one NAS security algorithm from the at least one NAS security algorithm according to priority, based on the UE's security capabilities.

[0278] Then, the second NF network element can determine whether the second NAS security algorithm and the first NAS security algorithm are consistent. If they are consistent, the first NAS security algorithm will continue to be used, and S716 will be executed. If they are inconsistent, the existing NAS security negotiation process can be resent or reused. For example, the second NF network element sends a NAS security mode command message to the UE. The NAS security mode command carries the second NAS security algorithm. The UE returns a NAS security mode complete message to the second NF network element.

[0279] S716, the second NF network element sends the second information to the UE.

[0280] The second information is encrypted and / or protected for integrity based on a first NAS security algorithm or a second NAS security algorithm.

[0281] The second piece of information can be a NAS security mode complete message. This message indicates that NAS security negotiation has been completed, or that NAS message verification has passed, allowing encryption and / or integrity protection to be enabled. The second piece of information may be based on a first or a second NAS security algorithm for encryption and / or integrity protection. Alternatively, the second piece of information can be a NAS security mode command message, which indicates that NAS security negotiation should be initiated.

[0282] Optionally, when the first NAS security algorithm and the second NAS security algorithm are the same, the second information carries the identifier of the first NAS security algorithm, and the second NF network element encrypts and / or protects the integrity of the second information based on the first NAS security algorithm; when the first NAS security algorithm and the second NAS security algorithm are different, the second information carries the identifier of the second NAS security algorithm, and the second NF network element encrypts and / or protects the integrity of the second information based on the first NAS security algorithm or the second NAS security algorithm.

[0283] S717, the UE decrypts and / or verifies the integrity of the second information based on the first NAS security algorithm or the second NAS security algorithm.

[0284] Specifically, the UE decrypts and / or verifies the integrity of the second information using the NAS encryption key and / or integrity protection key generated by the first or second NAS security algorithm. If the decryption and / or integrity protection verification passes, the UE completes NAS security negotiation with the second NF network element and establishes a NAS connection.

[0285] S718, the UE sends the third information to the second NF network element.

[0286] S718 is an optional step. If the second information is a NAS security mode command message, after the UE decrypts and / or verifies the integrity protection of the second information, it can send the third information to the second NF network element. The third information can be a NAS security mode completion message. The third information is used to indicate that NAS security negotiation has been completed. The third information is encrypted and / or protected for integrity based on the second NAS security algorithm.

[0287] The embodiment shown in Figure 7 uses a secure network element as the NAS endpoint. After the UE establishes a NAS connection with the secure network element, the UE and the second NF network element encrypt and / or protect the integrity of the NAS connection establishment message between the UE and the second NF network element based on the first NAS security algorithm negotiated between the UE and the secure network element. This enables the UE to establish NAS connections with multiple NAS endpoints, improving the security of establishing NAS connections.

[0288] As shown in Figure 8, Figure 8 is a flowchart illustrating another communication method provided in an embodiment of this application. The security network element is a non-NAS endpoint. The method mainly includes the following steps:

[0289] S801, the UE sends an access network message (AN message) to the RAN device.

[0290] Among them, the access network message is used to complete the access to the network.

[0291] S802, the RAN device sends an initial NAS message to the first NF network element, and the first NF network element forwards the NAS message to the security network element.

[0292] S803, UE and security network element complete the authentication and key derivation process.

[0293] S804, UE and the first NF network element establish NAS connection.

[0294] NAS connection can also be called NAS secure connection.

[0295] S805, UE and the first NF network element have negotiated the first NAS security algorithm.

[0296] After the UE establishes a NAS connection with the first NF network element, the first NAS security algorithm has been negotiated. The first NAS security algorithm may include encryption algorithms and / or integrity protection algorithms.

[0297] S806, the UE and RAN equipment establish an AS connection, and AS security protection is enabled.

[0298] S807, the first NF network element sends a registration request response message (registration accept) to the UE.

[0299] The registration request response message carries a first identifier, which can be used to identify the UE and / or the first NF network element.

[0300] S808, the UE generates a key based on the first NAS security algorithm.

[0301] Specifically, the UE determines whether the newly accessed second NF network element and the first NF network element with the established NAS connection belong to the same PLMN. If they belong to the same PLMN, the UE uses the negotiated first NAS security algorithm, takes the ID of the first NAS security algorithm as the input parameter, and generates the NAS encryption key and / or integrity protection key.

[0302] S809, the UE sends an AN message to the RAN device.

[0303] The AN message may include AN parameters and first information. The first information is encrypted and / or protected for integrity based on a first NAS security algorithm, and may be a NAS connection request. AN parameters may include the type of core network element, and the first information may include a first identifier and a service ID. Alternatively, AN parameters may include the type of core network element and a first identifier. There are no restrictions on the messages contained in the AN parameters and the first information.

[0304] The first identifier can be used by the second NF network element to determine the first NF network element, and the first identifier can also be used by the first NF network element to obtain the first NAS security algorithm.

[0305] It should be noted that the AN message has access stratum (AS) encryption and / or integrity protection, and the first information is encrypted and / or protected for integrity based on the first NAS security algorithm. If the first information contains an identifier of the first NAS security algorithm, the identifier of the first NAS security algorithm can be carried in the header of the first information, with only integrity protection and no encryption. Optionally, the identifier of the first NAS security algorithm can also be a newly added parameter in the access network parameters, with AS encryption and / or integrity protection, and subsequently sent to the second NF network element along with the first information. Optionally, if the UE does not report the identifier of the first NAS security algorithm, the second NF network element can determine the first NF network element based on the first identifier, and the first NF network element can obtain the first NAS security algorithm based on the first identifier.

[0306] S810, the RAN device sends the first information to the second NF network element.

[0307] The first piece of information is encrypted and / or protected for integrity based on the first NAS security algorithm.

[0308] Specifically, the RAN device determines whether the second NF network element meets the requirements. If it does, it selects the second NF network element and forwards the first information to the second NF network element.

[0309] S811, the second NF network element sends the first request to the first NF network element.

[0310] Specifically, the second NF network element can identify the first NF network element based on the first identifier. Then, it sends a first request to the first NF network element. This first request can be used to request the first NAS security algorithm. The first request can carry the first identifier.

[0311] S812, the first NF network element sends the first response to the second NF network element.

[0312] Specifically, the first NF network element can obtain the first NAS security algorithm based on the first identifier and send a first response to the second NF network element. The first response may include the NAS key of the second NF network element and / or the first NAS security algorithm.

[0313] The above sections S811-S812 mainly describe how the second NF network element requests the first NAS security algorithm from the first NF network element. The second NF network element can obtain the first NAS security algorithm in the following ways:

[0314] In another implementation, the identifier of the first NAS security algorithm is carried in the first information sent by the UE. Further, the first NAS security algorithm can be carried in the header of the first information, featuring AS layer encryption and integrity protection, as well as NAS integrity protection and no encryption. Optionally, the first NAS security algorithm can also be carried as a new information element (IE) in the access network parameters of the access network message, featuring AS layer encryption and / or integrity protection. If the UE reports the first NAS security algorithm, the second NF network element does not need to request the first NF network element from the first NF network element.

[0315] In another implementation, the second NF network element can receive the first NAS security algorithm from the first NF network element. After the first NF network element and the UE have established a NAS connection, the first NF network element can proactively send the first NAS security algorithm to the second NF network element within the same PLMN, without the second NF network element needing to request the first NAS security algorithm from the first NF network element.

[0316] S813, the second NF network element obtains the NAS key of the second NF network element from the security network element.

[0317] Specifically, the second NF network element can identify the security network element and then send a second request to the security network element. The second request is for the NAS key of the second NF network element.

[0318] Optionally, the NAS key of the second NF network element can be configured by the second NF network element or directly issued to the second NF network element by the security network element.

[0319] S814, the second NF network element decrypts and / or verifies the integrity of the first information based on the first NAS security algorithm.

[0320] Specifically, the second NF network element can use the ID of the first NAS security algorithm as input to generate a NAS key. Alternatively, the second NF network element can use the ID of the first NAS security algorithm and the NAS key of the second NF network element as input to generate a NAS key. Then, the second NF network element can use the generated NAS key to decrypt and / or verify the integrity of the encrypted and / or integrity-protected first information.

[0321] Optionally, the second NF network element can receive the security capabilities of the UE from the RAN equipment, and select a second NAS security algorithm from at least one NAS security algorithm based on the UE's security capabilities. The at least one NAS security algorithm can be configured for the second NF network element. The second NF network element can select one NAS security algorithm from the at least one NAS security algorithm according to priority, based on the UE's security capabilities.

[0322] Then, the second NF network element can determine whether the second NAS security algorithm and the first NAS security algorithm are consistent. If they are consistent, the first NAS security algorithm is continued to be used and S815 is executed. If they are inconsistent, the existing NAS security negotiation process can be resent or reused. For example, the second NF network element sends a NAS security mode command message to the UE. The NAS security mode command carries the second NAS security algorithm. The UE returns a NAS security mode complete message to the second NF network element.

[0323] S815, the second NF network element sends the second information to the UE.

