WO2022228455A1

WO2022228455A1 - Communication method and related apparatus

Info

Publication number: WO2022228455A1
Application number: PCT/CN2022/089520
Authority: WO
Inventors: 李�赫; 吴�荣
Original assignee: 华为技术有限公司
Priority date: 2021-04-28
Filing date: 2022-04-27
Publication date: 2022-11-03
Also published as: CN115250469A

Abstract

Embodiments of the present application disclose a communication method and a related apparatus, the method comprising: an access and mobility management function generates a second security context, the second security context being inconsistent with a first security context, and the first security context being security context currently used by the access and mobility management function; and the access and mobility management function determines whether to activate the second security context. In the embodiments of the present application, when a terminal device only needs to perform authentication, neither the terminal device side nor the network side need to update a new security context, the complexity of key update is reduced and device performance is improved.

Description

A communication method and related device

This application claims the priority of the Chinese patent application with the application number of 202110469602.1 and the invention titled "a communication method and related device", which was filed with the State Intellectual Property Office of China on April 28, 2021, the entire contents of which are incorporated herein by reference Applying.

technical field

The present application relates to the field of communication technologies, and in particular, to a communication method and related apparatus.

Background technique

With the rapid development of network technology, network security has become an increasingly prominent problem. With the development of the 5th generation (5G) mobile communication, application authentication and key management (authentication and key management) can be used between user equipment (UE) and application server (application function, AF). management for application, AKMA) process. In the AKMA process, the authentication server function (AUSF) sends an authentication vector acquisition request message (Numd_UEAuthentication Get Request) to the Unified Data Management (UDM), and the authentication vector acquisition request message carries the Permanent identity identifier (subscriber permanent identifier, SUPI) or subscription concealed identifier (subscription concealed identifier, SUCI), the authentication vector acquisition request message is used to trigger the primary authentication (Primary authentication) between the UE and the network side (core network). )process.

After the main authentication process, the AKMA anchor key Kakma is generated based on the intermediate key Kausf, and the AKMA key temporary identity identifier (AKMA-Key Identifier, A-KID) is generated based on the intermediate key Kausf. On the basis of the Kakma derived from the intermediate key Kausf, other keys can also be derived, for example, the key Kaf used by the application server AF. For ease of description in the embodiments of the present application, the above-mentioned key derived based on the intermediate key Kausf is referred to as a security context.

The validity time of Kausf, and the validity time of various keys in the security context may not be consistent. For example, the security context is derived based on the intermediate key Kausf#1. After the validity time of Kaf#1 in the security context expires, the Kaf#1 is invalid, and the AF and the UE cannot continue to use the Kaf#1. At this time, Kausf#1 is still in the valid time, and the new Kaf derived from this Kausf#1 is consistent with Kaf#1 and still cannot be used. Therefore, Kausf needs to be updated, and a new Kaf#2 is generated based on the new Kausf#2. However, after generating a new Kausf#2, the security context needs to be updated, otherwise it cannot continue to be used. Therefore, the complexity of the key update is relatively large, which affects the performance of the device.

SUMMARY OF THE INVENTION

In a first aspect, an embodiment of the present application proposes a communication method, including:

The access and mobility management function AMF generates a second security context, the second security context is inconsistent with the first security context, and the first security context is the security context currently used by the access and mobility management function; the The ingress and mobility management functions determine whether to activate the second security context.

Specifically, the first security context is a security context corresponding to the first intermediate key, and the first intermediate key is Kausf. The first security context is the currently used security context. The security context may also be a security context corresponding to Kamf. After the AMF receives the request message from other network elements, the AMF generates the second security context. The other network elements include but are not limited to: Authentication Management Function AUSF, Network Open Function NEF, Authentication and Key Management Anchor Function AAnF, Edge Configuration Server ECS, Edge Enablement Server EES, Mobile Edge Computing MEC or Application Function AF. The AMF can then determine whether to activate the second security context. Specifically, the AMF can use the second security context. The AMF may also update the first security context, and the updated security context is the second security context.

Wherein, in any embodiment of the present application, when one or more of the materials used for the security function, such as the key, algorithm, and counter included in the first security context, are different from the key, algorithm, When one or more of the materials used for security functions such as counters are inconsistent, the first security context is deemed to be inconsistent with the second security context. The security context in this embodiment of the present application includes materials used for security functions, such as keys, algorithms, and counters. Among them, the security context can be divided into: native security context and 5G security context. The native security context refers to the security context generated through the main authentication process. The 5G security context refers to the security context for the 5G system. 5G security context includes but is not limited to 5G NAS security context, 5G AS security context and 5G AKMA security context. The 5G NAS security context is used for security protection between UE and AMF, and the AS security context is used for security protection between UE and base station. The 5G AKMA security context includes keys (or security materials, or security keys) such as Kakma, A-KID, Kaf, etc. The 5G AKMA security context is generated on the AUSF side after the main authentication process and sent to the AAnF, and on the UE side before the AKMA service is initiated.

When the first security context includes: one or more of materials used for security functions such as keys, algorithms, counters, etc., and the second security context includes keys, algorithms, counters and other materials used for security functions, When one or more items are inconsistent, the first security context is deemed to be inconsistent with the second security context. In this embodiment of the present application, the AMF does not blindly activate the security context, and after generating a new security context, the AMF determines whether to activate it. This reduces the complexity of key update and improves device performance.

With reference to the first aspect, in a possible implementation manner of the first aspect, the access and mobility management function determining whether to activate the second security context includes: the access and mobility management function reporting to all The terminal device sends a second authentication request message containing a second key identifier, and the second authentication request message is used to trigger a second authentication (also referred to as the second key identifier) between the terminal device and the network. authentication process); after the second authentication is successful, the access and mobility management function determines whether it is necessary to activate the second security context generated in the second authentication process; In the case of two security contexts, the access and mobility management function sends a second non-access stratum security mode command NAS SMC message to the terminal device, and the second NAS SMC message includes the first key identifier; The first key identifier is the key identifier of the first security context currently used by the access and mobility management function. The first key identifier does not match the second key identifier.

In this embodiment of the present application, activation may also be replaced by update. Deactivating the second security context may mean not updating the second security context; or not using the second security context after generating the second security context; or not generating the second security context, which is not limited here. The first security context can continue to be used without activating the second security context.

Specifically, after the AMF triggers the second main authentication process, the AMF initiates the second main authentication process: the AMF requests the AUSF to authenticate the UE; the AUSF requests the UDM for an authentication vector; the UDM generates the authentication vector, and according to the selected The main authentication method determines whether to send the generated authentication vector or the processed authentication vector to the AUSF. After the AMF obtains the authentication vector from the AUSF, the AMF sends a second authentication request message to the UE. The second authentication request message The second key identifier is included, and the second authentication request message is used to trigger the second authentication between the UE and the network (also referred to as the second primary authentication procedure). In the embodiments of the present application, the key identifier is ngKSI as an example for description. It can be understood that the key identifier may also be other identifiers, which is not limited here. For the specific process, please refer to the description in Section 6.1.3 of the standard TS 33.501 version 17.1.0. The AMF sends the first key identifier to the UE through a second NAS SMC message ("NAS Security Mode Command" message). That is, the second NAS SMC message carries the first key identifier (eg, ngKSI#1). Specifically, the AMF puts the encryption algorithm and/or the integrity protection algorithm used by the first key identifier into the second NAS SMC message as the selected security algorithm. The second NAS SMC message uses K _NASint-1 corresponding to the first key identifier for integrity protection and/or K _NASenc-1 for confidentiality protection.

With reference to the first aspect, in a possible implementation manner of the first aspect, the access and mobility management function sends the second authentication request including the second key identifier to the terminal device Before the message, the method further includes:

The access and mobility management function sends a first authentication request message containing the first key identifier to the terminal device, and the first authentication request message is used to trigger an exchange between the terminal device and the network. the first authentication between; after the first authentication is successful, send a first NAS SMC message to the terminal device to activate the first security context generated in the first authentication process, the The first NAS SMC message includes the first key identifier. Specifically, the AMF sends a first authentication request message to the UE, where the first authentication request message includes a first key identifier, and the first authentication request message is used to trigger the first authentication ( Also known as the first primary authentication process). Exemplarily, the first key identifier is ngKSI#1, and the first key identifier corresponds to the first intermediate key. In the embodiment of the present application, the intermediate key is Kausf as an example for description. Then the first intermediate key is Kausf#1.

After the AMF receives the registration request message, the AMF initiates the main authentication process: the AMF requests the AUSF to authenticate the UE; the AUSF requests the UDM for the authentication vector; the UDM generates the authentication vector, and determines to send the generated authentication vector according to the selected primary authentication method. The authentication vector or the processed authentication vector is sent to the AUSF. After the AMF obtains the authentication vector from the AUSF, the AMF sends the first authentication request message to the UE, and the first authentication request message includes the first key identifier. . In the embodiments of the present application, the key identifier is ngKSI as an example for description. It can be understood that the key identifier may also be other identifiers, which is not limited here. For the specific process, please refer to the description in Section 6.1.3 of Standard TS 33.501 Version 17.1.0.

Specifically, the AMF sends a first authentication request message to the UE, where the first authentication request message includes a first key identifier, and the first authentication request message is used to trigger the first authentication ( Also known as the first primary authentication process).

With reference to the first aspect, in a possible implementation manner of the first aspect, the access and mobility management function sends the first authentication request including the first key identifier to the terminal device Before the message, the method further includes:

The access and mobility management function receives a registration request message from the terminal device. The UE sends a registration request message to the AMF, and the registration request message is forwarded by the network device. The registration request message carries the UE's Subscription Concealed Identifier (SUCI). Optionally, the registration request message may be "Registration Request". The registration request message triggers the first authentication, that is, the initial authentication of the terminal device. A first security context is generated in the first authentication, and the first security context is activated. The AMF does not need to determine whether to activate the first security context. The computing burden of the device is reduced, and the key complexity is reduced.

In conjunction with the first aspect, in a possible implementation manner of the first aspect, the access and mobility management function determines whether the second security context generated in the second authentication process needs to be activated, including:

When the access and mobility management function determines not to update the non-access stratum NAS key and/or the access stratum AS key, the access and mobility management function determines not to activate the second security context.

or,

When the access and mobility management function determines that a non-access stratum NAS counter (count) rolls over, the access and mobility management function determines to activate the second security context. Specifically, when the AMF determines to update the 5G NAS security context or the 5G AS security context, for example, the NAS COUNT is about to be overturned. The AMF determines to activate the second security context.

or,

When the access and mobility management function determines to update the non-access stratum NAS key context and/or the access stratum AS key context of the terminal device, the access and mobility management function determines to activate the first 2. Security context;

or,

The access and mobility management function determines that the second authentication is triggered by the first network element, then the access and mobility management function does not activate the second security context, and the first network element includes the following: Either: Authentication Management Function AUSF, Network Open Function NEF, Authentication and Key Management Anchor Function AAnF, Edge Configuration Server ECS, Edge Enablement Server EES, Mobile Edge Computing MEC or Application Function AF. That is, after the AMF receives the message for requesting to update the key from the first network element, the AMF does not activate the second security context.

or,

The access and mobility management function determines that the second authentication only needs to authenticate the terminal device, and the access and mobility management function does not activate the second security context;

or,

The access and mobility management function determines that the second authentication is triggered by the terminal device, and the access and mobility management function does not activate the second security context.

Alternatively, the AMF determines not to activate the second security context according to the local policy. An exemplary scenario is as follows: when the operator configures the following scenarios, the UE authentication is triggered and the second security context is not activated. open connection); AMF data is migrated, that is, migrated from AMF#1 to AMF#2.

Whether to activate the second security context is determined through various means, which improves the implementation flexibility of the solution.

With reference to the first aspect, in a possible implementation manner of the first aspect, the method further includes:

In the event that the access and mobility management function determines that activation of the second security context is required, the access and mobility management function sends the second key identifier to the terminal device.

Specifically, the AMF determines to initiate the main authentication process, the AMF requests the AUSF to authenticate the UE, the AUSF requests the authentication vector from the UDM, the UDM sends the authentication vector to the AUSF, and the AUSF sends the authentication vector to the AMF after processing. The AMF generates a second key identifier after receiving the processed authentication vector, and sends the second key identifier to the UE along with the processed authentication vector.

Exemplarily, the AMF sends the second key identifier to the UE through an "Authentication Request" message. The second key identifier may be ngKSI#2.

In the case that the access and mobility management function determines that the second security context needs to be activated, the access and mobility management function sends first indication information to the terminal device, where the first indication information is related to The second network element is associated, and the first indication information instructs the terminal device to update the communication key between the terminal device and the second network element;

The second network element includes any one of the following: an authentication management function AUSF, a network opening function NEF, an authentication and key management anchor function AAnF, an edge configuration server ECS, an edge enabling server EES, a mobile edge computing MEC or an application function AF.

Optionally, the first indication information comes from AAnf. The AAnF sends a second key request message to the AUSF, where the second key request message carries the first indication information. The AUSF sends the first indication information to the AMF. The AMF sends the first indication information to the UE. The first indication information is associated with the second network element, and the first indication information instructs the terminal device to update the communication key between the terminal device and the second network element. The second network element includes any of the following but not limited to NEF, AAnF, ECS, EES or AF. Exemplarily, when the second network element is an AF, the first indication information may be identification information (AF_ID) of the AF.

If the access and mobility management function determines that the second security context needs to be activated, the access and mobility management function activates the non-access stratum NAS key of the second intermediate key, the first The second security context corresponds to the second intermediate key;

The access and mobility management function does not activate the access stratum AS key of the second intermediate key.

Specifically, the AMF determines whether to update the AS key. If the primary authentication triggers the process because the NAS key needs to be updated, for example, the NAS counter value is about to roll over. In order to save the complexity of the UE, the AMF may determine not to update the AS key. Then, when the AMF activates the second security context, it does not activate the AS key corresponding to the second key identifier. That is, the second security context activated by the AMF does not include the AS key, and the AMF only activates the NAS key corresponding to the second key identifier. For example, the AMF does not activate the AS key corresponding to ngKSI#2, and the AS key includes but is not limited to: the key K _gNB . Specifically, AMF does not generate K _gNB corresponding to ngKSI#2 (AMF does not generate new K _gNB #2, and old K _gNB #1 corresponds to ngKSI#1), or after AMF generates K _gNB #2, it does not send the K gNB #2 _gNB #2 to network equipment (eg base station).

The access and mobility management function receives a third authentication request message sent by the first network element, wherein the third authentication request message carries the permanent identification information of the terminal device, and the third authentication request message The message is used to trigger the second authentication between the terminal device and the network;

The first network element includes any one of the following: an authentication management function AUSF, a network opening function NEF, an authentication and key management anchor function AAnF, an edge configuration server ECS, an edge enabling server EES, a mobile edge computing MEC or an application function AF.

Optionally, the third authentication request message instructs the AMF to determine whether to activate the second security context. Specifically, the third authentication request message is used to request the AMF to trigger the main authentication process. The third authentication request message carries the permanent identity information of the UE. Optionally, the third authentication request message carries indication information, where the indication information is used to indicate a reason value that needs to trigger the main authentication process.

The AMF may determine, according to the third authentication request message or the indication information carried in the third authentication request message, that the primary authentication process is to update the AKMA-related key, and the AMF determines not to activate the second security context. The third authentication request message may be "initial primary authentication Request". Optionally, or, the AMF determines whether the second security context needs to be activated according to the indication information. If the AMF determines that the NAS COUNT is about to be rolled over, that is, the rollover of the NAS COUNT requires the activation of the second security context, the AMF determines that the second security context is to be activated.

Optionally, the third authentication request message carries indication information, where the indication information is used to indicate a reason value that needs to trigger the main authentication process.

Exemplarily, the first network element is AAnF. The AAnF may directly send a third authentication request message to the AMF, where the third authentication request message carries the permanent identification information of the UE, and optionally carries the AF ID. Before the AAnF sends this message, the AAnF needs to determine the AMFs that can serve the UE. The AAnF determines the AMF serving the UE from the UDM according to the UE's permanent identity information.

With reference to the first aspect, in a possible implementation manner of the first aspect, the access and mobility management function sends the second NAS SMC message to the terminal device, including:

The access and mobility management function selects a security algorithm to perform integrity protection and confidentiality protection on the second NAS SMC message sent by the access and mobility management function to the terminal device; If the security algorithm selected by the mobility management function is the same as the security algorithm corresponding to the first security context, the access and mobility management function determines not to activate the second security context; The terminal device sends the second NAS SMC message, where the second NAS SMC message includes the first key identifier. The AMF determines whether to activate the second security context according to whether the selected security algorithm (the security algorithm for processing the second NAS SMC message) is the same as the security algorithm corresponding to the currently used first security context. If not activated, in NAS SMC process #2, the AMF sends a second NAS SMC message to the UE, where the second NAS SMC message includes the first key identifier. The NAS key identified by the first key identifier is the key currently being used by the AMF and the UE. Through the first key identifier, the UE is notified to not activate the second security context.

