A key derivation method, device and system thereof

Abstract

An embodiment of the present application discloses a key derivation method, an apparatus, and a system thereof, the method comprising: a user equipment UE receives an authentication success message from a mobility management function network element, and then generates a master session key MSK and an extended master session key EMSK based on the authentication success message; and determines whether the authentication device is located outside a third generation partnership project 3GPP network to determine whether Kausf is obtained based on EMSK or MSK, so that the UE can be compatible with the key derivation method used when the authentication device is located outside the 3GPP network and the key derivation method used when the authentication device is located within the 3GPP network.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to a key derivation method, device, and system thereof. Background Art

[0002] The importance of information security is unquestionable. With the continuous development of communication technology, higher requirements are placed on the secure transmission of information. Encrypting information with keys is an important means to achieve information security. In a communication system, after the user equipment (UE) and the network have mutually authenticated each other, the UE can interact with the network side. In order to ensure the security of the information, the UE needs to encrypt or integrity protect the information to be transmitted to the network side. For example, the information exchanged between the UE and the access and mobility management function (AMF) network element can be encrypted or integrity protected using a derived key from KAM.

[0003] Kamf can be derived from the authentication service key Kausf. To enable communication between the UE and the AMF network element, the Kamf generated by the UE and the AMF network element must be the same. Therefore, the Kausf generated by the UE and the network side must also be the same.

[0004] During the process of network authentication of UE, the UE can be authenticated by using the authentication server function (AUSF) network element as the authentication device, or by using a 3GPP (3rd Generation Partnership Project) rd In the case of the AUSF network element as the authentication device, both the AUSF network element and the UE obtain Kausf from the extended master session key (EMSK). In the case of the CdP as the authentication device, the AUSF network element can obtain Kausf based on the key from the CdP. Because the protocol (RFC3748) stipulates that EMSK cannot be transmitted out of the CdP. Therefore, when the CdP is used as the authentication device, the key used to obtain Kausf is not EMSK.

[0005] In this way, the keys used to obtain Kausf are different when the AUSF network element is used as the authentication device and when the CdP is used as the authentication device. In the prior art, the UE cannot perceive whether the network side uses the AUSF network element or the CdP to authenticate the UE. Therefore, the UE cannot determine which key is used to obtain Kausf. Summary of the Invention

[0006] The embodiments of the present application provide a key derivation method, device, and system thereof, so that the UE can determine whether the authentication device is located outside the 3GPP network, thereby determining how to obtain Kausf.

[0007] In a first aspect, an embodiment of the present application provides a key derivation method, which includes: a user equipment UE receives an authentication success message from a mobility management function network element; the authentication success message is used to indicate that the UE is successfully authenticated by the authentication device; the UE generates a master session key MSK and an extended master session key EMSK based on the authentication success message; and determines whether the authentication device is located outside the Third Generation Partnership Project 3GPP network; when the authentication device is located outside the 3GPP network, the UE generates an authentication service key Kausf based on the MSK.

[0008] In this technical solution, the UE can determine whether to obtain Kausf based on EMSK or MSK by judging whether the authentication device is located outside the 3GPP network, which is conducive to making the Kausf generated by the UE and the network side the same, thereby ensuring smooth communication between the UE and the network side.

[0009] In one implementation, the method further includes: when the authentication device is located in a 3GPP network, the UE generates Kausf according to the EMSK.

[0010] In this technical solution, the UE can be compatible with the network architecture in which the authentication device is located outside the 3GPP network and the network architecture in which the authentication device is located inside the 3GPP network.

[0011] In one implementation, the method further includes: the UE receiving first indication information from a mobility management function network element, the first indication information being used to indicate that the authentication device is located outside the 3GPP network or within the 3GPP network; a specific implementation method for the UE to determine whether the authentication device is located outside the 3GPP network may be: the UE determines whether the authentication device is located outside the 3GPP network based on the first indication information.

[0012] In this technical solution, the UE can determine whether to use EMSK or MSK to derive Kausf according to the first indication information.

[0013] In one implementation, the first indication information includes an architecture downgrade prevention ABBA. When the value of the ABBA is a first value, the ABBA is used to indicate that the authentication device is located outside the 3GPP network; when the value of the ABBA is a second value, the ABBA is used to indicate that the authentication device is located within the 3GPP network. For example, the first value may be a non-zero value; and the second value may be 0.

[0014] This technical solution, on the one hand, uses the existing information element ABBA as the first indication information, thus reducing modifications to existing protocols. Furthermore, since ABBA is also a parameter for deriving the Kamf, if ABBA is tampered with, the Kamf generated by the UE and the mobility management function network element will differ. This makes it possible to detect attacks and thus improve communication security.

[0015] In one implementation, the UE stores first configuration information, which includes second indication information for indicating whether the authentication device is located outside the 3GPP network; the specific implementation method of the UE determining whether the authentication device is located outside the 3GPP network may be: the UE determines whether the authentication device is located outside the 3GPP network based on the second indication information.

[0016] In this technical solution, the UE determines whether the authentication device is located outside the 3GPP network based on the second indication information pre-configured in the UE. The network side does not need to send indication information to the UE (such as the mobility management function network element does not need to send the first indication information to the UE), which is beneficial to reducing the power consumption of the network side equipment.

[0017] In one implementation, the specific implementation method of the UE determining whether the authentication device is located outside the 3GPP network may be: when the UE obtains the identification of the authentication device, the UE determines that the authentication device is located outside the 3GPP network; when the UE does not obtain the identification of the authentication device, the UE determines that the authentication device is located within the 3GPP network.

[0018] In one implementation, the specific implementation method of the UE generating the authentication service key Kausf based on the MSK may be: the UE generates the Kausf based on the MSK and a generation parameter; wherein the generation parameter includes one or more of the following: an identifier of the service network currently accessed by the UE or an identifier of the UE.

[0019] In one implementation, the identifier of the UE includes a first identifier of the UE, where the first identifier is used to identify the UE in a network outside the 3GPP network.

[0020] In the second aspect, an embodiment of the present application provides another key derivation method, which includes: an authentication service function AUSF network element sends a first trigger indication to an authentication device, and the first trigger indication is used to trigger the authentication of a user equipment UE; the AUSF network element receives an authentication success message and a first key from the authentication device; the authentication success message is used to indicate that the UE is successfully authenticated by the authentication device; the AUSF network element generates an authentication service key Kausf based on the first key; and sends the authentication success message and a third indication information to a mobility management function network element, and the third indication information is used to indicate that the authentication device is located outside the Third Generation Partnership Project 3GPP network or within the 3GPP network.

[0021] In this technical solution, the AUSF network element sends the third indication information to the mobility management function network element, so that the mobility management function network element can learn whether the authentication device is located outside the 3GPP network, thereby facilitating the mobility management function network element to inform the UE whether the authentication device is located outside the 3GPP network. Alternatively, the AUSF network element sends the third indication information to the mobility management function network element, so that the mobility management function network element can forward the third indication information to the UE, so that the UE can learn whether the authentication device is located outside the 3GPP network.

[0022] In one implementation, the specific implementation method of the AUSF network element generating the authentication service key Kausf based on the first key may be: the AUSF network element generates the Kausf based on the first key and generation parameters; wherein the generation parameters include one or more of the following: the identifier of the service network currently accessed by the UE or the identifier of the UE.

[0023] In one implementation, the identifier of the UE includes a first identifier of the UE, where the first identifier is used to identify the UE in a network outside the 3GPP network.

[0024] In one implementation, before the AUSF network element sends a first trigger indication to the authentication device, the method further includes: the AUSF network element determining that the UE needs to perform authentication with the authentication device.

[0025] In one implementation, the specific implementation method of the AUSF network element determining that the UE needs to perform authentication with the authentication device may be: the AUSF network element receives the second identifier of the UE from the mobility management function network element; and based on the second identifier, determines that the UE needs to perform authentication with the authentication device; the second identifier is a user hidden identifier SUCI or a user permanent identifier SUPI.

[0026] In one implementation, the specific implementation method of the AUSF network element determining that the UE needs to perform authentication with the authentication device may be: the AUSF network element receives a second identifier of the UE from the mobility management function network element; the second identifier is a hidden user identifier SUCI or a permanent user identifier SUPI; the AUSF network element sends a first request message to a unified data management (UDM) network element, and the first request message includes the SUCI or the SUPI; the AUSF network element receives a first response message from the UDM network element, and the first response message includes the identifier of the authentication device; the AUSF network element determines, based on the identifier of the authentication device, that the UE needs to perform authentication with the authentication device.

[0027] In one implementation, the method also includes: the AUSF network element determines the first identifier of the UE based on the second identifier of the UE; the first identifier is used to identify the UE in a network outside the 3GPP network; the second identifier is SUCI or SUPI; the second identifier is received by the AUSF network element from the mobility management function network element; the AUSF network element sends the first identifier to the authentication device; the aforementioned first trigger indication is specifically used to trigger authentication of the UE based on the authentication credentials corresponding to the first identifier.

[0028] In this technical solution, the second identifier of the UE (i.e., SUCI or SUPI) can be prevented from being sent to an authentication device located outside the 3GPP network. That is, the second identifier of the UE can be prevented from being transmitted from within the 3GPP network to outside the 3GPP network, thereby avoiding leakage of user privacy.

[0029] In a third aspect, an embodiment of the present application provides another key derivation method, which includes: a mobile management function network element receives an authentication success message and a third indication information from an authentication service function AUSF network element, the authentication success message being used to indicate that the user equipment UE is successfully authenticated by the authentication device; the third indication information being used to indicate that the authentication device is located outside the Third Generation Partnership Project 3GPP network or within the 3GPP network; the mobile management function network element sends the authentication success message and the first indication information to the UE, the first indication information being used to indicate that the authentication device is located outside the 3GPP network or within the 3GPP network; the first indication information is determined based on the third indication information.

[0030] In this technical solution, by sending the first indication information to the UE, the UE can determine whether to use EMSK or MSK to derive Kausf according to the first indication information.

[0031] In one implementation, the first indication information includes ABBA to prevent architecture degradation, and the method also includes: the mobile management function network element determines the value of the ABBA to be a non-zero value; when the value of the ABBA is a non-zero value, the ABBA is used to indicate that the authentication device is located outside the 3GPP network.

[0032] This technical solution, on the one hand, uses the existing information element ABBA as the first indication information, thus reducing modifications to existing protocols. Furthermore, since ABBA is also a parameter for deriving the Kamf, if ABBA is tampered with, the Kamf generated by the UE and the mobility management function network element will differ. This makes it possible to detect attacks and thus improve communication security.

[0033] In a fourth aspect, an embodiment of the present application provides another key derivation method, which includes: a protocol conversion network element receives a second trigger indication from an authentication service function AUSF network element, and the second trigger indication is used to trigger authentication of a user equipment UE; the protocol conversion network element sends a third trigger indication to the authentication device, and the third trigger indication is used to trigger authentication of the UE; the third trigger indication is obtained based on the second trigger indication; the protocol conversion network element receives an authentication success message and a first key from the authentication device; the authentication success message is used to indicate that the UE is successfully authenticated by the authentication device; the protocol conversion network element generates an authentication service key Kausf based on the first key; the protocol conversion network element sends the authentication success message to the AUSF network element.

[0034] In one implementation, the specific implementation method of the protocol conversion network element generating the authentication service key Kausf based on the first key can be: the protocol conversion network element generates Kausf based on the first key and generation parameters; wherein the generation parameters include one or more of the following: the identifier of the service network or the identifier of the UE.

[0035] In an implementation manner, the identifier of the UE includes a first identifier of the UE, where the first identifier is used to identify the UE in a network other than a Third Generation Partnership Project 3GPP network.

[0036] In one implementation, the method further includes: the protocol conversion network element sending the first identifier of the UE to the authentication device; and the third trigger indication is specifically used to trigger authentication of the UE according to the authentication credential corresponding to the first identifier.

[0037] In this technical solution, the UE's second identifier (i.e., SUCI or SUPI) can be prevented from being sent to an authentication device located outside the 3GPP network. That is, the UE's second identifier can be prevented from being transmitted from within the 3GPP network to outside the 3GPP network, thereby avoiding leakage of user privacy.

[0038] In a fifth aspect, an embodiment of the present application provides a communication device that has some or all of the functions of the UE in the method example described in the first aspect above. For example, the functions of the communication device may have some or all of the functions in the embodiments of the present application, or may have the functions of implementing any one of the embodiments of the present application separately. The functions can be implemented by hardware or by hardware executing corresponding software. The hardware or software includes one or more units or modules corresponding to the above functions.

[0039] In one implementation, the communication device may include a transceiver module and a processing module. The processing module is configured to support the communication device in performing the corresponding functions of the above-described method. The transceiver module is used to support communication between the communication device and other devices. The communication device may also include a storage module, which is coupled to the processing module and the transceiver module and stores computer programs and data necessary for the communication device.

[0040] In one implementation, the communication device includes: a transceiver module for receiving an authentication success message from a mobility management function network element; the authentication success message is used to indicate that the UE is successfully authenticated by the authentication device; a processing module for generating MSK and EMSK based on the authentication success message; determining whether the authentication device is located outside the 3GPP network; and generating Kausf based on the MSK when the authentication device is located outside the 3GPP network.

