Communication network identifier protection method and device, equipment, storage medium and product

Abstract

The invention relates to the technical field of security, and provides a communication network identifier protection method and device, equipment, a storage medium and a product, and the method comprises the steps: determining one or more cryptographic algorithm schemes selected from a predefined cryptographic algorithm set for protecting SUPI; respectively generating a temporary shared key based on each cryptographic algorithm scheme; deriving a final key based on each temporary shared key; protecting the SUPI based on the final key to obtain SUCI; the SUCI comprises a protection scheme identifier, the value of the identifier is used for indicating the combination of one or more cryptographic algorithm schemes adopted, the identifier comprises a plurality of flag bits, and each flag bit corresponds to a specific cryptographic algorithm scheme in a predefined cryptographic algorithm set; the value of each flag bit is used for indicating whether the corresponding cryptographic algorithm scheme is selected or not. According to the method and the device, the dynamic combination of a plurality of cryptographic algorithm schemes to be used can be supported, and the cryptographic algorithm scheme set to be used is expanded and stored so as to cope with quantum attacks.

Description

Technical Field

[0001] This application relates to the field of security technology, and in particular to a method, apparatus, device, storage medium and product for protecting the identification of communication networks. Background Technology

[0002] With the rapid development of Internet technology, the network security risks of information systems continue to increase, and the threats and challenges are becoming increasingly severe. Cryptographic security is an important foundation of information security and can be used to effectively protect the data security of network information systems. Cryptographic technology is a core technology and an important means to protect network information systems.

[0003] To enhance the security of SUPI (Subscription Permanent Identifier) ​​over the air interface, 5G communication networks employ a system where the terminal uses its home network's public key and the ECIES (Elliptic Curve Integrated Encryption Scheme) algorithm to encrypt and encapsulate the SUPI, generating a SUCI (Subscription Concealed Identifier). The SUCI is then used as the identifier for transmission over the air interface, ensuring user privacy and preventing attacks such as tracking. ECIES utilizes either Profile A or Profile B schemes based on the ECC (Elliptic Curve Cryptography) algorithm for key negotiation and data encryption.

[0004] However, with the rapid development of quantum computing technology, future networks (such as 6G) will present a complex scenario where multiple algorithms coexist, including traditional algorithms (ECC) and multiple PQC (Post-Quantum Cryptography) algorithms. This places higher demands on the algorithm compatibility of communication equipment, the uniformity of key management, and the flexibility of security protocols.

[0005] Therefore, how to provide an efficient and scalable integrated encryption mechanism to adapt to complex scenarios where diverse cryptographic algorithms coexist, and thus better cope with quantum attacks, is an urgent problem to be solved. Summary of the Invention

[0006] This application provides a communication network identifier protection method, apparatus, device, storage medium, and product to solve the technical problem of how to provide an efficient and scalable integrated encryption mechanism to adapt to complex scenarios where diverse cryptographic algorithms coexist.

[0007] In a first aspect, embodiments of this application provide a communication network identifier protection method, applied to user equipment, the method comprising: Determine one or more cryptographic algorithm schemes for protecting the user identity identifier SUPI, wherein the one or more cryptographic algorithm schemes are selected from a predefined set of cryptographic algorithms; Based on each of the aforementioned cryptographic algorithm schemes, temporary shared keys are generated respectively; Based on the aforementioned temporary shared keys, the final key is derived. Based on the final key, the SUPI is protected to obtain the user-hidden identifier SUCI; The SUCI includes a protection scheme identifier. The value of the protection scheme identifier is used to indicate a combination of one or more cryptographic algorithm schemes used to protect the SUCI. The protection scheme identifier contains multiple flag bits, each flag bit corresponding to a specific cryptographic algorithm scheme in the predefined cryptographic algorithm set. The value of each flag bit is used to indicate whether the cryptographic algorithm scheme corresponding to the flag bit is selected.

[0008] In one embodiment, the SUCI further includes a public key identification information field corresponding to each cryptographic algorithm scheme. The public key identification information field is used to store the identification information of the public key of the home network element used by the cryptographic algorithm scheme. The field order of the public key identification information field corresponding to each cryptographic algorithm scheme is determined based on the order of the cryptographic algorithm schemes corresponding to each flag bit in the protection scheme identifier.

[0009] In one embodiment, the SUCI further includes a scheme output field, which includes a temporary cryptographic data field corresponding to each cryptographic algorithm scheme. The temporary cryptographic data field is used to store temporary cryptographic data generated based on the cryptographic algorithm scheme. The field order of the temporary cryptographic data fields corresponding to each cryptographic algorithm scheme is determined based on the order of the cryptographic algorithm schemes corresponding to each flag bit in the protection scheme identifier.

[0010] In one embodiment, generating temporary shared keys based on each of the cryptographic algorithm schemes includes: For each cryptographic algorithm scheme, a temporary shared key is generated based on the public key of the network element used by the cryptographic algorithm scheme and the key encapsulation mechanism corresponding to the cryptographic algorithm scheme.

[0011] In one embodiment, deriving the final key based on each of the temporary shared keys includes: The temporary shared keys are combined to obtain a temporary shared key combination. The temporary shared key combination is input into the key derivation function to derive the final key; The final key includes a temporary encryption key, a temporary integrity protection key, and an initialization key block.

[0012] In one embodiment, upon receiving an information update request from the home network element, the method further includes: Based on the information update request, the protection scheme identifier is updated; the information update request is used to instruct the value of the corresponding flag bit in the protection scheme identifier to be updated based on one or more cryptographic algorithm schemes for protecting SUPI that have been redefined.

[0013] Secondly, embodiments of this application provide a communication network identifier protection method, applied to a home network element, the method comprising: The user equipment receives a user hidden identifier (SUCI) sent by the user equipment. The SUCI includes a protection scheme identifier. The value of the protection scheme identifier is used to indicate a combination of one or more cryptographic algorithm schemes used to protect the SUCI. The protection scheme identifier contains multiple flag bits. Each flag bit corresponds to a specific cryptographic algorithm scheme in the predefined cryptographic algorithm set. The value of each flag bit is used to indicate whether the cryptographic algorithm scheme corresponding to the flag bit is selected. Based on the various cryptographic algorithms used to protect the SUPI, temporary shared keys are generated respectively; Based on the aforementioned temporary shared keys, the final key is derived. The SUCI is decrypted using the final key to obtain the SUPI.

[0014] In one embodiment, the SUCI further includes a public key identification information field corresponding to each cryptographic algorithm scheme, the public key identification information field being used to store the identification information of the home network element public key used by the cryptographic algorithm scheme; the field order of the public key identification information fields corresponding to each cryptographic algorithm scheme is determined based on the order of the cryptographic algorithm schemes corresponding to each flag bit in the protection scheme identifier; after receiving the user hidden identifier SUCI sent by the user equipment, the following is also included: According to the order of the cryptographic algorithm schemes corresponding to each flag bit in the protection scheme identifier, the identification information of the public key of the network element used by each cryptographic algorithm scheme is obtained from the public key identification information field of the SUCI. Based on the identification information of the public key of the network element used by each cryptographic algorithm scheme, the private key of the network element corresponding to each cryptographic algorithm scheme is obtained.

[0015] In one embodiment, the SUCI further includes a scheme output field, which includes temporary cryptographic data fields corresponding to each cryptographic algorithm scheme. These temporary cryptographic data fields are used to store temporary cryptographic data generated based on the cryptographic algorithm schemes. The field order of the temporary cryptographic data fields corresponding to each cryptographic algorithm scheme is determined based on the order of the cryptographic algorithm schemes corresponding to each flag bit in the protection scheme identifier. After receiving the User Hidden Identifier (SUCI) sent by the user equipment, the following is also included: According to the order of the cryptographic algorithm schemes corresponding to each flag bit in the protection scheme identifier, the temporary cryptographic data generated based on each cryptographic algorithm scheme is obtained from the scheme output field of the SUCI.

[0016] In one embodiment, generating temporary shared keys based on the various cryptographic algorithm schemes used to protect the SUPI includes: For each cryptographic algorithm scheme, a temporary shared key is generated based on the private key of the network element corresponding to the cryptographic algorithm scheme, the temporary cryptographic data generated based on the cryptographic algorithm scheme, and the key decryption mechanism corresponding to the cryptographic algorithm scheme.

[0017] In one embodiment, deriving the final key based on each of the temporary shared keys includes: The temporary shared keys are combined to obtain a temporary shared key combination. The temporary shared key combination is input into the key derivation function to derive the final key; The final key includes a temporary encryption key, a temporary integrity protection key, and an initialization key block.

[0018] In one embodiment, the method further includes: If it is necessary to modify the SUPI encryption strategy, an information update request is sent to the user equipment; the information update request is used to instruct the value of the corresponding flag bit in the protection scheme identifier to be updated based on one or more cryptographic algorithm schemes for protecting SUPI that have been redefined.

[0019] Thirdly, embodiments of this application provide a communication network identifier protection device, applied to user equipment, comprising: The protection scheme determination module is used to determine one or more cryptographic algorithm schemes for protecting the user identity identifier SUPI, wherein the one or more cryptographic algorithm schemes are selected from a predefined set of cryptographic algorithms; The first key generation module is used to generate temporary shared keys based on each of the aforementioned cryptographic algorithm schemes; The first key derivation module is used to derive the final key based on each of the temporary shared keys; The SUCI generation module is used to protect the SUPI based on the final key to obtain the user hidden identifier SUCI; The SUCI includes a protection scheme identifier. The value of the protection scheme identifier is used to indicate a combination of one or more cryptographic algorithm schemes used to protect the SUCI. The protection scheme identifier contains multiple flag bits, each flag bit corresponding to a specific cryptographic algorithm scheme in the predefined cryptographic algorithm set. The value of each flag bit is used to indicate whether the cryptographic algorithm scheme corresponding to the flag bit is selected.

[0020] Fourthly, embodiments of this application provide a communication network identifier protection device, applied to a home network element, comprising: The SUCI receiving module is used to receive the User Hidden Identifier (SUCI) sent by the user equipment. The SUCI includes a protection scheme identifier, the value of which is used to indicate a combination of one or more cryptographic algorithm schemes used to protect the SUCI. The protection scheme identifier contains multiple flag bits, each flag bit corresponding to a specific cryptographic algorithm scheme in the predefined cryptographic algorithm set. The value of each flag bit is used to indicate whether the cryptographic algorithm scheme corresponding to the flag bit is selected. The second key generation module is used to generate temporary shared keys based on the various cryptographic algorithm schemes used to protect the SUPI. The second key derivation module is used to derive the final key based on each of the temporary shared keys; The decryption module is used to decrypt the SUCI based on the final key to obtain the SUPI.