With reference to the first aspect, in a possible implementation manner of the first aspect, after the access and mobility management function determines to activate the second security context, the method further includes:

The access and mobility management function sends a second non-access stratum security mode command NAS SMC message to the terminal device, the second NAS SMC message includes second indication information, and the second indication information indicates the The terminal device generates Kamf#2, and activates the second security context corresponding to Kamf#2, where Kamf#2 is the updated Kamf.

In another implementation, no primary authentication process occurs. When the AMF generates Kamf#2, but does not generate the second key identifier, the AMF determines that the second security context does not need to be activated. In order to synchronize the keys between the UE and the AMF, the second NAS SMC message includes second indication information (Kamf change), which indicates that the UE needs to generate a new Kamf, which is called Kamf#2 (the original used by the UE The Kamf is called Kamf#1). Optionally, the AMF carries the first key identifier in the second NAS SMC message,

In another implementation, the primary authentication process does not occur, but the AMF generates Kamf#2 and the second key identifier, and the AMF determines that the second security context does not need to be activated. In order to synchronize the keys between the UE and the AMF, the AMF sends the second indication information to the UE, and the second indication information informs the UE that a new Kamf needs to be generated, which is called Kamf#2. If the AMF obtains the second key identifier, the second NAS SMC message carries the first key identifier and the second indication information.

With reference to the first aspect, in a possible implementation manner of the first aspect, the second NAS SMC message further includes third indication information, where the third indication information instructs the terminal device to continue using the first security The NAS security context in the context and the AS security context in the first security context.

Optionally, when the main authentication process does not occur, if the AMF sends the first key identifier to the UE, the second NAS SMC message may also carry a third indication information. Specifically, the third indication information is used to inform the UE that the currently used NAS security context and AS security context do not need to be updated. The currently used NAS security context may also be referred to as the NAS security context in the first security context, and the currently used AS security context may also be referred to as the AS security context in the first security context. In this embodiment of the present application, the NAS security context may be a 5G NAS security context, and the AS security context may be a 5G AS security context.

The specific form of the third indication information is not specifically limited in this embodiment. It may be bit indication information, or enumeration type information, or it may be indicated by whether it appears or not. For example, a third indication appears in the second NAS SMC message. The information does not update the currently used 5G NAS security context and 5G AS security context. If it does not appear in the second NAS SMC message, it indicates that the UE needs to update the currently used 5G NAS security context and 5G AS security context.

In another implementation, no primary authentication process occurs. When the AMF generates Kamf#2, but does not generate the second key identifier, the AMF determines that the second security context does not need to be activated. In order to synchronize the keys between the UE and the AMF, the second NAS SMC message includes second indication information (Kamf change indicator), and the second indication information indicates that the UE needs to generate a new Kamf, which is called Kamf#2 (the original Kamf of the UE). The Kamf used is called Kamf#1). Optionally, the AMF carries the first key identifier in the second NAS SMC message, and optionally, the second NAS SMC message also carries third indication information.

In another implementation, the primary authentication process does not occur, but the AMF generates Kamf#2 and the second key identifier, and the AMF determines that the second security context does not need to be activated. In order to synchronize the keys between the UE and the AMF, the AMF sends the second indication information to the UE, and the second indication information informs the UE that a new Kamf needs to be generated, which is called Kamf#2. If the AMF obtains the second key identifier, the second NAS SMC message carries the first key identifier and the second indication information, or the second NAS SMC message carries the second key identifier and the third indication information and second indication information.

With reference to the first aspect, in a possible implementation manner of the first aspect, the second security context includes one or more of the following: Kseaf#2, Kamf#2, Kaf#2, Kakma#2, _{KNASint #2} , K _NASenc#2 , K _gNB#2 , K _RRCint#2 , K _RRCenc#2 , or K _N3IWF#2 .

In a second aspect, an embodiment of the present application proposes a communication method, including:

The terminal device receives a second non-access stratum security mode command NAS SMC message from the access and mobility management function AMF, and the second NAS SMC message carries the key identifier from the AMF; when the When the key identifier is the same as the first key identifier of the first security context being used by the terminal device, the terminal device determines not to activate the second security context, which is the same as the first security context. Inconsistent context.

The security context in this embodiment of the present application includes materials used for security functions, such as keys, algorithms, and counters. Among them, the security context can be divided into: native security context and 5G security context. The native security context refers to the security context generated through the main authentication process. The 5G security context refers to the security context for the 5G system. 5G security context includes but is not limited to 5G NAS security context, 5G AS security context and 5G AKMA security context. 5G NAS security context is used for security protection between UE and AMF, and AS security context is used for security protection between UE and base station. The 5G AKMA security context includes keys (or security materials, or security keys) such as Kakma, A-KID, Kaf, etc. The 5G AKMA security context is generated on the AUSF side after the main authentication process and sent to the AAnF, and on the UE side before the AKMA service is initiated.

In this embodiment of the present application, the UE does not blindly activate the security context, and after generating a new security context, the UE determines whether to activate it. This reduces the complexity of key update and improves device performance.

With reference to the second aspect, in a possible implementation manner of the second aspect, the terminal device determining not to activate the second security context includes: the terminal device determining not to activate the NAS in the second security context The security context and/or the AS security context in the second security context. The UE may not activate part of the NAS security context in the second security context and/or the AS security context in the second security context to improve the implementation flexibility of the solution.

With reference to the second aspect, in a possible implementation manner of the second aspect, before the terminal device determines not to activate the second security context, the method further includes: the terminal device verifies the password from the AMF Whether the security algorithm corresponding to the key identifier is the same as the security algorithm corresponding to the first security context, and the security algorithm corresponding to the key identifier from the AMF is the security algorithm selected by the access and mobility management function; When the security algorithm corresponding to the key identifier from the AMF is the same as the security algorithm corresponding to the first security context, the terminal device determines not to update the first security context.

After the UE receives the second NAS SMC message, if the second NAS SMC message is encrypted and protected, the UE decrypts and protects the message using the key currently being used by the UE.

Specifically, after the UE receives the second NAS SMC message, the UE performs integrity protection verification on the message using the key currently being used by the UE. And verify whether the security algorithm carried in the second NAS SMC message is the same as the security algorithm carried by the UE in the registration request message, and the security algorithm includes: the integrity protection algorithm and the encryption algorithm of the UE. After all verifications are passed, the UE determines the key to be used subsequently according to the first key identifier. The different schemes are described below:

(1), when the key identifier from the AMF is the same as the key identifier of the UE, and the security algorithm corresponding to the key identifier is the same as the security algorithm corresponding to the first intermediate key, the terminal device continues to use the first security algorithm context, the terminal device does not perform any processing, wherein the first security context corresponds to the first intermediate key;

(2), when the key identifier from the AMF is different from the key identifier of the UE, the terminal device uses the second intermediate key to generate the second security context, and the terminal device activates the second security context;

(3), when the key identifier from the AMF is the same as the key identifier of the UE, and the security algorithm corresponding to the key identifier is different from the security algorithm corresponding to the first intermediate key, then the terminal device according to the first intermediate key The key generates a third security context, and the terminal device activates the third security context.

Specifically, when the key identifier from the AMF is the first key identifier, the UE needs to use the key corresponding to the first key identifier, that is, the UE needs to use the first security context and the first intermediate key . The UE can continue to use the original intermediate key (the first intermediate key) and the first security context. The UE may reactivate the first intermediate key and the first security context, which is not limited here.

In another implementation method, the UE can compare whether the key identifier from the AMF in the second NAS SMC message is the same as the key identifier of the intermediate key currently being used by the UE, and the UE also needs to verify the second NAS SMC message. Whether the security algorithm corresponding to the key identifier is the same as the security algorithm currently being used by the UE. If all are the same, and the UE verifies that the integrity protection of the NAS SMC is correct, the UE can continue to use the current 5G NAS security context without performing any operations. That is, with the current key and security algorithm, the NAS COUNT does not need to be reset to 0 either.

In an implementation method, the UE can compare whether the key identifier from the AMF in the second NAS SMC message is the same as the key identifier of the intermediate key currently being used by the UE, and the UE also needs to verify that the second NAS SMC message contains the same key identifier. Whether the security algorithm corresponding to the key identifier from the AMF is the same as the security algorithm currently being used by the UE. If only the latter is different (that is, the key identifiers are the same, but the security algorithms are inconsistent), the UE needs to use the Kamf#1 corresponding to the Kausf#1 identified by ngKSI#1, and use the new security algorithm carried in the second NAS SMC message to generate the first Three security contexts. The third security context may be a new 5G NAS security context (corresponding to the first intermediate key), specifically, a new K _NAS-int and a new K _NASenc are generated, and the NAS COUNT is reset to 0. The UE verifies the integrity protection of the second NAS SMC message using the newly generated K _NAS-int . It can be understood that, because the second NAS SMC message carries ngKSI#1, only the first intermediate key corresponding to ngKSI#1 can be used to further derive the subkey. So just generate a new NAS key and that's it.

In another implementation method, the UE performs an activation operation on the key identified by the first key identifier, which may include at least one of the following steps: generating Kseaf#1 according to the Kausf#1 identified by the key identifier #1, generating Kseaf#1, Use Kseaf#1 to generate Kamf#1, then use Kamf#1 and the selected security algorithm carried in the second NAS SMC message to generate K _NASint#1 and K _NASenc#1 , and encrypt the K _NASint#1 and K _NASenc#1 algorithms and integrity protection algorithms are used for specific functions, but the NAS COUNT remains the same.

In another implementation manner, the UE only compares whether the key identifier from the AMF carried in the second NAS SMC message is the same as the key identifier corresponding to the key currently being used. If the integrity protection check of the SMC message is successful, no operation is performed and the current 5G NAS security context continues to be used.

In the case that the AMF may not generate the second key identifier, and the NAS SMC#2 also carries the second indication information, the UE further checks whether the third indication information is received. If the UE receives the third indication information, the UE only generates a new Kamf (generates Kamf#2), and does not update the 5G NAS and/or 5G AS security context.

In the case where the standard stipulates that the second key identifier will be generated every time the Kamf changes, if the NAS SMC#2 carries the first key identifier, the terminal device will continue to use the first security context, that is, only the Kamf#2 needs to be generated , and no other processing will be performed. That is to say, the terminal device can continue to use the 5G NAS security context and 5G AS security context generated based on Kausf#1. Alternatively, if the NAS SMC#2 carries the second key identifier and the third indication information, the terminal device only needs to generate Kamf#2, and no other processing is required.

With reference to the second aspect, in a possible implementation manner of the second aspect, when the access and mobility management function determines that the second security context needs to be activated, the AMF sends the NAS SMC#2 to the UE, The NAS SMC#2 also includes first indication information. The first indication information is associated with the second network element, and the first indication information instructs the terminal device to update the communication key between the terminal device and the second network element; the second network element includes Any of the following: Network Open Function NEF, Authentication and Key Management Anchor Function AAnF, Edge Configuration Server ECS, Edge Enablement Server EES, Mobile Edge Computing MEC or Application Function AF.

In a third aspect, an embodiment of the present application provides a communication device, including:

a processing module, configured to generate a second security context, where the second security context is inconsistent with the first security context, and the first security context is the security context currently used by the access and mobility management function;

The processing module is further configured to determine whether to activate the second security context.

In one possible implementation,

a transceiver module, configured to send a second authentication request message containing a second key identifier to the terminal device, where the second authentication request message is used to trigger a second authentication between the terminal device and the network ;

The processing module is further configured to determine whether the second security context generated in the second authentication process needs to be activated after the second authentication is successful;

The transceiver module is further configured to send a second non-access stratum security mode command NAS SMC message to the terminal device without activating the second security context, where the second NAS SMC message includes the first NAS SMC message. a key identifier; wherein the first key identifier is the key identifier of the first security context currently used by the access and mobility management function.

In one possible implementation,

The transceiver module is further configured to send a first authentication request message containing the first key identifier to the terminal device, where the first authentication request message is used to trigger the connection between the terminal device and the network the first authentication;

The transceiver module is further configured to, after the first authentication succeeds, send a first NAS SMC message to the terminal device to activate the first security context generated in the first authentication process, so the The first NAS SMC message includes the first key identifier.

In one possible implementation,

The transceiver module is further configured to receive a registration request message from the terminal device.

In one possible implementation,

The processing module is further configured to determine not to activate the second security context when it is determined not to update the non-access stratum NAS key and/or the access stratum AS key,

or,

The processing module is further configured to determine to activate the second security context when it is determined that the non-access stratum NAS counter rolls over,

or,

The processing module is further configured to determine to activate the second security context when it is determined to update the non-access stratum NAS key context and/or the access stratum AS key context of the terminal device;

or,

The processing module is further configured to not activate the second security context when it is determined that the second authentication is triggered by a first network element, and the first network element includes any one of the following: an authentication management function AUSF, Network Open Function NEF, Authentication and Key Management Anchor Function AAnF, Edge Configuration Server ECS, Edge Enablement Server EES, Mobile Edge Computing MEC or Application Function AF;

or,

The processing module is further configured to not activate the second security context when it is determined that the second authentication only needs to authenticate the terminal device;

or,

The processing module is further configured to not activate the second security context when it is determined that the second authentication is triggered by the terminal device.

In one possible implementation,

The transceiver module is further configured to send the second key identifier to the terminal device after it is determined that the second security context is activated.

In one possible implementation,

The transceiver module is further configured to, after determining to activate the second security context, send first indication information to the terminal device, where the first indication information is associated with the second network element, and the first indication information indicates The terminal device updates the communication key between the terminal device and the second network element;

In one possible implementation,

The transceiver module is further configured to activate, by the access and mobility management function, the non-access stratum NAS key of the second intermediate key after determining to activate the second security context, the second security context corresponding to the second intermediate key;

In one possible implementation,

The transceiver module is further configured to receive a third authentication request message sent by the first network element, wherein the third authentication request message carries the permanent identification information of the terminal device, and the third authentication request message for triggering the second authentication between the terminal device and the network;

The first network element includes any one of the following: AUSF, NEF, AAnF, ECS, EES or AF.

In one possible implementation,

The processing module is further configured to select a security algorithm to perform integrity protection and confidentiality protection on the second NAS SMC message sent by the access and mobility management function to the terminal device;

The processing module is further configured to determine that the second security context is not activated when the security algorithm selected by the access and mobility management function is the same as the security algorithm corresponding to the first security context;

The transceiver module is further configured to send the second NAS SMC message to the terminal device, where the second NAS SMC message includes the first key identifier.

In one possible implementation,

The transceiver module is further configured to send a second non-access stratum security mode command NAS SMC message to the terminal device, where the second NAS SMC message includes second indication information, and the second indication information indicates the terminal The device generates Kamf#2, and activates the second security context corresponding to Kamf#2, which is the updated Kamf.

In one possible implementation,

The second NAS SMC message further includes third indication information, where the third indication information instructs the terminal device to continue to use the NAS security context in the first security context and the AS security context in the first security context .

In one possible implementation,

The second security context includes one or more of the following: Kseaf#2, Kamf#2, Kaf#2, Kakma#2, K _NASint#2 , K _NASenc#2 , K _gNB#2 , K _RRCint#2 , K _RRCenc#2 or K _N3IWF#2 .

In a fourth aspect, an embodiment of the present application provides a communication device, including:

a transceiver module for receiving a second non-access stratum security mode command NAS SMC message from the access and mobility management function AMF, where the second NAS SMC message carries the key identifier from the AMF;

A processing module, configured to determine that the second security context is not activated when the key identifier is the same as the first key identifier of the first security context being used by the terminal device, and the second security context is the same as the first security context. The first security context described above is inconsistent.

In one possible implementation,

The processing module is further configured to determine not to activate the NAS security context in the second security context and/or the AS security context in the second security context.

In one possible implementation,

The processing module is further configured to verify whether the security algorithm corresponding to the key identifier from the AMF is the same as the security algorithm corresponding to the first security context, and the security algorithm corresponding to the key identifier from the AMF is the same a security algorithm selected for the access and mobility management function;

The processing module is further configured to determine not to update the first security context when the security algorithm corresponding to the key identifier from the AMF is the same as the security algorithm corresponding to the first security context.

In one possible implementation,

The transceiver module is further configured to receive first indication information sent by the access and mobility management function, where the first indication information is associated with a second network element, and the first indication information instructs the terminal device to update the communication key between the terminal device and the second network element;

The second network element includes any one of the following: a network opening function NEF, an authentication and key management anchor function AAnF, an edge configuration server ECS, an edge enabling server EES, a mobile edge computing MEC or an application function AF.