[0041] As an example, the processing module may be a processor, the transceiver module may be a transceiver, and the storage module may be a memory.

[0042] In one implementation, the communication device includes: a transceiver for receiving an authentication success message from a mobility management function network element; the authentication success message is used to indicate that the UE is successfully authenticated by the authentication device; a processor for generating an MSK and an EMSK based on the authentication success message; determining whether the authentication device is located outside the 3GPP network; and generating a Kausf based on the MSK when the authentication device is located outside the 3GPP network.

[0043] In a sixth aspect, an embodiment of the present application provides another communication device, which has some or all of the functions of the AUSF network element in the method example described in the second aspect above. For example, the functions of the communication device may have some or all of the functions in the embodiments of the present application, or may have the functions of implementing any one of the embodiments of the present application separately. The functions may be implemented by hardware, or by hardware executing corresponding software. The hardware or software includes one or more units or modules corresponding to the above functions.

[0044] In one implementation, the communication device may include a processing module and a transceiver module. The processing module is configured to support the communication device in performing the corresponding functions of the above-described method. The transceiver module is configured to support communication between the communication device and other devices. The communication device may also include a storage module, coupled to the processing module and the transceiver module, which stores computer programs and data necessary for the communication device.

[0045] In one implementation, the communication device includes: a transceiver module, used to send a first trigger indication to the authentication device, the first trigger indication is used to trigger the authentication of the UE; receiving an authentication success message and a first key from the authentication device; the authentication success message is used to indicate that the UE is successfully authenticated by the authentication device; a processing module, used to generate Kausf based on the first key; the transceiver module is also used to send an authentication success message and a third indication information to the mobile management function network element, the third indication information is used to indicate that the authentication device is located outside the 3GPP network or within the 3GPP network.

[0046] As an example, the processing module may be a processor, the transceiver module may be a transceiver, and the storage module may be a memory.

[0047] In one implementation, the communication device includes: a transceiver, used to send a first trigger indication to an authentication device, the first trigger indication being used to trigger authentication of a UE; receiving an authentication success message and a first key from the authentication device; the authentication success message being used to indicate that the UE is successfully authenticated by the authentication device; a processor, used to generate Kausf based on the first key; the transceiver is also used to send an authentication success message and a third indication information to a mobile management function network element, the third indication information being used to indicate that the authentication device is located outside the 3GPP network or within the 3GPP network.

[0048] In a seventh aspect, an embodiment of the present application provides another communication device, which has some or all of the functions of the mobile management function network element in the method example described in the third aspect above. For example, the functions of the communication device may have some or all of the functions in the embodiments of the present application, or may have the functions of implementing any one of the embodiments of the present application separately. The functions may be implemented by hardware, or by hardware executing corresponding software. The hardware or software includes one or more units or modules corresponding to the above functions.

[0049] In one implementation, the communication device may include a processing module and a transceiver module. The processing module is configured to support the communication device in performing the corresponding functions of the above-described method. The transceiver module is configured to support communication between the communication device and other devices. The communication device may also include a storage module, coupled to the processing module and the transceiver module, which stores computer programs and data necessary for the communication device.

[0050] In one implementation, the communication device includes: a transceiver module for receiving an authentication success message and a second indication information from an AUSF network element, the authentication success message being used to indicate that the UE has been successfully authenticated by the authentication device; the second indication information being used to indicate that the authentication device is located outside the 3GPP network or within the 3GPP network; sending an authentication success message and a first indication information to the UE, the first indication information being used to indicate that the authentication device is located outside the 3GPP network or within the 3GPP network; the second indication information being determined based on the first indication information.

[0051] As an example, the processing module may be a processor, the transceiver module may be a transceiver, and the storage module may be a memory.

[0052] In one implementation, the communication device includes: a transceiver, used to receive an authentication success message and second indication information from an AUSF network element, the authentication success message being used to indicate that the UE has been successfully authenticated by the authentication device; the second indication information being used to indicate that the authentication device is located outside the 3GPP network or within the 3GPP network; sending an authentication success message and first indication information to the UE, the first indication information being used to indicate that the authentication device is located outside the 3GPP network or within the 3GPP network; the second indication information being determined based on the first indication information.

[0053] In an eighth aspect, an embodiment of the present application provides another communication device, which has some or all of the functions of the protocol conversion function network element in the method example described in the third aspect above. For example, the functions of the communication device may have the functions of some or all of the embodiments in this application, or may have the functions of implementing any one of the embodiments in this application separately. The functions can be implemented by hardware, or by hardware executing corresponding software. The hardware or software includes one or more units or modules corresponding to the above functions.

[0054] In one implementation, the communication device may include a processing module and a transceiver module. The processing module is configured to support the communication device in performing the corresponding functions of the above-described method. The transceiver module is configured to support communication between the communication device and other devices. The communication device may also include a storage module, coupled to the processing module and the transceiver module, which stores computer programs and data necessary for the communication device.

[0055] In one implementation, the communication device includes: a transceiver module, used to receive a second trigger indication from an AUSF network element, the second trigger indication being used to trigger authentication of the UE; sending a third trigger indication to an authentication device, the third trigger indication being used to trigger authentication of the UE; the third trigger indication being obtained based on the second trigger indication; receiving an authentication success message and a first key from the authentication device; the authentication success message being used to indicate that the UE is successfully authenticated by the authentication device.

[0056] As an example, the processing module may be a processor, the transceiver module may be a transceiver, and the storage module may be a memory.

[0057] In one implementation, the communication device includes: a transceiver, used to receive a second trigger indication from an AUSF network element, the second trigger indication being used to trigger authentication of the UE; sending a third trigger indication to an authentication device, the third trigger indication being used to trigger authentication of the UE; the third trigger indication being obtained based on the second trigger indication; receiving an authentication success message and a first key from the authentication device; the authentication success message being used to indicate that the UE is successfully authenticated by the authentication device.

[0058] In a ninth aspect, an embodiment of the present application provides a key derivation system, which includes one or more communication devices as described in aspects 5 to 8.

[0059] In the tenth aspect, an embodiment of the present invention provides a computer-readable storage medium, which stores a computer program, wherein the computer program includes program instructions, and when the program instructions are executed by a communication device, the communication device executes the method of the first aspect above.

[0060] In the eleventh aspect, an embodiment of the present invention provides a computer-readable storage medium, which stores a computer program, wherein the computer program includes program instructions, and when the program instructions are executed by a communication device, the communication device executes the method of the above-mentioned second aspect.

[0061] In the twelfth aspect, an embodiment of the present invention provides a computer-readable storage medium, which stores a computer program, wherein the computer program includes program instructions, and when the program instructions are executed by a communication device, the communication device executes the method of the third aspect mentioned above.

[0062] In the thirteenth aspect, an embodiment of the present invention provides a computer-readable storage medium, which stores a computer program, wherein the computer program includes program instructions, and when the program instructions are executed by a communication device, the communication device executes the method of the fourth aspect mentioned above.

[0063] In a fourteenth aspect, the present application further provides a computer program product comprising a computer program, which, when executed on a computer, enables the computer to execute the method described in the first aspect above.

[0064] In a fifteenth aspect, the present application also provides a computer program product comprising a computer program, which, when executed on a computer, enables the computer to execute the method described in the second aspect above.

[0065] In a sixteenth aspect, the present application further provides a computer program product comprising a computer program, which, when executed on a computer, enables the computer to execute the method described in the third aspect above.

[0066] In the seventeenth aspect, the present application also provides a computer program product comprising a computer program, which, when executed on a computer, enables the computer to execute the method described in the fourth aspect above. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Figure 1a It is a schematic diagram of the network architecture of the 5G system;

[0068] Figure 1b This is a schematic diagram of the existing process of deducing Kamf;

[0069] Figure 1c is a schematic diagram of a network architecture applicable to embodiments of the present application;

[0070] Figure 2 This is a flowchart of a key derivation method provided in an embodiment of the present application;

[0071] Figure 3 1 is a flow chart of another key derivation method provided in an embodiment of the present application;

[0072] Figure 4 This is a flowchart of another key derivation method provided in an embodiment of the present application;

[0073] Figure 5 This is a flowchart of another key derivation method provided in an embodiment of the present application;

[0074] Figure 6 A schematic diagram of the structure of a communication device provided in an embodiment of the present application;

[0075] Figure 7 A schematic diagram of the structure of another communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0076] In order to better understand the technical solutions provided by the embodiments of the present application, the technical terms involved in the embodiments of the present application are first introduced.

[0077] 1. Fifth Generation Communications (5 th generation, 5G) system network architecture

[0078] See Figure 1a, which is a schematic diagram of the network architecture of the 5G system, which includes user equipment (UE), access network (AN) equipment, core network elements, data network (DN), protocol conversion network elements and authentication credential providers (CdP).

[0079] Among them, the access network device may also be a radio access network (RAN) device. The access network device may include a base station (BS), which may be a device deployed in a radio access network that can communicate wirelessly with a terminal device. Among them, the base station may have various forms, such as a macro base station, a micro base station, a relay station, and an access point. Exemplarily, the access network device involved in the embodiment of the present application may be a base station in 5G or a base station in long-term evolution (LTE), wherein the base station in 5G may also be referred to as a transmission reception point (TRP) or a next generation base station node (gNB).

[0080] Among them, the core network network elements may include: access and mobility management function (AMF), authentication server function (AUSF), unified data management (UDM), session management function (SMF), policy control function (PCF), application function (AF), user plane function (UPF) and network slice selection function (NSSF).

[0081] The AMF network element, the termination point for non-access stratum (NAS) signaling, is primarily responsible for user access authentication and mobility management. The UE and AMF can communicate via N1NAS messages, and messages between the UE and AMF can also be relayed via RAN N2 messages. The RAN and AMF communicate via N2 messages.

[0082] Security anchor function (SEAF) network element ( Figure 1a (not shown), has the function of authenticating the UE. Optionally, the AMF network element may have the function of a SEAF network element. In this case, the AMF network element and the SEAF network element may be combined into one entity.

[0083] AUSF network element: has authentication service function, used to process the 3GPP (3 rd Authentication request for 3GPP access and non-3GPP access.

[0084] UDM network element: used to manage user contract information and complete user authentication and authorization.

[0085] The SMF network element is responsible for session management, such as establishing and deleting user sessions, maintaining protocol data unit (PDU) session context and user plane forwarding channel information, etc.

[0086] The PCF network element is used to generate and manage user, session, and quality of service (QoS) flow processing policies.

[0087] AF network elements provide application services and can be located inside or outside the operator network.

[0088] UPF network element, used to process user messages, such as forwarding and billing.

[0089] The NSSF network element is used to support flexible slice selection based on user-requested and contracted network slice selection assistance information (NSSAI), user location area, slice capacity, slice current load and other information.

[0090] CdP: stores the UE's second authentication credentials and can provide services for authenticating the UE.

[0091] The authentication credentials of the UE may include a first authentication credential and a second authentication credential, wherein the first authentication credential of the UE is an authentication credential pre-configured in the UE, and the second authentication credential of the UE is an authentication credential pre-configured in the authentication device.

[0092] Authentication, authorization, and accounting (AAA) server ( Figure 1a(Not shown): A server program that can process user access requests, provide authentication authorization and account services. Its main purpose is to manage user access to the network server and provide services to users with access rights.

[0093] Default credential server (DCS) Figure 1a (not shown): stores the default authentication credentials of the UE (i.e., the first authentication credentials), and can provide authentication services for the UE. The default authentication credentials are authentication credentials pre-configured on the UE when it leaves the factory.

[0094] Protocol conversion network element: used to perform protocol conversion for the interaction between 3GPP internal network elements and 3GPP external network elements. For example, for the AUSF network element, the protocol conversion network element can provide the underlying protocol conversion from the service-based interface (SBI) protocol to the AAA protocol; for the AAA server, the protocol conversion network element can provide the underlying protocol conversion from the AAA protocol to the SBI protocol. Applied in the embodiment of the present application, the protocol conversion network element can be an AAA proxy (AAA-proxy, AAA-P), an AAA interworking function (AAA-interworking function, AAA-IWF) or a primary authentication function (PAF). Optionally, the AUSF network element can also have the functions provided by the above-mentioned protocol conversion network element, that is, the AUSF network element and the protocol conversion network element can be merged into one network element. In this case, Figure 1a The network architecture shown may not include a protocol conversion network element. It should be noted that the name of the protocol conversion network element is used for example and does not constitute a limitation on the embodiments of the present application. For example, the protocol conversion network element may also be called an authentication protocol conversion function network element.

[0095] DN is responsible for providing services to UE, including operator services, Internet services, and third-party services, such as providing Internet access and SMS functions to UE.

[0096] Figure 1a The network architecture diagram shown also includes interfaces between various network elements, for example, N2 represents the interface between the AMF network element and the RAN device.

[0097] 2. Non-public network (NPN)

[0098] Non-public networks (NPNs) are used for 3GPP networks established for non-public purposes, such as internal networks in factories, schools, and commercial areas. NPNs can be divided into two types: standalone NPNs (SNPNs) and public network integrated NPNs (PNI-NPNs). SNPNs do not rely on public network functionality, while PNI-NPNs do.