[0021] Fifthly, embodiments of this application provide a user equipment, including a memory, a transceiver, and a processor; A memory for storing computer programs; a transceiver for sending and receiving data under the control of the processor; and a processor for reading the computer programs from the memory and performing the following operations: Determine one or more cryptographic algorithm schemes for protecting the user identity identifier SUPI, wherein the one or more cryptographic algorithm schemes are selected from a predefined set of cryptographic algorithms; Based on each of the aforementioned cryptographic algorithm schemes, temporary shared keys are generated respectively; Based on the aforementioned temporary shared keys, the final key is derived. Based on the final key, the SUPI is protected to obtain the user-hidden identifier SUCI; The SUCI includes a protection scheme identifier. The value of the protection scheme identifier is used to indicate a combination of one or more cryptographic algorithm schemes used to protect the SUCI. The protection scheme identifier contains multiple flag bits, each flag bit corresponding to a specific cryptographic algorithm scheme in the predefined cryptographic algorithm set. The value of each flag bit is used to indicate whether the cryptographic algorithm scheme corresponding to the flag bit is selected.

[0022] Sixthly, embodiments of this application provide a home network element, including a memory, a transceiver, and a processor; A memory for storing computer programs; a transceiver for sending and receiving data under the control of the processor; and a processor for reading the computer programs from the memory and performing the following operations: The user equipment receives a user hidden identifier (SUCI) sent by the user equipment. The SUCI includes a protection scheme identifier. The value of the protection scheme identifier is used to indicate a combination of one or more cryptographic algorithm schemes used to protect the SUCI. The protection scheme identifier contains multiple flag bits. Each flag bit corresponds to a specific cryptographic algorithm scheme in the predefined cryptographic algorithm set. The value of each flag bit is used to indicate whether the cryptographic algorithm scheme corresponding to the flag bit is selected. Based on the various cryptographic algorithms used to protect the SUPI, temporary shared keys are generated respectively; Based on the aforementioned temporary shared keys, the final key is derived. The SUCI is decrypted using the final key to obtain the SUPI.

[0023] In a seventh aspect, embodiments of this application provide an electronic device, including a processor and a memory storing a computer program, wherein the processor executes the program to implement the steps of the communication network identifier protection method described in the first or second aspect.

[0024] Eighthly, embodiments of this application provide a non-transitory computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the communication network identifier protection method described in the first or second aspect.

[0025] Ninthly, embodiments of this application provide a computer program product, including a computer program that, when executed by a processor, implements the steps of the communication network identifier protection method described in the first or second aspect.

[0026] The communication network identifier protection method, apparatus, device, storage medium, and product provided in this application embodiment are designed with a protection scheme identifier containing multiple flag bits, each flag bit corresponding to a specific cryptographic algorithm scheme. The value of each flag bit is used to indicate whether the cryptographic algorithm scheme corresponding to the flag bit is selected. The value of the protection scheme identifier is used to indicate the combination of one or more cryptographic algorithm schemes used when protecting SUPI. This allows the protection scheme identifier to support a single cryptographic algorithm scheme or a dynamic combination of multiple cryptographic algorithm schemes to be used, which is beneficial for better dealing with quantum attacks. Furthermore, this design not only allows for flexible expansion to support other possible cryptographic algorithm schemes, but also allows for expansion of the storage set of SUPI protection schemes to be used. The format extensibility is not limited, thereby meeting the operator's need for flexible algorithm deployment, adjusting encryption strategies in real time according to different network environments, and improving the feasibility of cross-regional deployment. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is one of the flowcharts illustrating the communication network identifier protection method provided in the embodiments of this application.

[0029] Figure 2 This is a schematic diagram illustrating the determination of the protection scheme identifier based on bit combination method provided in the embodiments of this application.

[0030] Figure 3 This is a schematic diagram of the USIM card file corresponding to the bit combination method provided in the embodiments of this application.

[0031] Figure 4 This is a schematic diagram illustrating the determination of protection scheme identifiers based on a predefined identification method provided in an embodiment of this application.

[0032] Figure 5 This is a schematic diagram of the USIM card file corresponding to the use of a predefined identifier method provided in the embodiments of this application.

[0033] Figure 6 This is a schematic diagram of the SUCI format supporting dynamic scheme combination provided in the embodiments of this application.

[0034] Figure 7 This is an example schematic diagram illustrating the SUCI format that supports dynamic scheme combination provided in the embodiments of this application.

[0035] Figure 8 This is the second flowchart of the communication network identifier protection method provided in the embodiments of this application.

[0036] Figure 9 This is a schematic diagram of the identity submission process provided in the embodiments of this application.

[0037] Figure 10 This is a flowchart of the SUPI encryption mechanism that supports dynamic scheme combination provided in the embodiments of this application.

[0038] Figure 11 This is a flowchart of the SUCI decryption mechanism that supports dynamic scheme combination provided in the embodiments of this application.

[0039] Figure 12 This is one of the structural schematic diagrams of the communication network identification protection device provided in the embodiments of this application.

[0040] Figure 13 This is the second structural schematic diagram of the communication network identification protection device provided in the embodiments of this application.

[0041] Figure 14 This is a schematic diagram of the structure of the user equipment provided in the embodiments of this application.

[0042] Figure 15 This is a schematic diagram of the structure of the home network element provided in the embodiments of this application.

[0043] Figure 16 This is a schematic diagram of the structure of the electronic device provided in the embodiments of this application. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0045] With the rapid development of quantum computing technology, traditional public-key cryptosystems (such as ECC and RSA) face potential security threats. The mathematical problems they rely on (such as discrete logarithms and large integer factorization) may be efficiently cracked by quantum algorithms, rendering existing encryption mechanisms unable to resist quantum attacks. However, since post-quantum cryptography algorithms have only been proposed recently, their security has not yet been verified through long-term practical application. Therefore, during the transition period, a situation may arise where traditional cryptographic algorithms and post-quantum cryptography algorithms coexist.

[0046] Looking at the development of cryptography in various countries, they are accelerating the research and development of localized PQC algorithms, and each country may have its own PQC cryptographic algorithm. From a business perspective, some operators or private networks may adopt customized algorithms for specific security needs. Therefore, future networks (such as 6G) will present a complex scenario where traditional algorithms (ECC), multiple PQC algorithms, and other algorithms coexist. This places higher demands on the algorithm compatibility of communication equipment, the uniformity of key management, and the flexibility of security protocols.

[0047] However, existing technologies mainly have the following problems: (1) Limitations of a single algorithm.

[0048] The current 5G SUCI format and ECIES protection mechanism only support single elliptic curve cryptography (ECC) algorithms (such as Profile A / B), and are not compatible with pure post-quantum cryptography (PQC) algorithms or hybrid encryption (traditional cryptography + PQC) schemes.

[0049] Because SUCI's encryption field structure is fixed (e.g., the Protection Scheme Id only supports 0x0-0x2), it can only specify one scheme / algorithm and the corresponding public key, making it impossible to integrate quantum-resistant algorithms or hybrid encryption schemes such as KEM based on PQC, thus facing the risk of quantum computing attacks.

[0050] (2) The scalability of the scheme / algorithm is limited.

[0051] Existing improvement solutions, such as pure PQC replacing ECC, or ECC + PQC-based KEM hybrid solutions, only support fixed algorithms or combinations of algorithms. Their format extensibility is limited and they cannot be flexibly extended to support other possible PQC algorithms.

[0052] The subscription-based hidden identifier encryption scheme only supports a fixed combination of ECC and PQC schemes, and cannot combine multiple schemes. It does not define a SUPI protection scheme ID to support dynamic combination of multiple schemes, and its scalability is limited.

[0053] SUCI encryption schemes based on post-quantum key encapsulation mechanisms only support fixed PQC schemes and cannot combine multiple schemes. They also do not define SUPI protection scheme IDs to support dynamic combinations of multiple schemes, resulting in limited scalability.

[0054] (3) Insufficient dynamic support for algorithms.

[0055] The lack of algorithm selection and combination mechanisms makes it difficult to meet operators' needs for flexible algorithm deployment and to adjust encryption strategies in real time according to different network environments (such as operator policies and national cryptographic standards), thus affecting the feasibility of cross-regional deployment.

[0056] To address the aforementioned issues, this application designs a protection scheme identifier containing multiple flag bits, each corresponding to a specific cryptographic algorithm scheme. The value of each flag bit indicates whether to select the corresponding cryptographic algorithm scheme. The value of the protection scheme identifier indicates the combination of one or more cryptographic algorithm schemes used to protect SUPI. This allows the protection scheme identifier to support a single cryptographic algorithm scheme or a dynamic combination of multiple cryptographic algorithm schemes to be used, which is beneficial for better dealing with quantum attacks. Furthermore, this design not only allows for flexible expansion to support other possible cryptographic algorithm schemes but also allows for expansion to store the set of SUPI protection schemes to be used. The format extensibility is not limited, thereby meeting the operator's need for flexible algorithm deployment, adjusting encryption strategies in real time according to different network environments, and improving the feasibility of cross-regional deployment.

[0057] Figure 1 This is one of the flowcharts illustrating the communication network identifier protection method provided in this application. (Refer to...) Figure 1 This application provides a method for protecting communication network identifiers, which may specifically include the following steps: Step 101: Determine one or more cryptographic algorithm schemes for protecting the user identity identifier SUPI, wherein the one or more cryptographic algorithm schemes are selected from a predefined set of cryptographic algorithms.

[0058] It should be noted that the execution entity of the communication network SUCI calculation information update method provided in this application embodiment can be a user equipment, a USIM (Universal Subscriber Identity Module) or ME (Mobile Equipment) in the user equipment. The user equipment involved in this application embodiment can be a device that provides voice and / or data connectivity to the user, a handheld device with wireless connection function, or other processing devices connected to a wireless modem, etc.

[0059] It should be noted that the embodiments of this application are applicable not only to 5G communication networks, but also to future communication networks such as 6G, and this application makes no limitation herein. The following embodiments of this application use a 5G communication network as an example for illustration.