In a fifth aspect, an embodiment of the present application provides a communication device, which can implement the functions performed by the terminal device and the network device in the methods involved in the first and second aspects above. The communication device includes a processor, a memory, a receiver connected to the processor and a transmitter connected to the processor; the memory is used for storing program codes and transmitting the program codes to the processor; the processor is used for Drive the receiver and the transmitter to execute the methods in the first and second aspects according to the instructions in the program code; the receiver and the transmitter are respectively connected to the processor to execute the methods in the above aspects. Operation of equipment and network equipment. Specifically, the transmitter can perform the operation of sending, and the receiver can perform the operation of receiving. Optionally, the receiver and the transmitter can be a radio frequency circuit, and the radio frequency circuit can receive and send messages through an antenna; the receiver and the transmitter can also be a communication interface, and the processor and the communication interface are connected through a bus, and the processing The server implements receiving or sending messages through this communication interface.

In a sixth aspect, an embodiment of the present application provides a communication apparatus, where the communication apparatus may include entities such as network equipment or chips, or the communication apparatus may include entities such as terminal equipment or chips, and the communication apparatus includes: a processor and a memory; The memory is used to store instructions; the processor is used to execute the instructions in the memory, so that the communication device performs the method according to any one of the aforementioned first or second aspects.

In a seventh aspect, embodiments of the present application provide a computer-readable storage medium that stores one or more computer-executable instructions. When the computer-executable instructions are executed by a processor, the processor executes the first aspect or the second method described above. Any of the possible implementations of the aspect.

In an eighth aspect, an embodiment of the present application provides a computer program product (or a computer program) that stores one or more computer-executable instructions, and when the computer-executable instructions are executed by the processor, the processor executes the aforementioned first aspect or any possible implementation manner of the second aspect.

In a ninth aspect, the present application provides a chip system, where the chip system includes a processor for supporting a computer device to implement the functions involved in the above aspects. In a possible design, the chip system further includes a memory for storing necessary program instructions and data of the computer device. The chip system may be composed of chips, or may include chips and other discrete devices.

In a tenth aspect, the present application provides a communication system, where the communication system includes the communication apparatus in the fourth and fifth aspects above.

Description of drawings

1 is a schematic diagram of a network architecture of a communication system;

2 is a schematic diagram of a hardware structure of a communication device in an embodiment of the present application;

3 is a schematic diagram of an access flow of a UE through forwarding;

Fig. 4 is the generation flow schematic diagram of key Kaf;

FIG. 5 is a schematic flowchart of the NAS SMC involved in the embodiment of the application;

6 is a schematic flowchart of a communication method proposed by an embodiment of the present application;

FIG. 7 is a schematic diagram of an application scenario proposed by an embodiment of the present application;

FIG. 8 is a schematic diagram of another application scenario proposed by an embodiment of the present application;

FIG. 9 is a schematic diagram of another application scenario proposed by an embodiment of the present application;

FIG. 10 is a schematic diagram of an embodiment of a communication device in an embodiment of the present application;

FIG. 11 is a schematic diagram of an embodiment of a communication apparatus in an embodiment of the present application.

Detailed ways

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all of the embodiments. The terms "first", second" and the corresponding term labels in the description and claims of the present application and the above drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that The terms used in this way can be interchanged under appropriate circumstances, and this is only a way of distinguishing objects with the same attributes in the description of the embodiments of the present application. In addition, the terms "include" and "have" and any of them Variations, intended to cover non-exclusive inclusion, such that a process, method, system, product or device comprising a series of units is not necessarily limited to those units, but may include or are not expressly listed for such process, method, product or device inherent other units.

In the description of this application, unless otherwise stated, "/" means or means, for example, A/B can mean A or B; "and/or" in this application is only an association relationship that describes an associated object , which means that there can be three kinds of relationships, for example, A and/or B, which can mean that A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the present application, "at least one item" refers to one or more items, and "multiple items" refers to two or more items. "At least one item(s) below" or similar expressions thereof refer to any combination of these items, including any combination of single item(s) or plural items(s). For example, at least one item (a) of a, b, or c can represent: a, b, c, a-b, a-c, b-c, or a-b-c, where a, b, c may be single or multiple .

The technical solutions of the embodiments of the present application can be applied to various communication systems, such as: Wideband Code Division Multiple Access (WCDMA) system, general packet radio service (GPRS), Long Term Evolution (Long Term Evolution (LTE) system, LTE frequency division duplex (FDD) system, LTE time division duplex (TDD), universal mobile telecommunication system (UMTS), global interconnection microwave connection The world wide interoperability for microwave access (WiMAX) communication system, the fifth generation (5th generation, 5G) system or NR and the future sixth generation communication system, etc.

The part of various communication systems that is operated by an operator may be referred to as an operator network. The operator network, also known as the public land mobile network (PLMN) network, is a network established and operated by the government or government-approved operators for the purpose of providing land mobile communication services to the public. A mobile network operator (MNO) is a public network that provides users with mobile broadband access services. The operator network or PLMN network described in the embodiments of this application may be a network that meets the requirements of the 3rd generation partnership project (3rd generation partnership project, 3GPP) standard, which is referred to as a 3GPP network for short. Usually 3GPP networks are operated by operators, including but not limited to fifth-generation (5th-generation, 5G) networks (referred to as 5G networks), fourth-generation (4th-generation, 4G) networks (referred to as 4G networks) Or the third-generation mobile communication technology (3rd-generation, 3G) network (referred to as 3G network). Also includes future 6G networks. For the convenience of description, an operator network (such as a mobile network operator (mobile network operator, MNO) network) will be used as an example for description in this embodiment of the present application.

In order to facilitate the understanding of the embodiments of the present application, the 5G network architecture shown in FIG. 1 is taken as an example to describe the application scenarios used in the present application. It can be understood that other communication networks are similar to the 5G network architecture, and therefore will not be repeated. Please refer to FIG. 1. FIG. 1 is a schematic diagram of a network architecture of a communication system. The network architecture may include: a terminal device (also referred to as a user equipment part, an operator network part, and a data network (DN) part) .

The terminal equipment part includes a terminal equipment 110, and the terminal equipment 110 may also be referred to as user equipment (user equipment, UE). The terminal device 110 involved in the embodiments of the present application, as a device with a wireless transceiver function, can communicate with a device in the (radio) access network ((R)AN) 140 through the access network device in the (R)AN) 140 . or multiple core networks (core networks, CN) to communicate. Terminal equipment 110 may also be referred to as an access terminal, terminal, subscriber unit, subscriber station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, wireless network device, user agent or user device, and the like. The terminal device 110 can be deployed on land, including indoor or outdoor, hand-held or vehicle-mounted; can also be deployed on water (such as ships, etc.); and can also be deployed in the air (such as planes, balloons, satellites, etc.). The terminal device 110 may be a cellular phone (cellular phone), a cordless phone, a session initiation protocol (SIP) phone, a smart phone (smart phone), a mobile phone (mobile phone), a wireless local loop (WLL) ) station, a personal digital assistant (PDA), which can be a handheld device with wireless communication capabilities, a computing device or other device connected to a wireless modem, an in-vehicle device, a wearable device, a drone device, or the Internet of Things, The terminal in the Internet of Vehicles, the fifth generation (5G) network and any form of terminal in the future network, the relay user equipment or the public land mobile network (PLMN) evolved in the future. The terminal, etc., where the relay user equipment may be, for example, a 5G residential gateway (RG). For example, the terminal device 110 may be a virtual reality (VR) terminal, an augmented reality (AR) terminal, a wireless terminal in industrial control (industrial control), a wireless terminal in self driving, remote Wireless terminal in medical (remote medical), wireless terminal in smart grid (smart grid), wireless terminal in transportation safety, wireless terminal in smart city, wireless terminal in smart home (smart home) wireless terminals, etc. This embodiment of the present application does not limit this. For the convenience of description, in the embodiments of the present application, the terminal device 110 includes an unmanned aerial vehicle and an unmanned aerial vehicle remote controller as an example for description.

It should be noted that the drones involved in the embodiments of the present application may also include: a vehicle that can travel autonomously, or a vehicle that travels based on the control instructions of a remote controller; a ship that can travel autonomously , or ships sailing based on the control commands of the remote control.

The operator network may include unified data management (UDM) 134, authentication server function (AUSF) 136, access and mobility management function (AMF) 137, session management Function (session management function, SMF) 138, user plane function (user plane function, UPF) 139 and (R)AN 140 and so on. In the above-mentioned operator network, other parts other than the (R)AN 140 part may be referred to as a core network (core network, CN) part or a core network part. For convenience of description, in the embodiments of the present application, the (R)AN 140 is used as an RAN as an example for description.

The data network DN 120, which may also be referred to as a protocol data network (PDN), is usually a network outside the operator's network, such as a third-party network. The operator network can access multiple data networks DN 120, and multiple services can be deployed on the data network DN 120, which can provide services such as data and/or voice for the terminal device 110. For example, the data network DN 120 can be a private network of a smart factory, the sensors installed in the workshop of the smart factory can be terminal devices 110, and the control server of the sensor is deployed in the data network DN 120, and the control server can provide services for the sensor. The sensor can communicate with the control server, obtain instructions from the control server, and transmit the collected sensor data to the control server based on the instructions. For another example, the data network DN 120 can be an internal office network of a company, and the mobile phones or computers of employees of the company can be terminal devices 110, and the mobile phones or computers of employees can access information, data resources, etc. on the internal office network of the company.

The terminal device 110 may establish a connection with the operator's network through an interface (eg, N1, etc.) provided by the operator's network, and use services such as data and/or voice provided by the operator's network. The terminal device 110 can also access the data network DN 120 through the operator network, and use the operator services deployed on the data network DN 120, and/or services provided by third parties. The above-mentioned third party may be a service provider other than the operator network and the terminal device 110 , and may provide other data and/or voice services for the terminal device 110 . The specific expression form of the above third party can be specifically determined based on the actual application scenario, which is not limited here.

The following briefly introduces the network functions in the operator's network.

The (R)AN 140 can be regarded as a sub-network of the operator's network, and is an implementation system between the service node and the terminal device 110 in the operator's network. To access the operator network, the terminal device 110 first passes through the (R)AN 140, and then can be connected to the service node of the operator network through the (R)AN 140. The access network device (RAN device) in this embodiment of the application is a device that provides wireless communication functions for the terminal device 110, and may also be referred to as a network device. The RAN device includes but is not limited to: next-generation base stations in the 5G system Node (next generation node base station, gNB), evolved node B (evolved node B, eNB) in long term evolution (long term evolution, LTE), radio network controller (radio network controller, RNC), node B (node B) B, NB), base station controller (BSC), base transceiver station (base transceiver station, BTS), home base station (for example, home evolved nodeB, or home node B, HNB), base band unit (base band unit) , BBU), transmission point (transmitting and receiving point, TRP), transmitting point (transmitting point, TP), small base station equipment (pico), mobile switching center, or network equipment in future networks, etc. In systems using different wireless access technologies, the names of devices with access network device functions may be different. For the convenience of description, in all the embodiments of this application, the above-mentioned apparatuses for providing wireless communication functions for the terminal device 110 are collectively referred to as access network devices or simply referred to as RAN or AN. It should be understood that the specific type of the access network device is not limited herein.

The Access and Mobility Management Function AMF (also referred to as AMF network element, AMF network function or AMF network function entity) 137 is a control plane network function provided by the operator's network and is responsible for the connection of the terminal device 110 to the operator's network. Access control and mobility management, including functions such as mobility status management, assigning user temporary identities, authenticating and authorizing users.

The session management function SMF (also referred to as SMF network element, SMF network function or SMF network function entity) 138 is a control plane network function provided by the operator network, responsible for managing the protocol data unit (PDU) of the terminal device 110 ) session. The PDU session is a channel for transmitting PDUs, and the terminal device needs to transfer PDUs to and from the data network DN 120 through the PDU session. The PDU session is established, maintained and deleted by the SMF network function 138. SMF network functions 138 include session management (eg session establishment, modification and release, including tunnel maintenance between user plane functions UPF 139 and (R)AN 140), selection and control of UPF network functions 139, service and session continuity ( Service and session continuity, SSC) mode selection, roaming and other session-related functions.

The user plane function UPF (may also be referred to as UPF network element, UPF network function or UPF network function entity) 139 is a gateway provided by the operator, and is a gateway for the operator network to communicate with the data network DN 120. The UPF network function 139 includes user plane-related functions such as data packet routing and transmission, data packet detection, service usage reporting, quality of service (QoS) processing, legal interception, uplink data packet detection, and downlink data packet storage.

The unified data management network element UDM (also referred to as UDM network element, UDM network function or UDM network function entity) 134 is a control plane function provided by the operator, and is responsible for storing the permanent identity (subscriber permanent identity) of the subscriber in the operator's network. identifier, SUPI), the publicly used subscription identifier (generic public subscription identifier, GPSI) of the contracting user, credential (credential) and other information. The SUPI will be encrypted first in the transmission process, and the encrypted SUPI is called a hidden user subscription identifier (SUCI). This information stored by UDM 134 can be used for authentication and authorization of terminal device 110 to access the operator's network. The above-mentioned subscribers of the operator's network may specifically be users who use the services provided by the operator's network, such as users using "China Telecom" mobile phone SIM cards, or users using "China Mobile" mobile phone SIM cards, etc. The above-mentioned credential of the signing user may be: a long-term key stored in the mobile phone core card or a small file stored with information related to encryption of the mobile phone core card, etc., for authentication and/or authorization. It should be noted that permanent identifiers, credentials, security contexts, authentication data (cookies), and tokens are equivalent to verification/authentication, and authorization-related information are not differentiated and limited in the embodiments of the present application for convenience of description.

The authentication management function (authentication server function, AUSF) (also referred to as AUSF network element, AUSF network function or AUSF network function entity) 136 is a control plane function provided by the operator, usually used for main authentication, that is, the terminal device 110 Authentication between the (subscriber) and the operator network. After the AUSF 136 receives the authentication request initiated by the subscribed user, it can authenticate and/or authorize the subscribed user through the authentication information and/or authorization information stored in the UDM network function 134, or generate the authentication and/or authorization of the subscribed user through the UDM network function 134. / or authorization information. The AUSF network function 136 may feed back authentication information and/or authorization information to the subscriber. In an Authentication and Key Management for Application (AKMA) scenario, an AKMA Anchor Key is generated for the Authentication and Key Management for Application (AKMA) Anchor Function, AAnF) 130 The key Kakma (this key management key is also called the AKMA intermediate key), and is responsible for generating the key Kaf and the validity time of Kaf used by the AF 135 for the application function (AF) 135.

The Network Exposure Function (NEF) 131 acts as an intermediate network element for the external application function (application Function, AF) 135 and the authentication and key management for Application (AKMA) anchor function within the core network. )Anchor Function, AAnF) 130 provides interactive services.

The Network Repository Function (NRF) 132 is used for network function (Network Function, NF) registration, management, or state detection, and realizes the automatic management of all NFs. When each NF starts, it must register with the NRF. Only registration can provide services, and registration information includes NF type, address, or service list.

Policy control function (PCF) 133, PCF 133 interacts with AF 135 to obtain quality of service (Quality of Service, QoS) parameters, or provides QoS parameters to AF 135, thereby realizing a function that can affect application data transmission .

The application function AF 135 interacts with the 3rd Generation Partnership Project (3GPP) core network to provide application layer services. For example: provide data routing on the application layer and provide the ability to access the network. AF 135 can interact with NEF 131 and can interact with PCF 133. In the authentication and key management for Application (AKMA) scenario, the AF135 needs to interact with the AAnF 130 to obtain the AF intermediate key (Kaf) and the valid time of the Kaf. The location of AF 135 can be inside the 5G core network or outside the 5G core network. If the AF is inside the 5G core network, it can directly interact with the PCF 133. If the AF 135 is outside the 5G core network, the NEF 131 acts as an intermediate node to forward the interactive content between the AF 135 and the PCF 133. Such as forwarding through NEF.

Authentication and key management AKMA anchor function AAnF 130, AAnF 130 will interact with AUSF 136 to obtain the AKMA intermediate key (Kakma), and is responsible for generating the valid time of the key Kaf and Kaf used by AF 135 for AF 135.

In Figure 1, Nausf, Nudm, Namf, Nsmf, Nnrf, Nnef, Naanf, Naf, N1, N2, N3, N4, and N6 are interface serial numbers. For the meanings of these interface serial numbers, refer to the meanings defined in the 3GPP standard protocol, which will not be repeated here. It should be noted that, in FIG. 1, only the terminal device 110 is used as an example for the UE, and the interface names between various network functions in FIG. 1 are only an example. In the specific implementation, the interface names of the system architecture Other names may also be used, which are not specifically limited in this embodiment of the present application.

For convenience of description, in this embodiment of the present application, the mobility management network function is the AMF network function 137 as an example for description. It may also be other network functions with the above-mentioned AMF network function 137 in the future communication system. Alternatively, the mobility management network function in this application may also be a mobility management network element (Mobility Management Entity, MME) in LTE, or the like. Further, the AMF network function 137 is referred to as AMF for short, and the terminal device 110 is referred to as UE, that is, the AMF described later in the embodiments of the present application can be replaced by a mobility management network function, and the UE can be replaced by a terminal device. .

