CN111404669B - A key generation method, terminal equipment and network equipment - Google Patents

Abstract

The embodiment of the invention provides a key generation method, which relates to terminal equipment, network equipment, a computer readable storage medium and a system, wherein the method comprises the following steps: determining a first key based on the long-term key; determining a current session key generation mode from at least one session key generation mode based on the indication information sent by the network side; the indication information is used for indicating a session key generation mode; generating an authentication response and transmitting the authentication response to the network side when the authentication information transmitted by the network side successfully authenticates the network side, and generating a current session key based on the current session key generation mode; the at least one session key generation mode at least comprises the following steps: and generating a first session key generation mode of the session key based on the first key and the shared key stored by the terminal equipment.

Description

A key generation method, terminal equipment and network equipment

technical field

The present invention relates to the technical field of information processing, in particular to a method for generating a key, a terminal device, a network device, a computer storage medium and a system.

Background technique

5G will penetrate into all fields of the future society and play a key role in building a user-centered all-round information ecosystem. The security architecture is the guarantee for the normal operation of the 5G network. Authentication protocols are the cornerstone of building a 5G security architecture.

The 3rd Generation Partnership Project (3rd Generation Partnership Project, 3GPP) standard TS33.501 defines a 5G authentication and key agreement protocol (5G Authentication and Key Agreement, 5G-AKA) for authentication between the UE and the network, and During the mutual seriousness between the UE and the network, parameters related to the Diffie–Hellman key exchange (Diffie–Hellman key exchange, DH) key exchange must be generated each time. Generating these parameters requires the use of an asymmetric encryption algorithm, which consumes a large amount of computing resources, which is especially unacceptable for IoT terminals, because many IoT terminals require long-term working hours with limited-capacity batteries. Ability, the extensive use of asymmetric encryption algorithms will speed up the energy consumption of IoT devices and shorten the working hours of IoT devices.

Contents of the invention

To solve the above technical problems, embodiments of the present invention provide a method for generating a key, a terminal device, a network device, a computer storage medium, and a system.

In the first aspect, a method for generating a key is provided, which is applied to a terminal device, and the method includes:

determining a first key based on the long-term key;

Based on the indication information sent by the network side, determine the current session key generation method from at least one session key generation method;

When the network side is successfully authenticated based on the authentication information sent by the network side, an authentication response is generated and sent to the network side, and the current session key is generated based on the current session key generation method;

Wherein, the at least one session key generation method at least includes: a first session key generation method for generating a current session key based on the first key and a shared key stored in the terminal device.

In a second aspect, a method for generating a key is provided, which is applied to a network device, and the method includes:

determining a first key based on the long-term key;

Based on the indication information, determine the current session key generation method from at least one session key generation method;

When determining that the terminal device has successfully authenticated based on the authentication information and the authentication response sent by the terminal device, generating a current session key corresponding to the terminal device based on the current session key generation method;

Wherein, the at least one session key generation method at least includes: a first session key generation method for generating a current session key based on the first key and a shared key stored in the network device.

In a third aspect, a terminal device is provided, including:

The first communication unit is configured to receive indication information and authentication information sent by the network side;

The first key generation unit is configured to determine the first key based on the long-term key; determine the current session key generation method from at least one session key generation method based on the instruction information sent by the network side; based on the network side When the authentication information sent is successfully authenticated on the network side, an authentication response is generated and sent to the network side, and the current session key is generated based on the current session key generation method;

Wherein, the at least one session key generation method at least includes: a first session key generation method for generating a current session key based on the first key and a shared key stored in the terminal device.

In a fourth aspect, a terminal device is provided, including:

The first communication interface is used to receive indication information and authentication information sent by the network side;

The first processor is configured to determine the first key based on the long-term key; determine the current session key generation method from at least one session key generation method based on the indication information sent by the network side; When the authentication information is successfully authenticated to the network side, an authentication response is generated and sent to the network side, and the current session key is generated based on the current session key generation method;

Wherein, the at least one session key generation method at least includes: a first session key generation method for generating a current session key based on the first key and a shared key stored in the terminal device.

In the fifth aspect, a network device is provided, including:

The second communication unit is configured to send indication information and authentication information to the terminal device;

The second key generation unit is configured to determine the first key based on the long-term key; determine the current session key generation method from at least one session key generation method based on the indication information; and determine the session key generation method based on the authentication information and the terminal device sending When the authentication response determines that the terminal device is successfully authenticated, generate the current session key corresponding to the terminal device based on the current session key generation method;

Wherein, the at least one session key generation method at least includes: a first session key generation method for generating a current session key based on the first key and a shared key stored in the network device.

In a sixth aspect, a network device is provided, including:

The second communication interface is used to send instruction information and authentication information to the terminal device;

The second processor is configured to determine the first key based on the long-term key; determine the current session key generation method from at least one session key generation method based on the indication information; based on the authentication information and the authentication sent by the terminal device When the response determines that the authentication of the terminal device is successful, generate the current session key corresponding to the terminal device based on the current session key generation method;

Wherein, the at least one session key generation method at least includes: a first session key generation method for generating a current session key based on the first key and a shared key stored in the network device.

According to a seventh aspect, a computer storage medium is provided, on which a computer program is stored, wherein, when the computer program is executed by a processor, the steps of the aforementioned method for generating a key applied to a terminal device are implemented.

In an eighth aspect, a computer storage medium is provided, on which a computer program is stored, wherein, when the computer program is executed by a processor, the steps of the aforementioned method for generating a key applied to a network device are implemented.