[0324] The second information is encrypted and / or protected for integrity based on a first NAS security algorithm or a second NAS security algorithm.

[0325] The second piece of information can be a NAS security mode complete message. This message indicates that NAS security negotiation has been completed, or it indicates that NAS message verification has passed, allowing encryption and / or integrity protection to be enabled. The second piece of information indicates that encryption and / or integrity protection is based on a second NAS security algorithm.

[0326] Optionally, when the first NAS security algorithm and the second NAS security algorithm are the same, the second information carries the identifier of the first NAS security algorithm, and the second NF network element encrypts and / or protects the integrity of the second information based on the first NAS security algorithm; when the first NAS security algorithm and the second NAS security algorithm are different, the second information carries the identifier of the second NAS security algorithm, and the second NF network element encrypts and / or protects the integrity of the second information based on the first NAS security algorithm or the second NAS security algorithm.

[0327] S816, the UE decrypts and / or verifies the integrity of the second information based on the first NAS security algorithm or the second NAS security algorithm.

[0328] Specifically, the UE can decrypt and / or verify the integrity of the second information based on the NAS encryption key and / or integrity protection key generated by the first or second NAS security algorithm. If the decryption and / or integrity protection verification passes, the UE and the second NF network element complete NAS security negotiation and establish a NAS connection.

[0329] The second piece of information can be a NAS security mode complete message. This message indicates that NAS security negotiation has been completed, or that NAS message verification has passed, allowing encryption and / or integrity protection to be enabled. The second piece of information may be based on a first or a second NAS security algorithm for encryption and / or integrity protection. Alternatively, the second piece of information can be a NAS security mode command message, which indicates that NAS security negotiation should be initiated.

[0330] S817, the UE sends the third information to the second NF network element.

[0331] S817 is an optional step. If the second information is a NAS security mode command message, after the UE decrypts and / or verifies the integrity protection of the second information, it can send the third information to the second NF network element. The third information can be a NAS security mode completion message. The third information is used to indicate that NAS security negotiation has been completed. The third information is encrypted and / or protected for integrity based on the second NAS security algorithm.

[0332] The embodiment shown in Figure 8 uses a secure network element as a non-NAS endpoint. After the UE establishes a NAS connection with the first NF network element, the UE and the second NF network element encrypt and / or protect the integrity of the NAS connection establishment message between the UE and the second NF network element based on the first NAS security algorithm negotiated between the UE and the first NF network element. This enables the UE to establish NAS connections with multiple NAS endpoints, improving the security of establishing NAS connections.

[0333] As shown in Figure 9, Figure 9 is a flowchart illustrating another communication method provided in an embodiment of this application. The security network element is the NAS endpoint. The method mainly includes the following steps:

[0334] S901, Security Element Configuration Algorithm List, which includes multiple NAS security algorithms.

[0335] Each of the plurality of NAS security algorithms corresponds to at least one of the following: PLMN, slice information, and core network element type. The list of configured algorithms can be found in Tables 1-3 of the embodiment shown in Figure 6.

[0336] S902, the UE sends an access network message (AN message) to the RAN device.

[0337] Among them, the access network message is used to complete the access to the network.

[0338] S903, the RAN device sends an initial NAS message to the security network element.

[0339] S904, the UE and security network element complete the authentication and key derivation process.

[0340] S905, UE and security network element establish NAS connection.

[0341] NAS connection can also be called NAS secure connection.

[0342] S906, UE and security network element have negotiated the first NAS security algorithm.

[0343] After the UE establishes a NAS connection with the security network element, a first NAS security algorithm has been negotiated. The first NAS security algorithm may include encryption algorithms and / or integrity protection algorithms.

[0344] S907, the UE and RAN equipment establish an AS connection, and AS security protection is enabled.

[0345] S908: The security network element obtains at least one NAS security algorithm from the configured algorithm list based on the UE's subscription information.

[0346] The subscription information may include at least one of the following: the PLMN supported by the UE, slice information, and the type of core network element. The security network element may obtain at least one NAS security algorithm from a configured algorithm list based on at least one of the PLMN supported by the UE, slice information, and the type of core network element. Each of the at least one NAS security algorithm corresponds to at least one of the PLMN supported by the UE, slice information, and the type of core network element.

[0347] S909, the security network element sends a registration request response message (registration accept) to the UE.

[0348] The registration request response message may carry a first identifier, which can be used to identify the UE and / or security network element. Alternatively, the registration request response message may also carry at least one NAS security algorithm, where each of the at least one NAS security algorithm corresponds to at least one of the types of PLMN, slice information, and core network element supported by the UE.

[0349] Optionally, at least one of the following: at least one NAS security algorithm and / or its corresponding PLMN, slice information, and core network element type can also be carried in the remaining NAS downlink messages after security protection is enabled, such as downlink messages in the User Equipment Parameter Update (UPU) process. Alternatively, at least one NAS security algorithm can also be carried in downlink messages during the authentication process.

[0350] S910, the UE selects a second NAS security algorithm from at least one NAS security algorithm based on at least one of the PLMN, slice information and core network element types obtained by the UE.

[0351] The PLMN can be the PLMN stored when the UE establishes a NAS connection with a security network element, or it can be the PLMN obtained when the UE establishes a connection with a second NF network element. The UE can obtain the PLMN of the currently accessed network based on broadcast messages, and obtain slice information and the type of core network element (e.g., NF type) based on the message type and slice information it wants to send.

[0352] The second NAS security algorithm may be the same as or different from the first NAS security algorithm. The second NAS security algorithm may include encryption algorithms and / or integrity protection algorithms.

[0353] Optionally, the UE can use the ID of the encryption algorithm and / or integrity protection algorithm as input parameters to generate the corresponding NAS encryption key and / or integrity protection key.

[0354] S911, the UE sends an AN message to the RAN device.

[0355] The AN message may include AN parameters and first information. The first information is encrypted and / or protected for integrity based on the second NAS security algorithm, and may be a NAS connection request. AN parameters may include the type of core network element, and the first information may include a first identifier and a service ID. Alternatively, AN parameters may include the type of core network element and a first identifier. There are no restrictions on the messages contained in the AN parameters and the first information.

[0356] The first identifier can be used by the second NF network element to determine the security network element, and the first identifier can also be used by the security network element to obtain the first NAS security algorithm negotiated by the UE.

[0357] It should be noted that the AN message has access stratum (AS) encryption and / or integrity protection, and the first information is encrypted and / or protected for integrity based on the second NAS security algorithm. If the first information contains a first identifier, the first identifier can be carried in the header of the first information, with only integrity protection and no encryption. Optionally, the first identifier can also be a newly added parameter in the access network parameters, with AS encryption and / or integrity protection, and subsequently sent to the second NF network element along with the first information. Optionally, the second NF network element can determine the security network element based on the first identifier, and the security network element can obtain the first NAS security algorithm negotiated by the UE based on the first identifier.

[0358] S912, the RAN device sends the first information to the second NF network element.

[0359] The first piece of information is encrypted and / or protected for integrity based on the second NAS security algorithm.

[0360] Specifically, the RAN device determines whether the second NF network element meets the requirements. If it does, it selects the second NF network element and forwards the first information to the second NF network element.

[0361] S913, the second NF network element sends the first request to the security network element.

[0362] Specifically, the second NF network element can determine the security network element based on the first identifier. Then, it sends a first request to the security network element. This first request can be used to request a second NAS security algorithm, or it can be used to request the NAS key of the second NF network element. The first request can carry first indication information, which indicates the type of the NAS security algorithm. The type of the NAS security algorithm can include at least one of NF type, PLMN, and slice, or it can also be used to indicate the identifier of the NAS algorithm.

[0363] Optionally, the second NF network element can also forward the first information to the security network element. The first information is encrypted and / or protected for integrity based on the second NAS security algorithm.

[0364] S914, the security network element obtains the second NAS security algorithm according to the first instruction information.

[0365] S915, the security network element generates a key based on the second NAS security algorithm to decrypt and / or verify the integrity of the first information.

[0366] If the decryption and / or integrity protection verification passes, then execute S916.

[0367] S916, the security network element sends the first response to the second NF network element.

[0368] The first response may include the NAS key of the second NF network element and / or the second NAS security algorithm.

[0369] The above sections S913-S916 mainly describe how the second NF network element requests the second NAS security algorithm from the security network element. The second NF network element can also obtain the second NAS security algorithm in the following ways:

[0370] In another implementation, the identifier of the second NAS security algorithm is carried in the first information sent by the UE. Further, the second NAS security algorithm can be carried in the header of the first information, featuring AS layer encryption and integrity protection, as well as NAS integrity protection and no encryption. Optionally, the second NAS security algorithm can also be carried as a new information element (IE) in the access network parameters of the access network message, featuring AS layer encryption and / or integrity protection. If the UE reports the second NAS security algorithm, the second NF network element does not need to request the second NAS security algorithm from the security network element.

[0371] In another implementation, the second NF network element can also be configured with at least one NAS security algorithm, where each NAS security algorithm corresponds to at least one of the PLMN, slice information, and core network element types supported by the UE. When the second NF network element receives the first information, if the first information carries slice information, it selects the second NAS security algorithm from the configured at least one NAS security algorithm based on the slice information.