A method for generating a key identifier provided by this application can be applied to various communication systems, for example, it can be the Internet of Things (Internet of Things, IoT), the narrowband Internet of Things (NB-IoT), Long term evolution (LTE), it can also be the fifth generation (5G) communication system, it can also be a hybrid architecture of LTE and 5G, it can also be a 5G new radio (NR) system and it will appear in the future communication development. new communication systems, etc. The 5G communication system of the present application may include at least one of a non-standalone (NSA) 5G communication system and an independent (standalone, SA) 5G communication system. The communication system may also be a public land mobile network (PLMN) network, a device-to-device (D2D) network, a machine-to-machine (M2M) network, or other networks.

In addition, the embodiments of the present application may also be applicable to other future-oriented communication technologies, such as 6G and the like. The network architecture and service scenarios described in this application are for the purpose of illustrating the technical solutions of this application more clearly, and do not constitute a limitation on the technical solutions provided by this application. The appearance of each network function involved in this application may be changed, and the technical solutions provided in this application are also applicable to similar technical problems.

FIG. 2 is a schematic diagram of a hardware structure of a communication device according to an embodiment of the present application. The communication apparatus may be a possible implementation manner of the network device or the terminal device in the embodiment of the present application. As shown in FIG. 2 , the communication apparatus includes at least a processor 204 , a memory 203 , and a transceiver 202 , and the memory 203 is further configured to store instructions 2031 and data 2032 . Optionally, the communication device may further include an antenna 206 , an I/O (input/output, Input/Output) interface 210 and a bus 212 . The transceiver 202 further includes a transmitter 2021 and a receiver 2022. In addition, the processor 204 , the transceiver 202 , the memory 203 and the I/O interface 210 are communicatively connected to each other through the bus 212 , and the antenna 206 is connected to the transceiver 202 .

The processor 204 can be a general-purpose processor, such as, but not limited to, a central processing unit (Central Processing Unit, CPU), or can be a special-purpose processor, such as, but not limited to, a digital signal processor (Digital Signal Processor, DSP), application Application Specific Integrated Circuit (ASIC) and Field Programmable Gate Array (FPGA), etc. The processor 204 may also be a neural network processing unit (NPU). Furthermore, the processor 204 may also be a combination of multiple processors. In particular, in the technical solutions provided in the embodiments of the present application, the processor 204 may be configured to execute the relevant steps of the method for generating the key identifier in the subsequent method embodiments. The processor 204 may be a processor specially designed to perform the above steps and/or operations, or may be a processor that performs the above steps and/or operations by reading and executing the instructions 2031 stored in the memory 203, the processor 204 Data 2032 may be required in performing the steps and/or operations described above.

The transceiver 202 includes a transmitter 2021 and a receiver 2022 . In an optional implementation, the transmitter 2021 is used to transmit signals through the antenna 206 . The receiver 2022 is used to receive signals through at least one of the antennas 206 . In particular, in the technical solutions provided by the embodiments of the present application, the transmitter 2021 may be specifically configured to be executed by at least one antenna among the antennas 206. For example, the method for generating the key identifier in the subsequent method embodiments is applied to a network device or terminal device, the operation performed by the receiving module or the sending module in the network device or terminal device.

In this embodiment of the present application, the transceiver 202 is configured to support the communication device to perform the aforementioned receiving function and sending function. A processor with processing capabilities is considered processor 204 . The receiver 2022 may also be called an input port, a receiving circuit, and the like, and the transmitter 2021 may be called a transmitter or a transmitting circuit, and the like.

The processor 204 may be configured to execute the instructions stored in the memory 203 to control the transceiver 202 to receive messages and/or send messages, so as to complete the function of the communication device in the method embodiment of the present application. As an implementation manner, the function of the transceiver 202 may be implemented by a transceiver circuit or a dedicated chip for transceiver. In this embodiment of the present application, receiving a message by the transceiver 202 may be understood as an input message by the transceiver 202 , and sending a message by the transceiver 202 may be understood as an output message by the transceiver 202 .

The memory 203 may be various types of storage media, such as random access memory (Random Access Memory, RAM), read only memory (Read Only Memory, ROM), non-volatile RAM (Non-Volatile RAM, NVRAM), and Programmable ROM (Programmable ROM, PROM), Erasable PROM (Erasable PROM, EPROM), Electrically Erasable PROM (Electrically Erasable PROM, EEPROM), Flash memory, optical memory and registers, etc. The memory 203 is specifically used to store the instructions 2031 and the data 2032, and the processor 204 can perform the steps and/or operations described in the method embodiments of the present application by reading and executing the instructions 2031 stored in the memory 203. Data 2032 may be required during the operations and/or steps of a method embodiment.

Optionally, the communication apparatus may further include an I/O interface 210, and the I/O interface 210 is used for receiving instructions and/or data from peripheral devices, and outputting instructions and/or data to peripheral devices.

Below, some background technologies involved in the embodiments of the present application are introduced.

(1), the key structure.

Next, the key structure of the fifth generation mobile communication system is introduced. UE (or USIM) and UDM (or Authentication Credential Respository and Processing Function (ARPF) or Unified Data Repoitory (UDR)) save the UE's long-term key K.

On the network device side, the UDM or ARPF generates the key CK and the key IK based on the UE's long-term key K. The authentication methods selected by UDM are different, and the methods of generating the intermediate key Kausf are different. When the authentication method selected by the UDM is 5G authentication and key agreement (5G Authentication and Key Agreement, 5G AKA), the UDM or ARPF generates the intermediate key Kausf according to the key CK and the key IK. UDM sends the generated intermediate key Kausf to AUSF. When the authentication method selected by UDM is the Improved Extensible Authentication Protocol Method for 3rd Generation Authentication and Key Agreement (EAP-AKA'), the UDM or ARPF will use the key CK and key IK, generate key CK' and key IK'. The UDM sends the generated key CK' and key IK' to the AUSF. The AUSF generates the intermediate key Kausf based on the key CK' and the key IK'.

Based on this intermediate key Kausf, various keys can be derived. For convenience of description in the embodiments of the present application, the key derived based on the intermediate key Kausf is referred to as a security context. Security contexts include, but are not limited to: Kseaf, Kamf, Kaf, Kakma, K _NASint , K _NASenc , K _gNB , K _RRCint , K _RRCenc or K _N3IWF .

AUSF generates the key Kseaf based on the intermediate key Kausf, and sends the key Kseaf to SEAF. SEAF generates the key Kamf based on the key Kseaf and sends the key Kamf to the AMF. The AMF generates a non-access stratum (NAS) key and an access stratum (access stratum, AS) intermediate key K gNB according to the key _Kamf . The AMF delivers the K _gNB to the base station, and the base station further generates the AS security context according to the K _gNB , such as K _RRCint and K _RRCenc.

On the terminal device side, first, the USIM generates the key CK and the key IK based on the UE's long-term key K. The USIM sends the key CK and the key IK to the UE. Secondly, similar to the network side, there are differences in the way of generating the intermediate key Kausf under different authentication methods. When the authentication method used is 5G AKA, the UE generates the intermediate key Kausf according to the key CK and the key IK. When the authentication method used is EAP-AKA', the UE generates the key CK' and the key IK' according to the key CK and the key IK. The UE generates the intermediate key Kausf according to the key CK' and the key IK'.

The UE generates the key Kseaf according to the intermediate key Kausf. The UE generates the key Kamf according to the key Kseaf. The UE generates the NAS key and K _{gNB according to the key Kamf} . The UE further generates K _RRCint and K _RRCenc according to K _gNB .

(2), AKMA.

For ease of understanding, please refer to FIG. 3 , which is a schematic diagram of an access flow of a UE through forwarding. Take Figure 3 as an example to illustrate the AKMA process, specifically:

301. Perform a primary authentication process between the UE and the core network.

In step 301, a primary authentication (Primary authentication) process is performed between the UE and the core network. The main authentication process needs to use an authentication vector (authentication vector, AV), and the authentication vector is used to transfer the verification parameters of the main authentication process in the main authentication process. Specifically, through step 302, the AUSF obtains the authentication vector.

In this embodiment of the present application, the main authentication process is also called an authentication process, which is not limited here.

302. The AUSF sends an authentication vector acquisition request message to the UDM.

In step 302, the AUSF sends an authentication vector acquisition request message to the UDM, where the authentication vector acquisition request message is, for example, "Numd_UEAuthentication Get Request". The authentication vector acquisition request message is used to request an authentication vector from the UDM. The authentication vector acquisition request message carries SUPI or SUCI. Specifically, when the message sent by the AMF to the AUSF carries SUPI, the authentication vector acquisition request message carries SUPI; when the message sent by the AMF to the AUSF carries SUCI, the authentication vector acquisition request message carries SUCI.

SUCI can be understood as an encrypted form of SUPI. The specific generation method of SUCI can refer to 3GPP standard TS 33.501. In a nutshell, the part of SUPI other than the mobile country code (MCC) can be encrypted and calculated by the universal subscriber identity module (USIM) or mobile equipment (ME) to obtain the SUCI encryption part. In addition to the encryption part, SUCI also includes routing identifier RID, MCC, MNC and other contents.

303. The AUSF receives the authentication vector acquisition response message sent by the UDM.

In step 303, after the UDM receives the authentication vector acquisition request message in step 302, the UDM determines the corresponding authentication vector. The UDM sends an authentication vector acquisition response message to the AUSF, where the authentication vector acquisition response message carries the authentication vector. The authentication vector acquisition response message is, for example: "Num_UEAuthentication_Get Response".

Optionally, the UDM determines whether the UE corresponding to the main authentication process supports the AKMA service based on the user subscription data corresponding to the SUPI. When the UE supports the AKMA service, the authentication vector acquisition response message carries the AKMA service indication information, and the AKMA service indication information is "AKMA Indication". The AKMA service indication information is used to indicate that the AUSF needs to generate the AKMA anchor key Kakma for this UE. It can also be understood as: the AKMA service indication information is used to indicate that the UE supports the AKMA service. When the UE does not support the AKMA service, the authentication vector acquisition request message does not carry the AKMA service indication information.

304a. The UE generates an AKMA anchor key Kakma based on the AUSF intermediate key.

In step 304a, after the UE's primary authentication process is successfully completed, the UE generates an AKMA anchor key (Kakma) based on the same intermediate key (Kausf) used by the AUSF. Optionally, further, before the UE initiates the AKMA service, the UE generates an AKMA anchor key (Kakma) based on the same intermediate key (Kausf) used by the AUSF.

304b, the UE generates an authentication and key management-key temporary identity identifier A-KID.

In step 304b, after the UE's main authentication process is successfully completed, before the UE initiates the AKMA service, the UE generates authentication and key management-key temporary identity (AKMA) based on the same intermediate key (Kausf) used by the AUSF. -Key Identifier, A-KID). The A-KID is used to identify the UE's AKMA anchor key Kakma. Optionally, further, before the UE initiates the AKMA service, the UE generates an A-KID based on the same intermediate key (Kausf) used by the AUSF. Specifically, the UE generates the key management-key temporary identifier (AKMA Temporary UE Identifier, A-TID) part in the A-KID based on the same intermediate key (Kausf) used by the AUSF.

Specifically, the A-KID is generated based on the routing identifier RID. A-KID format is "username@exmaple". The "username" part includes the routing identifier, and the Authentication and Key Management-Key Temporary Identifier (AKMA Temporary UE Identifier, A-TID). The "example" part includes home network identifiers such as: mobile country code (MCC) and mobile network code (MNC). A-TID is a temporary identification based on Kausf.

It should be noted that the execution order of step 304a and step 304b is not limited.

305a. The AUSF generates the AKMA anchor key Kakma based on the AUSF intermediate key.

Step 305a is similar to the aforementioned step 304a, and will not be repeated here. The difference from 304a is that after the AUSF receives the authentication vector acquisition response message, if the message carries the AKMA service indication information, the AUSF uses the Kausf acquired by the AUSF to generate Kakma and A-KID. If the authentication vector acquisition response message does not carry the AKMA service indication information, the AUSF may not generate Kakma and A-KID.

305b, the AUSF generates an authentication and key management-key temporary identity identifier A-KID.

In step 305b, when in step 303, the authentication vector acquisition response message sent by the UDM carries the AKMA identification information, the AUSF determines that an A-KID needs to be generated based on the AKMA identification information.

306. The AUSF sends an AKMA anchor key registration request message to the AAnF.

In step 306, after the AUSF selects an AAnF, the AUSF sends an AKMA anchor key registration request message to the AAnF. The AKMA anchor key registration request message is for example: "Naanf_AKMA_AnchorKey_Register Request". Specifically, the AKMA anchor key registration request message carries SUPI, A-KID and Kakma.

307. The AUSF receives the AKMA anchor key registration response message sent by the AAnF.

In step 307, the AAnF sends an AKMA anchor key registration response message to the AUSF based on the AKMA anchor key registration request message in step 306. The AKMA anchor key registration response message is for example: "Naanf_AKMA_AnchorKey_Register Response".

308. AUSF deletes Kakma and A-KID.

In step 308, after the AUSF receives the AKMA anchor key registration response message sent from the AAnF, the AUSF deletes the Kakma and the A-KID.

(3) Route identifier RID.

RIDs are included in SUCI. The current standard specifies that RID is used for AMF to look up AUSF and AUSF to look up UDM. In the AKMA process, the RID is used to generate the A-KID. RID is also used to select AAnF.

In the 5G Global Subscriber Identity Module (USIM), the RID is stored in the USIM. When the 5G UE uses the 5G USIM, the 5G UE obtains the RID to be used from the 5G USIM. The value of the RID can be a non-default value or a default value.

However, there is no RID in 4G USIM, so if a 5G UE uses 4G USIM, the RID in SUCI will be filled with the default value.

In AMF, the RID is included in the context of the UE. It can be understood that after the AMF obtains the RID from the SUCI, the RID is stored in the AMF.

(4) The generation process of the key Kaf.

The key Kaf is a key derived based on the intermediate key Kausf, which is included in the security context. For the specific process of generating Kaf, please refer to Figure 4. Figure 4 is a schematic diagram of the generation process of the key Kaf, specifically:

401. The main authentication process is performed and Kakma is generated.

Step 401 is the main authentication process and generates Kakma. For specific steps, please refer to each step shown in FIG. 3 above, which will not be repeated here.

402. The UE sends an A-KID to the AF.

In step 402, the UE sends an "Application Session Establishment Request" message to the AF. The A-KID is carried in the message. AAnF searches for the corresponding Kakma according to the A-KID, and the A-KID of the Kakma is consistent with the A-KID in the message.

403. The AF sends the A-KID and the AF_ID to the AAnF.

In step 403, the AF sends a "Naanf_AKMA_ApplicationKey_Get_Request" message to the AAnF. The message carries A-KID and AF identification information (AF_ID). The A-KID comes from the aforementioned "Application Session Establishment Request" message. The AF_ID is used to generate Kaf.

404. AAnF determines Kakma according to the A-KID, and uses Kakma to generate Kaf.

In step 404, the AAnF determines the Kakma according to the A-KID. Then use Kakma to generate Kaf. And determine the validity time of Kaf (also known as expiration time).

405. AAnF sends Kaf to AF.

In step 405, the AAnF sends a "Naanf_AKMA_ApplicationKey_Get Response" message to the AF, where the message carries the generated Kaf and the expiration time of the Kaf.

406. The AF returns a response message to the UE.

In step 406, the AF replies a response message to the UE, and the response message may be an "Application Session Establishment Response" message.

It can be seen from the above steps that Kakma is generated using Kausf after the main authentication is completed. So without a new Kausf being generated, there will be no new Kakma being generated. So it can be understood that the effective time of Kakma is consistent with that of Kausf. The update time of Kausf depends on the frequency of the main authentication, and the time of the main authentication depends on the network configuration or trigger conditions. Therefore, the validity time of Kausf (also known as expiration time, validity period or life time) is uncertain. The validity time of Kakma generated based on this Kausf is also uncertain.

After the corresponding Kakma needs to be determined according to the A-KID, Kaf is generated based on the Kakma (and AF_ID). The valid time of this Kaf is set by AAnF, so the valid time of this Kaf may not be consistent with the valid time of Kausf.

Because Kaf has a separate validity period, when the validity period expires, Kaf expires. When the Kaf expires, the Kaf needs to be updated, otherwise there is a possibility that there is no key available between the UE and the AF.

Because the generation of Kaf needs to use Kakma, so if Kakma is not updated, then Kakma will generate the same Kaf. Therefore, when Kaf expires, if a new Kausf is generated, AAnF can generate a new Kaf for AF. But if no new Kausf is generated, AAnF will only generate expired Kaf again. At this time, if the UE and the AF continue to use the expired Kaf, it becomes meaningless to set the validity period of the Kaf, which is inconsistent with the original design of the validity period. For example: use Kakma#1 to generate Kaf#1, and generate Kakma#1 based on Kausf#1. When Kaf#1 expires, AF and UE need to use a new Kaf (Kaf#2). When Kausf is not updated, that is, Kausf is still Kausf#1, the Kaf generated based on Kausf#1 is still Kaf#1. Therefore, the UE and AF cannot continue to use the Kaf.