In the ninth aspect, a key generation system, wherein the system includes: at least one terminal device, and an authentication service function AUSF entity; wherein,

The terminal device is configured to determine the first key based on the long-term key; determine the current session key generation method from at least one session key generation method based on the instruction information sent by the network side; When the authentication information is successfully authenticated to the network side, an authentication response is generated and sent to the network side, and the current session key is generated based on the current session key generation method;

The AUSF entity is configured to determine the first key based on the long-term key; determine the current session key generation method from at least one session key generation method based on the indication information; based on the authentication information and the terminal When the authentication response sent by the device determines that the terminal device has successfully authenticated, generate the current session key corresponding to the terminal device based on the current session key generation method;

Wherein, the at least one session key generation method at least includes: a first session key generation method for generating a current session key based on the first key and a shared key stored in the network device.

According to the technical solution of the embodiment of the present invention, when performing key exchange, the terminal device can generate a session key according to the long-term key and the shared key, and the network side instructs the terminal device to use the stored shared key by sending instruction information to the terminal device. The key generates a session key, without the terminal device using an asymmetric encryption algorithm to generate a new shared key for this session. In this way, by reusing the shared key, the usage of the asymmetric encryption algorithm in the key exchange protocol is reduced, and the power consumption of the terminal equipment is reduced.

Description of drawings

Fig. 1 is a schematic diagram of a key generation method in the prior art;

FIG. 2 is a schematic flow diagram 1 of a method for generating a key provided in an embodiment of the present application;

FIG. 3 is a schematic flow diagram 2 of a key generation method provided by an embodiment of the present invention;

FIG. 4 is a schematic flow chart 3 of a key generation method provided by an embodiment of the present invention;

FIG. 5 is a schematic diagram 1 of the composition and structure of a terminal device provided by an embodiment of the present invention;

FIG. 6 is a schematic structural diagram 2 of a terminal device provided by an embodiment of the present invention;

FIG. 7 is a schematic diagram 1 of a network device composition structure provided by an embodiment of the present invention;

FIG. 8 is a schematic diagram 2 of a network device composition structure provided by an embodiment of the present invention;

FIG. 9 is a schematic diagram of a system composition structure provided by an embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, but not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of this application.

A AKA relies on the root key K stored in the Universal Subscriber Identity Module (USIM) to achieve mutual authentication between the UE and the network, and to derive the session key. The safe assumption is that the root key K is unknown to anyone except the network operator. However, this assumption is not always correct, because the root key K may have been leaked during the production stage of USIM cards. Thus, a passive attacker can eavesdrop on communications using the root key K, and the session key derived from the messages exchanged between the UE and the network. An active attacker may use a large number of stolen root keys to fake a base station and launch a man-in-the-middle attack. Long-term key compromise has been identified as a critical issue in Section 5.2.3.2 of TR33.899.

In response to the above-mentioned key leakage problem, the DH key exchange protocol enhances the security of 5G AKA, which is called using DH on SEAF (SEcurity Anchor Function). The principle is that the DH key exchange protocol is completed during the SEAF mutual authentication process between the UE and the network. In addition to the root key K, the session key is generated by adding the DH shared key K_DH between the UE and the network. Even if the attacker knows the root key K, he cannot derive the session key because he does not know the shared key K_DH.

As shown in Figure 1, the steps to exchange session keys using DH on SEAF are as follows:

1. UDM/ARPF (Unified Data Management/Authentication credentialRepository and Processing Function) generates authentication vector 5G HE AV (RAND, AUTN, XRES*, KAUSF), and decrypts SUCI (Subscription Concealed Identifier) to obtain SUPI of UE.

2. UDM/ARPF sends the authentication vector 5G HE AV and SUPI to AUSF (Authentication Server Function).

3. AUSF temporarily stores XRES* and the corresponding SUPI, and may also store KAUSF for other uses.

4. AUSF uses XRES* to deduce HXRES*, and uses KAUSF to deduce KSEAF. Thus AUSF obtains 5G AV (RAND, AUTN, HXRES*, KSEAF).

5. AUSF sends 5G AV message to SEAF.

6. SEAF generates DH-related parameters according to the algorithm indicator Alg (indicating the DH algorithm used), and generates the public-private key pair (APUB, APRI) of SEAF.

7. The SEAF sends an authentication request (Authentication Request) message to the UE, which includes RAND, AUTN, APUB, and Alg.

8. The UE verifies the network, and generates an authentication response RES* if the verification succeeds. And the UE generates DH-related parameters according to the algorithm indicator Alg, that is, the public-private key pair (BPUB, BPRI) of the UE. UE uses its own private key BPRI and the received public key APUB of SEAF to generate the key K_DH shared with SEAF. UE constructs session key KSEAF'=KSEAF||K_DH

9. The UE sends an Authentication Response (Authentication Response) message to the SEAF, which includes RES*, BPUB.

10. SEAF deduces HRES* from RES*, and compares HRES* with HXRES*, and if successful, completes SEAF's authentication of UE. SEAF uses its own private key APRI and the received UE's public key BPUB to generate a key K_DH shared with the UE. The UE constructs a session key KSEAF'=KSEAF||K_DH.

11. SEAF sends RES* to AUSF.

12. AUSF realizes the verification of RES* by comparing RES* with XRES*.

13. If AUSF succeeds in verifying RES*, AUSF sends a message of successful verification and SUPI of UE to SEAF.

Here, the solution of using DH on SEAF solves the problem that the attacker knows the long-term key and can deduce the session key. However, SEAF and UE need to generate parameters related to DH key exchange each time. Generating these parameters requires the use of an asymmetric encryption algorithm, which consumes a large amount of computing resources, which is unacceptable for IoT terminals, because many IoT terminals require long-term working capabilities with limited-capacity batteries. The extensive use of asymmetric encryption algorithms will speed up the energy consumption of IoT devices and shorten the working hours of IoT devices.

In addition, in the solution of using DH on SEAF, since SEAF belongs to the network element of the roaming network, the home network does not know whether the roaming network implements the DH key exchange protocol to strengthen the session key. The roaming network may deceive the home network, so that the communication of the UE on the air interface may be eavesdropped due to the leakage of the long-term key.