[0372] S917, the second NF network element decrypts and / or verifies the integrity of the first information based on the second NAS security algorithm.

[0373] Specifically, the second NF network element can use the ID of the second NAS security algorithm as input to generate a NAS key. Alternatively, the second NF network element can use the ID of the second NAS security algorithm and its own NAS key as input to generate a NAS key. The NAS key of the second NF network element can be requested from the security network element, configured by the second NF network element, or directly issued to the second NF network element by the security network element. Then, based on the generated NAS key, the second NF network element can decrypt and / or verify the integrity of the encrypted and / or integrity-protected first information.

[0374] S918, the second NF network element selects a third NAS security algorithm from at least one NAS security algorithm based on the UE's security capabilities.

[0375] Specifically, the second NF network element can receive the security capabilities of the UE from the RAN equipment. These security capabilities may be sent to the second NF network element along with the first information. Based on the UE's security capabilities, the second NF network element selects a third NAS security algorithm from at least one NAS security algorithm. The at least one NAS security algorithm can be configured for the second NF network element. The second NF network element can select one NAS security algorithm from the at least one NAS security algorithm based on the UE's security capabilities, according to priority.

[0376] The third NAS security algorithm may be the same as or different from the first NAS security algorithm, or the third NAS security algorithm may be the same as or different from the second NAS security algorithm.

[0377] S919, the second NF network element sends a NAS security mode command message to the UE.

[0378] The NAS security mode command message may carry a third NAS security algorithm. The second information is for encryption and / or integrity protection based on the second or third NAS security algorithm.

[0379] Optionally, the second NF network element can determine whether it is an initial registration / authentication process. If so, the second NF network element will only enable integrity protection for the second information. If it is otherwise, it will enable encryption and / or integrity protection.

[0380] S920, the UE decrypts and / or verifies the integrity of the NAS security mode command message based on the second or third NAS security algorithm.

[0381] Specifically, the UE can use the NAS encryption key and / or integrity protection key generated based on the second or third NAS security algorithm to decrypt and / or verify the integrity protection of the NAS security mode command message. If the decryption and / or integrity protection verification passes, the UE and the second NF network element complete NAS security negotiation and establish a NAS connection.

[0382] S921, UE and second NF network element generate keys based on third NAS security algorithm.

[0383] Specifically, the UE obtains the third NAS security algorithm from the decrypted second information, and generates an encryption key and / or an integrity protection key based on the third NAS security algorithm; the second NF network element can also generate the corresponding key according to the third NAS security algorithm.

[0384] S922, the UE sends a NAS security mode complete message to the second NF network element.

[0385] The NAS security mode completion message includes encryption and / or integrity protection based on a third-party NAS security algorithm. The NAS security mode completion message may include the third-party NAS security algorithm, and it enables encryption and / or integrity protection.

[0386] Optionally, after receiving the NAS security mode completion message, the second NF network element verifies the message based on the third NAS security algorithm. If the verification passes, downlink encryption is enabled. Then, the UE and the second NF network element complete NAS security negotiation and establish a NAS security connection.

[0387] The embodiment shown in Figure 9 uses a secure network element as the NAS endpoint. After the UE establishes a NAS connection with the secure network element, the UE and the second NF network element select a NAS security algorithm from a dynamically configured NAS security algorithm based on the PLMN, slice information, and the type of the core network element. This algorithm encrypts and / or protects the integrity of the NAS messages used to establish the NAS connection between the UE and the second NF network element. This enables the UE to establish NAS connections with multiple NAS endpoints, improving the security of establishing NAS connections.

[0388] As shown in Figure 10, Figure 10 is a flowchart illustrating another communication method provided in an embodiment of this application. The security network element is a non-NAS endpoint. The method mainly includes the following steps:

[0389] S1001, Security Element Configuration Algorithm List, which includes multiple NAS security algorithms.

[0390] Each of the plurality of NAS security algorithms corresponds to at least one of the following: PLMN, slice information, and core network element type. The list of configured algorithms can be found in Tables 1-3 of the embodiment shown in Figure 6.

[0391] S1002, the UE sends an access network message (AN message) to the RAN device.

[0392] Among them, the access network message is used to complete the access to the network.

[0393] S1003, the RAN device sends an initial NAS message to the first NF network element.

[0394] S1004, the first NF network element sends an authentication request to the security network element.

[0395] S1005, the UE and security network element complete the authentication and key derivation process.

[0396] S1006, the first NF network element selects the first NAS security algorithm based on the UE's security capabilities.

[0397] Specifically, the second NF network element selects a first NAS security algorithm from at least one NAS security algorithm based on the UE's security capabilities. The at least one NAS security algorithm can be locally configured on the second NF network element, and each NAS security algorithm corresponds to at least one of the following: PLMN, slice information, and core network element type. The second NF network element can select one NAS security algorithm from the at least one NAS security algorithm according to priority, based on the UE's security capabilities.

[0398] S1007, the UE and the first NF network element establish a NAS connection.

[0399] NAS connection can also be called NAS secure connection.

[0400] S1008, the UE and the first NF network element have negotiated the first NAS security algorithm.

[0401] After the UE establishes a NAS connection with the first NF network element, the first NAS security algorithm has been negotiated. The first NAS security algorithm may include encryption algorithms and / or integrity protection algorithms.

[0402] S1009, the UE and RAN equipment establish an AS connection, and AS security protection is enabled.

[0403] The following describes how a UE obtains at least one NAS security algorithm, wherein each NAS security algorithm corresponds to at least one of the types of PLMN, slice information, and core network elements supported by the UE.

[0404] The first method includes S1010-S1011:

[0405] S1010, the first NF network element is configured with at least one NAS security algorithm. At least one NAS security algorithm may correspond to at least one of the slice information and core network elements under the same PLMN.

[0406] S1011, the first NF network element sends a registration request response message (registration accept) to the UE.

[0407] The registration request response message may carry a first identifier, which can be used to identify the UE and / or the first NF network element. Alternatively, the registration request response message may also carry at least one NAS security algorithm, where each NAS security algorithm corresponds to at least one of the types of PLMN, slice information, and core network element supported by the UE.

[0408] Optionally, at least one NAS security algorithm can also be carried in other NAS downlink messages after security protection is enabled, such as downlink messages in the User Equipment Parameter Update (UPU) process. Alternatively, at least one NAS security algorithm can also be carried in downlink messages during the authentication process.

[0409] The second method includes S1012-S1015:

[0410] S1012, the first NF network element sends a second request to the security network element.

[0411] The second request is used to request at least one NAS security algorithm.

[0412] Optionally, the first NF network element can determine whether it is an initial registration. If it is an initial registration, it sends a second request to the security network element, the second request including the UE's identifier.

[0413] S1013, the security network element obtains at least one NAS security algorithm from the configured algorithm list based on the UE's subscription information.

[0414] S1014, the security network element sends a second response to the first NF network element.

[0415] The second response includes at least one NAS security algorithm.

[0416] Optionally, the security network element can determine whether it is an initial registration. If it is an initial registration, the security network element proactively sends at least one NAS security algorithm to the first NF network element. Therefore, the first NF network element does not need to send a second request to the security network element.

[0417] S1015, the first NF network element sends a registration request response message (registration accept) to the UE.

[0418] S1016, the UE selects a second NAS security algorithm from at least one NAS security algorithm based on at least one of the PLMN, slice information and core network element type obtained by the UE.

[0419] S1017, the UE sends an AN message to the RAN device.

[0420] S1018, the RAN device sends the first information to the second NF network element.

[0421] S1019, the second NF network element sends the first request to the security network element.

[0422] S1020, the security network element obtains the second NAS security algorithm according to the first instruction information.

[0423] S1021, the security element generates a key based on the second NAS security algorithm to decrypt and / or verify the integrity of the first information.

[0424] If the decryption and / or integrity protection verification passes, then execute S1022.

[0425] S1022, the security network element sends the first response to the second NF network element.

[0426] S1023, the second NF network element decrypts and / or verifies the integrity of the first information based on the second NAS security algorithm.

[0427] S1024, the second NF network element selects a third NAS security algorithm from at least one NAS security algorithm based on the UE's security capabilities.

[0428] S1025, the second NF network element sends a NAS security mode command message to the UE.

[0429] S1026, the UE decrypts and / or verifies the integrity of the NAS security mode command message based on the second or third NAS security algorithm.

[0430] S1027, the UE and the second NF network element generate a key based on the third NAS security algorithm.

[0431] S1028, the UE sends a NAS security mode completion message to the second NF network element.

[0432] The implementation process of S1016-S1028 is similar to that of S910-S922. The specific implementation methods of S1016-S1028 can be referred to S910-S922, and will not be repeated here.

[0433] The embodiment shown in Figure 10 uses a secure network element as a non-NAS endpoint. After the UE establishes a NAS connection with the first NF network element, the UE and the second NF network element use a dynamically configured NAS security algorithm selected from PLMN, slice information, and the type of core network element to encrypt and / or protect the integrity of the NAS message establishing the NAS connection between the UE and the second NF network element. This enables the UE to establish NAS connections with multiple NAS endpoints, improving the security of establishing NAS connections.