(5) The storage process of the intermediate key Kausf.

Kausf is generated in AUSF during the main authentication process, or sent to AUSF after UDM is generated. On the UE side, the UE can generate the same Kausf obtained by AUSF using the same method as AUSF or UDM. It is currently discussed how to ensure that the UE and the AUSF hold the same Kausf. The conclusion of the discussion is that the AUSF saves the new Kausf after determining that the authentication is successful, and the UE side saves the new Kausf after receiving the Non-access stratum security mode common (NAS SMC) message.

Specifically, the main authentication process occurs first, followed by the NAS SMC process. In order for the UE to save the latest Kausf, the NAS SMC process needs to be forced to occur after the main authentication process, and the idle time between the main authentication process and the NAS SMC process should be as small as possible. The NAS SMC process can be used to activate the native security context, which refers to the security context generated through the main authentication process. The security context includes keys, algorithms, counters, and other materials used for security functions. The 5G security context refers to the security context for the 5G system. 5G security context includes but is not limited to 5G NAS security context, 5G AS security context and 5G AKMA security context. The 5G NAS security context is used for security protection between UE and AMF, and the AS security context is used for security protection between UE and base station. The 5G AKMA security context includes keys (or security materials, or security keys) such as Kakma, A-KID, Kaf, etc. The 5G AKMA security context is generated on the AUSF side after the main authentication process and sent to the AAnF, and on the UE side before the AKMA service is initiated. Specifically, a new Kausf is generated in the main authentication process, and other new keys (eg, NAS keys) are generated based on the new Kausf. If the new key is to be activated, it must be activated through the NAS SMC process. The activation key means that the UE and AMF start to use the key for security protection. For ease of understanding, please refer to FIG. 5, which is a schematic flowchart of a NAS SMC involved in an embodiment of the present application. The NAS SMC process includes:

501. Start integrity protection.

In step 501, the AMF starts an integrity protection process.

502. The AMF sends a NAS SMC message to the UE.

In step 502, the AMF generates a 5G key identifier (Key Set Identifier in 5G, ngKSI) in the main authentication process, and the 5G key identifier is used to identify the 5G security context. The 5G key identifier carried in the NAS SMC message is used to inform the UE which set of keys to use for security protection in the future. The AMF sends a NAS SMC message to the UE, the NAS SMC message carries the 5G key identifier (Key Set Identifier in 5G, ngKSI), and the NAS SMC message also includes other information, such as: the selected encryption algorithm and/or the selected complete Security algorithm, security algorithm for replay, etc. Security algorithm includes: encryption algorithm and integrity protection algorithm, which will not be described here.

503. Start an uplink decryption process.

In step 503, the AMF starts the decryption process of the uplink.

504. Verify the integrity of the NAS SMC message.

In step 504, the UE verifies the integrity of the NAS SMC message, specifically, the UE also verifies whether the uplink encryption, downlink decryption and integrity protection are successfully activated.

505. The UE sends a NAS SMC completion response to the AMF.

In step 505, after the UE completes the verification of the NAS SMC message, the UE sends a NAS SMC completion response to the AMF. The NAS SMC Completion Response may be a NAS message.

506. Start the downlink encryption process.

In step 506, the AMF starts the downlink encryption process.

In the past, NAS SMC did not necessarily happen after the main authentication process. In the absence of the NAS SMC process, the UE and AMF continue to use the old key. That is to say, even if a new partial native key is generated after the main authentication process, AMF does not continue to generate the complete native key because there is no NAS SMC process. Among them, some native keys can be understood as keys other than NAS keys and AS keys, such as Kausf, Kseaf, Kamf. The complete native key means that the NAS key and the AS key are further generated. Under normal circumstances, the AMF and/or the UE will further generate the NAS key only after going through the NAS SMC process; the base station and/or the UE will further generate the AS key only after going through the AS SMC process.

It should be noted that the currently used key is not necessarily the key generated by the previous main authentication process, because there may not be a NAS SMC process after the previous main authentication process. Therefore, the key currently used in the NAS message is not directly related to whether the main authentication process occurs, but is related to whether the NAS SMC process occurs.

In the NAS SMC process, it is necessary to use ngkSI to indicate which set of keys to use for security protection. Therefore, the current key used to protect NAS messages is related to which ngKSI is carried in the NAS SMC process. For example, three primary authentications have occurred, and the key after the first primary authentication is currently used. The NAS SMC did not occur in the second primary authentication, but the NAS SMC occurred after the third primary authentication. If the NAS SMC after the third primary authentication carries the ng-KSI generated by the second primary authentication, the activated key is the second set of primary authentication-related keys.

In the prior art, it is stipulated that the main authentication process is bound to the NAS SMC process, that is, the NAS SMC process should be executed as soon as possible after the main authentication occurs. Currently, it is not specified which key identifier should be carried in the NAS SMC process. By default, the NAS SMC should carry the key identifier generated in the most recent main authentication process, which means that a key must be made after each main authentication process. renew. The key update involves not only the NAS key, but also the access stratum (AS) key, so the complexity of the key update is high, which affects the performance of the device, or affects the service life of the device. Based on this, the present application proposes a communication method, which will be described below with reference to the accompanying drawings. Please refer to FIG. 6. FIG. 6 is a schematic flowchart of a communication method proposed by an embodiment of the present application, including:

601. The UE sends a registration request message to the AMF.

The UE sends a registration request message to the AMF, and the registration request message is forwarded by the network device. The registration request message carries the UE's Subscription Concealed Identifier (SUCI).

Optionally, the registration request message may be "Registration Request".

602. The AMF sends the first key identifier to the UE.

Exemplarily, the first key identifier is ngKSI#1, and the first key identifier corresponds to the first intermediate key. In the embodiment of the present application, the intermediate key is Kausf as an example for description. Then the first intermediate key is Kausf#1.

603. The UE interacts with the AMF to complete the first primary authentication process.

The UE receives the first authentication request message (including the first key identifier), and the UE receives the authentication vector. Then the UE starts to authenticate the network side; after verifying that the network side is true, the UE will reply a message to the AMF to continue the main authentication process, and finally complete the two-way authentication from the UE to the AMF and the AUSF. The specific main authentication process standard TS 33.501 version 17.1.0 is described in Section 6.1.3, which will not be repeated here. Since the main authentication process is related to the first intermediate key and the first key identifier, the main authentication process is called the first main authentication process.

In the first primary authentication process, the AUSF stores the first intermediate key corresponding to the first key identifier. Exemplarily, AUSF stores Kasuf#1. Specifically, after the AUSF verifies that the UE is authentic, Kausf#1 is stored. It should be noted that the AUSF will not receive the first key identifier, therefore, the AUSF finally only stores the correspondence between Kausf#1 and the permanent identifier of the UE.

604. NAS SMC process #1.

After the first main authentication process ends, the AMF initiates the NAS SMC process. The specific NAS SMC process is the same as the process shown in the aforementioned Figure 5, and will not be repeated here. In the embodiment of the present application, the NAS SMC process related to the first main authentication process is referred to as NAS SMC process #1.

Specifically, in the NAS SMC process #1, the AMF sends the first NAS SMC message to the UE, and the first NAS SMC message carries the first key identifier. The AMF uses the NAS integrity protection key corresponding to the first key identifier to perform integrity protection verification on the first NAS SMC message.

After the UE receives the first NAS SMC message, the UE uses the NAS integrity protection key corresponding to the first key identifier to perform integrity protection verification on the first NAS SMC message. If the verification is successful, the UE performs confidentiality protection and integrity protection on the message by using the NAS encryption key and the NAS integrity protection key corresponding to the first key identifier. The UE side completes the activation process of the NAS key corresponding to the first key identifier. The UE replies with a "NAS Security Mode Complete" message to the AMF. The AMF uses the NAS integrity protection key and the NAS encryption key corresponding to the first key identifier to decrypt and verify the integrity of the message ("NAS Security Mode Complete" message). If the verification is successful, the AMF side completes the activation process of the NAS key corresponding to the first key identifier.

Exemplarily, because the first NAS SMC message carries ngKSI#1, the AMF uses the NAS integrity protection key corresponding to ngKSI#1 to perform integrity protection on the first NAS SMC message.

605. Trigger the second primary authentication process.

The AMF triggers the second main authentication process. Compared with the first main authentication process, the second main authentication process belongs to the re-authentication process. The triggering conditions of the second main authentication process include but are not limited to: AMF according to local policies Triggered, or the NAS counter (count) needs to be rolled over, or other network functions (or network elements) are triggered. The network function includes but is not limited to: AUSF or AAnF.

Specifically, the AMF may determine whether to activate the second security context through the triggering cause of the primary authentication process. There are various ways to trigger the main authentication process, including but not limited to:

a. The main authentication process is only used to authenticate the UE. For example, the AMF periodically authenticates the UE according to local policies and operator configuration.

b. The triggering reason for the main authentication process is to update the 5G NAS security context or the 5G AS security context. For example, NAS COUNT is about to flip.

c. The main authentication process is triggered by requests from other functional network elements. For example, the AMF receives a message for requesting key update from network elements such as AUSF, NEF, AAnF, ECS, and EES. In the case that the update can only be performed by triggering the main authentication process, the main authentication process is initiated.

d. The main authentication process is triggered by the terminal device. For example, the terminal device carries indication information through the registration request message, which is used to indicate that a certain key needs to be updated.

It should be noted that steps 605 to 607b are optional. Steps 605 to 607b are to illustrate the method of triggering the AMF to generate the second security context. When steps 605 to 607b are not executed, the AMF may also generate a second security context. For example, the AMF may generate a new Kamf through Kamf#1 in the first security context, and the Kamf is called Kamf#2. Kamf#2 represents the second security context as an intermediate key. AMF can further generate new 5G NAS keys and new 5G AS keys according to Kamf#2. For example, a new Kamf is generated through the horizontal Kamf deduction method in Section A.13 of the standard 33.501. In this case, the AMF may or may not generate a new second key identifier. The purpose of generating the second key identifier is to combine the existing technology, a Kamf should be in a one-to-one correspondence with a key identifier, and the newly generated Kamf should have a new key identifier, the new key identifier. character is used to identify the newly generated Kamf. This situation usually occurs in the context of AMF changes. If the second key identifier is not generated, it may happen that the AMF does not change, that is, the Kamf generated by the current AMF continues to be used by itself.

606. The AMF sends the second key identifier to the UE.

After the AMF triggers the second main authentication process, the AMF initiates the second main authentication process: the AMF requests the AUSF to authenticate the UE; the AUSF requests the UDM for the authentication vector; the UDM generates the authentication vector, and according to the selected main authentication The method determines whether to send the generated authentication vector or the processed authentication vector to the AUSF. After the AMF obtains the authentication vector from the AUSF, the AMF sends a second authentication request message to the UE, and the second authentication request message includes the second authentication request message. The key identifier, the second authentication request message is used to trigger the second authentication between the UE and the network (also referred to as the second main authentication process). In the embodiments of the present application, the key identifier is ngKSI as an example for description. It can be understood that the key identifier may also be other identifiers, which is not limited here. For the specific process, please refer to the description in Section 6.1.3 of Standard TS 33.501 Version 17.1.0.

Exemplarily, the second key identifier is ngKSI#2, and the second key identifier corresponds to the second intermediate key. In the embodiment of the present application, the intermediate key is Kausf as an example for description. Then the second intermediate key is Kausf#2.

607a, the UE and the AMF interact to complete the second primary authentication process.

The UE, AMF and AUSF continue to complete the second primary authentication process. The specific main authentication process is similar to the foregoing step 603, and will not be repeated here.

607b. Store the second intermediate key.

The AUSF stores the intermediate key corresponding to the second key identifier. In order to distinguish the first intermediate key in the first primary authentication process, the intermediate key corresponding to the second key identifier is called the second intermediate key. key. The second intermediate key may be Kausf#2. Specifically, after the AUSF verifies that the UE is authentic, Kausf#1 is stored. It should be noted that the AUSF will not receive the second key identifier, so the AUSF finally only stores the correspondence between Kausf#2 and the permanent identifier of the UE.

608. The AMF determines whether to activate the second security context.

The AMF determines whether to activate the security context corresponding to the second intermediate key. In order to distinguish the first security context corresponding to the first intermediate key, the security context of the intermediate key corresponding to the second intermediate key is referred to as the second security context. The second security context includes but is not limited to: the 5G NAS security context and/or the 5G AS security context generated based on the intermediate key. Therefore, the AMF determines whether to activate the second security context, which refers to whether to activate the 5G NAS security context and/or the 5G AS security context generated based on the intermediate key.

The AMF determines whether to activate the second security context. Several possible implementations are described below:

In a possible implementation manner, if the main authentication process occurs and the main authentication process is only used to authenticate the UE, the second security context does not need to be activated. That is, there is no need to further use the 5G NAS key and 5G AS key generated based on Kausf#2, or the UE and AMF do not need to further generate the 5G NAS key and 5G AS key generated based on Kausf#2. An exemplary scenario is as follows: when the operator configures the following scenarios, the UE authentication is triggered and the second security context is not activated. open connection); AMF data is migrated, that is, migrated from AMF#1 to AMF#2. In another possible implementation method, if the triggering reason for the main authentication process is to update the 5G NAS security context or the 5G AS security context, the AMF determines that the second security context needs to be activated. For example, the AMF determines that the primary authentication procedure is triggered because the NAS COUNT rolls over, or because the base station requests a new key. For example, when the NAS COUNT is about to be overturned, the AMF will trigger the main authentication process to generate a new 5G NAS security context, and activate the generated 5G NAS security context through the NAS SMC process.

In another possible implementation method, the main authentication process occurs, and the main authentication process is triggered by the request of other functional network elements. For example, when the main authentication procedure is requested by the AUSF for updating the Kakma-based, the AMF determines that the second security context does not need to be activated. For another example, if the main authentication process is triggered by the SMF and the UDM in order to synchronize the UE state, the AMF determines that the second security context does not need to be activated. For another example, if the initial registration request message sent by the terminal device is the main authentication process triggered by the AMF because the 5G security context of the UE cannot be found, the AMF determines not to activate the second security context.

In another possible implementation manner, if the main authentication process occurs, and the triggering condition of the main authentication process is not to update the 5G NAS security context, the second security context does not need to be activated by default.

In another possible implementation manner, the main authentication process occurs, and when the AMF cannot clearly activate the second security context, the AMF may activate the second security context by default. For example, when the AMF cannot determine whether to activate the second security context, the AMF activates the second security context by default. Or AMF may continue to use the first security context by default. For example, when the AMF cannot determine whether to activate the second security context, the AMF continues to use the first security context by default. It should be noted that the AMF may make a judgment according to at least one of the above conditions. When multiple conditions appear at the same time, comprehensive consideration is required. Specifically, for example, if a triggering condition that requires activation of the second security context occurs, the AMF must activate the second security context. For example, when the AMF is authenticated by the local policy and finds that the NAS COUNT is about to be rolled over, the AMF determines that the second security context needs to be activated according to the about to roll over of the NAS COUNT.

In another possible implementation manner, the main authentication process occurs, and the main authentication process is triggered by the terminal device. Then the AMF needs to determine whether the NAS key or the AS key needs to be updated. If the update is not required, the second security context may not be activated; if the update is required, the second security context is activated; in the case of uncertainty The second security context is activated by default.

In another possible implementation manner, the primary authentication process does not occur, and the AMF receives a request message for updating the key of the first network element, and the AMF triggers the second authentication according to the request message for updating the key. The first network element includes any one of the following but is not limited to: AAnF, an edge configuration server (Elastic Compute Service, ECS), an edge enabling server EES, or a mobile edge computing MEC functional network element. Then, after the AMF generates the second security context, it is determined not to activate the second security context.

After step 608, when the AMF determines that the second security context needs to be activated, the process proceeds to step 609; when the AMF determines that the second security context does not need to be activated, the process proceeds to step 612.

609. If it is determined to activate, in the NAS SMC process #2, when the primary authentication process occurs, the AMF sends the second key identifier to the UE. In the case that the main authentication process does not occur, the AMF sends the first key identifier and the second indication information to the UE.

If the AMF determines to activate the second security context, in the NAS SMC process #2, the AMF sends the second key identifier to the UE.

In a possible implementation manner, the AMF is triggered according to the primary authentication because the NAS key needs to be replaced, so it is determined to update the current key. Therefore, AMF generates Kseaf#2 according to Kausf#2. Use Kseaf#2 to generate Kamf#2. AMF selects an encryption algorithm and an integrity protection algorithm, and further generates K _NASint#2 and K _NASenc#2 . Optionally, the AMF may further generate K _gNB #2, and send K _gNB #2 to a network device (eg, a base station) through an N2 message.

Exemplarily, the AMF sends the second key identifier to the UE through a second NAS SMC message ("NAS Security Mode Command" message). That is, the second key identifier (eg ngKSI#2) is carried in the second NAS SMC message.