Therefore, an embodiment of the present invention provides a method for generating a key, which can reduce the usage of asymmetric encryption algorithms in the key exchange protocol and reduce the power consumption of terminal equipment.

As shown in Figure 2, an embodiment of the present invention provides a method for generating a key, which is applied to a terminal device, and the method includes:

Step 201: Determine the first key based on the long-term key;

Step 202: Based on the indication information sent by the network side, determine the current session key generation method from at least one session key generation method;

Step 203: When the network side is successfully authenticated based on the authentication information sent by the network side, an authentication response is generated and sent to the network side, and the current session key is generated based on the current session key generation method;

Wherein, at least one session key generation method at least includes: a first session key generation method for generating a current session key based on the first key and a shared key stored in the terminal device.

Here, the subject of execution of steps 201 to 203 may be a processor of the terminal device.

Step 201 specifically includes: the network side device deduces the first key based on the long-term key, and sends the first key to the terminal device, and the terminal device receives the first key. The network-side device may be a network-side device with an AUSF function.

The method further includes: receiving indication information and authentication information sent by the network side; wherein, the indication information is preset by the terminal device, or determined by the network side based on the security level of the terminal. Specifically, which generation to use is determined according to the indication information carried in the Profile of the terminal device. The relevant information profile of the terminal device can be written into Unified Data Management (UDM, Unified Data Management) when the terminal device signs a contract with the network side, and then when the terminal device and the network need to exchange DH keys, the UDM to determine which generation the end device uses to generate the session key. Authentication information is the information required for mutual authentication between the network side and the terminal during the 5G communication authentication process, such as 5G Home Environment Authentication Vector (5GHE AV), SUPI (Subscription Permanent Identifier) and other information.

Specifically, the terminal device receives the indication information and authentication information sent by the device with the AUSF function on the network side.

The indication information is any of the following: a first indication used to indicate the first session key generation method, a second indication used to indicate the second session key generation method, and a second indication used to indicate the second session key generation method. 2. Instructions.

In practical applications, at least one session key generation method also includes: a second session key generation method for generating the current session key based on the first key and the new shared key; using the first key as the current The third session key generation method of the secondary session key.

Correspondingly, based on the instruction information sent by the network side, determining the current session key generation method from at least one session key generation method includes: when the instruction information is the first instruction, determining that the current session key generation method is the second A session key generation method; when the instruction information is the second instruction, determine that the session key generation method is the second session key generation method; when the instruction information is the third instruction, determine that the session key generation method is the second session key generation method Three session key generation methods. That is to say, the instruction information is used to instruct the terminal device to reuse the shared key, generate a new shared key or not use the shared key when generating the session key.

Exemplarily, the first session key generation method specifically includes: performing a hash operation on the first key and the shared key stored in the terminal device to generate the current session key; the second session key generation method specifically includes: A hash operation is performed on the first key and the new shared key to generate the current session key.

The method further includes: when the indication information is the second indication, generating a new shared key to be shared with the network side; and saving the new shared key.

That is to say, when the terminal device connects to the network to generate the shared key, when using the second session key generation method to generate the shared key for the first time, the shared key generated for the first time is stored on the USIM card of the terminal device or the information cannot be tampered with. in the storage area. Afterwards, when the terminal device exchanges the DH session key with the network, the first session key generation method is used to instruct the terminal device to reuse the stored shared key to generate a session key, so that the terminal device does not need to use an asymmetric encryption algorithm to generate a new shared key every time. The key can reduce the usage of asymmetric encryption algorithms in the key exchange protocol and reduce the power consumption of terminal equipment.

Optionally, next time the shared key is generated using the second session key generation method, the old shared key stored in the terminal device is replaced with the newly generated shared key, and then the terminal device exchanges the DH session key with the network , use the first session key generation method to instruct the terminal device to reuse the latest stored shared key to generate a session key.

That is to say, the shared key stored in the terminal device may be a newly generated shared key during a certain session key exchange process, for example, the shared key generated for the first time; Once a new shared key is issued, the old shared key stored in the terminal device is replaced with the new shared key.

In practical applications, when the mutual authentication between the terminal device and the network side is successful, an authentication response is generated and sent to the network side, and a session key is directly generated based on the current session key generation method. For example, when the mutual authentication between the UE and the UDM/ARPF is successful, the terminal device will store the newly generated shared key at the same time, and use the stored shared key to generate a session key. When the network side also succeeds in authentication based on the authentication response, a session key corresponding to the terminal device is generated, and the network side and the terminal device communicate according to the obtained session key.

Referring to Figure 3, when the network side exchanges keys with the terminal device, the steps for the terminal device to generate a session key based on the indication information are as follows:

1. UDM/ARPF generates authentication vector 5G HE AV (RAND, AUTN, XRES*, KAUSF), and decrypts SUCI to obtain UE's long-term user identity SUPI.

2. UDM/ARPF sends the authentication vectors 5G HE AV, SUPI, and UE Profile to AUSF, where the authentication vectors 5G HE AV and SUPI contain authentication information, and UE Profile contains indication information.

3. AUSF temporarily stores XRES* and the corresponding SUPI, and may also store KAUSF for other uses.

4. AUSF uses XRES* to deduce HXRES*, and uses KAUSF to deduce KSEAF (that is, the first key in the embodiment of the present invention). Thus AUSF obtains 5G AV (RAND, AUTN, HXRES*, KSEAF). AUSF determines the value of DH_ind (indication information) according to UE Profile. If the value of DH_ind is set to a (the second indication), the parameters related to the DH key exchange are generated. It first generates the private key APRI of the AUSF and derives the public key APUB of the AUSF. If the value of DH_ind is set to b (first indication) or c (third indication), no parameters related to DH key exchange are generated.