[0434] As shown in Figure 11, Figure 11 is a flowchart illustrating another communication method provided in an embodiment of this application. The security network element is the NAS endpoint. The method mainly includes the following steps:

[0435] S1101, Security Element Configuration Algorithm List, which includes multiple NAS security algorithms.

[0436] S1102, the UE sends an access network message (AN message) to the RAN device.

[0437] S1103, the RAN device sends an initial NAS message to the security network element.

[0438] S1104, the UE and security network element complete the authentication and key derivation process.

[0439] S1105, UE and security network element establish NAS connection.

[0440] S1106, the UE and the security network element have negotiated the first NAS security algorithm.

[0441] S1107, the UE and RAN equipment establish an AS connection, and AS security protection is enabled.

[0442] S1108, the security network element obtains at least one NAS security algorithm from the configured algorithm list based on the UE's subscription information.

[0443] S1109, the security network element sends a registration request response message (registration accept) to the UE.

[0444] The implementation process of S1101-S1109 is similar to that of S901-S909. The specific implementation methods of S1101-S1109 can be referred to S901-S909, and will not be repeated here.

[0445] S1110, the UE and the first NF network element complete the negotiation of the NAS security algorithm.

[0446] The implementation method of S1110 is the same as the negotiation of the NAS security algorithm between the UE and the second NF network element in Figure 9. For the specific implementation process, please refer to S910-S920.

[0447] S1111, the UE and the first NF network element have negotiated the second NAS security algorithm.

[0448] S1112, the UE determines that the core network element that needs to be re-accessed and the first NF network element belong to the same core network element type and belong to the same PLMN, and generates a key based on the second NAS security algorithm.

[0449] Specifically, the UE determines whether the core network element to be re-accessed and the first NF network element belong to the same core network element type and whether they belong to the same PLMN. If they belong to the same core network element type and the same PLMN, for example, both belong to the SMF network element, then the second NAS security algorithm negotiated in S1111 is reused. The second NAS security algorithm includes a second NAS encryption algorithm and / or a second NAS integrity protection algorithm. The UE can use the IDs of the second NAS encryption algorithm and / or the second NAS integrity protection algorithm as input parameters to generate encryption keys and / or integrity protection keys.

[0450] S1113, the UE sends an AN message to the RAN device.

[0451] The AN message may include AN parameters and first information. The first information is encrypted and / or protected for integrity based on the second NAS security algorithm, and may be a NAS connection request. AN parameters may include the type of core network element, and the first information may include a first identifier and a service ID. Alternatively, AN parameters may include the type of core network element and a first identifier. There are no restrictions on the messages contained in the AN parameters and the first information.

[0452] The core network element type indicates the type of core network element the UE needs to access. The type of core network element the UE needs to access is the same as the type of the first NF network element that has been negotiated. The first identifier can be the UE's identifier or the identifier of the security network element. The first identifier can be used to determine the security network element, and it can also be used by the second NF network element to obtain the second NAS security algorithm negotiated by the UE.

[0453] It should be noted that the AN message has access stratum (AS) encryption and / or integrity protection, and the first information is encrypted and / or protected for integrity based on the second NAS security algorithm. If the first information contains an identifier of the second NAS security algorithm, the identifier of the second NAS security algorithm can be carried in the header of the first information, with only integrity protection and no encryption. Optionally, the identifier of the second NAS security algorithm can also be a newly added parameter in the access network parameters, with AS encryption and / or integrity protection, and subsequently sent to the second NF network element along with the first information. Optionally, if the UE does not report the identifier of the second NAS security algorithm, the second NF network element can determine the security network element based on the first identifier, and the security network element can obtain the second NAS security algorithm based on the first identifier.

[0454] S1114, the RAN device sends the first information to the second NF network element.

[0455] The first piece of information is encrypted and / or protected for integrity based on the second NAS security algorithm.

[0456] Specifically, the RAN device determines whether the second NF network element meets the requirements. If it does, it selects the second NF network element and forwards the first information to the second NF network element.

[0457] S1115, the second NF network element sends the first request to the security network element.

[0458] Specifically, the second NF network element can identify the security network element based on the first identifier. Then, it sends a first request to the security network element. This first request can be used to request the second NAS security algorithm, or it can be used to request the NAS key of the second NF network element. The first request can also carry the type of the core network element.

[0459] Optionally, the second NF network element can also forward the first information to the security network element. The first information is encrypted and / or protected for integrity based on the second NAS security algorithm.

[0460] S1116, the security network element obtains the second NAS security algorithm based on the type of the core network element.

[0461] Specifically, if the security network element determines that the type of the core network element that the UE needs to access is the same as the type of the first NF network element that has been negotiated, then it can obtain the second NAS security algorithm that has been negotiated between the UE and the first NF network element.

[0462] Optionally, the security element can also obtain the second NAS security algorithm based on the first identifier.

[0463] S1117, the security element generates a key based on the second NAS security algorithm to decrypt and / or verify the integrity of the first information.

[0464] If the decryption and / or integrity protection verification passes, then execute S1118.

[0465] S1118, the security network element sends the first response to the second NF network element.

[0466] The first response may include the NAS key of the second NF network element and / or the second NAS security algorithm.

[0467] S1119, the second NF network element decrypts and / or verifies the integrity of the first information based on the second NAS security algorithm.

[0468] Specifically, the second NF network element can use the ID of the second NAS security algorithm as input to generate a NAS key. Alternatively, the second NF network element can use the ID of the second NAS security algorithm and its own NAS key as input to generate a NAS key. The NAS key of the second NF network element can be requested from the security network element, configured by the second NF network element, or directly issued to the second NF network element by the security network element. Then, the second NF network element can use the generated NAS key to decrypt and / or verify the integrity of the encrypted and / or integrity-protected first information.

[0469] S1120, the second NF network element sends the second information to the UE.

[0470] The second message can be a NAS security mode complete message. This second message may carry a second NAS security algorithm. This second message indicates that NAS security negotiation has been completed, and that encryption and / or integrity protection are performed based on the second NAS security algorithm. The second message enables encryption and / or integrity protection.

[0471] S1121, the UE decrypts and / or verifies the integrity of the second information based on the second NAS security algorithm.

[0472] Specifically, the UE can use the NAS encryption key and / or integrity protection key generated by S1112 to decrypt and / or verify the integrity of the second information. If the decryption and / or integrity protection verification passes, the UE completes NAS security negotiation with the second NF network element and establishes a NAS connection.

[0473] The embodiment shown in Figure 11 uses a secure network element as the NAS endpoint. After the UE establishes a NAS connection with the first NF network element, the UE and the second NF network element obtain the second NAS security algorithm negotiated between the UE and the first NF network element, and encrypt and / or protect the integrity of the NAS message establishing the NAS connection between the UE and the second NF network element. This enables the UE to establish NAS connections with multiple NAS endpoints, improving the security of establishing NAS connections.

[0474] As shown in Figure 12, Figure 12 is a flowchart illustrating another communication method provided in an embodiment of this application. The security network element is the NAS endpoint. The method mainly includes the following steps:

[0475] S1201, the UE is configured with at least one NAS security algorithm.

[0476] In this embodiment, each NAS security algorithm corresponds to at least one of the following: PLMN, slice information, and core network element type. See Tables 1-3 in the example shown in Figure 6.

[0477] S1202, the UE sends an access network message (AN message) to the RAN device.

[0478] Among them, the access network message is used to complete the access to the network.

[0479] S1203, the RAN device sends an initial NAS message to the security network element.

[0480] S1204, the UE and security network element complete the authentication and key derivation process.

[0481] S1205, UE and security network element establish NAS connection.

[0482] NAS connection can also be called NAS secure connection.

[0483] S1206, the UE and the security network element have negotiated the first NAS security algorithm.

[0484] After the UE establishes a NAS connection with the security network element, a first NAS security algorithm has been negotiated. The first NAS security algorithm may include encryption algorithms and / or integrity protection algorithms.

[0485] S1207, the UE and RAN equipment establish an AS connection, and AS security protection is enabled.

[0486] S1208, the security network element sends a registration request response message (registration accept) to the UE.

[0487] The registration request response message carries a first identifier, which can be used to identify the UE and / or security network element.

[0488] S1209, the UE selects a second NAS security algorithm from at least one NAS security algorithm.

[0489] In one implementation, the UE can obtain at least one of the following: PLMN, slice information, and core network element type. Based on at least one of the PLMN, slice information, and core network element type obtained by the UE, a second NAS security algorithm can be selected from at least one NAS security algorithm.

[0490] In another implementation, the UE can acquire its own security capabilities and, based on those capabilities, select a second NAS security algorithm from at least one NAS security algorithm. Further, the UE selects a second NAS security algorithm from the at least one NAS security algorithm according to priority.

[0491] In another implementation, the UE is configured with a NAS security algorithm supported by all networks, such as AES or Snow. The UE can be configured with only one NAS security algorithm. If multiple NAS security algorithms are configured, the UE can choose randomly or select the NAS security algorithm negotiated during the last registration with the PLMN.