[0060] In this embodiment of the application, the USIM in the user equipment can obtain SUPI and SUCI calculation information (such as the USIM card file EF). SUCI_Calc_InfoThe SUCI calculation information can include a list of SUPI Protection Scheme Identifiers (PSIs) and the corresponding HN (Home Network) public key list. USIM can match the SUPI Protection Scheme Identifier list with the encryption algorithms it natively supports, and determine the highest priority SUPI Protection Scheme Identifier (i.e., protection scheme identifier) ​​and its corresponding HN public key set from the list.

[0061] In some embodiments, the USIM in the user equipment can obtain the set of SUPI protection schemes to be used and the corresponding set of HN public keys based on the SUPI protection scheme ID. The set of SUPI protection schemes may include one or more cryptographic algorithm schemes for protecting SUPI, and the set of HN public keys may include the HN public keys used by each cryptographic algorithm scheme.

[0062] The cryptographic algorithm scheme can refer to the cryptographic algorithm or encryption scheme used to protect SUPI, and these cryptographic algorithm schemes can be selected from a predefined set of cryptographic algorithms.

[0063] The predefined set of cryptographic algorithms can include various cryptographic schemes such as Profile A based on traditional cryptography, KEM based on PQC, and other cryptographic algorithms based on PQC.

[0064] It should be noted that the cryptographic algorithm schemes in the embodiments of this application may include existing cryptographic algorithm schemes, such as Profile A scheme, Profile B scheme, and the PQC-based KEM scheme, etc., and may also include other cryptographic algorithm schemes that may emerge in the future as cryptography develops, such as localized PQC cryptographic algorithms developed by various countries, and customized special algorithms that some operators or private networks may adopt for specific security needs. The embodiments of this application are not specifically limited here.

[0065] It should also be noted that the combination of one or more cryptographic algorithm schemes used to protect SUPI in the embodiments of this application can be obtained by combining existing cryptographic algorithm schemes, or by combining other cryptographic algorithm schemes that may appear in the future, or by combining existing cryptographic algorithm schemes and other cryptographic algorithm schemes that may appear in the future.

[0066] It should be noted that the cryptographic algorithm schemes included in the cryptographic algorithm set can be predefined based on actual needs (including existing cryptographic algorithm schemes and / or other cryptographic algorithm schemes that may emerge in the future as cryptography develops). This allows for flexible expansion to support other possible cryptographic algorithm schemes, enabling flexible combinations of multiple cryptographic algorithm schemes. This can meet the operators' needs for flexible algorithm deployment and can adjust encryption strategies in real time according to different network environments (such as operator policies and national cryptographic standards), improving the feasibility of cross-regional deployment.

[0067] Step 102: Generate temporary shared keys based on each of the cryptographic algorithm schemes.

[0068] In some embodiments, the USIM in the user equipment can generate temporary shared keys based on the key encapsulation mechanism or key negotiation mechanism corresponding to each cryptographic algorithm scheme included in the SUPI protection scheme set, as well as the HN public key used by each cryptographic algorithm scheme.

[0069] Step 103: Based on each of the temporary shared keys, derive the final key.

[0070] In some embodiments, the final key may include a temporary encryption key (Eph.enckey), a temporary integrity protection key (Eph.mackey), and an initialization counter block (ICB). The USIM in the user equipment can derive the temporary encryption key, the temporary integrity protection key, and the initialization counter block based on the generated temporary shared keys.

[0071] Step 104: Protect the SUPI based on the final key to obtain a user-hidden identifier SUCI; wherein, the SUCI includes a protection scheme identifier, the value of which is used to indicate a combination of one or more cryptographic algorithm schemes used to protect the SUPI, the protection scheme identifier contains multiple flag bits, each flag bit corresponds to a specific cryptographic algorithm scheme in the predefined cryptographic algorithm set, and the value of each flag bit is used to indicate whether the cryptographic algorithm scheme corresponding to the flag bit is selected.

[0072] In this embodiment, a temporary encryption key can be used to encrypt the SUPI using a symmetric cryptographic algorithm to obtain ciphertext data (Ciphertext), and a temporary integrity protection key can be used to calculate the MAC (Message Authentication Code) digest value (MAC-Tag) of the ciphertext data (Ciphertext). During the construction of the final output SUCI from the USIM, the Ciphertext field in the SUCI can be set to the Ciphertext encrypted with the SUPI, and the MAC-Tag field in the SUCI can be set to the MAC digest value (MAC-Tag) of the Ciphertext. The SUPI Type (SUPIType), Home Network Identifier (Home Network Identifier), and Routing Indicator (Routing Indicator) fields in the SUCI can be consistent with those in existing standards.

[0073] In some embodiments, the Protection Scheme ID field in SUCI can be set to the highest-priority SUPI protection scheme ID (i.e., protection scheme identifier). Compared to existing standards that can only specify one cryptographic algorithm scheme, the value of the protection scheme identifier in this application can indicate the set of SUPI protection schemes to be used (i.e., a combination of one or more cryptographic algorithm schemes used to protect SUPI). Therefore, the protection scheme identifier in this application, which supports dynamic combinations of one or more cryptographic algorithm schemes, can expand the storage of the set of SUPI protection schemes to be used, thus better addressing quantum attacks.

[0074] In some embodiments, the protection scheme identifier may include multiple flag bits, each flag bit may correspond to a specific cryptographic algorithm scheme in a predefined set of cryptographic algorithms, different flag bits may correspond to different cryptographic algorithm schemes, and the total number of specific cryptographic algorithm schemes included in the set of cryptographic algorithms may be the same as the total number of flag bits.

[0075] In one specific embodiment, bits can be used as flag bits (one bit is one flag bit), and the protection scheme identifier (i.e., SUPI protection scheme ID) can be determined by combining bits. The protection scheme identifier can be 1 to 2 bytes. The following embodiments of this application use a protection scheme identifier of 1 byte as an example for description.

[0076] The specific cryptographic algorithm scheme corresponding to each bit of the SUPI protection scheme ID can be predefined; when the bit is 1, it can indicate that the cryptographic algorithm scheme corresponding to that bit is selected, and when the bit is 0, it can indicate that the cryptographic algorithm scheme corresponding to that bit is not selected.

[0077] Figure 2 This is a schematic diagram illustrating the determination of the protection scheme identifier based on bit combination, as provided in an embodiment of this application. (Refer to...) Figure 2 The bits of the SUPI protection scheme ID, from least significant bit to most significant bit, correspond to cryptographic algorithm schemes 1, 2, 3, 4, 5, 6, 7, and 8, respectively. The bits corresponding to cryptographic algorithm schemes 1, 3, and 4 are all 1, indicating that the current SUPI protection scheme set = {cryptographic algorithm scheme 1 + cryptographic algorithm scheme 3 + cryptographic algorithm scheme 4}.

[0078] Figure 3 This is a schematic diagram of the USIM card file corresponding to the bit combination method provided in the embodiments of this application. (Refer to...) Figure 3 When the protection scheme identifier is determined by bit combination, the corresponding USIM card's EF... SUCI_Calc_Info The file can record the SUPI protection scheme ID set and the corresponding HN public key set. Among them, EF... SUCI_Calc_Info The file may include a SUPI protection scheme ID field and a key index field corresponding to each cryptographic algorithm scheme used to protect SUPI, as indicated by the SUPI protection scheme ID. The SUPI protection scheme ID field can be used to record the value of the SUPI protection scheme ID. For example, the value of SUPI protection scheme ID1 is 00000101, indicating that SUPI protection scheme set 1 = {cryptographic algorithm scheme 1 + cryptographic algorithm scheme 3}; the value of SUPI protection scheme ID2 is 00000001, and SUPI protection scheme set 2 = {cryptographic algorithm scheme 1}.

[0079] In another specific embodiment, a predefined identification method can be used to determine the protection scheme identifier (i.e., SUPI protection scheme ID). The protection scheme identifier can be 1 to 2 bytes. The following embodiments of this application use a protection scheme identifier of 1 byte as an example for description.

[0080] Figure 4 This is a schematic diagram illustrating the determination of a protection scheme identifier based on a predefined identification method, as provided in an embodiment of this application. (Refer to...) Figure 4It can be sequentially numbered and a set of SUPI protection schemes corresponding to each number can be predefined. Different numbers correspond to different sets of SUPI protection schemes. When the SUPI protection scheme ID is 0, its corresponding SUPI protection scheme set can be defined as Null-scheme; when the SUPI protection scheme ID is 1, its corresponding SUPI protection scheme set can be defined as Cryptographic Algorithm Scheme 1; when the SUPI protection scheme ID is 2, its corresponding SUPI protection scheme set can be defined as Cryptographic Algorithm Scheme 2; when the SUPI protection scheme ID is 3, its corresponding SUPI protection scheme set can be defined as Cryptographic Algorithm Scheme 3; when the SUPI protection scheme ID is 4, its corresponding SUPI protection scheme set can be defined as Cryptographic Algorithm Scheme 4; when the SUPI protection scheme ID is 5, its corresponding SUPI protection scheme set can be defined as Cryptographic Algorithm Scheme 5; when the SUPI protection scheme ID is 6, its corresponding SUPI protection scheme set can be defined as Cryptographic Algorithm Scheme 1 + Cryptographic Algorithm Scheme 3; when the SUPI protection scheme ID is 7, its corresponding SUPI protection scheme set can be defined as Cryptographic Algorithm Scheme 1 + Cryptographic Algorithm Scheme 4; when the SUPI protection scheme ID is 8, its corresponding SUPI protection scheme set can be defined as Cryptographic Algorithm Scheme 3 + Cryptographic Algorithm Scheme 4.

[0081] Figure 5 This is a schematic diagram of the USIM card file corresponding to the predefined identification method provided in the embodiments of this application. (Refer to...) Figure 5 When the protection scheme identifier is determined based on a predefined identification method, the corresponding USIM card's EF... SUCI_Calc_Info The file can record the SUPI protection scheme ID set and the corresponding HN public key set. Among them, EF... SUCI_Calc_Info The file may include a SUPI protection scheme ID field and a key index field corresponding to each cryptographic algorithm scheme used to protect SUPI, as indicated by the SUPI protection scheme ID. The SUPI protection scheme ID field can be used to record the value of the SUPI protection scheme ID. For example, a value of 6 for SUPI protection scheme ID1 indicates that SUPI protection scheme set 1 = {cryptographic algorithm scheme 1 + cryptographic algorithm scheme 3}; a value of 1 for SUPI protection scheme ID2 indicates that SUPI protection scheme set 2 = {cryptographic algorithm scheme 1}.