5. AUSF sends 5G AV message to SEAF, AUSF's public key APUB, and instruction Alg to use DH algorithm.

6. SEAF sends an authentication request (Authentication Request) message to the UE, which includes RAND, AUTN, APUB, DH_ind, and Alg. Among them, only when DH_ind is a, the Authentication Request message contains the public key APUB of AUSF.

7. The UE verifies the network, and generates an authentication response RES* if the verification succeeds. If DH_ind is a, the UE generates DH-related parameters according to the algorithm indicator Alg, that is, the UE’s public-private key pair (BPUB, BPRI). The UE uses its own private key BPRI and the received AUSF’s public key APUB to generate The key K_DH is stored on the USIM card or in a non-tamperable storage area. The UE generates the session key KSEAF' according to the DH_ind value as follows:

DH_ind=a, KSEAF'=HASH(KSEAF, K_DH), where K_DH is the newly generated shared key of the UE;

DH_ind=b, KSEAF'=HASH(KSEAF, K_DH), where K_DH is the shared key previously stored by the UE;

DH_ind=c, KSEAF'=KSEAF, the shared key is not used here, and the first key is used as the session key.

8. The UE sends an Authentication Response (Authentication Response) message to the SEAF, which includes RES*, BPUB.

9. SEAF deduces HRES* from authentication response RES*, and compares HRES* with HXRES*. If it succeeds, the authentication of the UE by SEAF is completed, and SEAF sends RES* and BPUB to AUSF.

10. AUSF realizes the verification of RES* by comparing the authentication response RES* with XRES*. AUSF uses its own private key APRI and received UE's public key BPUB to generate the key K_DH shared with UE and store it in the system. AUSF generates the session key KSEAF' according to the DH_ind value as follows:

DH_ind=a, KSEAF'=HASH(KSEAF, K_DH), where K_DH is the newly generated shared key of the UE;

DH_ind=b, KSEAF'=HASH(KSEAF, K_DH), where K_DH is the shared key previously stored by the UE;

DH_ind=c, KSEAF'=KSEAF, the shared key is not used here, and the first key is used as the session key.

11. If AUSF succeeds in verifying the authentication response RES*, AUSF sends a successful verification message, session key KSEAF', and UE's SUPI to SEAF.

Using the DH solution on the AUSF, since the AUSF belongs to the network element of the home network, the home network can know whether the AUSF implements the DH key exchange protocol to enhance the session key, which can prevent the roaming network from deceiving the home network to complete session key enhancement. In this way, the Internet of Things terminal can safely and efficiently complete the authentication process with the network. DH_ind is used to instruct terminal devices and network devices to reuse the shared key K_DH to generate a session key, thereby reducing the use of asymmetric encryption algorithms, and is suitable for use when IoT devices are connected to 5G networks.

It can be seen that by adopting the above scheme, during key exchange, the terminal device can generate a session key according to the long-term key and the shared key, and the network side instructs the terminal device to use the stored shared secret key by sending instruction information to the terminal device. key to generate a session key, without the need for the terminal device to use an asymmetric encryption algorithm to generate a new shared key for this session. In this way, by reusing the shared key, the usage of the asymmetric encryption algorithm in the key exchange protocol is reduced, and the power consumption of the terminal equipment is reduced.

As shown in Figure 4, the embodiment of the present invention provides a method for generating a key, which is applied to a network device, and the method includes:

Step 401: Determine the first key based on the long-term key;

Step 402: Based on the indication information, determine the current session key generation method from at least one session key generation method;

Step 403: When it is determined that the terminal device has successfully authenticated based on the authentication information and the authentication response sent by the terminal device, generate a current session key corresponding to the terminal device based on the current session key generation method;

Wherein, at least one session key generation method at least includes: a first session key generation method for generating the current session key based on the first key and a shared key stored in the network device.

Here, the subject of execution of steps 401 to 403 may be a processor of a network device. The network device involved in this embodiment may be regarded as a device with an AUSF function on the network side.

The method also includes: sending the first key to the terminal device; sending indication information and authentication information to the terminal device. Wherein, the indication information is preset by the terminal device, or determined by the network side based on the security level of the terminal. Specifically, which session key generation method to use is determined according to the indication information carried in the profile of the terminal device. The relevant information profile of the terminal device can be written into the UDM when the terminal device signs a contract with the network side, and then when the terminal device and the network need to exchange DH keys, the UDM determines which session the terminal device uses The key generation method is used to generate session keys. Authentication information is the information required for mutual authentication between the network side and the terminal during the 5G communication authentication process, such as 5G authentication vector, SUPI and other information.

The indication information is any of the following: a first indication used to indicate the first session key generation method, a second indication used to indicate the second session key generation method, and a second indication used to indicate the second session key generation method. 2. Instructions.

In practical applications, at least one session key generation method also includes: a second session key generation method for generating the current session key based on the first key and the new shared key; using the first key as the current The third session key generation method of the secondary session key.

Correspondingly, based on the instruction information sent by the network side, determining the current session key generation method from at least one session key generation method includes: when the instruction information is the first instruction, determining that the current session key generation method is the second A session key generation method; when the instruction information is the second instruction, determine that the session key generation method is the second session key generation method; when the instruction information is the third instruction, determine that the session key generation method is the second session key generation method Three session key generation methods. That is to say, the instruction information is used to instruct the network device to reuse the shared key, generate a new shared key or not use the shared key when generating the session key.

Exemplarily, the first session key generation method specifically includes: performing a hash operation on the first key and the shared key stored in the terminal device to generate the current session key; the second session key generation method specifically includes: A hash operation is performed on the first key and the new shared key to generate the current session key.

The method further includes: when the indication information is the second indication, generating a new shared key to be shared with the terminal device; and storing the new shared key.