[0099] 3. Derivation of Kamf process

[0100] See Figure 1b , which is a schematic diagram of the existing process of deducing Kamf when the AUSF network element is used as an authentication device. The process may include but is not limited to steps S101 to S113.

[0101] Step S101: The UE sends a registration request to the AMF network element to request registration with the network. The registration request includes the UE's subscription concealed identifier (SUCI).

[0102] Step S102: After receiving the registration request, the AMF network element sends an authentication request to the AUSF network element to request the AUSF network element to authenticate the UE. The authentication request includes the SUCI and the serving network identifier. The SUCI may include a public land mobile network identity (PLMN ID) and a routing ID (RID). The public land mobile network identity included in the SUCI indicates the home network of the UE, and the serving network refers to the network currently accessed by the UE, such as a roaming network.

[0103] Step S103: After receiving the authentication request, the AUSF network element determines the UDM network element based on the PLMN ID and routing ID of the SUCI. It then requests the UDM network element to parse the UE's subscription permanent identifier (SUPI) from the SUCI. The UDM network element notifies the AUSF network element of the UE's SUPI and the authentication method to be used (e.g., Extensible Authentication Protocol (EAP)-Transport Layer Security (TLS)).

[0104] Step S104: The AUSF network element obtains the authentication credential according to the SUPI.

[0105] For example, the AUSF network element locally stores the authentication credential corresponding to the SUPI, and the AUSF obtains the authentication credential based on the SUPI. It should be noted that the authentication credential is pre-configured in the AUSF network element and is used to authenticate the UE. The authentication credential is the second authentication credential of the UE.

[0106] Step S105: After obtaining the authentication credentials, the AUSF network element initiates the EAP authentication process (such as EAP-TLS authentication). After the authentication is completed, the UE and the AUSF network element both generate the master session key (MSK) and the extended master session key (EMSK).

[0107] It should be noted that the authentication process includes two sub-processes: UE authentication network and network authentication UE. The UE authentication network process can be performed first, and then the network authentication UE process. Therefore, after the UE is successfully authenticated by the network, the authentication process ends. Figure 1b In the process, the network authenticates the UE specifically through the AUSF network element.

[0108] It should also be noted that the UE and the AUSF network element may also generate the MSK and EMSK during the authentication process. For example, the AUSF network element may generate the MSK and EMSK after authenticating the UE and before the UE authenticates the AUSF network element.

[0109] The way in which the UE generates MSK and EMSK is: generating MSK and EMSK according to the above-mentioned first authentication credential. The way in which the authentication device generates MSK and EMSK is: generating MSK and EMSK according to the above-mentioned second authentication credential. It should be noted that the first authentication credential and the second authentication credential of the UE can be the same, such as a symmetric key. The first authentication credential and the second authentication credential of the UE can also be different, such as an asymmetric key, a certificate, etc. When the first authentication credential and the second authentication credential of the UE are the same, the MSK and EMSK generated by the UE and the authentication device are the same. When the first authentication credential and the second authentication credential of the UE are different, the way in which the UE generates MSK and EMSK according to the first authentication credential is different from the way in which the authentication device generates MSK and EMSK according to the second authentication credential, so that the MSK and EMSK generated by both are the same, for example, using Diffie-Hellman (DH) key exchange and the like.

[0110] Step S106: The AUSF network element obtains the first intermediate key (ie, the authentication service key Kausf) from the value of the highest 256 bits of EMSK.

[0111] Step S107: The AUSF network element generates a second intermediate key (ie, security anchor key Kseaf) based on the Kausf and the identifier of the service network.

[0112] Step S108: The AUSF network element sends an EAP success message, the Kseaf and the SUPI to the AMF network element. The EAP success message is used to indicate that the UE is successfully authenticated by the AUSF network element.

[0113] Step S109: After receiving the EAP success message, Kseaf and SUPI, the AMF network element generates Kamf according to the Kseaf, anti-bidding down between architectures (ABBA) and SUPI.

[0114] Step S110: The AMF network element sends an EAP success message, ABBA and SUPI to the UE.

[0115] Step S111: The UE receives the EAP success message, learns that the UE is successfully authenticated, and obtains Kausf from the value of the highest 256 bits of the EMSK.

[0116] Step S112: The UE generates Kseaf according to the Kausf and the identifier of the serving network.

[0117] Step S113: The UE generates Kamf according to the Kseaf, ABBA and SUPI.

[0118] After the above process, both the AMF network element and the UE generate a KAMf. Therefore, the UE and the AMF network element can subsequently use the key derived from the KAMf or the KAMf to protect communication. In order to achieve communication between the AMF network element and the UE, the KAMf generated by the AMF network element and the UE must be the same. Therefore, the Kausf generated by the AMF network element and the UE must also be the same.

[0119] 4. The authentication device is located outside the 3GPP network; the authentication device is located within the 3GPP network

[0120] The authentication device stores the authentication credentials of the UE and is used to authenticate the accessed UE. Figure 1a CdP, default credential server (DCS) or Figure 1aThe AUSF network element in the 3GPP network, or other equipment with the function of authenticating the UE. The authentication device can be located in or outside the 3GPP network.

[0121] Only after a UE is successfully authenticated by the authentication device can it communicate with network elements (such as the AMF) within the 3GPP network. To ensure communication security, communication information must be encrypted using a key. Once the UE is successfully authenticated by the authentication device, the authentication process ends, and both the UE and the authentication device generate two keys: the MSK and the EMSK.

[0122] 3GPP networks can refer to networks defined by 3GPP protocols, such as mobile communication networks, public land mobile networks (PLMNs), and non-public networks (NPNs), which include access networks, core networks, and UEs. They can be 5G networks or future evolved mobile communication networks. PLMNs are networks established and operated by the government or its approved operators to provide land mobile communication services to the public.

[0123] The authentication device is located in the 3GPP network, which means that the network element inside the 3GPP network authenticates the UE. In other words, the authentication credentials for authenticating the UE are stored in the network element inside the 3GPP network. When the authentication device is located in the 3GPP network, the authentication device can be specifically Figure 1a In combination with the above, it can be seen that in this case, after the UE is successfully authenticated by the AUSF network element (i.e., the authentication device) based on the EAP method, both the UE and the AUSF network element will generate MSK and EMSK. The authentication device is located in the 3GPP network. For example, when the AUSF network element in the 3GPP network acts as an authentication device to authenticate the UE, the way for the AUSF network element and the UE to obtain Kausf is: obtain Kausf from EMSK.

[0124] The authentication device is located outside the 3GPP network, which means that the entity outside the 3GPP network authenticates the UE. In other words, the authentication credentials for authenticating the UE are stored in an entity outside the 3GPP network. The entity can be an entity outside the network element of the 3GPP network, and the network elements inside the 3GPP network trust the authentication results of the entity on the UE. When the authentication device is located outside the 3GPP network, the authentication device can be a DCS, AAA server or Figure 1aIn combination with the above, it can be seen that in this case, after the UE is successfully authenticated by the authentication device (located outside the 3GPP network) based on the EAP method, both the UE and the authentication device will generate MSK and EMSK. When the authentication device is located outside the 3GPP network, for example, when the CdP outside the 3GPP network serves as the authentication device to authenticate the UE, the AUSF network element and the UE obtain Kausf in the following way: obtain Kausf based on the key from the CdP.

[0125] However, the existing protocol (RFC3748) stipulates that neither CdP nor AAA server can transmit EMSK or the value of the highest 256 bits of EMSK to other network elements. Therefore, when CdP is used as an authentication device, the key used to obtain Kausf is not EMSK. In this way, when the AUSF network element is used as an authentication device and the CdP is used as an authentication device (that is, the authentication device is located in the 3GPP network and the authentication device is located outside the 3GPP network), the key used to obtain Kausf is different. In the prior art, the UE cannot perceive whether the network side uses the AUSF network element or the CdP to authenticate the UE. Therefore, the UE cannot determine which key to use to obtain Kausf.

[0126] 5. Derivation method 1; Derivation method 2; First key

[0127] To accommodate situations where the authentication device is located in different locations, the present embodiment provides two derivation methods for obtaining Kausf. Derivation Method 1 is used to accommodate situations where the authentication device is located within the 3GPP network. Derivation Method 2 is used to accommodate situations where the authentication device is located outside the 3GPP network.

[0128] Derivation method 1 is to obtain Kausf from EMSK. For example, the value of some bits of EMSK (such as the highest 256 bits) is used as Kausf.

[0129] Derivation method 2 is: obtain Kausf from MSK. For example, the value of some bits of MSK (such as the highest 256 bits) is used as Kausf. Optionally, derivation method 2 can be specifically: obtain the first key from MSK, and then obtain Kausf from the first key. For example, the value of some bits of the first key (such as the highest 256 bits) is used as Kausf. Among them, the first key can be the MSK, or it can be some bits of MSK. Alternatively, the first key can be derived from the MSK, that is, the first key is obtained by performing operations such as calculations or processing on the MSK. This application does not limit the name of the first key. For example, the first key can also be called AAA-key.

[0130] It should be noted that the derivation method adopted by the UE side (i.e., UE) and the network side needs to be the same, or in other words, the UE side and the network side need to use the same key to derive Kausf to ensure that the Kausf generated by the UE side and the network side is the same. Among them, the network side may include multiple network elements, for example, the network side may include but is not limited to AUSF network elements, protocol conversion network elements, and one or more network elements located outside the 3G network. "The derivation method adopted by the network side" may refer to: one or more network elements on the network side participate in the derivation process, and then obtain Kausf.

[0131] For example, when the authentication device is located outside the 3GPP network, on the network side, the device that generates EMSK and MSK is the authentication device located outside the 3GPP network, and the device that obtains Kausf is the AUSF network element. The authentication device can provide the first key to the AUSF network element, and the AUSF network element then obtains Kausf from the first key.

[0132] The above example shows the case where the network side obtains Kausf through the derivation process of the authentication device (located outside the 3GPP network) and the AUSF network element. Since the first key is obtained from the MSK, the way to derive Kausf on the network side is actually the derivation method 2 mentioned above.

[0133] As can be seen from the above, different derivation methods result in different keys for generating Kausf. Derivation method 1 corresponds to EMSK, the key for generating Kausf. Derivation method 2 corresponds to MSK (or the first key) the key for generating Kausf. It should be noted that, in the embodiment of the present application, for the UE, if it is determined to adopt derivation method 2, it means that the UE obtains Kausf from MSK. For the network element on the network side used to obtain Kausf (such as an AUSF network element or a protocol conversion network element), if it is determined to adopt derivation method 2, it means that the network element obtains Kausf from the first key (provided by the authentication device).

[0134] See Figure 1c , which is a schematic diagram of a network architecture applicable to an embodiment of the present application. Figure 1c It includes UE101, mobility management function network element 102, AUSF network element 103 and authentication device 104.

[0135] Among them, the UE101 involved in the embodiment of the present application can be a device with wireless transceiver function, which can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; it can also be deployed on the water surface (such as ships, etc.); it can also be deployed in the air (for example, on airplanes, balloons and artificial satellites, etc.). UE includes handheld devices, vehicle-mounted devices, wearable devices or computing devices with wireless communication functions. Exemplarily, the UE can be a mobile phone, a tablet computer or a computer with wireless transceiver function. The terminal device can also be a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a smart vehicle terminal device, a wireless terminal in industrial control, a wireless terminal in unmanned driving, a drone, a drone controller, a wireless terminal in telemedicine, a wireless terminal in a smart grid, a wireless terminal in a smart city, a wireless terminal in a smart home, etc. The embodiments of the present application do not limit the specific technology and specific device form adopted by the UE.

[0136] Among them, the mobility management function network element 102 can be Figure 1a The AMF network element in the network can also be a security anchor function (SEAF) network element.

[0137] The AUSF network element 103 may be configured to provide UE authentication services for the mobility management function network element 102 .

[0138] The authentication device network element 104 is used to authenticate the UE. The authentication device 104 can be an AUSF network element, an AAA server, a DCS or Figure 1a In one implementation, the AUSF network element 103 may authenticate the UE on its own. In this case, the AUSF network element 103 and the authentication device 104 are combined into one entity. In another implementation, the AUSF network element may trigger the authentication device 104 located outside the 3GPP network to authenticate the UE.

[0139] Optional, Figure 1c The network architecture shown may further include a protocol conversion network element 105 for providing protocol conversion functionality for communication between the AUSF network element 103 and the authentication device 104 (outside the 3GPP network).

[0140] It should be noted that the names of the mobility management function network element 102, the authentication device 104 and the protocol conversion network element 105 are used for examples and do not constitute a limitation on the embodiments of the present application.

[0141] In the present application, the AUSF network element 103 sends a first trigger indication to the authentication device 104 located outside the 3GPP network. The first trigger indication is used to trigger the authentication of UE 101. After receiving the first trigger indication, the authentication device 104 authenticates UE 101. After successfully authenticating UE 101, the authentication device 104 generates an MSK and an EMSK; obtains a first key from the MSK, and then sends an authentication success message and the first key to the AUSF network element 103. The authentication success message is used to indicate that UE 101 has been successfully authenticated by the authentication device 104.