[0082] Compared to the existing technology where one SUPI protection scheme ID corresponds to one cryptographic algorithm scheme, the embodiments of this application support dynamic combination of SUPI protection scheme IDs. It can expand the storage of the set of SUPI protection schemes to be used. Through a scheme identification method based on bit combination or a scheme identification method based on predefined identifiers, the value of the SUPI protection scheme ID can support a combination of one or more cryptographic algorithm schemes.

[0083] Compared to existing technologies where one SUPI protection scheme ID corresponds to one cryptographic algorithm scheme, thus requiring only one key index, the embodiments of this application support USIM cards EF with dynamic scheme combinations. SUCI_Calc_Info The file format allows one SUPI protection scheme ID to support a set of schemes corresponding to multiple cryptographic algorithm schemes, thus supporting multiple corresponding key indices.

[0084] This application embodiment designs a protection scheme identifier containing multiple flag bits, each flag bit corresponding to a specific cryptographic algorithm scheme. The value of each flag bit indicates whether to select the corresponding cryptographic algorithm scheme. The value of the protection scheme identifier indicates the combination of one or more cryptographic algorithm schemes used to protect SUPI. This allows the protection scheme identifier to support a single cryptographic algorithm scheme or a dynamic combination of multiple cryptographic algorithm schemes to be used, which is beneficial for better dealing with quantum attacks. Furthermore, this design can not only flexibly expand to support other possible cryptographic algorithm schemes, but also expand the storage of the set of SUPI protection schemes to be used. The format extensibility is not limited, thereby meeting the operator's need for flexible algorithm deployment, adjusting the encryption strategy in real time according to different network environments, and improving the feasibility of cross-regional deployment.

[0085] In an optional embodiment, the SUCI further includes a public key identification information field corresponding to each cryptographic algorithm scheme. The public key identification information field is used to store the identification information of the public key of the home network element used by the cryptographic algorithm scheme. The field order of the public key identification information field corresponding to each cryptographic algorithm scheme is determined based on the order of the cryptographic algorithm schemes corresponding to each flag bit in the protection scheme identifier.

[0086] In some embodiments, the SUCI may further include a public key identification information field (i.e., an HN PubKeyId field) corresponding to each cryptographic algorithm scheme used to protect the SUPI. Each public key identification information field can be used to store the HN PubKeyId information used by its corresponding cryptographic algorithm scheme. Based on the number n cryptographic algorithm schemes in the adopted SUPI protection scheme set, and according to the order of the cryptographic algorithm schemes corresponding to each flag bit in the SUPI protection scheme ID, n HN PubKeyId fields can be dynamically added sequentially to the SUCI to store the public key IDs used by each cryptographic algorithm scheme, namely: HN PubKeyId_1, HN PubKeyId_2, ..., HN PubKeyId_n.

[0087] For example, you can set the IDs of PubKey_1, PubKey_2, and PubKey_3 separately in SUCI.

[0088] In some embodiments, n HN PubKeyId fields can be dynamically added sequentially in SUCI according to the order of the flag bits from high to low; alternatively, n HNPubKeyId fields can be dynamically added sequentially in SUCI according to the order of the flag bits from low to high.

[0089] Compared to existing standards that can only specify one public key, the SUCI format in this application embodiment can not only support the dynamic combination of multiple cryptographic algorithm schemes to be used, but also support the dynamic storage of multiple public keys, thus realizing the SUPI encryption mechanism that supports dynamic scheme combination.

[0090] In an optional embodiment, the SUCI further includes a scheme output field, which includes a temporary cryptographic data field corresponding to each cryptographic algorithm scheme. The temporary cryptographic data field is used to store temporary cryptographic data generated based on the cryptographic algorithm scheme. The field order of the temporary cryptographic data fields corresponding to each cryptographic algorithm scheme is determined based on the order of the cryptographic algorithm schemes corresponding to each flag bit in the protection scheme identifier.

[0091] In some embodiments, SUCI may further include a Scheme Output field, which may include temporary cryptographic data fields (ECD fields) corresponding to each cryptographic algorithm scheme protecting SUPI. These temporary cryptographic data fields can be used to store temporary cryptographic data generated based on the cryptographic algorithm schemes. Based on the number of cryptographic algorithm schemes n in the SUPI protection scheme set, and according to the order of the cryptographic algorithm schemes corresponding to each flag bit in the SUPI protection scheme ID, n ECD fields can be dynamically added sequentially to the Scheme Output field of SUCI to store the temporary encrypted data ECD generated by each cryptographic algorithm scheme, namely: ECD_1, ECD_2, ..., ECD_n.

[0092] For example, in SUCI, these can be set to Eph.PubKey_t, encrypted sk_2, and encrypted sk_3 respectively.

[0093] Compared to existing standards that can only set one temporary encrypted data, i.e.: scheme output=Eph.PubKey_t||encryptedsk_1||encryptedsk_2||Ciphertext||MAC-Tag{||any other parameters}, the SUCI format of this application embodiment can not only support the dynamic combination of multiple cryptographic algorithm schemes to be used, but also support the storage of multiple temporary cryptographic data, thereby realizing the SUPI encryption mechanism that supports dynamic scheme combination.

[0094] In one optional embodiment, generating temporary shared keys based on each of the cryptographic algorithm schemes includes: For each cryptographic algorithm scheme, a temporary shared key is generated based on the public key of the network element used by the cryptographic algorithm scheme and the key encapsulation mechanism corresponding to the cryptographic algorithm scheme.

[0095] In this embodiment, during the process of generating SUCI from encrypted SUPI, the USIM in the user equipment can generate temporary shared keys according to the encryption mechanism corresponding to the SUPI protection scheme set and the corresponding HN public key set. The following embodiment uses the example of SUPI protection scheme set = cryptographic algorithm scheme 1 + cryptographic algorithm scheme 2 + cryptographic algorithm scheme 3 for illustration. The temporary shared key generation process is similar when the SUPI protection scheme set contains only one, two, or more cryptographic algorithm schemes.

[0096] In generating the temporary shared key sk_1 using cryptographic algorithm scheme 1 (taking Profile A based on traditional cryptography as an example), we can first generate a temporary public-private key pair based on traditional cryptography: a temporary public key (Eph.PubKey_t) + a temporary private key (Eph.PriKey_t). The temporary public key (Eph.PubKey_t) is the output temporary cryptographic data (ECD1). Next, using the HN public key 1 (PubKey_1) and the temporary private key (Eph.PriKey_t), we can generate the temporary shared key (Eph.shared key, sk_1) based on the ECC key agreement mechanism. The temporary shared key sk_1 is the output temporary shared key.

[0097] In the process of generating the temporary shared key sk_2 using cryptographic algorithm scheme 2 (taking cryptographic algorithm scheme 2 using PQC-based KEM as an example), the HN public key 2 (PubKey_2) and the PQC-based KEM key encapsulation mechanism encapsulation mechanism encapsulation can be used to generate the temporary shared key (Eph.shared key, abbreviated as sk_2) and the encrypted encapsulated sk_2. The encrypted encapsulated sk_2 is the output temporary cryptographic data (abbreviated as ECD2), and the temporary shared key sk_2 is the output temporary shared key.

[0098] In the process of generating the temporary shared key sk_3 using cryptographic algorithm scheme 3 (taking the use of cryptographic algorithms based on other PQC as an example), the HN public key 3 (PubKey_3) can be used to generate the temporary shared key (Eph. shared key, abbreviated as sk_3) and the encrypted sk_3 (encryptedsk_3) based on other key encapsulation mechanisms (encaps). The encrypted sk_3 is the output temporary cryptographic data (abbreviated as ECD3), and the temporary shared key sk_3 is the output temporary shared key.

[0099] This application embodiment generates temporary shared keys based on the public key of the home network element used by one or more cryptographic algorithm schemes for protecting SUPI and the encryption mechanism corresponding to the cryptographic algorithm scheme. Subsequently, each temporary shared key can be used together to output the final key to encrypt and protect SUPI, thereby realizing a SUPI encryption mechanism that supports dynamic scheme combination.

[0100] Figure 6 This is a schematic diagram of the SUCI format supporting dynamic scheme combination provided in an embodiment of this application. (Refer to...) Figure 6 The SUCI format, which supports dynamic scheme combinations, can include a Protection Scheme Id field (this field records the protection scheme identifier, the value of which indicates the combination of n cryptographic schemes used to protect SUPI), an HN PubKeyId field corresponding to each of the n cryptographic schemes (used to store the home network public key ID information used by the n cryptographic schemes), and an ECD field corresponding to each of the n cryptographic schemes (used to store temporary cryptographic data generated based on the cryptographic schemes), etc. Here, n = 1, 2, 3, ..., n is a positive integer.

[0101] It should be noted that the network public key ID information used by each cryptographic algorithm scheme stored in SUCI corresponds one-to-one with the temporary cryptographic data generated based on each cryptographic algorithm scheme.

[0102] Figure 7 This is an example diagram illustrating the SUCI format supporting dynamic scheme combination provided in this application embodiment. (Refer to...) Figure 7 The values ​​of the protection scheme identifiers are shown as follows: (00000001) indicates the SUCI format when only cryptographic algorithm scheme 1 is used; (00000010) indicates the SUCI format when only cryptographic algorithm scheme 2 is used; (00000101) indicates the SUCI format when cryptographic algorithm scheme 1 + cryptographic algorithm scheme 3 is used; and (00001101) indicates the SUCI format when cryptographic algorithm scheme 1 + cryptographic algorithm scheme 3 + cryptographic algorithm scheme 4 is used.

[0103] In one optional embodiment, deriving the final key based on each of the temporary shared keys includes: The temporary shared keys are combined to obtain a temporary shared key combination. The temporary shared key combination is input into the key derivation function to derive the final key; The final key includes a temporary encryption key, a temporary integrity protection key, and an initialization key block.

[0104] In some embodiments, the USIM in the user equipment can derive temporary encryption keys, temporary integrity protection keys, and initialization encryption blocks based on the generated temporary shared keys.

[0105] In some embodiments, the temporary shared keys can be combined in a concatenated manner or by an XOR combination to obtain a temporary shared key combination. The temporary shared key combination is then input into the key derivation function to derive the temporary encryption key (Eph.enc key), the initialization block ICB (Initial Counter Block), and the temporary integrity protection key (Eph.mac key).