That is to say, when the network device is connected to the terminal device to generate a shared key, when the network device generates the shared key using the second session key generation method for the first time, it stores the first generated shared key on the network device and the information cannot be tampered with. in the storage area. Afterwards, when the terminal device and the network device perform DH session key exchange, the first session key generation method is used to instruct the terminal device to reuse the stored shared key to generate a session key, so that the network device does not need to use an asymmetric encryption algorithm to generate a new session key every time. Shared keys can reduce the usage of asymmetric encryption algorithms in the key exchange protocol and reduce the power consumption of terminal equipment.

Optionally, next time the shared key is generated using the second session key generation method, the old shared key stored in the network device is replaced with the newly generated shared key, and then the terminal device exchanges the DH session key with the network , use the first session key generation mode to instruct the network device to reuse the latest stored shared key to generate a session key.

That is to say, the shared key stored by the network device may be a newly generated shared key during a certain session key exchange process, for example, the shared key generated for the first time; Once a new shared key is issued, the old shared key stored in the network device is replaced with the new shared key.

In practical applications, when the mutual authentication between the terminal device and the network side is successful, an authentication response is generated and sent to the network side, and the current session key is directly generated based on the current session key generation method. For example, when the mutual authentication between the UE and the UDM/ARPF is successful, the terminal device will store the newly generated shared key at the same time, and use the stored shared key to generate a session key. When the network side also succeeds in authentication based on the authentication response, a session key corresponding to the terminal device is generated, and the network side and the terminal device communicate according to the obtained session key.

Referring to Figure 3, when the network side exchanges keys with the terminal device, the steps for AUSF to generate a session key based on the indication information are as follows:

1. UDM/ARPF generates authentication vector 5G HE AV (RAND, AUTN, XRES*, KAUSF), and decrypts SUCI to obtain UE's long-term user identity SUPI.

2. UDM/ARPF sends the authentication vectors 5G HE AV, SUPI, and UE Profile to AUSF, where the authentication vectors 5G HE AV and SUPI contain authentication information, and UE Profile contains indication information.

3. AUSF temporarily stores XRES* and the corresponding SUPI, and may also store KAUSF for other uses.

4. AUSF uses XRES* to deduce HXRES*, and uses KAUSF to deduce KSEAF (that is, the first key in the embodiment of the present invention). Thus AUSF obtains 5G AV (RAND, AUTN, HXRES*, KSEAF). AUSF determines the value of DH_ind (indication information) according to UE Profile. If the value of DH_ind is set to a (the second indication), the parameters related to the DH key exchange are generated. It first generates the private key APRI of the AUSF and derives the public key APUB of the AUSF. If the value of DH_ind is set to b (first indication) or c (third indication), no parameters related to DH key exchange are generated.

5. AUSF sends 5G AV message to SEAF, AUSF's public key APUB, and instruction Alg to use DH algorithm.

6. SEAF sends an authentication request (Authentication Request) message to the UE, which includes RAND, AUTN, APUB, DH_ind, and Alg. Among them, only when DH_ind is a, the Authentication Request message contains the public key APUB of AUSF.

7. The UE verifies the network, and generates an authentication response RES* if the verification succeeds. If DH_ind is a, the UE generates DH-related parameters according to the algorithm indicator Alg, that is, the UE’s public-private key pair (BPUB, BPRI). The UE uses its own private key BPRI and the received AUSF’s public key APUB to generate The key K_DH is stored on the USIM card or in a non-tamperable storage area. The UE generates the session key KSEAF' according to the DH_ind value as follows:

DH_ind=a, KSEAF'=HASH(KSEAF, K_DH), where K_DH is the newly generated shared key of the UE;

DH_ind=b, KSEAF'=HASH(KSEAF, K_DH), where K_DH is the shared key previously stored by the UE;

DH_ind=c, KSEAF'=KSEAF, the shared key is not used here, and the first key is used as the session key.

8. The UE sends an Authentication Response (Authentication Response) message to the SEAF, which includes RES*, BPUB.

9. SEAF deduces HRES* from authentication response RES*, and compares HRES* with HXRES*. If it succeeds, the authentication of the UE by SEAF is completed, and SEAF sends RES* and BPUB to AUSF.

10. AUSF realizes the verification of RES* by comparing the authentication response RES* with XRES*. AUSF uses its own private key APRI and received UE's public key BPUB to generate the key K_DH shared with UE and store it in the system. AUSF generates the session key KSEAF' according to the DH_ind value as follows:

DH_ind=a, KSEAF'=HASH(KSEAF, K_DH), where K_DH is the newly generated shared key of the UE;

DH_ind=b, KSEAF'=HASH(KSEAF, K_DH), where K_DH is the shared key previously stored by the UE;

DH_ind=c, KSEAF'=KSEAF, the shared key is not used here, and the first key is used as the session key.

11. If AUSF succeeds in verifying the authentication response RES*, AUSF sends a successful verification message, session key KSEAF', and UE's SUPI to SEAF.

Using the DH solution on the AUSF, since the AUSF belongs to the network element of the home network, the home network can know whether the AUSF implements the DH key exchange protocol to enhance the session key, which can prevent the roaming network from deceiving the home network to complete session key enhancement. In this way, the Internet of Things terminal can safely and efficiently complete the authentication process with the network. DH_ind is used to instruct terminal devices and network devices to reuse the shared key K_DH to generate a session key, thereby reducing the use of asymmetric encryption algorithms, and is suitable for use when IoT devices are connected to 5G networks.

It can be seen that by adopting the above scheme, during key exchange, the terminal device can generate a session key according to the long-term key and the shared key, and the network side instructs the terminal device to use the stored shared secret key by sending instruction information to the terminal device. key to generate a session key, without the need for the terminal device to use an asymmetric encryption algorithm to generate a new shared key for this session. In this way, by reusing the shared key, the usage of the asymmetric encryption algorithm in the key exchange protocol is reduced, and the power consumption of the terminal equipment is reduced.