[0142] After receiving the authentication success message and the first key, the AUSF network element 103 generates Kausf based on the first key and sends the authentication success message to the UE 101 via the mobility management function network element 102 (i.e., the authentication success message is transmitted to the UE 101 via the mobility management function network element 102). Accordingly, the UE 101 generates the MSK and EMSK based on the authentication success message; and determines whether the authentication device 104 is located outside the 3GPP network; if the authentication device 104 is located outside the 3GPP network, it generates Kausf based on the MSK (i.e., Kausf is obtained using derivation method 2).

[0143] UE 101 determines whether authentication device 104 is located outside the 3GPP network and, in this case, uses the MSK to generate Kausf. Furthermore, on the network side, the first key used by the AUSF network element to generate Kausf is obtained from the MSK by authentication device 104. Both UE 101 and the network use the MSK to generate Kausf. Therefore, the Kausf generated by UE 101 and the network are identical, thereby ensuring communication security.

[0144] In the embodiment of the present application, UE 101 can determine whether the authentication device 104 is located outside the 3GPP network in the following three ways:

[0145] Judgment method 1: UE 101 determines whether the authentication device 104 is located outside the 3GPP network based on the first indication information from the network side. The specific process is as follows:

[0146] In the above process, in addition to sending an authentication success message to the mobility management function network element 102, the AUSF network element 103 also sends a third indication message to it, and the third indication message is used to indicate that the authentication device 104 is located outside the 3GPP network or within the 3GPP network. The mobility management function network element 102 can obtain the first indication message based on the received third indication message, and send the first indication message and the aforementioned authentication success message to UE101. The first indication message is used to indicate that the authentication device 104 is located outside the 3GPP network or within the 3GPP network. Accordingly, UE101 receives the first indication message and can determine whether the authentication device 104 is located outside the 3GPP network. For a detailed description of the first judgment method, please refer to Figure 4 Description in the Examples.

[0147] Judgment method 2: UE 101 determines whether the authentication device 104 is located outside the 3GPP network based on the second indication information in the first configuration information. The second indication information is used to indicate whether the authentication device 104 is located outside the 3GPP network. The first configuration information can be pre-configured in the UE. For a detailed description of the judgment method 2, please refer to Figure 5 Description in the Examples.

[0148] Judgment method three, UE101 determines whether the authentication device 104 is located outside the 3GPP network based on the authentication device's identifier. For example, if the UE obtains the authentication device's identifier, the UE determines that the authentication device 104 is located outside the 3GPP network. For a detailed description of judgment method three, please refer to Figure 5 Description in the Examples.

[0149] It should be noted that UE101 determines whether the authentication device 104 is located outside the 3GPP network in order to enable UE101 and the network side to use the same derivation method (i.e., derivation method 1 or derivation method 2) to generate Kausf, so that the Kausf generated by the UE and the network side is the same.

[0150] It should be noted that the "whether the authentication device is located outside the 3GPP network" mentioned in the embodiments of the present application is for example only. In specific implementations, the network side (such as AUSF network element, protocol conversion network element, authentication device located outside the 3GPP network) and the UE can use the same derivation method to generate Kausf, all of which are within the protection scope of this application. For example, "whether the authentication device is located outside the 3GPP network" can be described as "whether MSK is used to derive Kausf", "whether the first key is used to derive Kausf", "whether EMSK is used to derive Kausf", "whether derivation method 1 is used to derive Kausf", and "whether derivation method 2 is used to derive Kausf". It can be understood that if it is determined not to use the first key or MSK to derive Kausf, it means that EMSK can be used to derive Kausf. Similarly, if it is determined not to use EMSK to derive Kausf, it means that the first key or MSK can be used to derive Kausf.

[0151] "Whether the authentication device is located outside the 3GPP network" can also be described as "whether the key used to derive Kausf is obtained from the external network", "whether the key used to derive Kausf is obtained from the internal network", "whether the key used to derive Kausf is obtained from outside the 3GPP network", "whether the key used to derive Kausf is obtained from within the 3GPP network", "whether the key used to derive Kausf is obtained from a network element in the internal network", "whether the key used to derive Kausf is obtained from a network element in the external network", "whether the key used to derive Kausf is obtained from a network element within the 3GPP network", "whether the key used to derive Kausf is obtained from a network element outside the 3GPP network". Among them, "the key used to derive Kausf" can refer to the first key, MSK or EMSK. If it is determined that the key used to derive Kausf is obtained from the external network, then the "key used to derive Kausf" refers to the first key or MSK. If it is determined that the key used to derive Kausf is not obtained from the external network, then the "key used to derive Kausf" refers to EMSK.

[0152] "Whether the authentication device is located outside the 3GPP network" can also be described as "authentication of an authentication credential located on a third party independent of SNPN is being performed", "external authentication is being performed", "3GPP external authentication is being performed", "authentication of an authentication credential located on a third party independent of SNPN has been completed", "external authentication has been completed", "3GPP external authentication has been completed", "authentication of an authentication credential located on a third party independent of SNPN is about to be performed", "external authentication is about to be performed", "3GPP external authentication is about to be performed", etc. It can be understood that if it is determined that external authentication is being performed, it means that the first key or MSK can be used to derive Kausf. If it cannot be determined that external authentication is being performed, or it is determined that internal authentication is being performed (that is, the UE is authenticated by a network element in the internal network), it means that EMSK can be used to derive Kausf.

[0153] It should be noted that the “internal network” and “external network” mentioned in the embodiments of the present application are corresponding concepts. “Internal network” may refer to a network defined by 3GPP, and it can be understood that “external network” may be understood as a network other than the “internal network”. The “internal authentication” and “external authentication” mentioned in the embodiments of the present application are corresponding concepts. “Internal authentication” may refer to authentication of the UE by a network element in a network defined by 3GPP, and it can be understood that “external authentication” may refer to authentication of the UE by a network element in a network other than the network defined by 3GPP.

[0154] The technology described in the embodiments of the present application can be used in various communication systems, such as fourth generation (4G) communication systems, 4.5G communication systems, 5G communication systems, systems that integrate multiple communication systems, or future evolved communication systems.

[0155] It can be understood that the communication system described in the embodiment of the present application is for the purpose of more clearly illustrating the technical solution of the embodiment of the present application, and does not constitute a limitation on the technical solution provided by the embodiment of the present application. Those skilled in the art will know that with the evolution of the system architecture and the emergence of new business scenarios, the technical solution provided in the embodiment of the present application is also applicable to similar technical problems.

[0156] The key derivation method provided in the embodiment of the present application will be specifically described below. It should be noted that the message names between the various network elements or the names of the parameters in the message in the following embodiment of the present application are only an example, and other names may be used in the specific implementation. The embodiment of the present application does not specifically limit this. It should also be noted that in the drawings of the embodiment of the present application, the steps shown in each embodiment and the order between the steps are used for example and do not constitute a limitation on the embodiment of the present application. It should be understood that the specific implementation of executing some of the steps in the diagram or adjusting the order of the steps falls within the scope of protection of the present application.

[0157] See Figure 2 , Figure 2 It is a flow chart of a key derivation method provided in an embodiment of the present application. Among them, the execution subject of step S201 and step S210 to step S212 is the UE, or the chip in the UE. The execution subject of step S202 and step S209 is the mobile management function network element, or the chip in the mobile management function network element. The execution subject of step S203 and step S207 to step S208 is the AUSF network element, or the chip in the AUSF network element. The execution subject of step S204 to step S206 is the authentication device, or the chip in the authentication device. The following is an example of the execution subject of the key derivation method using UE, mobile management function network element, AUSF network element, and authentication device. The method may include but is not limited to the following steps:

[0158] Step S201: The UE sends a registration request to the mobility management function network element.

[0159] The UE sends the registration request to request registration with the network. The registration request may include the second identifier of the UE, which may be a SUCI or a SUPI.

[0160] Step S202: After receiving the registration request, the mobility management function network element sends an authentication request to the AUSF network element.

[0161] The authentication request is used to request the AUSF network element to authenticate the UE. The authentication request may include the second identifier of the UE. The mobility management function network element may call the UE authentication service (Nausf_UEAuthentication) provided by the AUSF network element and send the registration request (Nausf_UEAuthentication_Authenticate Request) to the AUSF network element.

[0162] Step S203: The AUSF network element sends a first trigger indication to the authentication device, where the first trigger indication is used to trigger authentication of the UE.

[0163] In an embodiment of the present application, before the AUSF network element sends a first trigger indication to an authentication device located outside the 3GPP network, the AUSF network element may determine whether the UE needs to perform authentication with the authentication device. If the AUSF network element determines that the UE needs to perform authentication with the authentication device, it may indicate that the authentication device that authenticates the UE is outside the 3GPP network, or it may indicate that the AUSF network element is unable to authenticate the UE. Therefore, the AUSF network element may send a first trigger indication to the authentication device to trigger the authentication device located outside the 3GPP network to authenticate the UE. The first trigger indication may include a message that triggers EAP authentication, such as an EAP start (EAP-start) message, an EAP identity reply message, etc. The first trigger indication may also include a second identifier of the UE.

[0164] It is understandable that if the AUSF network element determines that the UE does not need to perform authentication with the authentication device, it may indicate that the AUSF network element can authenticate the UE on its own, or it may indicate that the authentication device that authenticates the UE is within the 3GPP network. Therefore, the AUSF network element may not send the first trigger indication to the authentication device. For example, in this case, the AUSF network element acts as the authentication device that authenticates the UE.

[0165] In one implementation, the AUSF network element may determine that the UE needs to perform authentication with an authentication device outside the 3GPP network by:

[0166] In the first method, the AUSF network element receives the second identifier of the UE from the mobility management function network element, and determines that the UE needs to perform authentication with the authentication device based on the second identifier. The second identifier includes a routing identifier RID, which can indicate the identifier of the authentication device that authenticates the UE. If the identifier of the authentication device is different from the identifier of the AUSF network element, it means that the authentication device is not the AUSF network element. Therefore, the AUSF network element can determine that the UE needs to perform authentication with the authentication device.

[0167] Among them, the identifier of the authentication device is used to uniquely identify the authentication device, and the identifier of the AUSF network element is used to uniquely identify the AUSF network element. Optionally, the identifier may refer to a domain name or an IP address. The AUSF network element can determine the identifier of the authentication device in the following manner: the second identifier is SUCI, and the AUSF network element obtains the IP address of the authentication device based on the PLMN ID and RID in the SUCI. For another example, the second identifier is in the network access identifier (NAI) format, and the AUSF network element determines the domain name of the authentication device based on the second identifier in the NAI format. The second identifier in the NAI format includes a user part and a domain name part (that is, the second identifier is in the form of: <user part>@<domain name part>, for example 1234@abcd). Among them, the domain name part may include the domain name of the authentication device.

[0168] If the identification of the authentication device is different from the identification of the AUSF network element, it may include but is not limited to the following situations: 1. The domain name of the authentication device is different from the domain name of the AUSF network element, indicating that the authentication device is not the AUSF network element. 2. The IP address of the authentication device is different from the IP address of the AUSF network element, which means that the authentication device is not the AUSF network element. Therefore, the AUSF network element can determine that the UE needs to perform authentication with the authentication device. 3. The IP address of the authentication device and the IP address of the AUSF network element do not belong to the same network segment, which may indicate that the authentication device and the AUSF network element are not located in the same local area network. Therefore, it can be considered that the authentication device and the AUSF network element are located in different networks. Since the AUSF network element is located in the 3GPP network, it can be considered that the authentication device is located inside or outside the 3GPP network. Therefore, the AUSF network element can determine that the UE needs to perform authentication with the authentication device.

[0169] Optionally, if the identifier of the authentication device is the same as the identifier of the AUSF network element, it means that the UE needs to perform authentication with the AUSF network element. At this time, the AUSF network element does not need to send the above-mentioned first trigger indication. The above-mentioned second identifier can be the SUCI or SUPI of the UE. It should be noted that the second identifier received by the AUSF network element can be carried in the above-mentioned registration request.

[0170] In the second method, the AUSF network element receives a second identifier of the UE from the mobility management function network element, where the second identifier is SUCI or SUPI; the AUSF network element sends a first request message to the unified data management (UDM) network element, where the first request message includes the SUCI or the SUPI; the AUSF network element receives a first response message from the UDM network element, where the first response message includes the identifier of the authentication device; the AUSF network element determines, based on the identifier of the authentication device, that the UE needs to perform authentication with the authentication device.

[0171] The identifier of the authentication device for authenticating the UE may be stored in the UDM network element. The AUSF network element sends a first request message to the UDM network element to request the identifier of the authentication device for authenticating the UE. If the identifier of the authentication device is different from the identifier of the AUSF network element, it indicates that the authentication device is not the AUSF network element. Therefore, the AUSF network element may determine that the UE needs to perform authentication with the authentication device.

[0172] The UDM network element can obtain the identifier of the authentication device that authenticates the UE based on the SUCI or SUPI of the UE. For example, the UDM network element stores a first correspondence between the SUCI of the UE and the identifier of the authentication device that authenticates the UE. After the UDM network element receives the first request message, it can obtain the identifier of the authentication device that authenticates the UE based on the SUCI carried by the first request message and the first correspondence. For another example, the UDM network element stores a second correspondence between the SUPI of the UE and the identifier of the authentication device that authenticates the UE. After the UDM network element receives the first request message, it can obtain the identifier of the authentication device that authenticates the UE based on the SUPI carried by the first request message and the second correspondence. Alternatively, after receiving the first request message, the UDM network element can determine the SUPI of the UE based on the SUCI carried by the first request message; and then obtain the identifier of the authentication device that authenticates the UE based on the SUPI and the second correspondence.