[0106] In one example, when generating temporary shared keys sk_1, sk_2, and sk_3, they can be concatenated to obtain the temporary shared key combination sk = sk_1||sk_2||sk_3, or they can be XORed to obtain the temporary shared key combination sk = sk_1⊕sk_2⊕sk_3.

[0107] This application embodiment achieves key isolation for different security functions through key layer derivation, which is used for subsequent encryption of different data to protect SUPI, thereby realizing a SUPI encryption mechanism that supports dynamic scheme combination.

[0108] In an optional embodiment, upon receiving an information update request from the home network element, the method further includes: Based on the information update request, the protection scheme identifier is updated; the information update request is used to instruct the value of the corresponding flag bit in the protection scheme identifier to be updated based on one or more cryptographic algorithm schemes for protecting SUPI that have been redefined.

[0109] In this embodiment, the user equipment's USIM card can receive an information update request sent by the home network element (HN) to update the protection scheme identifier. This allows the HN to remotely update the EF on the USIM card when it needs to modify the SUPI encryption policy. SUCI_Calc_Info The file updates the SUPI protection scheme set recorded in the SUCI calculation information. The updated SUPI protection scheme ID value can be used to indicate the combination of multiple cryptographic algorithm schemes selected according to actual needs, thus eliminating the need to change the card.

[0110] For example, assuming that the user equipment (UE) supports the empty scheme, Profile A, Profile B, PQC-based KEM, and other cryptographic algorithm schemes that may emerge in the future as cryptography develops (such as other PQC algorithms, customized special algorithm schemes that some operators or private networks may adopt for specific security needs, etc.), the policy can be dynamically updated according to the network-side modifications.

[0111] For example, when the network-side HN is not modified, PQC is not supported: the issued SUPI encryption policy can be an empty scheme, Profile A, or Profile B. When the network-side HN has been modified, PQC is supported: the issued SUPI encryption policy can be Profile A + PQC-based KEM, or Profile A + other PQC schemes. When PQC is already maturely applied: the issued SUPI encryption policy can be a pure PQC algorithm scheme. When it needs to be applied to specific industry sectors: the issued SUPI encryption policy can be a dedicated algorithm scheme developed based on specific security requirements.

[0112] Figure 8 This is the second flowchart illustrating the communication network identifier protection method provided in this application. (Refer to...) Figure 8 This application provides a method for protecting communication network identifiers, which may specifically include the following steps: Step 801: Receive a User Hidden Identifier (SUCI) sent by the user equipment; the SUCI includes a protection scheme identifier, the value of which is used to indicate a combination of one or more cryptographic algorithm schemes used to protect the SUCI, the protection scheme identifier contains multiple flag bits, each flag bit corresponds to a specific cryptographic algorithm scheme in the predefined cryptographic algorithm set, and the value of each flag bit is used to indicate whether the cryptographic algorithm scheme corresponding to the flag bit is selected.

[0113] It should be noted that the execution subject of the communication network SUCI calculation information update method provided in this application embodiment can be a home network element, such as a UDM / ARPF (Unified Data Management / Authentication Credential Repository and Processing Function) network element.

[0114] It should be noted that the embodiments of this application are applicable not only to 5G communication networks, but also to future communication networks such as 6G, and this application makes no limitation herein. The following embodiments of this application use a 5G communication network as an example for illustration.

[0115] In this embodiment of the application, the user equipment can submit a SUCI to the home network element, and the home network element can decrypt the SUCI to obtain the SUPI. The home network element can obtain the protection scheme identifier (i.e., the SUPI protection scheme ID) from the Protection Scheme Id field of the SUCI. The protection scheme identifier can indicate the set of SUPI protection schemes to be used (i.e., a combination of one or more cryptographic algorithm schemes used to protect the SUPI).

[0116] In some embodiments, the protection scheme identifier (i.e., SUPI protection scheme ID) may contain multiple flag bits, each flag bit corresponding to a specific cryptographic algorithm scheme in a predefined set of cryptographic algorithms. Different flag bits may correspond to different cryptographic algorithm schemes, and the total number of specific cryptographic algorithm schemes included in the cryptographic algorithm set may be the same as the total number of flag bits. Therefore, the home network element can parse the set of SUPI protection schemes used for SUPI encryption based on the SUPI protection scheme ID.

[0117] In one specific embodiment, bits can be used as flag bits (one bit per flag bit), and the protection scheme identifier can be determined by combining bits. Specific cryptographic algorithm schemes corresponding to each bit of the SUPI protection scheme ID can be predefined; a bit of 1 indicates that the corresponding cryptographic algorithm scheme is selected, while a bit of 0 indicates that the corresponding cryptographic algorithm scheme is not selected.

[0118] In another specific embodiment, a predefined identification method can be used to determine the protection scheme identifier (i.e., SUPI protection scheme ID). Sequential numbering can be performed in advance, and a set of SUPI protection schemes corresponding to each number can be predefined; different numbers can correspond to different sets of SUPI protection schemes.

[0119] Step 802: Generate temporary shared keys based on the various cryptographic algorithm schemes used to protect the SUPI.

[0120] In some embodiments, the home network element may generate a temporary shared key based on the encryption mechanism (including key encapsulation mechanism or key negotiation mechanism) corresponding to each cryptographic algorithm scheme included in the SUPI protection scheme set, and the HN public key used by each cryptographic algorithm scheme.

[0121] Step 803: Based on each of the temporary shared keys, derive the final key.

[0122] In some embodiments, the final key may include a temporary encryption key (Eph.enckey), a temporary integrity protection key (Eph.mackey), and an initialization counter block (ICB). The home network element can derive the temporary encryption key, temporary integrity protection key, and initialization counter block based on the generated temporary shared keys.

[0123] Step 804: Decrypt the SUCI based on the final key to obtain the SUPI.

[0124] In this embodiment of the application, the Ciphertext field in SUCI is used to record the ciphertext data after SUPI encryption, the MAC-Tag field in SUCI is used to record the MAC digest value MAC-Tag of the ciphertext data, and the SUPIType field, Home Network Identifier field, and Routing Indicator field in SUCI can be consistent with those in existing standards.

[0125] In some embodiments, a temporary encryption key can be used to decrypt the Ciphertext field using a symmetric cryptographic algorithm to obtain the plaintext SUPI, and a temporary integrity protection key can be used to verify the correctness of the MAC digest value MAC-Tag of the ciphertext Ciphertext.

[0126] This application embodiment designs a protection scheme identifier containing multiple flag bits, each flag bit corresponding to a specific cryptographic algorithm scheme. The value of each flag bit indicates whether to select the corresponding cryptographic algorithm scheme. The value of the protection scheme identifier indicates the combination of one or more cryptographic algorithm schemes used to protect SUPI. This allows the protection scheme identifier to support a single cryptographic algorithm scheme or a dynamic combination of multiple cryptographic algorithm schemes to be used, which is beneficial for better dealing with quantum attacks. Furthermore, this design can not only flexibly expand to support other possible cryptographic algorithm schemes, but also expand the storage of the set of SUPI protection schemes to be used. The format extensibility is not limited, thereby meeting the operator's need for flexible algorithm deployment, adjusting the encryption strategy in real time according to different network environments, and improving the feasibility of cross-regional deployment.

[0127] In an optional embodiment, the SUCI further includes a public key identification information field corresponding to each cryptographic algorithm scheme, the public key identification information field being used to store the identification information of the home network element public key used by the cryptographic algorithm scheme; the field order of the public key identification information fields corresponding to each cryptographic algorithm scheme is determined based on the order of the cryptographic algorithm schemes corresponding to each flag bit in the protection scheme identifier; after receiving the user hidden identifier SUCI sent by the user equipment, the embodiment further includes: According to the order of the cryptographic algorithm schemes corresponding to each flag bit in the protection scheme identifier, the identification information of the public key of the network element used by each cryptographic algorithm scheme is obtained from the public key identification information field of the SUCI. Based on the identification information of the public key of the network element used by each cryptographic algorithm scheme, the private key of the network element corresponding to each cryptographic algorithm scheme is obtained.

[0128] In some embodiments, the SUCI may further include a public key identification information field (i.e., an HN PubKeyId field) corresponding to each cryptographic algorithm scheme used to protect the SUPI. Each public key identification information field can be used to store the HN PubKeyId information used by its corresponding cryptographic algorithm scheme. Based on the number n of cryptographic algorithm schemes in the SUPI protection scheme set, and according to the order of the cryptographic algorithm schemes corresponding to each flag bit in the SUPI protection scheme ID, the public key IDs used by each cryptographic algorithm scheme in the SUPI protection scheme set can be obtained from the SUCI, namely: HN PubKeyId_1, HN PubKeyId_2, ..., HN PubKeyId_n, and then the corresponding private keys can be obtained. For example, the obtained private keys can be PriKey_1, PriKey_2, and PriKey_3.

[0129] Compared to existing standards that can only specify one public key, the SUCI format in this application embodiment can not only support the dynamic combination of multiple cryptographic algorithm schemes to be used, but also support the dynamic storage of multiple public keys, thus realizing a SUCI decryption mechanism that supports dynamic scheme combination.

[0130] In an optional embodiment, the SUCI further includes a scheme output field, which includes temporary cryptographic data fields corresponding to each cryptographic algorithm scheme. These temporary cryptographic data fields are used to store temporary cryptographic data generated based on the cryptographic algorithm schemes. The field order of the temporary cryptographic data fields corresponding to each cryptographic algorithm scheme is determined based on the order of the cryptographic algorithm schemes corresponding to each flag bit in the protection scheme identifier. After receiving the User Hidden Identifier (SUCI) sent by the user equipment, the following is also included: According to the order of the cryptographic algorithm schemes corresponding to each flag bit in the protection scheme identifier, the temporary cryptographic data generated based on each cryptographic algorithm scheme is obtained from the scheme output field of the SUCI.

[0131] In some embodiments, SUCI may further include a scheme output field (i.e., a Scheme Output field). This field may include temporary cryptographic data fields (ECD fields) corresponding to each cryptographic algorithm scheme protecting SUPI. These temporary cryptographic data fields can be used to store temporary cryptographic data generated based on the cryptographic algorithm schemes. Based on the number of cryptographic algorithm schemes *n* in the SUPI protection scheme set, and according to the order of the cryptographic algorithm schemes corresponding to each flag bit in the SUPI protection scheme ID, the temporary encrypted data ECDs generated by each cryptographic algorithm scheme in the SUPI protection scheme set can be obtained from the Scheme Output field of SUCI. These ECDs are: ECD_1, ECD_2, ..., ECD_n. For example, they can be Eph.PubKey_t, encrypted sk_2, and encrypted sk_3, respectively.