[0492] Optionally, the UE determines whether the current PLMN is a Home Public Land Mobile Network (HPLMN), an Equivalent Home Public Land Mobile Network (EHPLMN), or a Virtual Public Land Mobile Network (VPLMN). If it is an HPLMN or an EHPLMN, the UE selects a second NAS security algorithm from at least one configured NAS security algorithm.

[0493] Optionally, the second NAS security algorithm may include a second NAS encryption algorithm and / or a second NAS integrity protection algorithm. The UE may use the IDs of the second NAS encryption algorithm and / or the second NAS integrity protection algorithm as input parameters to generate encryption keys and / or integrity protection keys.

[0494] S1210, the UE sends an AN message to the RAN device.

[0495] The AN message may include AN parameters and first information. The first information is encrypted and / or protected for integrity based on the second NAS security algorithm, and may be a NAS connection request. AN parameters may include the type of core network element, and the first information may include a first identifier and a service ID. Alternatively, AN parameters may include the type of core network element and a first identifier. There are no restrictions on the messages contained in the AN parameters and the first information.

[0496] The first identifier can be used by the second NF network element to determine the security network element, and it can also be used by the security network element to obtain the UE's second NAS security algorithm. The second NF network element can determine the security network element based on the first identifier, and the security network element can obtain the first NAS security algorithm negotiated by the UE based on the first identifier.

[0497] It should be noted that the AN message has access stratum (AS) encryption and / or integrity protection, while the first message is encrypted and / or protected for integrity based on the second NAS security algorithm. If the first message contains the ID of the second NAS security algorithm, the ID of the second NAS security algorithm can be carried in the header of the first message, with only integrity protection and no encryption. Optionally, the ID of the second NAS security algorithm can also be a newly added parameter in the access network parameters, with AS encryption and / or integrity protection, and subsequently sent to the second NF network element along with the first message.

[0498] S1211, the RAN device sends the first information to the second NF network element.

[0499] The first piece of information is encrypted and / or protected for integrity based on the second NAS security algorithm.

[0500] Specifically, the RAN device determines whether the second NF network element meets the requirements. If it does, it selects the second NF network element and forwards the first information to the second NF network element.

[0501] S1212, the second NF network element sends the first request to the security network element.

[0502] Specifically, the second NF network element can identify the security network element based on the first identifier. Then, it sends a first request to the security network element. This first request can also be used to request the NAS key of the second NF network element. Furthermore, the first request can carry the ID of the second NAS security algorithm.

[0503] Optionally, the second NF network element can also forward the first information to the security network element. The first information is encrypted and / or protected for integrity based on the second NAS security algorithm.

[0504] S1213, the security element generates a key based on the second NAS security algorithm to decrypt and / or verify the integrity of the first information.

[0505] If the decryption and / or integrity protection verification passes, then execute S1214.

[0506] S1214, the security network element sends the first response to the second NF network element.

[0507] The first response may include the NAS key of the second NF network element.

[0508] S1215, the second NF network element decrypts and / or verifies the integrity of the first information based on the second NAS security algorithm.

[0509] Specifically, the second NF network element can use the ID of the second NAS security algorithm and the NAS key of the second NF network element as input parameters to generate a NAS key. Based on the generated NAS key, the encrypted and / or integrity-protected first information is decrypted and / or its integrity protection is verified.

[0510] S1216, the second NF network element selects a third NAS security algorithm from at least one NAS security algorithm based on the UE's security capabilities.

[0511] Specifically, the second NF network element can receive the security capabilities of the UE from the RAN equipment. These security capabilities may be sent to the second NF network element along with the first information. Based on the UE's security capabilities, the second NF network element selects a third NAS security algorithm from at least one NAS security algorithm. The at least one NAS security algorithm can be configured for the second NF network element, and the second NF network element can select one NAS security algorithm from the at least one NAS security algorithm according to priority and based on the UE's security capabilities.

[0512] S1217, the second NF network element determines whether the second NAS security algorithm and the third NAS security algorithm are the same.

[0513] S1218, if they are the same, the second NF network element sends a NAS security mode completion message to the UE.

[0514] The NAS security mode completion message carries the ID of the second NAS security algorithm. The NAS security mode completion message uses the second NAS security algorithm for encryption and / or integrity protection.

[0515] S1219, the UE performs decryption and / or integrity protection verification on the NAS security mode completion message based on the second NAS security algorithm.

[0516] Specifically, the UE can use the NAS encryption key and / or integrity protection key generated by S1209 to decrypt and / or verify the integrity of the NAS security mode completion message. If the decryption and / or integrity protection verification pass, the UE completes NAS security negotiation with the second NF network element and establishes a NAS connection.

[0517] S1220, if different, the second NF network element sends a NAS security mode command message to the UE.

[0518] The NAS security mode completion message carries the ID of the third NAS security algorithm. The NAS security mode command message uses encryption and / or integrity protection based on the second NAS security algorithm.

[0519] S1221, the UE decrypts and / or verifies the integrity protection of the NAS security mode command message based on the second NAS security algorithm.

[0520] Specifically, the UE can use the NAS encryption key and / or integrity protection key generated in S1209 to decrypt and / or verify the integrity protection of the NAS security mode command message. If the decryption and / or integrity protection verification passes, then proceed to S1222.

[0521] S1222, the UE and the second NF network element generate a key based on the third NAS security algorithm.

[0522] Specifically, the UE obtains the third NAS security algorithm from the decrypted NAS security mode command message, and generates an encryption key and / or an integrity protection key based on the third NAS security algorithm; the second NF network element can also generate the corresponding key according to the third NAS security algorithm.

[0523] S1223, the UE sends a NAS security mode completion message to the second NF network element.

[0524] The NAS security mode completion message includes encryption and / or integrity protection based on a third-party NAS security algorithm. The NAS security mode completion message may include the third-party NAS security algorithm, and it enables encryption and / or integrity protection.

[0525] Optionally, after receiving the NAS security mode completion message, the second NF network element verifies the message based on the third NAS security algorithm. If the verification passes, downlink encryption is enabled. Then, the UE and the second NF network element complete NAS security negotiation and establish a NAS security connection.

[0526] The embodiment shown in Figure 12 uses a secure network element as the NAS endpoint. After the UE establishes a NAS connection with the secure network element, the UE selects a NAS security algorithm from at least one locally configured NAS security algorithm based on the PLMN, slice information, and the type of the core network element. This algorithm encrypts and / or protects the integrity of the NAS message used to establish the NAS connection between the UE and the second NF network element. This enables the UE to establish NAS connections with multiple NAS endpoints, improving the security of establishing NAS connections.

[0527] It is understood that, in the above-described method embodiments, the methods and operations implemented by the terminal device can also be implemented by components (e.g., chips or circuits) that can be used in the terminal device, and the methods and operations implemented by the network device can also be implemented by components (e.g., chips or circuits) that can be used in the network device. The network device can be a first network element or a second network element.

[0528] This application embodiment can divide terminal devices or network devices into functional modules according to the above method examples. For example, each function can be divided into its own functional modules, or two or more functions can be integrated into one processing module. The integrated modules can be implemented in hardware or software functional modules. It should be noted that the module division in this application embodiment is illustrative and only represents one logical functional division. In actual implementation, there may be other division methods. The following description uses the division of functional modules according to each function as an example.

[0529] The methods provided by the embodiments of this application have been described in detail above with reference to Figures 6-12. The communication apparatus provided by the embodiments of this application will be described in detail below with reference to Figures 13 to 16. It should be understood that the descriptions of the apparatus embodiments correspond to the descriptions of the method embodiments; therefore, any content not described in detail can be referred to the method embodiments above, and for the sake of brevity, will not be repeated here.

[0530] Please refer to Figure 13, which is a schematic diagram of a communication device provided in an embodiment of this application. This communication device can implement the steps or processes executed by the terminal device corresponding to the method embodiments described above. In one possible design, the communication device may include a sending module 1301, a processing module 1302, and a receiving module 1303. Optionally, the communication device may further include a storage module for storing device program code and / or data.

[0531] The processing module 1302 is used to obtain a first non-access stratum NAS security algorithm, and after establishing a NAS connection with the first network element, to encrypt and / or protect the integrity of the first information based on the first NAS security algorithm; or, after establishing a NAS connection with the first network element, to obtain a first non-access stratum NAS security algorithm, and to encrypt and / or protect the integrity of the first information based on the first NAS security algorithm.

[0532] The sending module 1301 is used to send encrypted and / or integrity-protected first information, which is used to establish a NAS connection with the second network element.

[0533] Optionally, the receiving module 1303 is used to receive second information from the second network element, the second information being encrypted and / or protected for integrity based on the first NAS security algorithm or the second NAS security algorithm, and the second information being used to indicate that NAS security negotiation has been started or that NAS security negotiation has been completed.

[0534] The processing module 1302 is used to decrypt and / or verify the integrity of the second information based on the first NAS security algorithm or the second NAS security algorithm.

[0535] Optionally, the first NAS security algorithm is either negotiated between the terminal device and the first network element, or configured by the terminal device.