As shown in Figure 5, an embodiment of the present invention provides a terminal device, including:

The first communication unit 51 is configured to receive indication information and authentication information sent by the network side;

The first key generation unit 52 is configured to determine the first key based on the long-term key; determine the current session key generation method from at least one session key generation method based on the instruction information sent by the network side; When the authentication information sent by the network side is successfully authenticated to the network side, an authentication response is generated and sent to the network side, and the current session key is generated based on the current session key generation method;

Wherein, at least one session key generation method at least includes: a first session key generation method for generating a current session key based on the first key and a shared key stored in the terminal device.

As shown in Figure 6, an embodiment of the present invention provides a terminal device, including:

The first communication interface 61 is configured to receive indication information and authentication information sent by the network side;

The first processor 62 is configured to determine the first key based on the long-term key; determine the current session key generation method from at least one session key generation method based on the indication information sent by the network side; When the authentication information is successfully authenticated to the network side, an authentication response is generated and sent to the network side, and the current session key is generated based on the current session key generation method;

Wherein, at least one session key generation method at least includes: a first session key generation method for generating a current session key based on the first key and a shared key stored in the terminal device.

In some embodiments, at least one session key generation method further includes: a second session key generation method for generating the current session key based on the first key and the new shared key; The third session key generation method used as the current session key.

In some embodiments, the first session key generation method specifically includes: performing a hash operation on the first key and the shared key stored in the terminal device to generate the current session key; the second session key generation method specifically includes : Perform hash operation on the first key and the new shared key to generate the current session key.

In some embodiments, the first processor 62 is specifically configured to determine that the current session key generation mode is the first session key generation mode when the indication information is the first indication; and determine the current session key generation mode when the indication information is the second indication. The second session key generation method is the second session key generation method; when the indication information is the third instruction, it is determined that the current session key generation method is the third session key generation method.

In some embodiments, the first processor 62 is further configured to generate a new shared key to be shared with the network side when the indication information is the second indication; and store the new shared key.

As shown in Figure 7, an embodiment of the present invention provides a network device, including:

The second communication unit 71 is configured to send indication information and authentication information to the terminal device;

The second key generation unit 72 is configured to determine the first key based on the long-term key; based on the indication information, determine the current session key generation method from at least one session key generation method; based on the authentication information and the terminal device When the sent authentication response determines that the terminal device has successfully authenticated, generate the current session key corresponding to the terminal device based on the current session key generation method;

Wherein, at least one session key generation method at least includes: a first session key generation method for generating the current session key based on the first key and a shared key stored in the network device.

As shown in Figure 8, an embodiment of the present invention provides a network device, including:

The second communication interface 81 is configured to send indication information and authentication information to the terminal device;

The second processor 82 is configured to determine the first key based on the long-term key; determine the current session key generation method from at least one session key generation method based on the indication information; When the authentication response determines that the authentication of the terminal device is successful, the current session key corresponding to the terminal device is generated based on the current session key generation method;

Wherein, at least one session key generation method at least includes: a first session key generation method for generating the current session key based on the first key and a shared key stored in the network device.

In some embodiments, at least one session key generation method further includes: a second session key generation method for generating the current session key based on the first key and the new shared key; The third session key generation method used as the current session key.

In some embodiments, the method for generating the first session key specifically includes: performing a hash operation on the first key and a shared key stored in the terminal device to generate the current session key;

The method for generating the second session key specifically includes: performing a hash operation on the first key and the new shared key to generate the current session key.

In some embodiments, the second processor 82 is specifically configured to determine that the current session key generation method is the first session key generation method when the indication information is the first indication; The second session key generation method is the second session key generation method; when the indication information is the third instruction, it is determined that the current session key generation method is the third session key generation method.

In some embodiments, the second processor 82 is further configured to generate a new shared key to be shared with the terminal device when the indication information is the second indication; and store the new shared key.

The network device involved in this embodiment may be regarded as a device with an AUSF function on the network side.

The embodiment of the present application also provides a computer-readable storage medium for storing computer programs.

Optionally, the computer-readable storage medium can be applied to any terminal device in the embodiments of the present application, and the computer program enables the computer to execute the corresponding processes implemented by the terminal device in the methods of the embodiments of the present application. For the sake of brevity , which will not be repeated here.

Alternatively, the computer-readable storage medium can be applied to any network device in the embodiments of the present application, and the computer program enables the computer to execute the corresponding processes implemented by the network device in the methods of the embodiments of the present application. For brevity, the This will not be repeated here.

The embodiment of the present application also provides a key generation system, as shown in FIG. 9 , the system includes: at least one terminal device 91, and an authentication service function AUSF entity 92; wherein,

The terminal device 91 is configured to determine the first key based on the long-term key; determine the current session key generation method from at least one session key generation method based on the instruction information sent by the network side; When the authentication information on the network side is successfully authenticated, an authentication response is generated and sent to the network side, and the current session key is generated based on the current session key generation method;

The AUSF entity 92 is configured to determine the first key based on the long-term key; determine the current session key generation method from at least one session key generation method based on the indication information; and determine the current session key generation method based on the authentication information and the When the authentication response sent by the terminal device determines that the terminal device has successfully authenticated, generate the current session key corresponding to the terminal device based on the current session key generation method;

Wherein, the at least one session key generation method at least includes: a first session key generation method for generating a current session key based on the first key and a shared key stored in the network device.

The at least one session key generation method further includes: a second session key generation method for generating the current session key based on the first key and the new shared key; The third session key generation method used as the current session key.