After receiving the key identifier, the UE determines the key to be used subsequently according to the key identifier. When the key identifier is the second key identifier, the UE needs to use the key material corresponding to the second key identifier, that is, the UE needs to use the 5G NAS key generated based on the second intermediate key. Specifically, the UE generates Kseaf#2 according to Kausf#2. Use Kseaf#2 to generate Kamf#2. Then use Kamf#2 and the selected security algorithm carried in the NAS SMC to generate K _NASint#2 and K _NASenc#2 . The UE uses K _NASint#2 to verify the integrity protection of the NAS SMC. In addition, the UE also needs to verify whether the security algorithm carried in the second NAS SMC message is the same as that carried in the registration request message by the UE. After the verification is passed, the UE starts to use K _NASint#2 and K _NASenc#2 to perform integrity protection and encryption protection on the subsequently sent NAS messages, and perform integrity protection verification and decryption on the subsequently received NAS messages.

610. The UE stores the second intermediate key corresponding to the second key identifier.

After the UE receives the NAS SMC message, the UE stores the second key identifier, and the UE stores the second intermediate key corresponding to the second key identifier. Exemplarily, the UE stores ngKSI#2 and Kausf#2 (Kausf#2 corresponds to ngKSI#2).

The activation operation is as follows: create a security function function, and put the updated key into the security function for use. The UE deletes or stops the security function used before.

The UE replies with a NAS SMP message ("NAS Security Mode complete" message) to the AMF.

611. AMF does not activate the new AS key.

Step 611 is an optional step. AMF determines whether to update the AS key. If the primary authentication triggers the process because the NAS key needs to be updated, for example, the NAS counter value is about to roll over. In order to save the complexity of the UE, the AMF may determine not to update the AS key. Then, when the AMF activates the second security context, it does not activate the AS key corresponding to the second key identifier. That is, the second security context activated by the AMF does not include the AS key, and the AMF only activates the NAS key corresponding to the second key identifier. For example, the AMF does not activate the AS key corresponding to ngKSI#2, and the AS key includes but is not limited to: the key K _gNB . Specifically, AMF does not generate K _gNB corresponding to ngKSI#2 (AMF does not generate new K _gNB #2, and old K _gNB #1 corresponds to ngKSI#1), or after AMF generates K _gNB #2, it does not send the K gNB #2 _gNB #2 to network equipment (eg base station).

612. If the second security context is not activated, in the NAS SMC process #2, the AMF sends the first key identifier to the UE.

Or the AMF sends the second key identifier and the third indication information to the UE.

If not activated, in NAS SMC process #2, the AMF sends a second NAS SMC message to the UE, where the second NAS SMC message includes the first key identifier. The NAS key identified by the first key identifier is the key currently being used by the AMF and the UE.

In a possible implementation manner, the AMF preliminarily determines that the current key does not need to be updated according to the triggering cause of the primary authentication. Further, the AMF may select a security algorithm, the security algorithm includes: an encryption algorithm and an integrity protection algorithm, and compare whether the security algorithm is the same as the currently used security algorithm identified by the current first key identifier. If it is the same, it is finalized to do nothing, i.e. not update the key. If different, the key needs to be updated through the NAS SMC process #2 to activate the second security context. Exemplarily, the AMF sends the first key identifier to the UE through a second NAS SMC message ("NAS Security Mode Command" message). That is, the second NAS SMC message carries the first key identifier (eg, ngKSI#1). Specifically, the AMF puts the encryption algorithm and/or the integrity protection algorithm used by the first key identifier into the second NAS SMC message as the selected security algorithm. The second NAS SMC message uses K _NASint-1 corresponding to the first key identifier for integrity protection and/or K _NASenc-1 for confidentiality protection.

In another implementation, no primary authentication process occurs. When the AMF generates Kamf#2, but does not generate the second key identifier, the AMF determines that the second security context does not need to be activated. In order to synchronize the keys between the UE and the AMF, the second NAS SMC message includes second indication information (Kamf change), which indicates that the UE needs to generate a new Kamf, which is called Kamf#2 (the original used by the UE The Kamf is called Kamf#1). Optionally, the AMF carries the first key identifier in the second NAS SMC message, and optionally, the second NAS SMC message also carries third indication information.

In another implementation method, the UE can compare whether the key identifier from the AMF in the second NAS SMC message is the same as the key identifier of the intermediate key currently being used by the UE, and the UE also needs to verify the second NAS SMC message. Whether the security algorithm corresponding to the key identifier is the same as the security algorithm currently being used by the UE. If all are the same, and the UE verifies that the integrity protection of the NAS SMC is correct, the UE may continue to use the current 5G NAS security context without updating the first security context. That is, with the current key and security algorithm, the NAS COUNT does not need to be reset to 0 either.

In another implementation method, the UE may activate the key identified by the first key identifier according to the description in step 610, which may include at least one of the following steps: generating the key identified by the key identifier #1 according to Kausf#1 , generate Kseaf#1, use Kseaf#1 to generate Kamf#1, and then use Kamf#1 and the selected security algorithm carried in the second NAS SMC message to generate K _NASint#1 and K _NASenc#1 , K NASint#1, K _NASint#1 , K _NASenc#1 encryption algorithm and integrity protection algorithm are used for specific functions, but the NAS COUNT remains unchanged.

In another implementation manner, the UE only compares whether the key identifier from the AMF carried in the second NAS SMC message is the same as the key identifier corresponding to the key currently being used. If the integrity protection check of the SMC message is successful, the first security context will not be updated, and the current 5G NAS security context will continue to be used.

In this embodiment of the present application, when the UE only needs to perform authentication, neither the UE side nor the network side need to update a new security context, which reduces the complexity of key update and improves device performance.

In the following, an application scenario proposed by the embodiments of the present application is introduced in conjunction with the foregoing embodiments. In this application scenario, the intermediate key is Kausf, and the security context is Kaf. It should be noted that the above-mentioned intermediate keys and security contexts are only illustrative, and the security contexts may also be other keys generated based on the intermediate keys, security algorithms, or key variants, which are not limited here. Specifically, please refer to FIG. 7, which is a schematic diagram of an application scenario proposed by an embodiment of the present application, including:

701. The UE sends a registration request message to the AMF.

702. The AMF sends the first key identifier to the UE.

703. The UE interacts with the AMF to complete the first primary authentication process.

704. NAS SMC process #1.

Steps 701-704 are the same as the aforementioned steps 601-604, and are not repeated here.

705. Store Kausf#1, and generate Kakma#1.

After the first main authentication process ends, the AUSF stores Kausf#1, and generates Kakma#1 according to the Kausf#1.

For the convenience of distinction, the AUSF storing Kausf#1 in step 705 is called AUSF#1.

706. Generate Kakma#1.

After the NAS SMC process #1 ends, the UE generates Kakma#1 according to Kausf#1.

707. Generate Kaf#1 (A-KID#1).

After the UE generates Kakma#1, the UE sends an A-KID to the AF, and the A-KID corresponds to Kakma#1, so the A-KID is called A-KID#1. The A-KID#1 is used to generate a corresponding Kaf, which is called Kaf#1.

For the specific process of generating Kaf#1, please refer to the aforementioned steps 402-406, which will not be repeated here.

708. When Kaf#1 is about to expire, the AF sends a first key request message to AAnF, where the first key request message carries A-KID#1.

When the AF determines that Kaf#1 is about to expire, the AF sends a first key request message to the AAnF, where the first key request message carries A-KID#1.

Optionally, when the AF has the identification information of the UE, the AF carries the identification information of the UE in the first key request message.

Specifically, when the AF is an AF outside the operator, the identification information of the UE may be GPSI; when the AF is an AF within the operator, the identification information of the UE may be SUPI. The A-KID#1 is obtained when the UE accesses the AF for the first time, and the AF stores the A-KID#1.

709. The AAnF determines whether A-KID#1 exists according to the first key request message.

The AAnF determines whether A-KID#1 exists according to the first key request message. When the first key request message carries A-KID#1, the AAnF checks whether the same A-KID as the A-KID#1 exists locally.

When the first key request message carries the identity information of the UE, the AAnF further determines whether Kakma#2 exists, and Kakma#2 is the updated Kakma. Kakma#1 is relative to the key generated by the first intermediate key (Kausf#1), so Kakma#2 is the updated Kakma, which is generated by the second intermediate key (Kausf#2).

If A-KID#1 exists, go to step 710 .

If the AAnF determines that the A-KID#1 is not present locally, the AAnF determines whether there is Kakma#2 by using the identification information of the UE carried in the first key request message. If so, go to step 717 (steps 710-716b are not executed). If not, a failure message code is returned in the response message (in step 717, steps 710-716b are not performed), indicating that Kakma could not be found.

The first key request request message may be a "Naanf_AKMA_ApplicationKey_Get request" message.

710. If A-KID#1 exists, the AAnF sends a second key request message to the AUSF, where the second key request message carries the permanent identification information of the UE.

Optionally, the second key request message carries the first indication information. The first indication information is associated with the second network element, and the first indication information instructs the terminal device to update the communication key between the terminal device and the second network element. The second network element includes any of the following but not limited to NEF, AAnF, ECS, EES or AF. Exemplarily, when the second network element is an AF, the first indication information may be identification information of the AF.

Before the AAnF sends the second key request message, the AAnF selects the AUSF. The AAnF can determine the AUSF that provides the server for the UE in various ways. The following are respectively explained:

(1) The AAnF determines the AUSF that serves the UE from the UDM according to the permanent identification information (SUPI) of the UE corresponding to the A-KID#1. This AUSF is called AUSF#1. Specifically, the UDM determines an AUSF according to the identification information of the UE, and Kausf#1 is stored in the AUSF. Since the AUSF receives the indication information sent by the UDM that the UE supports the AKMA service (that is, the foregoing steps 302-303 have been performed between AUSF#1 and the UDM), the AUSF confirms that the UE supports the AKMA service. In this embodiment of the present application, the AKMA service indication information may be "AKMA Indication (AKMA Ind)" or "AKMA ID", which is not limited.

(2) The AAnF requests the NRF to acquire an AUSF according to the RID in A-KID#1, and the AUSF can provide services for the UE. The AUSF may be AUSF#1, or may be another AUSF (eg, AUSF#2). If the AUSF is AUSF#2, since the AUSF#2 has not received the indication information that the UE supports the AKMA service, the AUSF#2 cannot confirm whether the UE supports the AKMA service. The foregoing steps 302-303 need to be passed between AUSF#2 and the UDM, so that AUSF#2 obtains the AKMA service indication information of the UE.

Specifically, the second key request message is used to instruct the AMF to determine not to activate the second security context. Optionally, the second key request message carries indication information, where the indication information is used to instruct the AMF to determine not to activate the second security context. Optionally, the second key request message carries the identification information of the AF, where the identification information of the AF is used to indicate that the AMF does not activate the second security context.

The identification information of the UE may be SUPI or SUCI, and the identification information of the AF may be AF_ID. The identification information of the UE is used to notify the AUSF to determine the data related to the UE (for example, Kausf#1 and the AKMA service indication information of the UE). The identification information of the AF is also used to inform the AUSF of which AF's key needs to be updated.

It should be noted that the second key request message may not include the first indication information, and the first indication information may be sent to the UE in other ways, which is not limited here.

In another implementation manner, the AAnF may directly send a third authentication request message to the AMF, where the third authentication request message carries the permanent identification information of the UE, and optionally carries the AF ID. Before the AAnF sends this message, the AAnF needs to determine the AMFs that can serve the UE. The AAnF determines the AMF serving the UE from the UDM according to the UE's permanent identity information. When the AAnF directly sends the user third authentication request message to the AMF, steps 711 and 712 are not executed.

711. The AUSF determines an AMF serving the UE.

The AUSF determines the AMF serving the UE from the UDM according to the UE's permanent identity information.

Before the AUSF determines the AMF serving the UE, the AUSF first determines that the UE supports the AKMA service.

The AAnF may determine that the UE supports the AKMA service in various ways. The following are respectively explained:

(1) After determining AUSF #1 for the first method of selecting AUSF in step 710 . Since the AUSF receives the indication information sent by the UDM that the UE supports the AKMA service (that is, the foregoing steps 302-303 have been performed between AUSF#1 and the UDM), the AUSF confirms that the UE supports the AKMA service. In this embodiment of the present application, the AKMA service indication information may be "AKMA Indication (AKMA Ind)" or "AKMA ID", which is not limited.

(2) After determining the AUSF for the second method of selecting AUSF in step 710, if the AUSF is not AUSF#1, since the AUSF#2 has not received the indication information that the UE supports the AKMA service, the AUSF#2 It cannot be confirmed whether the UE supports the AKMA service. Then AUSF#2 needs to request the UDM whether the UE supports the AKMA service. This process may be that AUSF#2 sends a request message to the UDM, the request message is used to request the UDM whether the U supports AKMA, and the message carries the permanent identifier SUPI of the user. The UDM can directly reply a response message indicating support or non-support, or carry AKMA indication information in the response message. AUSF#2 determines whether the UE supports the AKMA service according to the response message or the indication information in the response message. For example, if the response message is a success message or carries AKMA indication information, it is determined that the UE supports the AKMA service. In another possible implementation manner, the foregoing steps 302-303 need to be passed between AUSF#2 and the UDM, so that AUSF#2 obtains the AKMA service indication information of the UE. This process may occur in the second main authentication process, or may be issued before step 712 . If it occurs before step 712, it means that the AUSF needs to determine that the UE can support the AKMA service, and then proceed to step 712, that is, request to trigger the main authentication process. If this process occurs in the step-master authentication process, after receiving the authentication response message, the AUSF should first check whether the message carries AKMA indication information, and if so, continue the process. If not carried, terminate the process.

The purpose of determining whether the UE supports AKMA is to prevent an AAnF from randomly carrying SUPI to initiate a key update process. Because the main authentication process affects the current service of the UE, certain deterministic checks are required.

After the AUSF determines the AMF serving the UE, the AUSF replies to the AAnF with a response message corresponding to the second key request message.

712. The AUSF sends a third authentication request message to the AMF, and after receiving the third authentication request message, the AMF sends a response message to the AUSF.

Since it is determined in step 709 that A-KID#1 does not exist, the final purpose of the third authentication request message is to request to update Kakma, that is, to request to obtain Kakma#2. Optionally, the indication information carried in the third authentication request message is the identification information of the AF, and the AMF may determine not to activate the second security context according to the indication of the identification information of the AF. That is, the indication information is used for the AMF to judge that the second security context is not activated.

Optionally, before step 712, the AUSF obtains the authentication vector from the UDM, and the specific manner is the same as the foregoing steps 302-303, which will not be repeated here.

It should be noted that the AUSF may also instruct the AMF to determine whether to activate the second security context through other messages, which is not limited here. The third authentication request message is just an example.

713. Trigger the second primary authentication process.

After receiving the third authentication request message, the AMF triggers the second main authentication process.

It should be noted that it is only a possible example that the AMF receives the third authentication request message sent by the AUSF. The AMF may also receive a third authentication request message sent by the first network element, where the third authentication request message carries the permanent identification information of the terminal device, and the third authentication request message is used to trigger the second authentication request message between the UE and the network. Authentication.

The first network element includes any one of but not limited to: AUSF, NEF, AAnF, ECS, EES or AF.

714. The AMF sends the second key identifier to the UE.

Step 715 is a part of step 713. Specifically, the AMF determines to initiate the main authentication process, the AMF requests the AUSF to authenticate the UE, the AUSF requests the authentication vector from the UDM, the UDM sends the authentication vector to the AUSF, and the AUSF authenticates the UE. The vector is processed and sent to the AMF. The AMF generates a second key identifier after receiving the processed authentication vector, and sends the second key identifier to the UE along with the processed authentication vector.

715. The UE interacts with the AMF to complete the second primary authentication process (the AUSF obtains the second key identifier).

The UE, AMF and AUSF continue to complete the second primary authentication process.

After step 715, step 716a and step 720 are executed respectively. It should be noted that the execution order of step 716a and step 720 is not limited here.

716a. Store the second intermediate key.

The AUSF stores the intermediate key corresponding to the second key identifier, and the second intermediate key is Kausf#2. The AUSF generates Kakma#2 and A-KID#2 based on the second intermediate key.

716b. Send the identification information of the UE, A-KID#2 and Kakma#2.

The AUSF sends the UE's Permanent Identity Information (SUPI), A-KID#2 and Kakma#2 to the AAnF.

717. AAnF uses Kakma#2 to generate Kaf#2.

718. The AAnF sends a first key request response message to the AF, where the first key request message carries the expiration time of A-KID#2, Kaf#2, and Kaf#2.

The AAnF sends a first key request response message to the AF, where the first key request response message may be a "Naanf_AKMA_ApplicationKey_Get response" message.

The first key request message carries the expiration time of A-KID#2, Kaf#2 and Kaf#2.

719. Store A-KID#2 and Kaf#2.

AF stores A-KID#2 and Kaf#2.

720. The AMF determines whether to activate the second security context.

The AMF may be determined in step 712 , and may be determined at any time between steps 712 and 721 . For example, it is determined in step 720 . Step 720 can be understood as an action immediately before sending 721 . For details, please refer to the description in step 712.