[0536] Optionally, the processing module 1302 is further configured to acquire at least one of the Public Land Mobile PLMN, slice information, and core network element type obtained by the terminal device or by the second network element itself; and select the first NAS security algorithm from at least one NAS security algorithm based on at least one of the PLMN, slice information, and core network element type obtained by the terminal device or by the second network element itself, wherein each of the at least one NAS security algorithms corresponds to at least one of the PLMN, slice information, and core network element type supported by the terminal device.

[0537] In one possible design, the processing module 1302 is further configured to acquire the security capabilities of the terminal device; and select the first NAS security algorithm from at least one NAS security algorithm based on the security capabilities of the terminal device.

[0538] In one possible design, the receiving module 1303 is configured to receive the at least one NAS security algorithm from the first network element; or

[0539] The processing module 1302 is also used to configure the at least one NAS security algorithm.

[0540] Optionally, the first information or the access network parameters sent together with the first information may include the type of core network element, wherein the type of core network element is used to indicate the core network element that the terminal device needs to access.

[0541] Optionally, the first information or the access network parameters sent together with the first information may include a first identifier, which is used to obtain the NAS security algorithm corresponding to the terminal device.

[0542] Optionally, the first information or the access network parameters sent together with the first information may include the identifier of the first NAS security algorithm.

[0543] Optionally, the NAS security algorithm includes an integrity protection algorithm and / or an encryption algorithm.

[0544] In one possible design, when the communication device is a terminal device or a communication module within a terminal device, the functionality of the processing module 1302 can be implemented by one or more processors. Specifically, the processor may include a modem chip, or a system-on-a-chip (SoC) chip or a SIP chip containing a modem core. The functions of the receiving module 1303 and the transmitting module 1301 can be implemented by transceiver circuitry.

[0545] In one possible design, when the communication device is a circuit or chip responsible for communication functions in a terminal device, such as a modem chip or a system-on-a-chip (SoC) or SIP chip containing a modem core, the function of the processing module 1302 can be implemented by a circuit system in the aforementioned chip that includes one or more processors or processor cores. The functions of the receiving module 1303 and the transmitting module 1301 can be implemented by interface circuits or data transceiver circuits on the aforementioned chip.

[0546] It should be noted that the implementation of each module can also refer to the corresponding descriptions of the method embodiments shown in Figures 6-12, and execute the methods and functions performed by the terminal device in the above embodiments.

[0547] Please refer to Figure 14, which is a schematic diagram of another communication device provided in an embodiment of this application. This communication device can implement the steps or processes executed by the second network element corresponding to the method embodiments described above. In one possible design, the communication device may include a receiving module 1401, a processing module 1402, and a transmitting module 1403. Optionally, the communication device may further include a storage module for storing device program code and / or data.

[0548] The receiving module 1401 is used to receive first information after the terminal device establishes a NAS connection with the first network element. The first information is encrypted and / or protected for integrity. The first information is used to establish a non-access stratum NAS connection with the second network element.

[0549] The processing module 1402 is used to obtain the first NAS security algorithm; and based on the first NAS security algorithm, to decrypt and / or verify the integrity protection of the encrypted and / or integrity-protected first information.

[0550] Optionally, the sending module 1403 is used to send second information to the terminal device. The second information is encrypted and / or protected for integrity based on a first NAS security algorithm or a second NAS security algorithm. The second information is used to indicate that NAS security negotiation has been started or completed.

[0551] Optionally, the sending module 1403 is used to send a first request to the first network element or the third network element, wherein the first request is used to request the first NAS security algorithm.

[0552] The receiving module 1401 is used to receive a first response from the first network element or the third network element, wherein the first response includes the first NAS security algorithm.

[0553] Optionally, the receiving module 1401 is used to receive the first NAS security algorithm from the first network element or the third network element.

[0554] Optionally, the processing module 1402 is further configured to configure at least one NAS security algorithm, wherein each of the at least one NAS security algorithm corresponds to at least one of PLMN, slice information and core network element type; and select the first NAS security algorithm from the at least one NAS security algorithm based on at least one of PLMN, slice information and core network element type obtained by the terminal device or by the second network element itself.

[0555] Optionally, the identifier of the first NAS security algorithm is carried in the first information.

[0556] Optionally, the first NAS security algorithm is configured for the second network element.

[0557] Optionally, the receiving module 1401 is further configured to receive security capabilities from the terminal device of the access network device;

[0558] Processing module 1402 is further configured to select the second NAS security algorithm from at least one NAS security algorithm based on the security capabilities of the terminal device;

[0559] Wherein, when the first NAS security algorithm and the second NAS security algorithm are the same, the second information carries the identifier of the first NAS security algorithm, and the second network element encrypts and / or protects the integrity of the second information based on the first NAS security algorithm; when the first NAS security algorithm and the second NAS security algorithm are different, the second information carries the identifier of the second NAS security algorithm, and the second network element encrypts and / or protects the integrity of the second information based on the first NAS security algorithm or the second NAS security algorithm.

[0560] Optionally, the first information or the access network parameters sent together with the first information may include the type of core network element, wherein the type of core network element is used to indicate the core network element that the terminal device needs to access.

[0561] Optionally, the first information or the access network parameters sent together with the first information may include a first identifier, which is used to obtain the NAS security algorithm corresponding to the terminal device.

[0562] Optionally, the first information or the access network parameters sent together with the first information may include the identifier of the first NAS security algorithm.

[0563] In one possible design, when the communication device is a second network element or a communication module within a second network element, the functionality of the processing module 1402 can be implemented by one or more processors. Specifically, the processor may include a modem chip, or a system-on-a-chip (SoC) chip or a SIP chip containing a modem core. The functions of the receiving module 1401 and the transmitting module 1403 can be implemented by transceiver circuitry.

[0564] In one possible design, when the communication device is a circuit or chip responsible for communication functions in a second network element, such as a modem chip or a system-on-a-chip (SoC) or SIP chip containing a modem core, the function of the processing module 1402 can be implemented by a circuit system in the aforementioned chip that includes one or more processors or processor cores. The functions of the receiving module 1401 and the transmitting module 1403 can be implemented by the interface circuits or data transceiver circuits on the aforementioned chip.

[0565] It should be noted that the implementation of each module can also refer to the corresponding descriptions of the method embodiments shown in Figures 6-12, and execute the methods and functions performed by the second network element in the above embodiments.

[0566] Please refer to Figure 15, which is a schematic diagram of another communication device provided in an embodiment of this application. This communication device can implement the steps or processes executed by the second network element corresponding to the method embodiments described above. In one possible design, the communication device may include a receiving module 1501, a processing module 1502, and a sending module 1503. Optionally, the communication device may further include a storage module for storing device program code and / or data.

[0567] The receiving module 1501 is used to receive a first request from the second network element, wherein the first request is used to request a first NAS security algorithm;

[0568] The sending module 1503 is used to send a first response to the second network element. The first response includes the first NAS security algorithm, which is used to encrypt and / or protect the integrity of NAS messages between the second network element and the terminal device.

[0569] Optionally, the first request includes a first identifier; the processing module 1502 is configured to obtain the first NAS security algorithm based on the first identifier.

[0570] Optionally, the first request includes first indication information, which is used to indicate the type of NAS security algorithm;

[0571] Processing module 1502 is used to obtain the first NAS security algorithm according to the first indication information.

[0572] Optionally, the sending module 1503 is used to send at least one NAS security algorithm to the terminal device.

[0573] Optionally, each of the at least one NAS security algorithms corresponds to at least one of the types of PLMN, slice information, and core network elements supported by the terminal device.

[0574] Optionally, the processing module 1502 is configured to obtain the subscription information of the terminal device; and, based on the subscription information, obtain the at least one NAS security algorithm from a configured algorithm list.

[0575] Optionally, the configured algorithm list includes multiple NAS security algorithms, each of which corresponds to at least one of the following: PLMN, slice information, and core network element type.

[0576] In one possible design, when the communication device is a first network element or a communication module within a first network element, the functionality of the processing module 1502 can be implemented by one or more processors. Specifically, the processor may include a modem chip, or a system-on-a-chip (SoC) chip or a SIP chip containing a modem core. The functions of the receiving module 1501 and the transmitting module 1503 can be implemented by transceiver circuitry.

[0577] In one possible design, when the communication device is a circuit or chip responsible for communication functions in the first network element, such as a modem chip or a system-on-a-chip (SoC) or SIP chip containing a modem core, the function of the processing module 1502 can be implemented by a circuit system in the aforementioned chip that includes one or more processors or processor cores. The functions of the receiving module 1501 and the transmitting module 1503 can be implemented by the interface circuits or data transceiver circuits on the aforementioned chip.

[0578] It should be noted that the implementation of each module can also refer to the corresponding descriptions of the method embodiments shown in Figures 6-12, and execute the methods and functions performed by the first network element in the above embodiments.

[0579] Please refer to Figure 16, which is a schematic diagram of another communication device provided in an embodiment of this application. This communication device can implement the steps or processes executed by the second network element corresponding to the method embodiments described above. In one possible design, the communication device may include a receiving module 1601, a processing module 1602, and a sending module 1603. Optionally, the communication device may further include a storage module for storing device program code and / or data.