[0132] Compared to existing standards that can only set one temporary encrypted data, i.e.: scheme output=Eph.PubKey_t||encryptedsk_1||encryptedsk_2||Ciphertext||MAC-Tag{||any other parameters}, the SUCI format of this application embodiment can not only support the dynamic combination of multiple cryptographic algorithm schemes to be used, but also support the storage of multiple temporary cryptographic data, thereby realizing a SUCI decryption mechanism that supports dynamic scheme combination.

[0133] In an optional embodiment, generating temporary shared keys based on the various cryptographic algorithm schemes used to protect the SUPI includes: For each cryptographic algorithm scheme, a temporary shared key is generated based on the private key of the network element corresponding to the cryptographic algorithm scheme, the temporary cryptographic data generated based on the cryptographic algorithm scheme, and the key decryption mechanism corresponding to the cryptographic algorithm scheme.

[0134] In this embodiment, the home network element can generate a temporary shared key based on the SUPI protection scheme set and the corresponding HN private key set. The following embodiment uses the example of SUPI protection scheme set = cryptographic algorithm scheme 1 + cryptographic algorithm scheme 2 + cryptographic algorithm scheme 3 for illustration. The temporary shared key generation process is similar when the SUPI protection scheme set contains only one, two, or more cryptographic algorithm schemes.

[0135] In the process of generating a temporary shared key sk_1 using cryptographic algorithm scheme 1 (taking the traditional cryptographic Profile A as an example), the HN private key 1 (PriKey_1) and the temporary public key (Eph. PubKey_t) can be used to generate a temporary shared key (Eph. shared key, abbreviated as sk_1) based on the key agreement mechanism of traditional cryptography.

[0136] In the process of generating the temporary shared key sk_2 using cryptographic algorithm scheme 2 (taking cryptographic algorithm scheme 2 using PQC-based KEM as an example), the temporary shared key (Eph. shared key, abbreviated as sk_2) can be obtained by using HN private key 2 (PriKey_2) and encrypted sk_2, and the key decapsulation mechanism of PQC-based KEM.

[0137] In the process of generating the temporary shared key sk_3 using cryptographic algorithm scheme 3 (taking cryptographic algorithm scheme 3 using other PQC-based cryptographic algorithms as an example), the HN private key 3 (PriKey_3) and the encrypted sk_3 can be used to obtain the temporary shared key (Eph. shared key, abbreviated as sk_3) based on other key decapsulation mechanisms (decaps).

[0138] This application embodiment generates temporary shared keys based on the private key of the home network element corresponding to one or more cryptographic algorithm schemes used to protect SUCI, temporary cryptographic data generated based on the cryptographic algorithm scheme, and the decryption mechanism corresponding to the cryptographic algorithm scheme. Subsequently, the various temporary shared keys can be used together to output the final key to decrypt SUCI, thereby realizing a SUCI decryption mechanism that supports dynamic scheme combination.

[0139] In one optional embodiment, deriving the final key based on each of the temporary shared keys includes: The temporary shared keys are combined to obtain a temporary shared key combination. The temporary shared key combination is input into the key derivation function to derive the final key; The final key includes a temporary encryption key, a temporary integrity protection key, and an initialization key block.

[0140] In some embodiments, the home network element can derive temporary encryption keys, temporary integrity protection keys, and initialization encryption blocks based on the generated temporary shared keys.

[0141] In some embodiments, the temporary shared keys can be combined in a concatenated manner or by an XOR combination to obtain a temporary shared key combination. The temporary shared key combination is then input into the key derivation function to derive the temporary encryption key (Eph.enc key), the initialization block ICB (Initial Counter Block), and the temporary integrity protection key (Eph.mac key).

[0142] In one example, when generating temporary shared keys sk_1, sk_2, and sk_3, they can be concatenated to obtain the temporary shared key combination sk = sk_1||sk_2||sk_3, or they can be XORed to obtain the temporary shared key combination sk = sk_1⊕sk_2⊕sk_3.

[0143] This application embodiment achieves key isolation for different security functions through key layer derivation, which is used for subsequent decryption of SUCI, thereby realizing a SUCI decryption mechanism that supports dynamic scheme combination.

[0144] In an optional embodiment, the method further includes: If it is necessary to modify the SUPI encryption strategy, an information update request is sent to the user equipment; the information update request is used to instruct the value of the corresponding flag bit in the protection scheme identifier to be updated based on one or more cryptographic algorithm schemes for protecting SUPI that have been redefined.

[0145] In this embodiment, when the SUPI encryption policy of the USIM card needs to be modified, the home network element (HN) can send an information update request to the user equipment's (UE) USIM card. The UE's USIM card can receive the information update request from the HN and update the protection scheme identifier. This allows the HN to remotely update the EF on the USIM card when it needs to modify the SUPI encryption policy. SUCI_Calc_Info The file updates the SUPI protection scheme set recorded in the SUCI calculation information. The updated SUPI protection scheme ID value can be used to indicate the combination of multiple cryptographic algorithm schemes selected according to actual needs, thus eliminating the need to change the card.

[0146] To better understand the embodiments of this application, the following specific embodiment will be used to illustrate the embodiments of this application.

[0147] Figure 9 This is a schematic diagram of the identity submission process provided in the embodiments of this application. Figure 10 This is a flowchart of the SUPI encryption mechanism that supports dynamic scheme combination provided in the embodiments of this application. Figure 11This is a flowchart of the SUCI decryption mechanism that supports dynamic scheme combination provided in the embodiments of this application.

[0148] Reference Figures 9-11 During the identity submission process, both the UE-side USIM and ME can perform encryption of SUPI. The following description uses USIM as an example.

[0149] Step 1: Obtain SUPI from USIM and SUCI calculation information (such as the USIM card file EF). SUCI_Calc_Info This includes a list of SUPI protection scheme IDs (Protection Scheme Identifier or Protection Scheme Id, abbreviated as PSI) and a list of corresponding home network HN public keys.

[0150] Step 2: USIM matches the SUPI protection scheme ID list based on the encryption algorithms supported by USIM locally, and determines the highest priority SUPI protection scheme ID and the corresponding HN public key set that can be supported.

[0151] Step 3: Obtain the set of SUPI protection schemes and HN public keys to be used based on the SUPI protection scheme ID.

[0152] Step 3.1, Example 1 - Bit Combination Method (Assuming the SUPI protection scheme ID is 1-2 bytes, using 1 byte as an example): 1) Predefined cryptographic algorithm schemes corresponding to each bit of the SUPI protection scheme ID. The current bit being 1 indicates that the cryptographic algorithm scheme has been selected.

[0153] 2) Reference Figure 2 The SUPI protection scheme ID is 00001101, which means that the current SUPI protection scheme ID represents the SUPI protection scheme set = {crypto algorithm scheme 1 + crypto algorithm scheme 3 + crypto algorithm scheme 4}.

[0154] Step 3.2, Example 2 - Predefined Identification Method (Assuming the SUPI protection scheme ID is 1-2 bytes, using 1 byte as an example): 1) Sequential numbering, predefined SUPI protection schemes corresponding to each number.

[0155] 2) Reference Figure 3 If the SUPI protection scheme ID is 6, it means that the SUPI protection scheme set = {crypto algorithm scheme 1 + cryptographic algorithm scheme 3}.

[0156] Step 4: Use USIM to encrypt SUPI and generate SUCI.

[0157] Step 4.1: USIM generates shared keys based on the SUPI protection scheme set and the HN public key set. The following example illustrates this using the SUPI protection scheme set = cryptographic algorithm scheme 1 + cryptographic algorithm scheme 2 + cryptographic algorithm scheme 3. The process is similar if the SUPI protection scheme set contains only one cryptographic algorithm scheme, or two or more. Step 4.1.1: Generate a temporary shared key sk_1 using cryptographic algorithm scheme 1 (taking Profile A based on traditional cryptography as an example): 1) Generate a temporary public-private key pair based on traditional cryptography: Temporary public key (Eph.PubKey_t) + Temporary private key (Eph.PriKey_t). The temporary public key (Eph.PubKey_t) is the output temporary cryptographic data (ECD1).

[0158] 2) Using HN public key 1 (PubKey_1) and temporary private key (Eph. PriKey_t), a temporary shared key (Eph. shared key, abbreviated as sk_1) is generated based on the ECC key agreement mechanism. The temporary shared key sk_1 is the output shared key.

[0159] Step 4.1.2: Generate a temporary shared key sk_2 using cryptographic algorithm scheme 2 (taking KEM based on PQC as an example): 1) Using HN public key 2 (PubKey_2), a temporary shared key (Eph. shared key, abbreviated as sk_2) and an encrypted sk_2 are generated based on the KEM key encapsulation mechanism of PQC.

[0160] 2) The encrypted sk_2 is the output temporary cryptographic data (ECD2), and the temporary shared key sk_2 is the output temporary shared key.

[0161] Step 4.1.3: Generate a temporary shared key sk_3 using cryptographic algorithm scheme 3 (taking cryptographic algorithm scheme 3 using cryptographic algorithms based on other PQC as an example): 1) Using HN public key 3 (PubKey_3), a temporary shared key (Eph. shared key, abbreviated as sk_3) and an encrypted sk_3 are generated based on other key encapsulation mechanisms (encaps).

[0162] 2) The encrypted sk_3 is the output temporary cryptographic data (ECD3 for short), and the temporary shared key sk_3 is the output temporary shared key.

[0163] Step 4.2: USIM derives the temporary encryption key, temporary integrity protection key, and initialization encryption block based on the generated temporary shared key (sk_1, sk_2, sk_3).

[0164] Step 4.2.1: Combine the temporary shared keys (sk_1, sk_2, sk_3).

[0165] 1) Method 1: Series combination sk = sk_1||sk_2||sk_3.

[0166] 2) Method 2: XOR combination sk = sk_1⊕sk_2⊕sk_3.

[0167] Step 4.2.2: Input the temporary shared key combination into the key derivation function to derive the temporary encryption key (Eph.enc key), the initialization block ICB (Initial Counter Block), and the temporary integrity protection key (Eph.mac key).