[0173] It should be noted that, when the first request message sent by the AUSF network element includes SUCI, the SUCI may be received by the AUSF network element from the mobility management function network element. When the first request message sent by the AUSF network element includes SUPI, the SUPI may be received by the AUSF network element from the mobility management function network element; or, the SUPI may be determined by the SUCI received by the AUSF network element from the mobility management function network element. It should also be noted that the second identifier received by the AUSF network element from the mobility management function network element may be carried in the above-mentioned registration request.

[0174] In one implementation, the AUSF network element can determine the first identifier of the UE based on the second identifier of the UE; and send the first identifier to the authentication device; the first trigger indication is specifically used to trigger the authentication of the UE based on the authentication credential corresponding to the first identifier (i.e., the aforementioned second authentication credential). The first identifier is used to identify the UE in a network outside the 3GPP network, for example, to identify the UE in an authentication device located outside the 3GPP network. The first identifier can also be called an external identifier. The first identifier can be a general public subscription identifier (GPSI). The second identifier is SUCI or SUPI; the second identifier is received by the AUSF network element from the mobile management function network element, for example, the second identifier is carried in the above-mentioned registration request.

[0175] In this manner, the UE's second identifier (i.e., SUCI or SUPI) can be prevented from being sent to an authentication device located outside the 3GPP network. This means that the UE's second identifier can be prevented from being transmitted from within the 3GPP network to outside the 3GPP network, thereby preventing leakage of user privacy. Optionally, the first identifier can be sent separately from the first trigger indication, or sent together with the first trigger indication, which is not limited in this embodiment of the present application.

[0176] Optionally, the authentication credentials corresponding to the first identifiers of different UEs may be the same or different. The authentication credentials corresponding to the first identifiers of different UEs are the same, so that the authentication device can use one authentication credential to authenticate multiple UEs. In one implementation, the first identifiers of different UEs may be the same or different. When the first identifiers of different UEs are the same, the first identifiers of different UEs may correspond to the same authentication credential.

[0177] Optionally, the AUSF network element may determine the first identifier of the UE by itself, or request the UDM network element to obtain the first identifier of the UE. If the AUSF network element stores the first identifier of the UE, the AUSF network element may determine the first identifier of the UE by itself based on the second identifier of the UE. The first identifier and the second identifier of the UE may be the same or different. The AUSF network element sends a request to the UDM network element to request to obtain the first identifier of the UE, and the request includes the second identifier of the UE. The UDM network element stores the first identifier of the UE, and the UDM network element determines the first identifier corresponding to the second identifier based on the second identifier of the UE, and sends the first identifier to the AUSF network element. For example, the UDM network element parses the SUPI from the second identifier of the UE (such as SUCI), and then obtains the GPSI (i.e., the second identifier) corresponding to the SUPI based on the SUPI, and returns the GPSI to the AUSF. The request sent by the above-mentioned AUSF network element to the UDM network element may be carried in the UE authentication service request (Nudm_UEAuthentication_Get Request) message.

[0178] It should be noted that the AUSF network element can determine the identity of the authentication device and / or the first identity of the UE. The first identity of the UE can be used to determine the identity of the authentication device, and can also be sent to the authentication device to trigger the authentication device to authenticate the UE based on the authentication credentials corresponding to the first identity. The identity of the authentication device can be determined by the second identity of the UE, or by the first identity of the UE.

[0179] Step S204: The authentication device authenticates the UE.

[0180] After receiving the first trigger indication, the authentication device begins to authenticate the UE. The embodiment of the present application does not limit the authentication method adopted by the authentication device. The authentication method may include but is not limited to the EAP authentication method, the EAP-TLS authentication method, the EAP-AKA' authentication method, the 5G AKA authentication method, the authentication method using a certificate, or the authentication method specified in the protocol (such as RFC3748, RFC5216, RFC5281, 3GPP TS 33.501, etc.).

[0181] The UE stores the UE's first authentication credentials, and the authentication device stores the UE's second authentication credentials. The UE and the authentication device can mutually authenticate each other based on the UE's first authentication credentials and the UE's second authentication credentials. For example, the authentication device authenticates the UE based on the UE's second authentication credentials. The UE authenticates the authentication device based on the UE's first authentication credentials. Optionally, the authentication device can obtain the UE's second authentication credentials based on the UE's second identifier or first identifier.

[0182] In an embodiment of the present application, the authentication device may independently determine which authentication method to use to authenticate the UE; or, the AUSF network element may instruct the authentication device to use which authentication method to authenticate the UE. The AUSF network element may independently determine and instruct the authentication device to use which authentication method to authenticate the UE; or, based on notification information from the UDM network element, instruct the authentication device to use which authentication method to authenticate the UE.

[0183] Step S205: When the UE is successfully authenticated, the authentication device generates an MSK and an EMSK.

[0184] The authentication device generates an MSK and an EMSK according to the second authentication credential of the UE.

[0185] Step S206: The authentication device sends an authentication success message and a first key to the AUSF network element. The authentication success message is used to indicate that the UE is successfully authenticated by the authentication device.

[0186] It should be noted that the authentication success message and the first key can be sent at the same time or separately. In the case of sending them separately, the authentication success message can be sent first, or the first key can be sent first. Figure 2 It can be seen that the authentication success message is sent from the authentication device, and is successively transferred through the AUSF network element and the mobility management function network element to be transmitted to the UE. It should be noted that, in one implementation, when a protocol conversion network element is deployed in the network architecture that implements the key derivation method described in the embodiment of the present application, the authentication success message can also be transferred through the AUSF network element, the protocol conversion network element, and the mobility management function network element to be transmitted to the UE.

[0187] The generation of the first key can refer to derivation method 2.

[0188] Step S207: The AUSF network element generates an authentication service key Kausf based on the first key.

[0189] After receiving the authentication success message and the first key from the authentication device, the AUSF network element can obtain some bits from the first key as Kausf. For example, the value of the highest 256 bits of the first key is taken as Kausf.

[0190] In one implementation, the AUSF network element may generate Kausf based on the first key and generation parameters. The generation parameters may include, but are not limited to, one or more of the following: an identifier of the service network currently accessed by the UE or an identifier of the UE. The service network currently accessed by the UE may be the home network or the roaming network of the UE. The identifier of the UE may include the aforementioned first identifier or the second identifier.

[0191] Optionally, the generation parameter may include but is not limited to one or more of the following: an identifier of the service network currently accessed by the UE, an identifier of the UE, or a derivation method parameter. When the AUSF network element generates Kausf based on the first key and the generation parameter, the value of the derivation method parameter in the generation parameter is different from the value of the derivation method parameter in the generation parameter when the AUSF network element generates Kausf based on the EMSK and the generation parameter. For the AUSF network element, when the AUSF network element determines that the UE needs to perform authentication with an authentication device located outside the 3GPP network, the AUSF network element can generate Kausf based on the first key and the generation parameter. When the AUSF network element determines that the UE does not need to perform authentication with an authentication device located outside the 3GPP network, the AUSF network element can generate Kausf based on the EMSK and the generation parameter. Therefore, the AUSF network element can determine whether the UE needs to perform authentication with an authentication device located outside the 3GPP network and determine the value of the derivation method parameter. By using the derivation mode parameter as one of the parameters for determining Kausf, it is advantageous to make the Kausf generated when authenticating the UE outside the 3GPP network different from the Kausf generated when authenticating the UE within the 3GPP network, thereby achieving key isolation. The derivation mode parameter can be a 1-bit binary bit (represented as 0 or 1), an input value of a key derivation function (KDF) algorithm (such as an FC value), or other value, which is not limited in the embodiments of the present application.

[0192] It should be noted that after the AUSF network element generates Kausf, the process of deriving Kseaf from Kausf and Kamf from Kseaf can be found in Figure 1bThe description of the corresponding process in will not be repeated here.

[0193] If the AUSF network element determines that the UE does not need to perform authentication with the authentication device, it may indicate that the AUSF network element can authenticate the UE on its own, or it may indicate that the authentication device that authenticates the UE is within the 3GPP network. At this time, the AUSF network element can use derivation method 1 to generate Kausf, that is, the AUSF network element generates Kausf based on EMSK. Optionally, the AUSF network element can generate Kausf based on EMSK and generation parameters. The generation parameters are described above and will not be repeated here.

[0194] Step S208: The AUSF network element sends the authentication success message to the mobility management function network element.

[0195] It should be noted that there is no particular order in which step S207 and step S208 are executed. They can be executed simultaneously or one after the other.

[0196] Step S209: After receiving the authentication success message from the AUSF network element, the mobility management function network element sends the authentication success message to the aforementioned UE.

[0197] Step S210: The UE generates the MSK and EMSK according to the authentication success message.

[0198] After receiving the authentication success message from the mobility management function network element, the UE generates the MSK and EMSK. It should be noted that the execution process of step S210 can be found in Figure 1b The specific description of step S105 is omitted here.

[0199] Step S211: The UE determines whether the authentication device is located outside the 3GPP network.

[0200] After receiving the authentication success message from the mobility management function network element, the UE determines whether the authentication device is located outside the 3GPP network to determine which derivation method to use to obtain Kausf. The specific implementation method of the UE determining whether the authentication device is located outside the 3GPP network can be found in Figure 4 and Figure 5 The embodiment shown.

[0201] It should be noted that the UE's determination of "whether the authentication device is located outside the 3GPP network" is only for example. "whether the authentication device is located outside the 3GPP network" can also be described as "whether to use MSK to derive Kausf," "whether to use the first key to derive Kausf," "whether to use EMSK to derive Kausf," "whether to use derivation method 1 to derive Kausf," "whether to use derivation method 2 to derive Kausf," and so on. For details, please refer to the previous description and will not be repeated here.

[0202] Step S212: When the authentication device is located outside the 3GPP network, the UE generates an authentication service key Kausf according to the MSK.

[0203] If the authentication device is outside the 3GPP network, the UE can use derivation method 2 to generate Kausf, that is, generate Kausf based on the MSK. Optionally, the UE can obtain the first key from the MSK and then generate Kausf based on the first key. The first key is described above and will not be repeated here.

[0204] It should be noted that the MSK generated by the network side and the UE are the same, and the first keys obtained by the network side and the UE from the MSK are also the same. Therefore, the Kausf generated by the network side and the UE are also the same. As a result, the Kseaf and Kamf generated by the UE and the network side are also the same, which is conducive to ensuring smooth communication between the UE and the mobile management function network element. In addition, on the network side, the first key received by the AUSF network element from the authentication device outside the 3GPP network is obtained from the MSK, so it does not violate the protocol provisions (that is, neither the CdP nor the AAA server can transmit the EMSK or the value of the highest 256 bits of the EMSK to other network elements).

[0205] In one implementation, the UE can generate Kausf based on the first key and generation parameters; wherein the generation parameters include but are not limited to one or more of the following: an identifier of the service network currently accessed by the UE or an identifier of the UE. The service network currently accessed by the UE may be the UE's home network or a roaming network. Optionally, the generation parameters include but are not limited to one or more of the following: an identifier of the service network currently accessed by the UE, an identifier of the UE or a derivation method parameter. It should be noted that the execution process of the UE generating Kausf based on the first key and generation parameters is the same as the execution process of the AUSF network element generating Kausf based on the first key and generation parameters. For details, please refer to the description in step S207.

[0206] In one implementation, if the UE determines that the authentication device is located within a 3GPP network, the UE may use derivation method 1 to generate Kausf, that is, to generate Kausf based on the EMSK. For example, a portion of bits from the EMSK may be used as Kausf. For example, the value of the highest 256 bits of the EMSK may be used as Kausf.

[0207] In the embodiment of the present application, when the authentication device is located outside the 3GPP network, the UE generates Kausf based on the MSK; when the authentication device is located within the 3GPP network, the UE generates Kausf based on the EMSK. In this way, the UE is compatible with the key derivation method used when the authentication device is located outside the 3GPP network (i.e., derivation method 2) and the key derivation method used when the authentication device is located within the 3GPP network (i.e., derivation method 1).

[0208] Since the key (i.e., MSK or EMSK) used to generate Kausf is different when the authentication device is located outside the 3GPP network or inside the 3GPP network, the generated Kausf can be different, thereby achieving key isolation. When the authentication device is located outside the 3GPP network or inside the 3GPP network, the derivation method parameter is used as one of the parameters for determining Kausf, and the value of the derivation method parameter is different when the authentication device is located outside the 3GPP network and inside the 3GPP network, which can make the Kausf generated when the authentication device is located outside the 3GPP network different from the Kausf generated when the authentication device is located inside the 3GPP network, thereby further achieving key isolation.