[0580] The receiving module 1601 is used to receive a second request from the first network element, the second request being used to request at least one NAS security algorithm;

[0581] The sending module 1603 is used to send a second response to the first network element, the second response including at least one NAS security algorithm.

[0582] Optionally, the at least one NAS security algorithm may also include at least one of the following: the type of PLMN, slice information, and core network element supported by the terminal device for each NAS security algorithm.

[0583] Optionally, the processing module 1602 is used to obtain the subscription information of the terminal device, and according to the subscription information, to obtain the at least one NAS security algorithm from a configured algorithm list, wherein the configured algorithm list includes multiple NAS security algorithms.

[0584] Optionally, the plurality of NAS security algorithms may also include at least one of the following: the PLMN corresponding to each NAS security algorithm, slice information, and the type of core network element.

[0585] In one possible design, when the communication device is a third network element or a communication module within a third network element, the functionality of the processing module 1602 can be implemented by one or more processors. Specifically, the processor may include a modem chip, or a system-on-a-chip (SoC) chip or a SIP chip containing a modem core. The functions of the receiving module 1601 and the transmitting module 1603 can be implemented by transceiver circuitry.

[0586] In one possible design, when the communication device is a circuit or chip responsible for communication functions in a third network element, such as a modem chip or a system-on-a-chip (SoC) or SIP chip containing a modem core, the function of the processing module 1602 can be implemented by a circuit system in the aforementioned chip that includes one or more processors or processor cores. The functions of the receiving module 1601 and the transmitting module 1603 can be implemented by the interface circuits or data transceiver circuits on the aforementioned chip.

[0587] It should be noted that the implementation of each module can also refer to the corresponding descriptions of the method embodiments shown in Figures 6-12, and execute the methods and functions performed by the third network element in the above embodiments.

[0588] Figure 17 is a schematic diagram of a terminal device provided in an embodiment of this application. This terminal device can be applied to the systems shown in Figures 1 and 2 to perform the functions of the terminal device in the above method embodiments, or to implement the steps or processes executed by the terminal device in the above method embodiments.

[0589] As shown in Figure 17, the terminal device includes a processor 1701 and a transceiver 1702. The transceiver 1702 includes a transmitter 1721, a receiver 1722, and an antenna 1723. The receiver 1722 can be used to receive transmission control information through the antenna 1723, and the transmitter 1721 can be used to send transmission feedback information to the network device through the antenna 1723. Optionally, the terminal device also includes a memory 1703. The processor 1701, transceiver 1702, and memory 1703 can communicate with each other through internal connection paths to transmit control and / or data signals. The memory 1703 stores computer programs, and the processor 1701 calls and runs the computer programs from the memory 1703 to control the transceiver 1702 to transmit and receive signals. Optionally, the terminal device may also include an antenna for transmitting uplink data or uplink control signaling output by the transceiver 1702 via wireless signals.

[0590] The processor 1701 and memory 1703 can be integrated into a single processing device. The processor 1701 executes the program code stored in the memory 1703 to achieve the aforementioned functions. In specific implementations, the memory 1703 can be integrated into the processor 1701 or independent of the processor 1701. The processor 1701 can correspond to the processing module in Figure 13.

[0591] The transceiver 1702 described above can correspond to the receiving module and transmitting module in Figure 13, and can also be referred to as a transceiver unit or transceiver module. The transceiver 1702 may include a receiver (or receiver circuit) and a transmitter (or transmitter circuit). The receiver is used to receive signals, and the transmitter is used to transmit signals.

[0592] It should be understood that the terminal device shown in Figure 17 can implement the various processes involving the terminal device in the method embodiments shown in Figures 6-12. The operation and / or function of each module in the terminal device are respectively for implementing the corresponding processes in the above method embodiments. For details, please refer to the description in the above method embodiments; to avoid repetition, detailed descriptions are appropriately omitted here.

[0593] The processor 1701 described above can be used to execute the actions implemented internally by the terminal device as described in the preceding method embodiments, while the transceiver 1702 can be used to execute the actions described in the preceding method embodiments of sending data to or receiving data from the network device by the terminal device. Please refer to the descriptions in the preceding method embodiments for details, which will not be repeated here.

[0594] The processor 1701 can be a central processing unit, a general-purpose processor, a digital signal processor, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. It can implement or execute various exemplary logic blocks, modules, and circuits described in conjunction with the disclosure of this application. The processor 1701 can also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of a digital signal processor and a microprocessor, etc. The terminal device may also include a communication bus, which can be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. The communication bus is used to realize the connection and communication between these components. In this embodiment, the transceiver 1702 is used for signaling or data communication with other node devices. The memory 1703 may include volatile memory, such as nonvolatile random access memory (NVRAM), phase change RAM (PRAM), magnetoresistive RAM (MRAM), etc., and may also include non-volatile memory, such as at least one disk storage device, electrically erasable programmable read-only memory (EEPROM), flash memory devices, such as NOR flash memory or NAND flash memory, semiconductor devices, such as solid-state disks (SSDs), etc. Optionally, the memory 1703 may also be at least one storage device located remotely from the aforementioned processor 1701. Optionally, the memory 1703 may also store a set of computer program code or configuration information. Optionally, the processor 1701 may also execute the program stored in the memory 1703. The processor can cooperate with the memory and transceiver to execute any of the methods and functions of the terminal device in the above-described embodiments.

[0595] Figure 18 is a schematic diagram of the structure of a network device provided in an embodiment of this application. This network device can be applied to the system shown in Figures 1 and 2 to perform the functions of the network device (e.g., the first network element, the second network element, or the third network element) in the above method embodiments, or to implement the steps or processes performed by the network device in the above method embodiments.

[0596] As shown in Figure 18, the network device includes a processor 1801 and a transceiver 1802. The transceiver 1802 includes a transmitter 1821, a receiver 1822, and an antenna 1823. The transmitter 1821 can be used to send transmission control information to the terminal device through the antenna 1823, and the receiver 1822 can be used to receive transmission feedback information sent by the terminal device through the antenna 1823. Optionally, the network device also includes a memory 1803. The processor 1801, transceiver 1802, and memory 1803 can communicate with each other through internal connection paths to transmit control and / or data signals. The memory 1803 is used to store computer programs, and the processor 1801 is used to call and run the computer programs from the memory 1803 to control the transceiver 1802 to transmit and receive signals. Optionally, the network device may also include an antenna for transmitting uplink data or uplink control signaling output by the transceiver 1802 via wireless signals.

[0597] The processor 1801 described above can correspond to the processing modules in Figures 14-16. The processor 1801 and the memory 1803 can be integrated into a single processing device. The processor 1801 is used to execute the program code stored in the memory 1803 to achieve the above functions. In specific implementations, the memory 1803 can be integrated into the processor 1801 or independent of the processor 1801.

[0598] The transceiver 1802 described above can correspond to the receiving module and transmitting module in Figures 14-16, and can also be referred to as a transceiver unit or transceiver module. The transceiver 1802 may include a receiver (or receiver circuit) and a transmitter (or transmitter circuit). The receiver is used to receive signals, and the transmitter is used to transmit signals.

[0599] It should be understood that the network device shown in Figure 18 can implement the various processes involved in the network device in the method embodiments shown in Figures 6-12. The operation and / or function of each module in the network device are respectively for implementing the corresponding processes in the above method embodiments. For details, please refer to the description in the above method embodiments; to avoid repetition, detailed descriptions are appropriately omitted here.

[0600] The processor 1801 described above can be used to perform the actions implemented internally by the network device as described in the preceding method embodiments, while the transceiver 1802 can be used to perform the actions described in the preceding method embodiments of sending data from the network device to the terminal device or receiving data from the terminal device. For details, please refer to the descriptions in the preceding method embodiments; they will not be repeated here.

[0601] The processor 1801 can be any of the processors mentioned above. The network device may also include a communication bus, which can be a PCI bus (Peripheral Component Interconnect Standard) or an EISA bus (Extended Industry Standard Architecture). The bus can be divided into an address bus, a data bus, and a control bus. The communication bus is used to enable communication between these components. In this embodiment, the transceiver 1802 is used for signaling or data communication with other devices. The memory 1803 can be any of the memory types mentioned above. Optionally, the memory 1803 can also be at least one storage device located remotely from the processor 1801. The memory 1803 stores a set of computer program code or configuration information, and the processor 1801 executes the program in the memory 1803. The processor can cooperate with the memory and the transceiver to execute any of the methods and functions of the network device in the above embodiments.

[0602] This application also provides a chip system including a processor for supporting terminal devices, second network elements, or first network elements to implement the functions involved in any of the above embodiments, such as generating or processing the NAS security algorithms involved in the above methods.

[0603] In one possible design, the chip system may further include a memory for storing necessary computer programs and data for the terminal device or network device. The chip system may be composed of chips or may include chips and other discrete components. The inputs and outputs of the chip system correspond to the receiving and transmitting operations of the terminal device or network device in the method embodiment, respectively.

[0604] According to the method provided in the embodiments of this application, this application also provides a computer program product, which includes: a computer program that, when run on a computer, causes the computer to execute the method of any one of the embodiments shown in FIG6-FIG12.