The terminal device is configured to perform a hash operation on the first key and the shared key stored in the terminal device to generate a current session key; the method for generating the second session key specifically includes: Perform a hash operation on the first key and the new shared key to generate the session key;

The AUSF entity is configured to perform a hash operation on the first key and the shared key stored in the terminal device to generate a current session key; the second session key generation method specifically includes: The first key and the new shared key are hashed to generate the current session key.

The terminal device is configured to determine that the current session key generation mode is the first session key generation mode when the indication information is the first indication; and determine that the current session key generation mode is the second indication information when the indication information is the second indication information. The second session key generation method is the second session key generation method; when the instruction information is the third instruction, it is determined that the current session key generation method is the third session key generation method;

The AUSF entity is configured to determine that the current session key generation mode is the first session key generation mode when the indication information is the first indication; determine that the current session key generation mode is the second indication information when the indication information is the second indication information. The second session key generation method is the second session key generation method; when the indication information is the third instruction, it is determined that the current session key generation method is the third session key generation method.

The terminal device is configured to generate a new shared key shared with the network side when the indication information is the second indication; save the new shared key;

The AUSF entity is configured to generate a new shared key to be shared with the terminal device when the indication information is the second indication; and store the new shared key.

In addition, the functions of each device in this system are the same as those of the aforementioned method or device embodiments, so details are not repeated here.

Those skilled in the art can appreciate that the units and algorithm steps of the examples described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed by hardware or software depends on the specific application and design constraints of the technical solution. Skilled artisans may use different methods to implement the described functions for each specific application, but such implementation should not be regarded as exceeding the scope of the present application.

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

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

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

In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, each unit may exist separately physically, or two or more units may be integrated into one unit.

If the functions described above are realized in the form of software function units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or the part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including Several instructions are used to make a computer device (which may be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage media include: U disk, mobile hard disk, read-only memory (Read-Only Memory,) ROM, random access memory (Random Access Memory, RAM), magnetic disk or optical disc, etc., which can store program codes. .

The above is only a specific implementation of the application, but the scope of protection of the application is not limited thereto. Anyone familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the application. Should be covered within the protection scope of this application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims (29)

1. A key generation method applied to a terminal device, the method comprising:

determining a first key based on the long-term key;

determining a current session key generation mode from at least one session key generation mode based on the indication information sent by the network side;

generating an authentication response and transmitting the authentication response to the network side when the authentication information transmitted by the network side successfully authenticates the network side, and generating a current session key based on the current session key generation mode;

the at least one session key generation mode at least comprises the following steps: and generating a first session key generation mode of the session key based on the first key and the shared key stored by the terminal equipment.

2. The method of claim 1, wherein the at least one session key generation manner further comprises: generating a second session key generation mode of the session key based on the first key and the new shared key;

and taking the first key as a third session key generation mode of the current session key.

3. The method of claim 2, wherein the first session key generation mode specifically comprises: carrying out hash operation on the first key and the shared key stored by the terminal equipment to generate a session key;

The second session key generation mode specifically includes: and carrying out hash operation on the first key and the new shared key to generate a current session key.

4. The method of claim 2, wherein the determining the current session key generation mode from the at least one session key generation mode based on the indication information sent by the network side includes:

when the indication information is a first indication, determining that the current session key generation mode is a first session key generation mode;

when the indication information is a second indication, determining that the current session key generation mode is a second session key generation mode;

and when the indication information is a third indication, determining that the current session key generation mode is a third session key generation mode.

5. The method of claim 4, wherein the method further comprises:

generating a new shared key shared with the network side when the indication information is a second indication;

the new shared key is saved.

6. A key generation method applied to a network device, the method comprising:

determining a first key based on the long-term key;

determining a current session key generation mode from at least one session key generation mode based on the indication information;

When the authentication of the terminal equipment is successful based on the authentication information and the authentication response sent by the terminal equipment, generating a current session key corresponding to the terminal equipment based on the current session key generation mode;

the at least one session key generation mode at least comprises the following steps: and generating a first session key generation mode of the session key based on the first key and the shared key stored by the network equipment.

7. The method of claim 6, wherein the at least one session key generation manner further comprises: generating a second session key generation mode of the session key based on the first key and the new shared key;

and taking the first key as a third session key generation mode of the current session key.

8. The method of claim 7, wherein the first session key generation manner specifically comprises: carrying out hash operation on the first key and the shared key stored by the terminal equipment to generate a session key;

the second session key generation mode specifically includes: and carrying out hash operation on the first key and the new shared key to generate a current session key.

9. The method of claim 7, wherein the determining the current session key generation mode from the at least one session key generation mode based on the indication information comprises:

when the indication information is a first indication, determining that the current session key generation mode is a first session key generation mode;

when the indication information is a second indication, determining that the current session key generation mode is a second session key generation mode;

and when the indication information is a third indication, determining that the current session key generation mode is a third session key generation mode.

10. The method of claim 9, wherein the method further comprises:

generating a new shared key shared with the terminal equipment when the indication information is a second indication;

the new shared key is saved.

11. A terminal device, comprising:

the first communication unit is used for receiving the indication information and the authentication information sent by the network side;

a first key generation unit for determining a first key based on the long-term key; determining a current session key generation mode from at least one session key generation mode based on the indication information sent by the network side; generating an authentication response and transmitting the authentication response to the network side when the authentication information transmitted by the network side successfully authenticates the network side, and generating a current session key based on the current session key generation mode;

The at least one session key generation mode at least comprises the following steps: and generating a first session key generation mode of the session key based on the first key and the shared key stored by the terminal equipment.