[0168] Step 4.3: Use a temporary encryption key to encrypt SUPI using a symmetric cryptographic algorithm to obtain ciphertext data.

[0169] Step 4.4: Calculate the MAC digest value (MAC-Tag) of the ciphertext data using the temporary integrity protection key.

[0170] Step 4.5: USIM constructs the final output SUCI.

[0171] Step 4.5.1: The SUPI Type field, Home Network Identifier field, and Routing Indicator field are consistent with those in the existing standard.

[0172] Step 4.5.2: Set the Protection Scheme ID field to the highest priority SUPI protection scheme ID obtained in Step 2, which indicates the set of SUPI protection schemes to be used. (Existing standards can only specify one scheme).

[0173] Step 4.5.3: Based on the number n cryptographic schemes in the SUPI protection scheme set, dynamically add n HN PubKeyId fields to SUCI sequentially according to the cryptographic scheme set specified in the SUPI protection scheme ID. These fields are used to store the public key IDs used by each cryptographic scheme, namely: HN PubKeyId_1, HN PubKeyId_2, ..., HN PubKeyId_n. Here, they are set as the IDs of PubKey_1, PubKey_2, and PubKey_3, respectively. (While existing standards can only specify one public key).

[0174] Step 4.5.4: Based on the number n cryptographic schemes in the SUPI protection scheme set, dynamically add n ECD fields sequentially to the Scheme Output field of SUCI according to the cryptographic scheme set specified in the SUPI protection scheme ID. These fields are used to store the temporary encrypted data ECDs generated by each cryptographic scheme, namely: ECD_1, ECD_2, ..., ECD_n. Here, they are set to Eph.PubKey_t, encrypted sk_2, and encrypted sk_3, respectively. (While the existing standard can only set one temporary encrypted data). That is: scheme output = Eph.PubKey_t||encrypted sk_1||encrypted sk_2||Ciphertext||MAC-Tag{||any other parameters}.

[0175] Step 4.5.5: Set the Ciphertext field to the Ciphertext encrypted with SUPI.

[0176] Step 4.5.6: Set the MAC-Tag field to the MAC summary value MAC-Tag of Ciphertext.

[0177] Step 5: USIM submits SUCI to the network side HN.

[0178] Step 6: HN decrypts SUCI to obtain SUPI.

[0179] Step 6.1: HN obtains the SUPI protection scheme ID from the Protection Scheme Id field in SUCI, which indicates the set of SUPI protection schemes to be used.

[0180] Step 6.2: HN parses the set of SUPI protection schemes used by the SUCI encryption based on the SUPI protection scheme ID. The method is the same as the two embodiments in Step 3.

[0181] Step 6.3: Based on the number n of cryptographic algorithm schemes in the SUPI protection scheme set, obtain the public key IDs used by each cryptographic algorithm scheme in the SUPI protection scheme set from SUCI in the order specified in the SUPI protection scheme ID. These public key IDs are: HN PubKeyId_1, HN PubKeyId_2, ..., HN PubKeyId_n. Then, obtain the corresponding private keys. Here, the obtained private keys are PriKey_1, PriKey_2, and PriKey_3.

[0182] Step 6.4: Based on the number n of cryptographic algorithm schemes in the SUPI protection scheme set, retrieve the temporary encrypted data ECDs generated by each cryptographic algorithm scheme in the SUPI protection scheme set from the Scheme Output field of SUCI, in the order specified in the SUPI protection scheme ID: ECD_1, ECD_2, ..., ECD_n. Here, they are Eph.PubKey_t, encrypted sk_2, and encrypted sk_3, respectively.

[0183] Step 6.5: HN generates a shared key based on the SUPI protection scheme set and the HN private key set.

[0184] Step 6.5.1: Generate a temporary shared key sk_1 using cryptographic algorithm scheme 1 (taking Profile A based on traditional cryptography as an example): Using HN private key 1 (PriKey_1) and temporary public key (Eph. PubKey_t), a temporary shared key (Eph. shared key, abbreviated as sk_1) is generated based on the key agreement mechanism of traditional cryptography.

[0185] Step 6.5.2: Generate a temporary shared key sk_2 using cryptographic algorithm scheme 2 (taking KEM based on PQC as an example): Using HN private key 2 (PriKey_2) and encrypted sk_2, a temporary shared key (Eph. shared key, abbreviated as sk_2) is obtained by decapsulation of the KEM key based on PQC.

[0186] Step 6.5.3: Generate a temporary shared key sk_3 using cryptographic algorithm scheme 3 (taking cryptographic algorithm scheme 3 using cryptographic algorithms based on other PQC as an example): Using HN private key 3 (PriKey_3) and encrypted sk_3, a temporary shared key (Eph.shared key, abbreviated as sk_3) is obtained based on other key decapsulation mechanisms (decaps).

[0187] Step 6.6: HN derives the temporary encryption key, temporary integrity protection key, and initialization encryption block based on the generated temporary shared key (sk_1, sk_2, sk_3).

[0188] Step 6.6.1: Combine the temporary shared keys (sk_1, sk_2, sk_3): 1) Method 1 (Recommended): Series combination sk = sk_1||sk_2||sk_3.

[0189] 2) Method 2: XOR combination sk = sk_1⊕sk_2⊕sk_3.

[0190] Step 6.6.2: Input the temporary shared key combination into the key derivation function to derive the temporary encryption key (Eph.enc key), the initialization block ICB (Initial Counter Block), and the temporary integrity protection key (Eph.mac key).

[0191] Step 6.7: Use a temporary encryption key to decrypt the Ciphertext field using a symmetric cryptography algorithm to obtain the plaintext SUPI.

[0192] Step 6.8: Verify the correctness of the MAC digest value MAC-Tag of the ciphertext using the temporary integrity protection key.

[0193] In summary, the embodiments of this application have the following technical advantages.

[0194] (1) SUPI encryption can support a single cryptographic algorithm scheme or a combination of multiple cryptographic algorithm schemes to cope with quantum attacks.

[0195] (2) When the home network HN needs to modify the SUPI encryption policy, it only needs to remotely update the EF on the USIM card. SUCI_Calc_Info Files can be transferred without changing the card.

[0196] (3) It is compatible with the mechanisms in the existing 3GPP (3rd Generation Partnership Project) standards, supports a single cryptographic algorithm scheme, does not modify the service network, and does not modify the ME when USIM is supported. Furthermore, it does not modify any of the interfaces.

[0197] The communication network identifier protection device provided in the embodiments of this application is described below. The communication network identifier protection device described below can be referred to in correspondence with the communication network identifier protection method described above.

[0198] Figure 12 This is one of the structural schematic diagrams of the communication network identifier protection device provided in the embodiments of this application. (Refer to...) Figure 12 This invention provides a communication network identifier protection device, applied to user equipment, which may specifically include the following modules: The protection scheme determination module 1210 is used to determine one or more cryptographic algorithm schemes for protecting the user identity identifier SUPI, wherein the one or more cryptographic algorithm schemes are selected from a predefined set of cryptographic algorithms; The first key generation module 1220 is used to generate temporary shared keys based on each of the aforementioned cryptographic algorithm schemes; The first key derivation module 1230 is used to derive the final key based on each of the temporary shared keys; The SUCI generation module 1240 is used to protect the SUPI based on the final key to obtain the user hidden identifier SUCI; The SUCI includes a protection scheme identifier. The value of the protection scheme identifier is used to indicate a combination of one or more cryptographic algorithm schemes used to protect the SUCI. The protection scheme identifier contains multiple flag bits, each flag bit corresponding to a specific cryptographic algorithm scheme in the predefined cryptographic algorithm set. The value of each flag bit is used to indicate whether the cryptographic algorithm scheme corresponding to the flag bit is selected.

[0199] Figure 13 This is a second structural schematic diagram of the communication network identification protection device provided in the embodiments of this application. (Refer to...) Figure 13 This invention provides a communication network identifier protection device, applied to a home network element. The device may specifically include the following modules: SUCI receiving module 1310 is used to receive a user hidden identifier (SUCI) sent by a user equipment. The SUCI includes a protection scheme identifier. The value of the protection scheme identifier is used to indicate a combination of one or more cryptographic algorithm schemes used to protect the SUCI. The protection scheme identifier contains multiple flag bits. Each flag bit corresponds to a specific cryptographic algorithm scheme in the predefined cryptographic algorithm set. The value of each flag bit is used to indicate whether the cryptographic algorithm scheme corresponding to the flag bit is selected. The second key generation module 1320 is used to generate temporary shared keys based on the various cryptographic algorithm schemes used to protect the SUPI. The second key derivation module 1330 is used to derive the final key based on each of the temporary shared keys; The decryption module 1340 is used to decrypt the SUCI based on the final key to obtain the SUPI.

[0200] Figure 14 This is a schematic diagram of the structure of a user equipment provided in an embodiment of this application. (Refer to...) Figure 14 This application also provides a user equipment, which may include: a memory 1410, a transceiver 1420, and a processor 1430; Memory 1410 is used to store computer programs; transceiver 1420 is used to send and receive data under the control of processor 1430; processor 1430 is used to read the computer program in memory 1410 and perform the following operations: Determine one or more cryptographic algorithm schemes for protecting the user identity identifier SUPI, wherein the one or more cryptographic algorithm schemes are selected from a predefined set of cryptographic algorithms; Based on each of the aforementioned cryptographic algorithm schemes, temporary shared keys are generated respectively; Based on the aforementioned temporary shared keys, the final key is derived. Based on the final key, the SUPI is protected to obtain the user-hidden identifier SUCI; The SUCI includes a protection scheme identifier. The value of the protection scheme identifier is used to indicate a combination of one or more cryptographic algorithm schemes used to protect the SUCI. The protection scheme identifier contains multiple flag bits, each flag bit corresponding to a specific cryptographic algorithm scheme in the predefined cryptographic algorithm set. The value of each flag bit is used to indicate whether the cryptographic algorithm scheme corresponding to the flag bit is selected.

[0201] Among them, Figure 14 In this context, the bus architecture can include any number of interconnected buses and bridges, specifically linking various circuits together, such as one or more processors represented by processor 1430 and memory represented by memory 1410. The bus architecture can also link together various other circuits, such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art and therefore will not be described further herein. The bus interface provides an interface. Transceiver 1420 can be multiple elements, including transmitters and receivers, providing a unit for communicating with various other devices over a transmission medium. For different user equipment, user interface 1440 can also be an interface capable of connecting external or internal devices as needed.