[0605] According to the method provided in the embodiments of this application, this application also provides a computer-readable medium storing a computer program that, when run on a computer, causes the computer to perform the method of any one of the embodiments shown in FIG6-FIG12.

[0606] According to the method provided in the embodiments of this application, this application also provides a communication system, which includes one or more terminal devices as described above and one or more network devices (e.g., a first network element, a second network element, or a third network element).

[0607] In the above-described device embodiments, the network devices and terminal devices in the method embodiments correspond to each other, and the corresponding modules or units execute the corresponding steps. For example, the communication unit (transceiver) executes the receiving or sending steps in the method embodiments, while other steps besides sending and receiving can be executed by the processing unit (processor). The functions of specific units can be found in the corresponding method embodiments. There can be one or more processors.

[0608] The terms “component,” “module,” “system,” etc., used in this specification are used to refer to computer-related entities, hardware, firmware, combinations of hardware and software, software, or software in execution. For example, a component can be, but is not limited to, a process running on a processor, a processor, an object, an executable file, an execution thread, a program, and / or a computer. As illustrated, applications running on computing devices and computing devices can both be components. One or more components may reside in a process and / or an execution thread, and components may be located on a single computer and / or distributed among two or more computers. Furthermore, these components can be executed from various computer-readable media on which various data structures are stored. Components can communicate, for example, via local and / or remote processes based on signals having one or more data packets (e.g., data from two components interacting with another component between a local system, a distributed system, and / or a network, such as the Internet interacting with other systems via signals).

[0609] Those skilled in the art will recognize that the various illustrative logical blocks and steps described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this application.

[0610] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0611] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0612] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0613] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0614] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0615] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A communication method characterized by comprising: The method includes: After the terminal device obtains the first non-access stratum NAS security algorithm and establishes a NAS connection with the first network element, it encrypts and / or protects the first information based on the first NAS security algorithm; or After the terminal device establishes a NAS connection with the first network element, it obtains the first non-access stratum NAS security algorithm and encrypts and / or protects the integrity of the first information based on the first NAS security algorithm. The terminal device sends encrypted and / or integrity-protected first information, which is used to establish a NAS connection with the second network element.

2. The method of claim 1, wherein, The method further includes: The terminal device receives second information from the second network element. The second information is encrypted and / or protected for integrity based on the first NAS security algorithm or the second NAS security algorithm. The second information is used to indicate that NAS security negotiation has been started or that NAS security negotiation has been completed. The terminal device decrypts and / or verifies the integrity of the second information based on the first NAS security algorithm or the second NAS security algorithm.

3. The method of claim 1 or 2, wherein, The first NAS security algorithm is either negotiated between the terminal device and the first network element, or configured by the terminal device.

4. The method of claim 1 or 2, wherein, The terminal device obtains the first non-access stratum NAS security algorithm, which includes: The terminal device acquires at least one of the following: Public Land Mobile PLMN, slice information, and core network element type, either acquired by the terminal device or by the second network element itself. The terminal device selects the first NAS security algorithm from at least one NAS security algorithm based on at least one of the PLMN, slice information and core network element type obtained by the terminal device or by the second network element itself, wherein each of the at least one NAS security algorithms corresponds to at least one of the PLMN, slice information and core network element type supported by the terminal device.

5. The method of claim 1 or 2, wherein, The terminal device obtains the first non-access stratum NAS security algorithm, which includes: The terminal device acquires the security capabilities of the terminal device; The terminal device selects the first NAS security algorithm from at least one NAS security algorithm based on its security capabilities.

6. The method of claim 4 or 5, wherein, The method further includes: The terminal device receives at least one NAS security algorithm from the first network element; or The terminal device is configured with at least one NAS security algorithm.

7. The method according to any one of claims 1 to 6, wherein The first information or the access network parameters sent together with the first information include the type of core network element, and the type of core network element is used to indicate the core network element that the terminal device needs to access.

8. The method according to any one of claims 1 to 7, wherein The first information or the access network parameters sent together with the first information include a first identifier, which is used to obtain the NAS security algorithm corresponding to the terminal device.

9. The method according to any one of claims 1 to 8, wherein, The first information or the access network parameters sent together with the first information include the identifier of the first NAS security algorithm.

10. The method of any one of claims 1-9, wherein, The NAS security algorithm includes integrity protection algorithms and / or encryption algorithms.

11. A communication method, comprising: The method includes: After the terminal device establishes a NAS connection with the first network element, the second network element receives the first information, which is encrypted and / or protected for integrity. The first information is used to establish a non-access stratum NAS connection with the second network element. The second network element acquires the first NAS security algorithm; The second network element decrypts and / or verifies the integrity of the encrypted and / or integrity-protected first information based on the first NAS security algorithm.

12. The method of claim 11, wherein, The method further includes: The second network element sends a second message to the terminal device. The second message is for encryption and / or integrity protection based on a first NAS security algorithm or a second NAS security algorithm. The second message is used to indicate that NAS security negotiation has been started or completed.

13. The method of claim 11 or 12, wherein, The second network element acquires the first NAS security algorithm including: The second network element sends a first request to the first network element or the third network element, the first request being used to request the first NAS security algorithm; The second network element receives a first response from the first network element or the third network element, the first response including the first NAS security algorithm.

14. The method of claim 11 or 12, wherein, The second network element acquires the first NAS security algorithm including: The second network element receives the first NAS security algorithm from the first network element or the third network element.

15. The method of claim 11 or 12, wherein, The second network element acquires the first NAS security algorithm including: The second network element is configured with at least one NAS security algorithm, wherein each of the at least one NAS security algorithms corresponds to at least one of the types of PLMN, slice information, and core network element; The second network element selects the first NAS security algorithm from the at least one NAS security algorithm based on at least one of the PLMN, slice information obtained by the terminal device or by the second network element itself, and the type of the core network element.

16. The method of claim 11 or 12, wherein, The identifier of the first NAS security algorithm is carried in the first information.

17. The method of claim 11 or 12, wherein, The first NAS security algorithm is configured for the second network element.

18. The method of any one of claims 12-17, wherein, The method further includes: The second network element receives security capabilities from the terminal device; The second network element selects the second NAS security algorithm from at least one NAS security algorithm based on the security capabilities of the terminal device; Wherein, when the first NAS security algorithm and the second NAS security algorithm are the same, the second information carries the identifier of the first NAS security algorithm, and the second network element encrypts and / or protects the integrity of the second information based on the first NAS security algorithm; when the first NAS security algorithm and the second NAS security algorithm are different, the second information carries the identifier of the second NAS security algorithm, and the second network element encrypts and / or protects the integrity of the second information based on the first NAS security algorithm or the second NAS security algorithm.

19. A method of communication, comprising: The method includes: The first network element receives a first request from the second network element, the first request being used to request a first NAS security algorithm; The first network element sends a first response to the second network element. The first response includes the first NAS security algorithm, which is used to encrypt and / or protect the integrity of NAS messages between the second network element and the terminal device.

20. The method of claim 19, wherein, The first request includes a first identifier; the method further includes: The first network element obtains the first NAS security algorithm based on the first identifier.

21. The method of claim 19, wherein, The first request includes first indication information, which indicates the type of NAS security algorithm; the method further includes: The first network element obtains the first NAS security algorithm based on the first instruction information.

22. The method of any one of claims 19-21, wherein, The method further includes: The first network element sends at least one NAS security algorithm to the terminal device.

23. The method of claim 22, wherein, The method further includes: The first network element obtains the subscription information of the terminal device; The first network element obtains at least one NAS security algorithm from a configured algorithm list based on the subscription information, wherein the configured algorithm list includes multiple NAS security algorithms.

24. The method of claim 22 or 23, wherein, The at least one NAS security algorithm also includes at least one of the following: the type of PLMN, slice information, and core network element supported by the terminal device corresponding to each NAS security algorithm.

25. A method of communication, comprising: The method includes: The third network element receives a second request from the first network element, the second request being used to request at least one NAS security algorithm; The third network element sends a second response to the first network element, the second response including at least one NAS security algorithm.

26. The method of claim 25, wherein, The method further includes: The third network element obtains the contract information of the terminal device; The third network element obtains at least one NAS security algorithm from a configured algorithm list based on the subscription information. The configured algorithm list includes multiple NAS security algorithms.

27. The method of claim 25 or 26, wherein, The at least one NAS security algorithm also includes at least one of the following: the type of PLMN, slice information, and core network element supported by the terminal device corresponding to each NAS security algorithm.

28. A communications device, characterized by The device includes a memory and a processor, the memory being used to store a computer program, and the processor running the computer program to cause the communication device to perform the method of any one of claims 1-10, any one of claims 11-18, any one of claims 19-24, and any one of claims 25-27.

29. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a computer program that, when executed by a processor, causes the method of any one of claims 1-10, any one of claims 11-18, any one of claims 19-24, and any one of claims 25-27 to be implemented.

30. A chip, characterized by The chip includes a processor and a communication interface, the communication interface being used to communicate with external or internal devices, and the processor being used to implement the method as described in any one of claims 1-10, 11-18, 19-24, and 25-27.

Images