12. A terminal device, comprising:

the first communication interface is used for receiving the indication information and the authentication information sent by the network side;

a first processor for determining a first key based on the long-term key; determining a current session key generation mode from at least one session key generation mode based on the indication information sent by the network side; generating an authentication response and transmitting the authentication response to the network side when the authentication information transmitted by the network side successfully authenticates the network side, and generating a current session key based on the current session key generation mode;

the at least one session key generation mode at least comprises the following steps: and generating a first session key generation mode of the session key based on the first key and the shared key stored by the terminal equipment.

13. The terminal device of claim 12, wherein the at least one session key generation manner further includes: generating a second session key generation mode of the session key based on the first key and the new shared key;

And taking the first key as a third session key generation mode of the current session key.

14. The terminal device of claim 13, wherein the first session key generation manner specifically includes: carrying out hash operation on the first key and the shared key stored by the terminal equipment to generate a session key;

the second session key generation mode specifically includes: and carrying out hash operation on the first key and the new shared key to generate a current session key.

15. The terminal device of claim 13, wherein the first processor is specifically configured to determine that the current session key generation manner is a first session key generation manner when the indication information is a first indication; when the indication information is a second indication, determining that the current session key generation mode is a second session key generation mode; and when the indication information is a third indication, determining that the current session key generation mode is a third session key generation mode.

16. The terminal device of claim 15, wherein the first processor is further configured to generate a new shared key shared with the network side when the indication information is a second indication; the new shared key is saved.

17. A network device, comprising:

a second communication unit for transmitting the indication information and the authentication information to the terminal device;

a second key generation unit for determining the first key based on the long-term key; determining a current session key generation mode from at least one session key generation mode based on the indication information; when the authentication of the terminal equipment is successful based on the authentication information and the authentication response sent by the terminal equipment, generating a current session key corresponding to the terminal equipment based on the current session key generation mode;

the at least one session key generation mode at least comprises the following steps: and generating a first session key generation mode of the session key based on the first key and the shared key stored by the network equipment.

18. A network device, comprising:

the second communication interface is used for sending indication information and authentication information to the terminal equipment;

a second processor for determining a first key based on the long-term key; determining a current session key generation mode from at least one session key generation mode based on the indication information; when the authentication of the terminal equipment is successful based on the authentication information and the authentication response sent by the terminal equipment, generating a current session key corresponding to the terminal equipment based on the current session key generation mode;

The at least one session key generation mode at least comprises the following steps: and generating a first session key generation mode of the session key based on the first key and the shared key stored by the network equipment.

19. The network device of claim 18, wherein the at least one session key generation manner further comprises: generating a second session key generation mode of the session key based on the first key and the new shared key;

and taking the first key as a third session key generation mode of the current session key.

20. The network device of claim 19, wherein the first session key generation means specifically comprises: carrying out hash operation on the first key and the shared key stored by the terminal equipment to generate a session key;

the second session key generation mode specifically includes: and carrying out hash operation on the first key and the new shared key to generate a current session key.

21. The network device of claim 19, wherein the second processor is specifically configured to determine that the current session key generation manner is a first session key generation manner when the indication information is a first indication; when the indication information is a second indication, determining that the current session key generation mode is a second session key generation mode; and when the indication information is a third indication, determining that the current session key generation mode is a third session key generation mode.

22. The network device of claim 21, wherein the second processor is further configured to generate a new shared key shared with the terminal device when the indication information is a second indication; the new shared key is saved.

23. A computer storage medium having stored thereon a computer program, wherein the computer program when executed by a processor realizes the steps of the method according to any of claims 1-5.

24. A computer storage medium having stored thereon a computer program, wherein the computer program when executed by a processor realizes the steps of the method according to any of claims 6-10.

25. A key generation system, wherein the system comprises: at least one terminal equipment, authentication service function AUSF entity; wherein,,

the terminal equipment is used for determining a first key based on the long-term key; determining a current session key generation mode from at least one session key generation mode based on the indication information sent by the network side; generating an authentication response and transmitting the authentication response to the network side when the authentication information transmitted by the network side successfully authenticates the network side, and generating a current session key based on the current session key generation mode;

The AUSF entity for determining a first key based on the long-term key; determining a current session key generation mode from at least one session key generation mode based on the indication information; when the authentication of the terminal equipment is successful based on the authentication information and the authentication response sent by the terminal equipment, generating a current session key corresponding to the terminal equipment based on the current session key generation mode;

the at least one session key generation mode at least comprises the following steps: and generating a first session key generation mode of the session key based on the first key and the shared key stored by the network equipment.

26. The system of claim 25, wherein the at least one session key generation manner further comprises: generating a second session key generation mode of the session key based on the first key and the new shared key; and taking the first key as a third session key generation mode of the current session key.

27. The system of claim 26, wherein the terminal device is configured to perform a hash operation on the first key and a shared key stored by the terminal device to generate a current session key; the second session key generation mode specifically includes: carrying out hash operation on the first key and the new shared key to generate a current session key;

The AUSF entity is used for carrying out hash operation on the first key and the shared key stored by the terminal equipment to generate a current session key; the second session key generation mode specifically includes: and carrying out hash operation on the first key and the new shared key to generate a current session key.

28. The system of claim 27, wherein the terminal device is configured to determine that the current session key generation manner is a first session key generation manner when the indication information is a first indication; when the indication information is a second indication, determining that the current session key generation mode is a second session key generation mode; when the indication information is a third indication, determining that the current session key generation mode is a third session key generation mode;

the AUSF entity is used for determining that the current session key generation mode is a first session key generation mode when the indication information is a first indication; when the indication information is a second indication, determining that the current session key generation mode is a second session key generation mode; and when the indication information is a third indication, determining that the current session key generation mode is a third session key generation mode.

29. The system according to claim 28, wherein the terminal device is configured to generate a new shared key shared with the network side when the indication information is a second indication; saving the new shared key;

the AUSF entity is used for generating a new shared key shared with the terminal equipment when the indication information is a second indication; the new shared key is saved.

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