[0209] It should be noted that, in conjunction with the description in step S211: the content judged by the UE as "whether the authentication device is located outside the 3GPP network" is only used as an example, and "whether the authentication device is located outside the 3GPP network" can also be described as "whether to use MSK to derive Kausf", "whether to use the first key to derive Kausf", "whether to use EMSK to derive Kausf", "whether to use derivation method 1 to derive Kausf", "whether to use derivation method 2 to derive Kausf", and so on. It can be understood that when the content judged by the UE is different, the content determined by the UE changes accordingly. For example, when the content judged by the UE is "whether to use derivation method 2 to derive Kausf", the content determined by the UE is: determining to use derivation method 2 to derive Kausf, or determining not to use derivation method 2 to derive Kausf. For other descriptions of the content judged by the UE, the content determined by the UE will not be given examples one by one here.

[0210] In implementing the embodiment of the present application, the UE determines whether to obtain Kausf based on EMSK or MSK by judging whether the authentication device is located outside the 3GPP network, so that the UE can be compatible with the key derivation method adopted when the authentication device is located outside the 3GPP network (i.e., derivation method 2) and the key derivation method adopted when the authentication device is located within the 3GPP network (i.e., derivation method 1).

[0211] See Figure 3 , Figure 3This is a flow chart of another key derivation method provided by an embodiment of the present application, which describes in detail the Figure 1c The flow of the key derivation method when the network architecture shown includes a protocol conversion network element. Among them, the execution subject of step S301 and step S312 to step S314 is the UE, or the chip in the UE. The execution subject of step S302 and step S311 is the mobile management function network element, or the chip in the mobile management function network element. The execution subject of step S303 and step S310 is the AUSF network element, or the chip in the AUSF network element. The execution subject of step S304 and step S308 to step S309 is the protocol conversion device, or the chip in the protocol conversion device. The execution subject of step S305 to step S307 is the authentication device, or the chip in the authentication device. The following description takes the UE, mobile management function network element, AUSF network element, protocol conversion device, and authentication device as the execution subjects of the key derivation method as an example.

[0212] The method may include but is not limited to the following steps:

[0213] Step S301: The UE sends a registration request to the mobility management function network element.

[0214] Step S302: After receiving the registration request, the mobility management function network element sends an authentication request to the AUSF network element.

[0215] It should be noted that the execution process of step S301 to step S302 can be found in Figure 2 The detailed description of steps S201 to S202 will not be repeated here.

[0216] Step S303: The AUSF network element sends a second trigger indication to the protocol conversion network element, and the second trigger indication is used to trigger the authentication of the UE. The second trigger indication may include a message that triggers EAP authentication, such as an EAP start (EAP-start) message, an EAP identity reply message, etc. The second trigger indication may also include an explicit indication information and a UE identifier. For example, when the indication information is 1, it represents triggering the authentication of the UE, and when the indication information is 0, it represents not triggering the authentication of the UE. The second trigger indication may also include an implicit indication information. For example, when the second trigger indication includes the UE identifier, it may indicate that the second trigger indication includes the implicit indication information. When the second trigger indication includes implicit indication information, it represents triggering the authentication of the UE. The UE identifier may be the first identifier of the UE or the second identifier of the UE.

[0217] The AUSF network element sends a second trigger indication to the protocol conversion network element to trigger the protocol conversion network element to send a third trigger indication to the authentication device, thereby triggering the authentication device to authenticate the UE. The content of the second trigger indication sent by the AUSF network element can be found in Figure 2 The relevant description of step S203 in the embodiment will not be repeated here.

[0218] Step S304: After receiving the second trigger indication, the protocol conversion network element sends a third trigger indication to the authentication device. The third trigger indication is used to trigger authentication of the UE; the third trigger indication is obtained according to the second trigger indication.

[0219] The third trigger indication can be used to trigger the authentication device to authenticate the UE. Optionally, the third trigger indication can be the second trigger indication, that is, the protocol conversion network element forwards the received second trigger indication to the authentication device. Alternatively, the third trigger indication is constructed by the protocol conversion network element based on the second trigger indication. The content of the third trigger indication can be found in Figure 2 The description of the first trigger indication in step S203 of the embodiment will not be repeated here. The difference is that in step S203, the first trigger indication is sent by the AUSF network element to the authentication device. In step S304, the first trigger indication is sent by the protocol conversion network element to the authentication device. For example, the protocol conversion network element obtains the second trigger indication (explicit indication) from the AUSF network element. If the value of the explicit indication information in the second trigger indication is 1, the protocol conversion network element generates a third trigger indication (EAP start message).

[0220] Step S305: The authentication device authenticates the UE.

[0221] Step S306: When the UE is successfully authenticated, the authentication device generates MSK and EMSK.

[0222] It should be noted that the execution process of steps S305 to S306 can be found in Figure 2 The specific description of steps S204 to S205 will not be repeated here.

[0223] Step S307: The authentication device sends an authentication success message and the first key to the protocol conversion network element. The authentication success message is used to indicate that the UE is successfully authenticated by the authentication device.

[0224] It should be noted that the execution process of step S307 can be found in Figure 2 The specific description of step S206 in FIG. 2 is omitted here. The difference is that in step S206, the authentication success message and the first key are sent by the authentication device to the AUSF network element; in step S307, they are sent by the authentication device to the protocol conversion network element.

[0225] Step S308: The protocol conversion network element generates an authentication service key Kausf according to the first key.

[0226] It should be noted that in step S308, after the protocol conversion network element receives the authentication success message and the first key from the authentication device, the generation of Kausf is only for example and does not constitute a limitation on the embodiments of the present application. In other feasible implementations, after receiving the authentication success message and the first key from the authentication device, the protocol conversion network element can send the authentication success message and the first key to the AUSF network element. Correspondingly, the AUSF network element can generate Kausf based on the first key from the protocol conversion network element. In other words, on the network side, the network element that generates Kausf can be a protocol conversion network element or an AUSF network element. When the network element that generates Kausf is a protocol conversion network element, the protocol conversion network element can send the generated Kausf to the AUSF network element, and the AUSF network element will derive Kseaf from Kausf. The subsequent process of deriving Kamf from Kseaf can be found in Figure 1b The description of the corresponding process in will not be repeated here.

[0227] The derivation of the key is based on a one-way function (hash function). Therefore, although the AUSF network element receives Kausf, it cannot obtain the first key used to derive Kausf, thereby achieving key isolation between the protocol conversion network element and the AUSF network element. Among them, the key isolation between the protocol conversion network element and the AUSF network element means that the AUSF network element cannot obtain the key (i.e., the first key) used by the protocol conversion network element. In the case that the Kausf received by the AUSF network element comes from the authentication device, key isolation between the AUSF network element and the authentication device can be achieved.

[0228] It should be noted that the process of the protocol conversion network element generating Kausf according to the first key can be the same as the process of the AUSF network element generating Kausf according to the first key. For details, please refer to Figure 2 The detailed description of step S207 is omitted here.

[0229] Step S309: The protocol conversion network element sends the authentication success message to the AUSF network element.

[0230] It should be noted that there is no particular order in which step S308 and step S309 are executed. They can be executed simultaneously or one after the other.

[0231] Step S310: After receiving the authentication success message from the protocol conversion network element, the AUSF network element sends the authentication success message to the mobility management function network element.

[0232] Step S311: After receiving the authentication success message from the AUSF network element, the mobility management function network element sends the authentication success message to the aforementioned UE.

[0233] Step S312: The UE generates the MSK and EMSK according to the authentication success message.

[0234] Step S313: The UE determines whether the authentication device is located outside the 3GPP network.

[0235] Step S314: When the authentication device is located outside the 3GPP network, the UE generates an authentication service key Kausf according to the MSK.

[0236] It should be noted that the execution process of steps S311 to S314 can be found in Figure 2 The detailed description of steps S209 to S212 will not be repeated here.

[0237] In an embodiment of the present application, Kausf is derived through a protocol conversion network element, so that even if the AUSF network element receives Kausf, it cannot obtain the first key used to derive Kausf, thereby achieving key isolation between the protocol conversion network element and the AUSF network element to improve the security of communication.

[0238] It should be noted that Figure 4 、 Figure 5 The embodiment takes the network architecture for implementing the key derivation method as an example, which does not include a protocol conversion network element, and does not constitute a limitation on the embodiment of the present application. Figure 4 or Figure 5 The network architecture of the key derivation method in the embodiment can be deployed with a protocol conversion network element. When a protocol conversion network element is deployed, the process of the key derivation method can refer to Figure 3 Description in the Examples.

[0239] See Figure 4 , Figure 4 It is a flow chart of another key derivation method provided by an embodiment of the present application, which describes in detail how the UE determines whether the authentication device is located outside the 3GPP network based on the first indication information. Among them, the execution subject of step S401 and step S410 to step S412 is the UE, or the chip in the UE. The execution subject of step S402 and step S409 is the mobile management function network element, or the chip in the mobile management function network element. The execution subject of step S403 and step S407 to step S408 is the AUSF network element, or the chip in the AUSF network element. The execution subject of step S404 to step S406 is the authentication device, or the chip in the authentication device. The following is an example of the execution subject of the key derivation method using UE, mobile management function network element, AUSF network element, and authentication device. The method may include but is not limited to the following steps:

[0240] Step S401: The UE sends a registration request to the mobility management function network element.

[0241] Step S402: After receiving the registration request, the mobility management function network element sends an authentication request to the AUSF network element.

[0242] Step S403: The AUSF network element sends a first trigger indication to the authentication device, where the first trigger indication is used to trigger authentication of the UE.

[0243] Step S404: The authentication device authenticates the UE.

[0244] Step S405: When the UE is successfully authenticated, the authentication device generates an MSK and an EMSK.

[0245] Step S406: The authentication device sends an authentication success message and a first key to the AUSF network element. The authentication success message is used to indicate that the UE is successfully authenticated by the authentication device.

[0246] Step S407: The AUSF network element generates an authentication service key Kausf based on the first key.

[0247] It should be noted that the execution process of steps S401 to S407 can be referred to Figure 2 The detailed description of steps S201 to S207 will not be repeated here.

[0248] Step S408: The AUSF network element sends the authentication success message and the third indication information to the mobility management function network element.

[0249] The third indication information is used to indicate that the authentication device is located outside the 3GPP network or within the 3GPP network; or, the third indication information can be used to indicate the use of MSK (or the first key) to derive Kausf; or, the third indication information can be used to indicate the use of EMSK to derive Kausf; or, the third indication information can be used to indicate the use of derivation method 1 to derive Kausf; or, the third indication information can be used to indicate the use of derivation method 2 to derive Kausf.

[0250] Alternatively, the third indication information may be used to indicate that the key used to derive Kausf is obtained from an external network (or outside the 3GPP network); or, the third indication information may be used to indicate that the key used to derive Kausf is obtained from an internal network (or within the 3GPP network); or, the third indication information may be used to indicate that the key used to derive Kausf is obtained from a network element in an external network (or outside the 3GPP network); or, the third indication information may be used to indicate that the key used to derive Kausf is obtained from a network element in an internal network (or within the 3GPP network).

[0251] Alternatively, the third indication information may be used to indicate that authentication of an authentication credential located at a third party independent of the SNPN is being performed; or, the third indication information may be used to indicate that external (or 3GPP external) authentication is being performed. Alternatively, the third indication information may be used to indicate that authentication of an authentication credential located at a third party independent of the SNPN has been completed; or, the third indication information may be used to indicate that external (or 3GPP external) authentication has been completed. Alternatively, the third indication information may be used to indicate that authentication of an authentication credential located at a third party independent of the SNPN is about to be performed; or, the third indication information may be used to indicate that external (or 3GPP external) authentication is about to be performed. It should be noted that the role of the third indication information mentioned in the embodiment of the present application is only for example. In a specific implementation, the UE generates Kausf in accordance with the indication information from the network side in a manner that is the same as the Kausf generated by the network side, which is within the scope of protection of the present application. The third indication information may also be referred to as a second derivation indication.

[0252] The AUSF network element sends the third indication information to the mobility management function network element, so that the mobility management function network element can learn whether the authentication device is located outside the 3GPP network, which is conducive to the mobility management function network element informing the UE (through the first indication information) whether the authentication device is located outside the 3GPP network. Alternatively, the AUSF network element sends the third indication information to the mobility management function network element, so that the mobility management function network element can forward the third indication information to the UE, so that the UE can learn whether the authentication device is located outside the 3GPP network. In this case, the third indication information is the same as the first indication information.

[0253] It should be noted that the AUSF network element can send the third indication information during the authentication process, or it can send the third indication information after the authentication is completed. It should also be noted that this application does not limit the order in which the AUSF network element sends the authentication success message and sends the third indication information.

[0254] In an embodiment of the present application, the AUSF network element may send third indication information to the mobility management function network element if it determines that the UE needs to perform authentication with the authentication device. Optionally, the AUSF network element may send the third indication information to the mobility management function network element if it sends a first trigger indication to the authentication device. Optionally, the AUSF network element may send the third indication information to the mobility management function network element if it receives an authentication success message from the authentication device. Optionally, the AUSF network element may send the third indication information to the mobility management function network element if it sends a first trigger indication to the authentication device and receives an authentication success message from the authentication device. Optionally, the AUSF network element may send the third indication information to the mobility management function network element if it sends a second trigger indication to the protocol conversion network element. Optionally, the AUSF network element may send the third indication information to the mobility management function network element if it receives an authentication success message from the protocol conversion network element. Optionally, the AUSF network element may send the third indication information to the mobility management function network element if it sends a second trigger indication to the protocol conversion network element and receives an authentication success message from the protocol conversion network element.