That is, after step 712, the AMF determines not to activate the second security context after comprehensive judgment according to the third authentication request message from the AUSF.

721. It is determined that it is not activated, and the NAS SMC process #2 carries the first key identifier.

If not activated, in NAS SMC procedure #2, the AMF sends the first key identifier to the UE.

Exemplarily, the AMF sends the first key identifier to the UE through a NAS SMC message ("NAS Security Mode Command" message). That is, the NAS SMC message carries the first key identifier (eg, ngKSI#1).

Optionally, the AMF may also send indication information for updating Kakma to the UE, where the indication information for updating Kakma is used to instruct the UE to generate Kakma#2 and A-KID#2. Optionally, the indication information for updating the Kakma may be the identification information (AF_ID) of the AF, or may be an indication information. The identification information of the AF can also be used to instruct the UE to generate a new Kaf, that is, Kaf#2 (the UE generates Kaf#2 according to the AF_ID).

722. The UE stores the Kausf#2 corresponding to the second key identifier.

When the UE stores Kausf#2 successfully, the UE replies a NAS SMP message ("NAS Security Mode complete" message) to the AMF. The NAS SMP message uses the integrity protection key and encryption key corresponding to the second key identifier (ngKSI#2) to perform confidentiality protection and integrity protection.

723. The UE generates Kakma#2 and Kaf#2 based on Kausf#2, and updates the key corresponding to the identification information of the AF to Kaf#2. Optionally, the UE generates Kakma#2 and Kaf#2 according to the indication information for updating the Kakma.

724. The UE sends a first activation request message to the AF, where the first activation request message carries A-KID#2, and the first activation request message instructs the AF to activate Kaf#2.

After the UE generates a new Kaf (ie, Kaf#2), the UE initiates the activation process of the Kaf#2. Specifically, the UE sends a first activation request message to the AF, where the first activation request message carries A-KID#2, and the first activation request message instructs the AF to activate Kaf#2.

The UE determines which AF to send the first activation request message with according to the AF ID carried by the NAS SMC, that is, initiates the Kaf update process.

The first activation request message carries A-KID#2.

Optionally, the time interval between step 724 and step 723 may be as small as possible to ensure the normal operation of the AF.

Exemplarily, the first activation request message may be an "application session reestablishment request" message.

725. The AF sends a first activation response message to the UE.

After the AF receives the first activation request message, the AF determines whether the Kaf#2 corresponding to the A-KID#2 has been stored locally according to the A-KID#2, and if so, activates the Kaf#2. The activation operation is as follows: create a security function function, and put the updated key into the security function for use. AF removes or stops the safety function used before (put the safety function of Kaf#1).

After the activation is successful, the AF sends a first activation response message to the UE.

Exemplarily, the first activation response message may be an "application session reestablishment response" message.

In the application scenario illustrated in FIG. 7 , the new key (Kaf#2) for AF activation is indicated by the UE, and the UE itself activates the Kaf#2. Based on this, an embodiment of the present application further proposes an application scenario, please refer to FIG. 8 , and FIG. 8 is a schematic diagram of another application scenario proposed by the embodiment of the present application. In the application scenario shown in FIG. 8 , the AF itself activates Kaf#2, and the local Kaf#2 of the UE is instructed to activate by the AF. Specifically, the application scenarios include:

801. The UE sends a registration request message to the AMF.

802. The AMF sends the first key identifier to the UE.

803. The UE interacts with the AMF to complete the first primary authentication process.

804. NAS SMC process #1.

805. Store Kausf#1, and generate Kakma#1.

806. Generate Kakma#1.

807. Generate Kaf#1 (A-KID#1).

808. When the Kaf#1 is about to expire, the AF sends a first key request message to the AAnF, where the first key request message carries the A-KID#1.

809. The AAnF determines whether A-KID#1 exists according to the first key request message.

810. If A-KID#1 exists, the AAnF sends a second key request message to the AUSF, where the second key request message carries the permanent identification information of the UE.

811. The AUSF determines the AMF that serves the UE.

812. The AUSF sends a third authentication request message to the AMF, and after receiving the third authentication request message, the AMF sends a response message to the AUSF.

813. Trigger the second primary authentication process.

814. The AMF sends the second key identifier to the UE.

815. The UE and the AMF interact to complete the second primary authentication process (the AUSF obtains the second key identifier).

816a. Store the second intermediate key.

816b. Send the identification information of the UE, A-KID#2 and Kakma#2.

817. AAnF uses Kakma#2 to generate Kaf#2.

818. The AAnF sends a first key request response message to the AF, where the first key request message carries the expiration time of A-KID#2, Kaf#2, and Kaf#2.

819. Store A-KID#2 and Kaf#2.

820. The AMF determines whether to activate the second security context.

821. If it is determined not to activate, the NAS SMC process #2 carries the first key identifier.

822. The UE stores the Kausf#2 corresponding to the second key identifier.

Steps 801-822 are the same as the aforementioned steps 701-722, and are not repeated here.

823. The AF sends a second activation request message to the UE, where the second activation request message carries A-KID#2, and the second activation request message instructs the UE to generate a new Kaf.

824. If the UE has not generated A-KID#2, the UE generates Kakma#2 and A-KID#2 based on Kausf#2. If the UE has generated A-KID#2, the UE compares the locally generated A-KID# 2 is the same as the A-KID#2 from the AF, if it is the same, the key corresponding to the identification information of the AF is updated to Kaf#2.

825. The AF sends a second activation response message to the UE.

After the AF activates Kaf#2 successfully, the AF sends a second activation response message to the UE.

The activation operation is as follows: create a security function function, and put the updated key into the security function for use. AF removes or stops the safe function used before (put the safe function of Kaf#1).

Based on the foregoing embodiments, an embodiment of the present application further proposes an application scenario, please refer to FIG. 9 , and FIG. 9 is a schematic diagram of another application scenario proposed by an embodiment of the present application. In the application scenario of Figure 9, the AMF does not initiate the NAS SMC process, so that the UE does not store the new intermediate key for a long time. Specifically, the application scenarios include:

901. The UE sends a registration request message to the AMF.

902. The AMF sends the first key identifier to the UE.

903. The UE interacts with the AMF to complete the first primary authentication process.

904. NAS SMC process #1.

905. Store Kausf#1, and generate Kakma#1.

906. Generate Kakma#1.

907. Generate Kaf#1 (A-KID#1).

908. When Kaf#1 is about to expire, the AF sends a first key request message to AAnF, where the first key request message carries A-KID#1.

909. The AAnF determines whether A-KID#1 exists according to the first key request message.

910. If A-KID#1 exists, the AAnF sends a second key request message to the AUSF, where the second key request message carries the permanent identification information of the UE.

911. The AUSF determines the AMF that serves the UE.

912. The AUSF sends a third authentication request message to the AMF, and after receiving the third authentication request message, the AMF sends a response message to the AUSF.

913. Trigger the second primary authentication process.

914. The AMF sends the second key identifier to the UE.

915. The UE interacts with the AMF to complete the second primary authentication process (the AUSF obtains the second key identifier).

916a. Store the second intermediate key.

916b. Send the identification information of the UE, A-KID#2 and Kakma#2.

917. AAnF uses Kakma#2 to generate Kaf#2.

918. The AAnF sends a first key request response message to the AF, where the first key request message carries the expiration time of A-KID#2, Kaf#2, and Kaf#2.

919. Store A-KID#2 and Kaf#2.

Steps 901-919 are the same as the aforementioned steps 701-719, and are not repeated here.

920. The AMF determines not to initiate the NAS SMC process.

When AMF learns that only Kakma and Kaf need to be updated, AMF determines not to initiate the NAS SMC process to ensure that the existing key structure is not affected and the complexity of key update is reduced.

921. Since the UE has not received the NAS SMC message, the UE only caches Kausf#2.

Since the AMF does not initiate the NAS SMC process, the AMF does not send the NAS SMC message to the UE. Therefore, the UE only caches Kausf#2. Specifically, the Kausf#2 is stored in the cache area of the UE, and the Kausf#2 is not stored in the long-term storage area of the UE.

922. The AF sends a second activation request message to the UE, where the second activation request message carries A-KID#2, and the second activation request message instructs the AF to generate a new Kaf.

After the AF receives the new Kaf (ie, Kaf#2), the AF initiates the activation process of the Kaf#2. Specifically, the AF sends a second activation request message to the UE, where the second activation request message carries A-KID#2, and the activation request message instructs the UE to generate Kaf#2.

Optionally, the time interval between step 922 and step 919 may be as small as possible to ensure the normal operation of the AF.

Exemplarily, the second activation request message may be an "application session reestablishment request" message.

923. The UE generates Kakma#2 and A-KID#2 based on Kausf#2. If the A-KID#2 locally generated by the UE is the same as the A-KID#2 from the AF, the key corresponding to the identification information of the AF is updated for Kaf#2.

924. The AF sends a second activation response message to the UE.

The solutions provided by the embodiments of the present application are described above mainly from the perspective of methods. It can be understood that, in order to realize the above-mentioned functions, the communication apparatus includes corresponding hardware structures and/or software modules for executing each function. Those skilled in the art should easily realize that the present application can be implemented in hardware or in the form of a combination of hardware and computer software. Whether a function is performed by hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Skilled artisans may implement the described functionality using different methods for each particular application, but such implementations should not be considered beyond the scope of this application.

In this embodiment of the present application, the communication device may be divided into functional modules according to the foregoing method examples. For example, each functional module may be divided corresponding to each function, or two or more functions may be integrated into one transceiver module. The above-mentioned integrated modules can be implemented in the form of hardware, and can also be implemented in the form of software function modules. It should be noted that, the division of modules in the embodiments of the present application is schematic, and is only a logical function division, and there may be other division manners in actual implementation.

The communication device in the present application will be described in detail below, please refer to FIG. 10 , which is a schematic diagram of an embodiment of the communication device in the embodiment of the present application. The communication apparatus can be deployed in a network device or a chip or a chip system, and the communication apparatus 1000 includes:

A processing module 1001, configured to generate a second security context, where the second security context is inconsistent with the first security context, and the first security context is the security context currently used by the access and mobility management function;

The processing module 1001 is further configured to determine whether to activate the second security context.

In one possible implementation,

The transceiver module 1002 is configured to send a second authentication request message including a second key identifier to the terminal device, where the second authentication request message is used to trigger a second authentication between the terminal device and the network. right;

The processing module 1001 is further configured to, after the second authentication succeeds, determine whether to activate the second security context generated in the second authentication process;

The transceiver module 1002 is further configured to send a second non-access stratum security mode command NAS SMC message to the terminal device without activating the second security context, where the second NAS SMC message includes a first key identifier; wherein the first key identifier is the key identifier of the first security context currently used by the access and mobility management function.

In one possible implementation,

The transceiver module 1002 is further configured to send a first authentication request message including the first key identifier to the terminal device, where the first authentication request message is used to trigger the communication between the terminal device and the network. the first authentication between

The transceiver module 1002 is further configured to, after the first authentication succeeds, send a first NAS SMC message to the terminal device to activate the first security context generated in the first authentication process, The first NAS SMC message includes the first key identifier.

In one possible implementation,

The transceiver module 1002 is further configured to receive a registration request message from the terminal device.

In one possible implementation,

The processing module 1001 is further configured to determine not to activate the second security context when it is determined not to update the non-access stratum NAS key and/or the access stratum AS key,

or,

The processing module 1001 is further configured to determine to activate the second security context when it is determined that the non-access stratum NAS counter rolls over,

or,

The processing module 1001 is further configured to determine to activate the second security context when it is determined to update the non-access stratum NAS key context and/or the access stratum AS key context of the terminal device;

or,

The processing module 1001 is further configured to not activate the second security context when it is determined that the second authentication is triggered by a first network element, and the first network element includes any one of the following: an authentication management function AUSF , Network Open Function NEF, Authentication and Key Management Anchor Function AAnF, Edge Configuration Server ECS, Edge Enablement Server EES, Mobile Edge Computing MEC or Application Function AF;

or,

The processing module 1001 is further configured to not activate the second security context when it is determined that the second authentication only needs to authenticate the terminal device;

or,

The processing module 1001 is further configured to not activate the second security context when it is determined that the second authentication is triggered by the terminal device.

In one possible implementation,

The transceiver module 1002 is further configured to send the second key identifier to the terminal device after it is determined that the second security context is activated.

In one possible implementation,

The transceiver module 1002 is further configured to, after determining to activate the second security context, send first indication information to the terminal device, where the first indication information is associated with a second network element, and the first indication information instructing the terminal device to update the communication key between the terminal device and the second network element;

In one possible implementation,

The transceiver module 1002 is further configured to activate, by the access and mobility management function, a non-access stratum NAS key of a second intermediate key after determining to activate the second security context, the second security context corresponding to the second intermediate key;

In one possible implementation,

The transceiver module 1002 is further configured to receive a third authentication request message sent by the first network element, wherein the third authentication request message carries the permanent identification information of the terminal device, and the third authentication request message The message is used to trigger the second authentication between the terminal device and the network;

In one possible implementation,

The processing module 1001 is further configured to select a security algorithm to perform integrity protection and confidentiality protection on the second NAS SMC message sent by the access and mobility management function to the terminal device;

The processing module 1001 is further configured to determine not to activate the second security context when the security algorithm selected by the access and mobility management function is the same as the security algorithm corresponding to the first security context;

The transceiver module 1002 is further configured to send the second NAS SMC message to the terminal device, where the second NAS SMC message includes the first key identifier.

In one possible implementation,

The transceiver module 1002 is further configured to send a second non-access stratum security mode command NAS SMC message to the terminal device, where the second NAS SMC message includes second indication information, and the second indication information indicates the The terminal device generates Kamf#2, and activates the second security context corresponding to Kamf#2, where Kamf#2 is the updated Kamf.

In one possible implementation,

Please refer to FIG. 11 . FIG. 11 is a schematic diagram of an embodiment of a communication device according to an embodiment of the present application. The communication apparatus can be deployed in a terminal device or a chip or a chip system, and the communication apparatus 1100 includes:

A transceiver module 1101, configured to receive a second non-access stratum security mode command NAS SMC message from the access and mobility management function AMF, where the second NAS SMC message carries the key identifier from the AMF;

The processing module 1102 is configured to determine not to activate the second security context when the key identifier is the same as the first key identifier of the first security context being used by the terminal device, and the second security context is the same as the first security context. The first security contexts are inconsistent.

In one possible implementation,

The processing module 1102 is further configured to determine not to activate the NAS security context in the second security context and/or the AS security context in the second security context.

In one possible implementation,

The processing module 1102 is further configured to verify whether the security algorithm corresponding to the key identifier from the AMF is the same as the security algorithm corresponding to the first security context, and the security algorithm corresponding to the key identifier from the AMF is the same. algorithm is the security algorithm selected by the access and mobility management function;

The processing module 1102 is further configured to determine not to update the first security context when the security algorithm corresponding to the key identifier from the AMF is the same as the security algorithm corresponding to the first security context.

In one possible implementation,

The transceiver module 1101 is further configured to receive first indication information sent by the access and mobility management function, where the first indication information is associated with a second network element, and the first indication information indicates the terminal device updating the communication key between the terminal device and the second network element;

The communication device in the foregoing embodiment may be a network device, or may be a chip applied in the network device, or other combined devices or components that can implement the functions of the foregoing network device. When the communication device is a network device, the transceiver module may be a transceiver, the transceiver may include an antenna and a radio frequency circuit, etc., and the processing module may be a processor, such as a baseband chip. When the communication device is a component having the above-mentioned network equipment function, the transceiver module may be a radio frequency unit, and the processing module may be a processor. When the communication device is a chip system, the transceiver module may be an input port of the chip system, the transceiver module may be an output interface of the chip system, and the processing module may be a processor of the chip system, such as a central processing unit (CPU) .

The communication device in the above-mentioned embodiment may be a terminal device, or a chip applied in the terminal device or other combined devices, components, etc. that can realize the functions of the above-mentioned terminal device. When the communication device is a terminal device, the transceiver module may be a transceiver, the transceiver may include an antenna and a radio frequency circuit, and the like, and the processing module may be a processor, such as a baseband chip. When the communication device is a component having the functions of the above terminal equipment, the transceiver module may be a radio frequency unit, and the processing module may be a processor. When the communication device is a chip system, the transceiver module may be an input port of the chip system, the transceiver module may be an output interface of the chip system, and the processing module may be a processor of the chip system, such as a central processing unit.

It should be noted that the information exchange, execution process and other contents between the modules/or components of the communication device are based on the same concept as the method embodiments corresponding to FIGS. 6 to 9 in this application. The descriptions in the method embodiments shown are not repeated here.

It should be noted that, for the specific implementation manner of the communication device and the beneficial effects brought about, reference may be made to the descriptions in the respective method embodiments corresponding to FIG. 6 to FIG. 9 , which will not be repeated here.