[0255] Step S409: After receiving the authentication success message and the third indication information from the AUSF network element, the mobility management function network element sends the authentication success message and the first indication information to the aforementioned UE.

[0256] The first indication information may be used to indicate that the authentication device is located outside the 3GPP network or within the 3GPP network, and the third indication information is determined based on the first indication information. It should be noted that the first indication information and the third indication information indicate the same content. For the content of the first indication information, please refer to the description in step S408.

[0257] In one implementation, the first indication information can be indicated via an existing information element. In this case, the first indication information is an implicit indication, meaning that no new message is generated or new message elements are added to the existing message. For example, if the information element is ABBA, the first indication information includes ABBA. If the mobility management function network element receives third indication information, and the third indication information indicates that the authentication device is located outside the 3GPP network, the mobility management function network element may determine the value of ABBA to be non-zero. If the value of ABBA is non-zero, the ABBA indicates that the authentication device is located outside the 3GPP network. It is understood that if the third indication information indicates that the authentication device is located within the 3GPP network, the mobility management function network element may determine the value of ABBA to be 0. If the value of ABBA is 0, the ABBA indicates that the authentication device is located within the 3GPP network. It should be noted that the meanings of the aforementioned ABBA values are for illustrative purposes only and do not constitute limitations of the embodiments of this application. For example, if the value of ABBA is 0, the ABBA may indicate that the authentication device is located outside the 3GPP network. If the value of ABBA is non-zero, the ABBA may indicate that the authentication device is located within the 3GPP network. By using the existing information element to indicate the first indication information, changes to the existing protocol can be reduced.

[0258] In another implementation, the first indication information may include a flag bit 1 (flag) or indication field 1, and the flag bit 1 (or indication field 1) may be used to indicate that the authentication device is located outside the 3GPP network or within the 3GPP network. For example, if the first indication information includes the flag bit 1 (or indication field 1), the first indication information may be used to indicate that the authentication device is located outside the 3GPP network. It is understood that if the first indication information does not include the flag bit 1 (or indication field 1), the first indication information may be used to indicate that the authentication device is located within the 3GPP network. Alternatively, if the first indication information includes the flag bit 1 (or indication field 1), the first indication information may be used to indicate that the authentication device is located within the 3GPP network. If the first indication information does not include the flag bit 1 (or indication field 1), the first indication information may be used to indicate that the authentication device is located outside the 3GPP network. The mobility management function network element may determine whether the constructed first indication information includes the flag bit 1 (or indication field 1) based on the content indicated by the third indication information.

[0259] In another implementation manner, the mobility management function network element may forward the received third indication information to the UE. In this case, the third indication information is the same as the first indication information, and both the third indication information and the first indication information are explicit indications.

[0260] Step S410: The UE generates the MSK and EMSK according to the authentication success message.

[0261] It should be noted that the execution process of step S410 can be found in Figure 2 The detailed description of step S210 is omitted here.

[0262] Step S411: The UE determines whether the authentication device is located outside the 3GPP network according to the first indication information.

[0263] After receiving the first indication information from the mobility management function network element, the UE may determine whether the authentication device is located outside the 3GPP network according to the first indication information.

[0264] Specifically, the UE may determine whether the authentication device is located outside the 3GPP network based on the content indicated by the first indication information. For example, the first indication information may be used to indicate that the authentication device is located outside the 3GPP network, and the UE may determine whether the authentication device is located outside the 3GPP network.

[0265] In one implementation, the first indication information and the third indication information may indicate whether the authentication device is located outside the 3GPP network or outside the 3GPP network by carrying an indication parameter. For example, the third indication information includes an indication parameter, and when the value of the indication parameter is non-zero, the third indication information may be used to indicate that the authentication device is located outside the 3GPP network. When the value of the indication parameter is 0, the third indication information may be used to indicate that the authentication device is located within the 3GPP network. After the mobility management function network element receives the third indication information, if it forwards the third indication information, then the first indication information is the same as the third indication information, that is, the first indication information also includes the indication parameter. The UE may determine whether the authentication device is located outside the 3GPP network based on the value of the indication parameter in the first indication information.

[0266] Optionally, the UE may determine whether the authentication device is located outside the 3GPP network based on whether the first indication information is received. For example, if the first indication information is used to indicate that the authentication device is located outside the 3GPP network, if the UE receives an authentication success message from the mobility management function network element but does not receive the first indication information, the UE may determine whether the authentication device is located within the 3GPP network. Similarly, if the first indication information is used to indicate that the authentication device is located within the 3GPP network, if the UE receives an authentication success message from the mobility management function network element but does not receive the first indication information, the UE may determine whether the authentication device is located outside the 3GPP network. Optionally, if the mobility management function network element determines that the authentication device is located within the 3GPP network, it may not send the first indication information to the UE.

[0267] It is understood that, with respect to the third indication information, the mobility management function network element may also determine whether the authentication device is located outside the 3GPP network based on whether the third indication information is received. For example, if the third indication information is used to indicate that the authentication device is located outside the 3GPP network, and if the mobility management function network element does not receive the third indication information after receiving an authentication success message, the mobility management function network element may determine whether the authentication device is located within the 3GPP network. Similarly, if the third indication information is used to indicate that the authentication device is located within the 3GPP network, and if the mobility management function network element does not receive the third indication information after receiving an authentication success message, the mobility management function network element may determine that the authentication device is located outside the 3GPP network.

[0268] Step S412: When the authentication device is located outside the 3GPP network, the UE generates an authentication service key Kausf according to the MSK.

[0269] It should be noted that the execution process of step S412 can be found in Figure 2 The specific description of S212 is omitted here.

[0270] In the embodiment of the present application, Kāf can be derived from Kseaf, ABBA, and SUPI. By using the existing information element ABBA as the first indication information, on the one hand, modifications to the existing protocol can be reduced; on the other hand, since ABBA is also a parameter for deriving Kāf, if ABBA is tampered with, the Kāf generated by the UE and the mobility management function network element will be different. This can detect the attack and thus help improve communication security.

[0271] In one implementation, when the authentication device is located in the 3GPP network, the UE may generate Kausf according to the EMSK. For details on how the UE generates Kausf according to the EMSK, please refer to the detailed description in step S211, which will not be repeated here.

[0272] In an embodiment of the present application, the first indication information is used to indicate that the authentication device is located outside the 3GPP network or within the 3GPP network. The UE can determine which derivation method (either EMSK or MSK) to use to derive Kausf based on the first indication information.

[0273] See Figure 5 , Figure 5 This is a flow chart of another key derivation method provided in an embodiment of the present application. Figure 5The illustrated embodiment describes in detail how the UE determines whether the authentication device is located outside the 3GPP network based on the first configuration information pre-configured in the UE. Among them, the execution subject of step S501 and step S510 to step S512 is the UE, or the chip in the UE. The execution subject of step S502 and step S509 is the mobile management function network element, or the chip in the mobile management function network element. The execution subject of step S503 and step S507 to step S508 is the AUSF network element, or the chip in the AUSF network element. The execution subject of step S504 to step S506 is the authentication device, or the chip in the authentication device. The following is an example of the execution subject of the key derivation method using UE, mobile management function network element, AUSF network element, and authentication device. The method may include but is not limited to the following steps:

[0274] Step S501: The UE sends a registration request to the mobility management function network element.

[0275] Step S502: After receiving the registration request, the mobility management function network element sends an authentication request to the AUSF network element.

[0276] Step S503: The AUSF network element sends a first trigger indication to the authentication device, where the first trigger indication is used to trigger the authentication of the UE.

[0277] Step S504: The authentication device authenticates the UE.

[0278] Step S505: When the UE is successfully authenticated, the authentication device generates an MSK and an EMSK.

[0279] Step S506: The authentication device sends an authentication success message and a first key to the AUSF network element. The authentication success message is used to indicate that the UE is successfully authenticated by the authentication device.

[0280] Step S507: The AUSF network element generates an authentication service key Kausf based on the first key.

[0281] Step S508: The AUSF network element sends the authentication success message to the mobility management function network element.

[0282] Step S509: After receiving the authentication success message from the AUSF network element, the mobility management function network element sends the authentication success message to the aforementioned UE.

[0283] Step S510: The UE generates the MSK and EMSK according to the authentication success message.

[0284] The execution process of steps S501 to S510 can be referred to in Figure 2 The detailed description of steps S201 to S210 will not be repeated here.

[0285] Step S511: The UE determines whether the authentication device is located outside the 3GPP network according to the second indication information.

[0286] In the embodiment of the present application, the UE may determine whether the authentication device is located outside the 3GPP network according to the following method.

[0287] In one implementation, the UE determines whether the authentication device is located outside the 3GPP network based on second indication information. The second indication information is used to indicate whether the authentication device is located outside the 3GPP network. The second indication information is included in the first configuration information. The UE may be pre-configured with the first configuration information and the first authentication credential.

[0288] Specifically, when the UE determines to use the first authentication credential for EAP authentication, the UE obtains the first authentication credential and generates an MSK and an EMSK based on the first authentication credential. While obtaining the first authentication credential, the UE can also obtain first configuration information corresponding to the first authentication credential, and then determine whether the authentication device is located outside the 3GPP network based on the second indication information in the first configuration information. Optionally, the UE selects the first network based on an identifier broadcast by the network, and then determines the first authentication credential corresponding to the first network.

[0289] It should be noted that the second indication information can be explicit indication information or implicit indication information. An example of the second indication information being explicit indication information is as follows: the second indication information is a 1-bit binary bit (represented as 0 or 1), and when the value of the second indication information is 1, the second indication information is used to indicate that the authentication device is located outside the 3GPP network; when the value of the second indication information is 0, the second indication information is used to indicate that the authentication device is located within the 3GPP network. Alternatively, when the value of the second indication information is 0, the second indication information is used to indicate that the authentication device is located outside the 3GPP network; when the value of the second indication information is 1, the second indication information is used to indicate that the authentication device is located within the 3GPP network.

[0290] An example of the second indication information being implicit is as follows: the second indication information includes a flag bit 2 or an indication field 2, where the flag bit 2 (or indication field 2) is used to indicate whether the authentication device is located outside the 3GPP network or within the 3GPP network. For example, if the flag bit 2 (or indication field 2) is used to indicate that the authentication device is located outside the 3GPP network, and the second indication information includes the flag bit 2 (or indication field 2), then the second indication information indicates that the authentication device is located outside the 3GPP network. It will be understood that if the second indication information does not include the flag bit 2 (or indication field 2), then the second indication information may indicate that the authentication device is located within the 3GPP network. Alternatively, if the flag bit 2 (or indication field 2) is used to indicate that the authentication device is located within the 3GPP network, and the second indication information includes the flag bit 2 (or indication field 2), then the second indication information may indicate that the authentication device is located within the 3GPP network. If the second indication information does not include the flag bit 2 (or indication field 2), then the second indication information may indicate that the authentication device is located outside the 3GPP network.

[0291] It should be noted that the second indication information is used to indicate whether the authentication device is located outside the 3GPP network. It is used for example and does not constitute a limitation on the embodiments of the present application. For example, the second indication information can be used to indicate whether the authentication credential of the authentication UE is located outside the 3GPP network; or, the second indication information can be used to indicate the use of MSK (or the first key) to derive Kausf; or, the second indication information can be used to indicate the use of EMSK to derive Kausf; or, the second indication information can be used to indicate the use of derivation method 1 to derive Kausf; or, the second indication information can be used to indicate the use of derivation method 2 to derive Kausf. The content indicated by the second indication information can be the same as the content indicated by the first indication information (or the third indication information). For details, please refer to the description in steps S408 to S409, which will not be repeated here.

[0292] In another implementation, the UE determines whether the authentication device is located outside the 3GPP network based on the authentication device's identifier. Alternatively, if the UE obtains the authentication device's identifier, the UE determines that the authentication device is located outside the 3GPP network. Alternatively, if the UE does not obtain the authentication device's identifier, the UE determines that the authentication device is located within the 3GPP network. The authentication device's identifier may be a service provider identity (SP ID), a PLMN ID, a SNPN ID, or the like.

[0293] The UE can obtain the identity of the authentication device in the following ways:

[0294] 1. The UE obtains one or more authentication device identifiers from a broadcast message from an access network device, and the UE selects the identifier of the first authentication device. For example, the UE displays all authentication device identifiers obtained from the broadcast message to the user, and the user manually selects the identifier of the first authentication device.

[0295] 2. The UE pre-configures a correspondence between the access network identifier and the authentication device identifier. The UE obtains one or more access network identifiers from a broadcast message from the access network device and selects the identifier of the first access network. Based on this pre-configured correspondence, the UE can obtain the identifier of the authentication device corresponding to the identifier of the first access network. For example, the UE selects the identifier of the first access network based on a network priority list and obtains the identifier of the first authentication device based on the pre-configured correspondence between the identifier of the first access network and the identifier of the first authentication device.

[0296] 3. The UE obtains one or more access network identifiers from a broadcast message of the access network device, selects the identifier of the first access network, accesses the first access network, and then receives the identifier of the authentication device from the first access network.

[0297] Before the authentication device authenticates the UE (e.g., EAP authentication), the UE may obtain the authentication device's identifier through any of the above methods. After the UE is successfully authenticated by the authentication device, the UE may generate Kausf using derivation method 2. Alternatively, if the UE cannot obtain the authentication device's identifier, the UE may generate Kausf using derivation method 1.

[0298] Step S512: When the authentication device is located outside the 3GPP network, the UE generates an authentication service key Kausf according to the MSK.

[0299] It should be noted that the execution process of step S512 can be found in Figure 2 The specific description of step S212 is omitted here.

[0300] In an embodiment of the present application, the UE determines whether the authentication device is located outside the 3GPP network based on the second indication information pre-configured in the UE. The network side does not need to send indication information to the UE (that is, the AUSF network element does not need to send the third indication information to the mobility management function network element, and the mobility management function network element does not need to send the first indication information to the UE), which is beneficial to reducing the power consumption of the network side equipment.

[0301] Corresponding to the method provided in the above method embodiment, the present application embodiment also provides a corresponding device, including a module for executing the corresponding module of the above embodiment. The module can be software, hardware, or a combination of software and hardware.

[0302] See Figure 6 , is a structural diagram of a communication device provided in this application. Figure 6 The communication device 600 shown includes a transceiver module 601 and a processing module 602 .

[0303] In one design, apparatus 600 is a UE:

[0304] Exemplarily, the transceiver module 601 is configured to receive an authentication success message from a mobility management function network element; the authentication success message is used to indicate that the UE is successfully authenticated by the authentication device;

[0305] The processing module 602 is configured to generate an MSK and an EMSK according to the authentication success message; determine whether the authentication device is located outside the 3GPP network; and generate a Kausf according to the MSK if the authentication device is located outside the 3GPP network.

[0306] When the device 600 is a UE, it is used to implement Figures 2 to 5 Functions of the UE in the illustrated embodiment.

[0307] In one design, apparatus 600 is an AUSF network element:

[0308] Exemplarily, the transceiver module 601 is configured to send a first trigger indication to the authentication device, where the first trigger indication is used to trigger authentication of the UE; receive an authentication success message and a first key from the authentication device; the authentication success message is used to indicate that the UE is successfully authenticated by the authentication device;

[0309] A processing module 602 is configured to generate Kausf according to the first key;

[0310] The transceiver module 601 is further configured to send an authentication success message and third indication information to the mobility management function network element, where the third indication information is used to indicate whether the authentication device is located outside the 3GPP network or within the 3GPP network.

[0311] When the device 600 is an AUSF network element, it is used to implement Figures 2 to 5 Functions of the AUSF network element in the illustrated embodiment.

[0312] In one design, apparatus 600 is a mobility management function network element:

[0313] Exemplarily, the transceiver module 601 is used to receive an authentication success message and a second indication message from the AUSF network element, where the authentication success message is used to indicate that the UE has been successfully authenticated by the authentication device; the second indication information is used to indicate that the authentication device is located outside the 3GPP network or within the 3GPP network; and the authentication success message and the first indication information are sent to the UE, where the first indication information is used to indicate that the authentication device is located outside the 3GPP network or within the 3GPP network; the second indication information is determined based on the first indication information.

[0314] When the device 600 is a mobile management function network element, it is used to implement Figures 2 to 5 The functions of the mobility management function network element in the illustrated embodiment.

[0315] In one design, apparatus 600 is a protocol translation network element:

[0316] Exemplarily, the transceiver module 601 is configured to receive a second trigger indication from an AUSF network element, the second trigger indication being used to trigger authentication of the UE; send a third trigger indication to the authentication device, the third trigger indication being used to trigger authentication of the UE; the third trigger indication being obtained based on the second trigger indication; receive an authentication success message and a first key from the authentication device; the authentication success message being used to indicate that the UE is successfully authenticated by the authentication device;

[0317] A processing module 602 is configured to generate Kausf according to a first key;

[0318] The transceiver module 601 is also used to send an authentication success message to the AUSF network element.

[0319] When the device 600 is a protocol conversion network element, it is used to implement Figure 3 The functions of the protocol conversion network element in the illustrated embodiment.

[0320] See Figure 7 , is a structural diagram of another communication device provided in this application. Figure 7 The communication device 700 shown includes at least one processor 701 , a memory 702 , and optionally, a communication interface 703 .

[0321] The memory 702 may be a volatile memory, such as a random access memory; the memory may also be a non-volatile memory, such as a read-only memory, a flash memory, a hard disk drive (HDD) or a solid-state drive (SSD); or the memory 702 may be any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but is not limited thereto. The memory 702 may be a combination of the above memories.

[0322] The specific connection medium between the processor 701 and the memory 702 is not limited in the embodiment of the present application. In the figure, the memory 702 and the processor 701 are connected via a bus 704. The bus 704 is represented by a thick line in the figure. The connection between other components is only for schematic illustration and is not limited. The bus 704 can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 7 Only one thick line is used in the diagram, but this does not mean that there is only one bus or one type of bus.

[0323] The processor 701 may have a data transceiver function and may communicate with other devices. Figure 7 An independent data transceiver module, such as a communication interface 703 , may also be provided in the device for transmitting and receiving data. When the processor 701 communicates with other devices, data may be transmitted through the communication interface 703 .

[0324] In one example, when the UE uses Figure 7 When the form shown is Figure 7 The processor in the UE can call the computer-executable instructions stored in the memory 702 to enable the UE to execute the method executed by the UE in any of the above method embodiments.

[0325] In one example, when the AUSF network element adopts Figure 7 When the form shown is Figure 7 The processor in can call the computer execution instructions stored in the memory 702 to enable the AUSF network element to execute the method executed by the AUSF network element in any of the above method embodiments.

[0326] In one example, when the mobility management function network element adopts Figure 7 When the form shown is Figure 7 The processor in the memory 702 can call the computer execution instructions stored in the memory 702 to enable the mobility management function network element to execute the method executed by the mobility management function network element in any of the above method embodiments.

[0327] In one example, when the protocol conversion network element adopts Figure 7 When the form shown is Figure 7 The processor in the protocol conversion network element can call the computer execution instructions stored in the memory 702 to enable the protocol conversion network element to execute the method executed by the protocol conversion network element in any of the above method embodiments.

[0328] Specifically, Figure 6 The functions / implementation processes of the processing module and the transceiver module can be achieved through Figure 7 The processor 701 in the embodiment calls the computer execution instruction stored in the memory 702 to implement. Or, Figure 6 The function / implementation process of the processing module can be achieved through Figure 7 The processor 701 in the embodiment calls the computer execution instruction stored in the memory 702 to implement the above. Figure 6 The function / implementation process of the transceiver module can be achieved through Figure 7 It is implemented by the communication interface 703 in.

[0329] The embodiment of the present application also provides a key derivation system, which may include Figures 2 to 5The mobile management function network element and AUSF network element in the network. Optionally, it also includes Figures 2 to 5 UE in. Optionally, it also includes Figure 3 The protocol conversion network element in the network.

[0330] It is understandable that some optional features in the embodiments of the present application may, in certain scenarios, be implemented independently of other features, such as the solution on which they are currently based, to solve corresponding technical problems and achieve corresponding effects. They may also be combined with other features in certain scenarios as needed. Accordingly, the devices provided in the embodiments of the present application may also implement these features or functions accordingly, which will not be described in detail here.

[0331] Those skilled in the art will also appreciate that the various illustrative logical blocks and steps listed in the embodiments of the present application can be implemented by electronic hardware, computer software, or a combination of both. Whether such functions are implemented by hardware or software depends on the specific application and the design requirements of the entire system. Those skilled in the art may use various methods to implement the described functions for corresponding applications, but such implementation should not be construed as exceeding the scope of protection of the embodiments of the present application.

[0332] The solutions described in this application can be implemented in various ways. For example, these technologies can be implemented in hardware, software, or a combination of hardware. For hardware implementation, the processing module used to execute these technologies at a communication device (e.g., a base station, a terminal, a network entity, a core network element, or a chip) can be implemented in one or more general-purpose processors, digital signal processors (DSPs), digital signal processing devices, application-specific integrated circuits (ASICs), programmable logic devices, field programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic, discrete hardware components, or any combination thereof. The general-purpose processor can be a microprocessor, and optionally, the general-purpose processor can also be any conventional processor, controller, microcontroller, or state machine. The processor can also be implemented by a combination of computing devices, such as a digital signal processor and a microprocessor, multiple microprocessors, one or more microprocessors combined with a digital signal processor core, or any other similar configuration.

[0333] It is understood that the memory in the embodiments of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), and direct RAM bus RAM (DR RAM). It should be noted that the memory of the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0334] The present application also provides a computer-readable medium having a computer program stored thereon, which implements the functions of any of the above method embodiments when executed by a computer.

[0335] The present application also provides a computer program product, which implements the functions of any of the above method embodiments when executed by a computer.

[0336] In the above embodiments, all or part of the embodiments may be implemented by software, hardware, firmware, or any combination thereof. When implemented using software, all or part of the embodiments may be implemented in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of the present application are generated. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via a wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) method. The computer-readable storage medium may be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrated therein. The available medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a high-density digital video disc (DVD)), or a semiconductor medium (eg, a solid state disk (SSD)).

[0337] It will be understood that the “embodiment” mentioned throughout the specification means that the specific features, structures or characteristics related to the embodiment are included in at least one embodiment of the present application. Therefore, the various embodiments in the entire specification do not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner. It will be understood that in the various embodiments of the present application, the size of the sequence numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0338] It can be understood that in this application, "when", "if" and "if" all mean that the device will perform corresponding processing under certain objective circumstances, and do not limit the time. It does not require that the device must perform a judgment action when it is implemented, nor does it mean that there are other limitations.

[0339] In this application, elements expressed in the singular are intended to mean "one or more" rather than "one and only one" unless otherwise specified. In this application, unless otherwise specified, "at least one" is intended to mean "one or more" and "a plurality" is intended to mean "two or more."

[0340] Additionally, the terms "system" and "network" are often used interchangeably. The term "and / or" is simply a description of an association between related objects, indicating that three possible relationships exist. For example, "A and / or B" can mean: A exists alone, A and B exist simultaneously, or B exists alone. A can be singular or plural, and B can be singular or plural.

[0341] The predefined in this application may be understood as defined, predefined, stored, pre-stored, pre-negotiated, pre-configured, solidified, or pre-burned.

[0342] Those skilled in the art will appreciate that, for the sake of convenience and brevity of description, the specific working processes of the above-described systems, devices, and units may refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0343] The same or similar parts between the various embodiments in this application can refer to each other. In the various embodiments in this application, and the various implementation methods / implementation methods / implementation methods in each embodiment, if there is no special explanation and logical conflict, the terms and / or descriptions between different embodiments and the various implementation methods / implementation methods / implementation methods in each embodiment are consistent and can be referenced to each other. The technical features in different embodiments and the various implementation methods / implementation methods / implementation methods in each embodiment can be combined to form new embodiments, implementation methods, implementation methods, or implementation methods according to their inherent logical relationships. The above-described implementation methods of this application do not constitute a limitation on the scope of protection of this application.

[0344] The above is only a specific implementation method of the present application, but the scope of protection of the present application is not limited thereto. Any technician familiar with this technical field can easily think of changes or replacements within the technical scope disclosed in this application, which should be covered by the scope of protection of the present application.

Claims

1. A key derivation method, characterized in that: The method comprises: During the authentication process, the communication device generates a master session key MSK and an extended master session key EMSK based on a first authentication credential; the communication device stores first configuration information, the first configuration information including second indication information for indicating whether to use the MSK to generate Kausf; the first authentication credential is pre-configured by the communication device and corresponds to the first configuration information; After receiving the authentication success message from the mobility management function network element, the communication device determines whether to use the MSK to generate the authentication service key Kausf; wherein the authentication success message is used to indicate that the communication device is successfully authenticated by the authentication device; In the case of determining to use the MSK to generate the Kausf, the communication device generates the Kausf according to the MSK; The method further comprises: The communication device selects a first network according to the identifier broadcast by the network, and determines the first authentication credential corresponding to the first network.

2. The method according to claim 1, wherein The communication device determines whether to use the MSK to generate Kausf, including: The communication device determines, based on the second indication information, to use the MSK to generate the Kausf.

3. The method according to claim 1 or 2, wherein: The communication device generates Kausf according to the generated MSK, including: The communication device generates the Kausf according to the generated MSK and generation parameters; The generation parameter includes one or more of the following: an identifier of a service network currently accessed by the communication device or an identifier of the communication device.

4. The method according to claim 1 or 2, wherein: The communication device is a user equipment UE, or a chip in the UE.

5. The method according to claim 3, wherein The communication device is a user equipment UE, or a chip in the UE.

6. A communication device, characterized in that: The device includes a processing module and a transceiver module, and the processing module and the transceiver module are used for the device to execute the method according to any one of claims 1 to 5.

7. A communication device, characterized in that: The device includes: a processor, the processor is coupled to a memory, the memory is used to store a program, and when the program is executed by the processor, the device performs the method according to any one of claims 1 to 5.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed, the computer is caused to perform the method according to any one of claims 1 to 5.

Images