An embodiment of the present application further provides a processing apparatus, where the processing apparatus includes a processor and an interface; the processor is configured to execute the finite field encoding or decoding method according to any of the foregoing method embodiments.

It should be understood that the above-mentioned processing device may be a chip, and the processor may be implemented by hardware or software. When implemented by hardware, the processor may be a logic circuit, an integrated circuit, etc.; when implemented by software, The processor may be a general-purpose processor, and is implemented by reading software codes stored in a memory, which may be integrated in the processor, or located outside the processor, and exists independently.

Wherein, "implemented by hardware" means that the functions of the above-mentioned modules or units are realized by a hardware processing circuit that does not have the function of processing program instructions. The hardware processing circuit can be composed of discrete hardware components or an integrated circuit. In order to reduce power consumption and reduce size, it is usually implemented in the form of integrated circuits. The hardware processing circuit may include ASIC (application-specific integrated circuit, application-specific integrated circuit), or PLD (programmable logic device, programmable logic device); wherein, PLD may include FPGA (field programmable gate array, field programmable gate array) , CPLD (complex programmable logic device, complex programmable logic device) and so on. These hardware processing circuits can be a single semiconductor chip packaged separately (such as packaged into an ASIC); they can also be integrated with other circuits (such as CPU, DSP) and packaged into a semiconductor chip, for example, can be formed on a silicon substrate A variety of hardware circuits and CPUs are individually packaged into a chip, which is also called SoC, or circuits and CPUs for implementing FPGA functions can also be formed on a silicon substrate and individually enclosed into a single chip. Also known as SoPC (system on a programmable chip, programmable system on a chip).

The present application also provides a communication system, which includes at least one or more of a sender, a receiver, and an intermediate node.

An embodiment of the present application further provides a computer-readable storage medium, including instructions, which, when executed on a computer, cause the computer to control a network device to execute any one of the implementations shown in the foregoing method embodiments.

An embodiment of the present application also provides a computer program product, the computer program product includes computer program code, and when the computer program code runs on a computer, the computer can execute any one of the implementations shown in the foregoing method embodiments.

An embodiment of the present application further provides a chip system, including a memory and a processor, the memory is used to store a computer program, and the processor is used to call and run the computer program from the memory, so that the chip executes any one of the implementations shown in the foregoing method embodiments. Way.

Embodiments of the present application further provide a chip system, including a processor, where the processor is configured to call and run a computer program, so that the chip executes any one of the implementations shown in the foregoing method embodiments.

In addition, it should be noted that the device embodiments described above are only schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be A physical unit, which can be located in one place or distributed over multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution in this embodiment. In addition, in the drawings of the device embodiments provided in the present application, the connection relationship between the modules indicates that there is a communication connection between them, which may be specifically implemented as one or more communication buses or signal lines.

From the description of the above embodiments, those skilled in the art can clearly understand that the present application can be implemented by means of software plus necessary general-purpose hardware. Special components, etc. to achieve. Under normal circumstances, all functions completed by a computer program can be easily implemented by corresponding hardware, and the specific hardware structures used to implement the same function can also be various, such as analog circuits, digital circuits or special circuit, etc. However, a software program implementation is a better implementation in many cases for this application. Based on this understanding, the technical solutions of the present application can be embodied in the form of software products in essence, or the parts that make contributions to the prior art. The computer software products are stored in a readable storage medium, such as a floppy disk of a computer. , U disk, mobile hard disk, ROM, RAM, magnetic disk or optical disk, etc., including several instructions to make a computer device execute the methods described in the various embodiments of the present application.

In the above-mentioned embodiments, it may be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented in software, it can be implemented in whole or in part in the form of a computer program product.

The computer program product includes one or more computer instructions. When the computer program 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, special purpose computer, computer network, or other programmable device. The computer instructions may be stored in or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be downloaded from a website, computer, communication device, computing equipment or data center to another website site, computer, communication device, computing device, or data center by wire (eg, coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (eg, infrared, wireless, microwave, etc.) transmission. The computer-readable storage medium can be any available medium that can be stored by a computer, or a data storage device such as a communication device, a data center, or the like that includes one or more available media integrated. The usable media may be magnetic media (eg, floppy disks, hard disks, magnetic tapes), optical media (eg, DVD), or semiconductor media (eg, Solid State Disk (SSD)), and the like.

It is to be understood that reference throughout the specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic associated with the embodiment is included in at least one embodiment of the present application. Thus, appearances of "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily necessarily referring to the same embodiment. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner in one or more embodiments. It should be understood that, in various embodiments of the present application, the size of the sequence numbers of the above-mentioned processes does not mean the sequence of execution, and the execution sequence of each process should be determined by its functions and internal logic, and should not be dealt with in the embodiments of the present application. implementation constitutes any limitation.

Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. Interchangeability, the above description has generally described the components and steps of each example in terms of function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Skilled artisans may implement the described functionality using different methods for each particular application, but such implementations should not be considered beyond the scope of this application.

Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the system, device and unit described above may refer to the corresponding process in the foregoing method embodiments, which will not be repeated here.

In the several embodiments provided in this application, it should be understood that the disclosed system, apparatus and method may be implemented in other manners. For example, the apparatus embodiments described above are only illustrative. For example, the division of units is only a logical function division. In actual implementation, there may be other division methods, for example, multiple units or components may be combined or integrated. to another system, or some features can be ignored, or not implemented. On the other hand, the shown or discussed mutual coupling or direct coupling or communication connection may be through some interfaces, indirect coupling or communication connection of devices or units, and may be in electrical, mechanical or other forms.

Units described as separate components may or may not be physically separated, and components shown as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution in this embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically alone, or two or more units may be integrated into one unit. The above-mentioned integrated units may be implemented in the form of hardware, or may be implemented in the form of software functional units.

The integrated unit, if implemented as a software functional unit and sold or used as a stand-alone product, may be stored in a computer-readable storage medium. Based on this understanding, the technical solutions of the present application can be embodied in the form of software products in essence, or the parts that contribute to the prior art, or all or part of the technical solutions, and the computer software products are stored in a storage medium , including several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods in the various embodiments of the present application.

Claims

A communication method, comprising:

The access and mobility management function sends a second authentication request message containing a second key identifier to the terminal device, the second authentication request message being used to trigger a second authentication between the terminal device and the network ;

After the second authentication is successful, the access and mobility management function determines whether the second security context generated during the second authentication needs to be activated;

In the case where activation of the second security context is not required, the access and mobility management function sends a second non-access stratum security mode command NAS SMC message to the terminal device, the second NAS SMC message including a first key identifier; wherein the first key identifier is the key identifier of the first security context currently used by the access and mobility management function.
The method of claim 1, wherein before the access and mobility management function sends the second authentication request message containing the second key identifier to the terminal device, the The method also includes:

The access and mobility management function sends a first authentication request message containing the first key identifier to the terminal device, and the first authentication request message is used to trigger an exchange between the terminal device and the network. the first authentication between

After the first authentication is successful, a first NAS SMC message is sent to the terminal device to activate the first security context generated during the first authentication process, the first NAS SMC message includes the the first key identifier.
The method of claim 2, wherein before the access and mobility management function sends the first authentication request message containing the first key identifier to the terminal device, the Methods also include:

The access and mobility management function receives a registration request message from the terminal device.
The method according to any one of claims 1-3, wherein the access and mobility management function determines whether the second security context generated in the second authentication process needs to be activated, comprising: :

When the access and mobility management function determines that it is not necessary to update the non-access stratum NAS key and/or the access stratum AS key, the access and mobility management function determines not to activate the second security context,

or,

when the access and mobility management function determines that the non-access stratum NAS counter rolls over, the access and mobility management function determines to activate the second security context,

or,

When the access and mobility management function determines that it is necessary to update the non-access stratum NAS key context and/or the access stratum AS key context of the terminal device, the access and mobility management function determines to activate the the second security context;

or,

The access and mobility management function determines that the second authentication is triggered by the first network element, the access and mobility management function determines not to activate the second security context, and the first network element includes Any of the following: Authentication Management Function AUSF, Network Open Function NEF, Authentication and Key Management Anchor Function AAnF, Edge Configuration Server ECS, Edge Enablement Server EES, Mobile Edge Computing MEC or Application Function AF;

or,

The access and mobility management function determines that the second authentication only needs to authenticate the terminal device, then the access and mobility management function determines not to activate the second security context;

or,

The access and mobility management function determines that the second authentication is triggered by the terminal device, and the access and mobility management function determines not to activate the second security context.
The method according to any one of claims 1-4, wherein the method further comprises:

In the event that the access and mobility management function determines that activation of the second security context is required, the access and mobility management function sends the second key identifier to the terminal device.
The method according to any one of claims 1-5, wherein the method further comprises:

In the case that the access and mobility management function determines that the second security context needs to be activated, the access and mobility management function sends first indication information to the terminal device, where the first indication information is related to The second network element is associated, and the first indication information instructs the terminal device to update the communication key between the terminal device and the second network element;

The second network element includes any one of the following: an authentication management function AUSF, a network opening function NEF, an authentication and key management anchor function AAnF, an edge configuration server ECS, an edge enabling server EES, a mobile edge computing MEC or an application function AF.
The method according to any one of claims 1-6, wherein,

The second security context includes one or more of the following: Kseaf#2, Kamf#2, Kaf#2, Kakma#2, K NASint#2 , K NASenc#2 , K gNB#2 , K RRCint#2 , K RRCenc#2 or K N3IWF#2 .
A communication method, characterized in that the method is applied to a terminal device, and the method includes:

the terminal device receives a second non-access stratum security mode command NAS SMC message from the access and mobility management function AMF, the second NAS SMC message carrying the key identifier from the AMF;

When the key identifier is the same as the first key identifier of the first security context being used by the terminal device, the terminal device determines not to activate the second security context, the second security context and the The first security context is inconsistent.
The method according to claim 8, wherein determining by the terminal device not to activate the second security context comprises:

The terminal device determines not to activate the NAS security context in the second security context and/or the AS security context in the second security context.
The method according to any one of claims 8-9, wherein before the terminal device determines not to activate the second security context, the method further comprises:

The terminal device verifies whether the security algorithm corresponding to the key identifier from the AMF is the same as the security algorithm corresponding to the first security context, and the security algorithm corresponding to the key identifier from the AMF is the security algorithms selected for ingress and mobility management functions;

When the security algorithm corresponding to the key identifier from the AMF is the same as the security algorithm corresponding to the first security context, the terminal device determines not to update the first security context.
The method according to any one of claims 8-10, wherein the method further comprises:

The terminal device receives the first indication information sent by the access and mobility management function, the first indication information is associated with the second network element, and the first indication information instructs the terminal device to update the terminal the communication key between the device and the second network element;

The second network element includes any one of the following: a network opening function NEF, an authentication and key management anchor function AAnF, an edge configuration server ECS, an edge enabling server EES, a mobile edge computing MEC or an application function AF.
A communication device, characterized in that it includes:

a transceiver module, configured to send a second authentication request message including a second key identifier to the terminal device, where the second authentication request message is used to trigger the second authentication between the terminal device and the network;

a processing module, configured to determine whether the second security context generated in the second authentication process needs to be activated after the second authentication is successful;

The transceiver module is further configured to send a second non-access stratum security mode command NAS SMC message to the terminal device without activating the second security context, where the second NAS SMC message includes the first NAS SMC message. a key identifier; wherein the first key identifier is the key identifier of the first security context currently used by the access and mobility management function.
The communication device according to claim 12, wherein:

The transceiver module is further configured to send a first authentication request message containing the first key identifier to the terminal device, where the first authentication request message is used to trigger the connection between the terminal device and the network the first authentication;

The transceiver module is further configured to, after the first authentication succeeds, send a first NAS SMC message to the terminal device to activate the first security context generated in the first authentication process, so the The first NAS SMC message includes the first key identifier.
The communication device according to claim 13, wherein:

The transceiver module is further configured to receive a registration request message from the terminal device.
The communication device according to any one of claims 12-14,

The processing module is further configured to determine not to activate the second security context when it is determined that the non-access stratum NAS key and/or the access stratum AS key need not be updated,

or,

The processing module is further configured to determine to activate the second security context when it is determined that the non-access stratum NAS counter rolls over,

or,

The processing module is further configured to determine to activate the second security context when it is determined that the non-access stratum NAS key context and/or the access stratum AS key context of the terminal device needs to be updated;

or,

The processing module is further configured to not activate the second security context when it is determined that the second authentication is triggered by a first network element, and the first network element includes any one of the following: an authentication management function AUSF, Network Open Function NEF, Authentication and Key Management Anchor Function AAnF, Edge Configuration Server ECS, Edge Enablement Server EES, Mobile Edge Computing MEC or Application Function AF;

or,

The processing module is further configured to not activate the second security context when it is determined that the second authentication only needs to authenticate the terminal device;

or,

The processing module is further configured to not activate the second security context when it is determined that the second authentication is triggered by the terminal device.
The communication device according to any one of claims 12-15,

The transceiver module is further configured to send the second key identifier to the terminal device after it is determined that the second security context is activated.
The communication device according to any one of claims 12-16,

The transceiver module is further configured to, after determining to activate the second security context, send first indication information to the terminal device, where the first indication information is associated with the second network element, and the first indication information indicates The terminal device updates the communication key between the terminal device and the second network element;

The second network element includes any one of the following: an authentication management function AUSF, a network opening function NEF, an authentication and key management anchor function AAnF, an edge configuration server ECS, an edge enabling server EES, a mobile edge computing MEC or an application function AF.
The communication device according to any one of claims 12-17, characterized in that,

The processing module is further configured to select a security algorithm to perform integrity protection and confidentiality protection on the second NAS SMC message sent by the access and mobility management function to the terminal device;

The processing module is further configured to determine that the second security context is not activated when the security algorithm selected by the access and mobility management function is the same as the security algorithm corresponding to the first security context;

The transceiver module is further configured to send the second NAS SMC message to the terminal device, where the second NAS SMC message includes the first key identifier.
The communication device according to claim 12, wherein:

The transceiver module is further configured to send a second non-access stratum security mode command NAS SMC message to the terminal device, where the second NAS SMC message includes second indication information, and the second indication information indicates the terminal The device generates Kamf#2, and activates the second security context corresponding to Kamf#2, which is the updated Kamf.
The communication apparatus according to claim 19, wherein the second NAS SMC message further includes third indication information, wherein the third indication information instructs the terminal device to continue to use the NAS in the first security context A security context and an AS security context in the first security context.
The communication device according to any one of claims 12-20, characterized in that,

The second security context includes one or more of the following: Kseaf#2, Kamf#2, Kaf#2, Kakma#2, K NASint#2 , K NASenc#2 , K gNB#2 , K RRCint#2 , K RRCenc#2 or K N3IWF#2 .
A communication device, characterized in that:

a transceiver module for receiving a second non-access stratum security mode command NAS SMC message from the access and mobility management function AMF, where the second NAS SMC message carries the key identifier from the AMF;

A processing module, configured to determine that the second security context is not activated when the key identifier is the same as the first key identifier of the first security context being used by the terminal device, and the second security context is the same as the first security context. The first security context described above is inconsistent.
The communication device according to claim 22, wherein,

The processing module is further configured to determine not to activate the NAS security context in the second security context and/or the AS security context in the second security context.
The communication device according to any one of claims 22-23, characterized in that,

The processing module is further configured to verify whether the security algorithm corresponding to the key identifier from the AMF is the same as the security algorithm corresponding to the first security context, and the security algorithm corresponding to the key identifier from the AMF is the same a security algorithm selected for the access and mobility management function;

The processing module is further configured to determine not to update the first security context when the security algorithm corresponding to the key identifier from the AMF is the same as the security algorithm corresponding to the first security context.
The communication device according to any one of claims 22-24, characterized in that,

The transceiver module is further configured to receive first indication information sent by the access and mobility management function, where the first indication information is associated with a second network element, and the first indication information instructs the terminal device to update the communication key between the terminal device and the second network element;

The second network element includes any one of the following: a network opening function NEF, an authentication and key management anchor function AAnF, an edge configuration server ECS, an edge enabling server EES, a mobile edge computing MEC or an application function AF.
A communication device, characterized in that the communication device comprises: a memory and a processor;

The processor is adapted to execute a computer program or instructions stored in the memory to cause the communication device to perform the method of any one of claims 1-7 or 8-11.
A computer-readable storage medium, characterized in that the computer-readable storage medium has program instructions, and when the program instructions are directly or indirectly executed, the program instructions are as described in claims 1-7 or 8-11. Any of the described methods are implemented.
A chip system, characterized in that the chip system includes at least one processor, and the processor is configured to execute a computer program or an instruction stored in a memory, when the computer program or the instruction is executed in the at least one processor When executed, the method as claimed in any one of claims 1-7, or any of claims 8-11 is implemented.
A communication system, characterized in that the communication system includes terminal equipment and network equipment;

The network device is used to implement the method according to any one of claims 1-7;

The terminal device is used to implement the method of any one of claims 8-11.