[0202] Processor 1430 is responsible for managing the bus architecture and general processing, while memory 1410 can store data used by processor 1430 when performing operations.

[0203] The processor 1430 executes any of the methods described in the embodiments of this application by calling a computer program stored in the memory 1410, according to the obtained executable instructions. The processor and the memory may also be physically separated.

[0204] Figure 15 This is a schematic diagram of the structure of a home network element provided in an embodiment of this application. (Refer to...) Figure 15 This application embodiment also provides a home network element, which may include: a memory 1510, a transceiver 1520 and a processor 1530; The memory 1510 is used to store computer programs; the transceiver 1520 is used to send and receive data under the control of the processor 1530; the processor 1530 is used to read the computer program in the memory 1510 and perform the following operations: The user equipment receives a user hidden identifier (SUCI) sent by the user equipment. The SUCI includes a protection scheme identifier. The value of the protection scheme identifier is used to indicate a combination of one or more cryptographic algorithm schemes used to protect the SUCI. The protection scheme identifier contains multiple flag bits. Each flag bit corresponds to a specific cryptographic algorithm scheme in the predefined cryptographic algorithm set. The value of each flag bit is used to indicate whether the cryptographic algorithm scheme corresponding to the flag bit is selected. Based on the various cryptographic algorithms used to protect the SUPI, temporary shared keys are generated respectively; Based on the aforementioned temporary shared keys, the final key is derived. The SUCI is decrypted using the final key to obtain the SUPI.

[0205] Among them, Figure 15 In this context, the bus architecture may include any number of interconnected buses and bridges, specifically linking various circuits together, represented by one or more processors (processor 1530) and memory (memory 1510). The bus architecture may also link together various other circuits such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art and therefore will not be described further herein. The bus interface provides an interface. The transceiver 1520 may be multiple elements, including transmitters and receivers, providing a unit for communicating with various other devices over a transmission medium. The processor 1530 is responsible for managing the bus architecture and general processing, and the memory 1510 may store data used by the processor 1530 during operation.

[0206] Optionally, the processor 1530 is also used to perform the following operations: The user equipment receives a user hidden identifier (SUCI) sent by the user equipment. The SUCI includes a protection scheme identifier. The value of the protection scheme identifier is used to indicate a combination of one or more cryptographic algorithm schemes used to protect the SUCI. The protection scheme identifier contains multiple flag bits. Each flag bit corresponds to a specific cryptographic algorithm scheme in the predefined cryptographic algorithm set. The value of each flag bit is used to indicate whether the cryptographic algorithm scheme corresponding to the flag bit is selected. Based on the various cryptographic algorithms used to protect the SUPI, temporary shared keys are generated respectively; Based on the aforementioned temporary shared keys, the final key is derived. The SUCI is decrypted using the final key to obtain the SUPI.

[0207] It should be noted that the user equipment and home network element provided in this application embodiment can implement all the method steps implemented in the above method embodiment and can achieve the same technical effect. Therefore, the parts and beneficial effects that are the same as those in the method embodiment will not be described in detail here.

[0208] Figure 16 An example is a schematic diagram of the physical structure of an electronic device. For example... Figure 16 As shown, the electronic device may include: a processor 1610, a communication interface 1620, a memory 1630, and a communication bus 1640, wherein the processor 1610, the communication interface 1620, and the memory 1630 communicate with each other via the communication bus 1640. The processor 1610 can call a computer program in the memory 1630 to execute the steps of the communication network identification protection method, such as including: Determine one or more cryptographic algorithm schemes for protecting the user identity identifier SUPI, wherein the one or more cryptographic algorithm schemes are selected from a predefined set of cryptographic algorithms; Based on each of the aforementioned cryptographic algorithm schemes, temporary shared keys are generated respectively; Based on the aforementioned temporary shared keys, the final key is derived. Based on the final key, the SUPI is protected to obtain the user-hidden identifier SUCI; The SUCI includes a protection scheme identifier, the value of which indicates a combination of one or more cryptographic algorithm schemes used to protect the SUCI. The protection scheme identifier contains multiple flag bits, each flag bit corresponding to a specific cryptographic algorithm scheme in the predefined set of cryptographic algorithms. The value of each flag bit indicates whether the cryptographic algorithm scheme corresponding to the flag bit is selected; or The user equipment receives a user hidden identifier (SUCI) sent by the user equipment. The SUCI includes a protection scheme identifier. The value of the protection scheme identifier is used to indicate a combination of one or more cryptographic algorithm schemes used to protect the SUCI. The protection scheme identifier contains multiple flag bits. Each flag bit corresponds to a specific cryptographic algorithm scheme in the predefined cryptographic algorithm set. The value of each flag bit is used to indicate whether the cryptographic algorithm scheme corresponding to the flag bit is selected. Based on the various cryptographic algorithms used to protect the SUPI, temporary shared keys are generated respectively; Based on the aforementioned temporary shared keys, the final key is derived. The SUCI is decrypted using the final key to obtain the SUPI.

[0209] Furthermore, the logical instructions in the aforementioned memory 1630 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0210] On the other hand, embodiments of this application also provide a computer program product, which includes a computer program that can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can perform the steps of the communication network identifier protection method provided in the above embodiments, such as including: Determine one or more cryptographic algorithm schemes for protecting the user identity identifier SUPI, wherein the one or more cryptographic algorithm schemes are selected from a predefined set of cryptographic algorithms; Based on each of the aforementioned cryptographic algorithm schemes, temporary shared keys are generated respectively; Based on the aforementioned temporary shared keys, the final key is derived. Based on the final key, the SUPI is protected to obtain the user-hidden identifier SUCI; The SUCI includes a protection scheme identifier, the value of which indicates a combination of one or more cryptographic algorithm schemes used to protect the SUCI. The protection scheme identifier contains multiple flag bits, each flag bit corresponding to a specific cryptographic algorithm scheme in the predefined set of cryptographic algorithms. The value of each flag bit indicates whether the cryptographic algorithm scheme corresponding to the flag bit is selected; or The user equipment receives a user hidden identifier (SUCI) sent by the user equipment. The SUCI includes a protection scheme identifier. The value of the protection scheme identifier is used to indicate a combination of one or more cryptographic algorithm schemes used to protect the SUCI. The protection scheme identifier contains multiple flag bits. Each flag bit corresponds to a specific cryptographic algorithm scheme in the predefined cryptographic algorithm set. The value of each flag bit is used to indicate whether the cryptographic algorithm scheme corresponding to the flag bit is selected. Based on the various cryptographic algorithms used to protect the SUPI, temporary shared keys are generated respectively; Based on the aforementioned temporary shared keys, the final key is derived. The SUCI is decrypted using the final key to obtain the SUPI.

[0211] On the other hand, embodiments of this application also provide a processor-readable storage medium storing a computer program, the computer program being used to cause a processor to execute the steps of the communication network identifier protection method provided in the above embodiments, for example including: Determine one or more cryptographic algorithm schemes for protecting the user identity identifier SUPI, wherein the one or more cryptographic algorithm schemes are selected from a predefined set of cryptographic algorithms; Based on each of the aforementioned cryptographic algorithm schemes, temporary shared keys are generated respectively; Based on the aforementioned temporary shared keys, the final key is derived. Based on the final key, the SUPI is protected to obtain the user-hidden identifier SUCI; The SUCI includes a protection scheme identifier, the value of which indicates a combination of one or more cryptographic algorithm schemes used to protect the SUCI. The protection scheme identifier contains multiple flag bits, each flag bit corresponding to a specific cryptographic algorithm scheme in the predefined set of cryptographic algorithms. The value of each flag bit indicates whether the cryptographic algorithm scheme corresponding to the flag bit is selected; or The user equipment receives a user hidden identifier (SUCI) sent by the user equipment. The SUCI includes a protection scheme identifier. The value of the protection scheme identifier is used to indicate a combination of one or more cryptographic algorithm schemes used to protect the SUCI. The protection scheme identifier contains multiple flag bits. Each flag bit corresponds to a specific cryptographic algorithm scheme in the predefined cryptographic algorithm set. The value of each flag bit is used to indicate whether the cryptographic algorithm scheme corresponding to the flag bit is selected. Based on the various cryptographic algorithms used to protect the SUPI, temporary shared keys are generated respectively; Based on the aforementioned temporary shared keys, the final key is derived. The SUCI is decrypted using the final key to obtain the SUPI.

[0212] The processor-readable storage medium can be any available medium or data storage device that the processor can access, including but not limited to magnetic memory (e.g., floppy disk, hard disk, magnetic tape, magneto-optical disk (MO)), optical memory (e.g., CD, DVD, BD, HVD), and semiconductor memory (e.g., ROM, EPROM, EEPROM, non-volatile memory (NAND FLASH), solid-state drive (SSD)).

[0213] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0214] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0215] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A method for protecting the identifier of a communication network, characterized in that, Applied to user equipment, the method includes: Determine one or more cryptographic algorithm schemes for protecting the user identity identifier SUPI, wherein the one or more cryptographic algorithm schemes are selected from a predefined set of cryptographic algorithms; Based on each of the aforementioned cryptographic algorithm schemes, temporary shared keys are generated respectively; Based on the aforementioned temporary shared keys, the final key is derived. Based on the final key, the SUPI is protected to obtain the user-hidden identifier SUCI; The SUCI includes a protection scheme identifier. The value of the protection scheme identifier is used to indicate a combination of one or more cryptographic algorithm schemes used to protect the SUCI. The protection scheme identifier contains multiple flag bits, each flag bit corresponding to a specific cryptographic algorithm scheme in the predefined cryptographic algorithm set. The value of each flag bit is used to indicate whether the cryptographic algorithm scheme corresponding to the flag bit is selected.

2. The communication network identifier protection method according to claim 1, characterized in that, The SUCI also includes a public key identification information field corresponding to each cryptographic algorithm scheme. The public key identification information field is used to store the identification information of the public key of the network element used by the cryptographic algorithm scheme. The field order of the public key identification information field corresponding to each cryptographic algorithm scheme is determined based on the order of the cryptographic algorithm schemes corresponding to each flag bit in the protection scheme identifier.

3. The communication network identifier protection method according to claim 1, characterized in that, The SUCI also includes a scheme output field, which includes a temporary cryptographic data field corresponding to each cryptographic algorithm scheme. The temporary cryptographic data field is used to store temporary cryptographic data generated based on the cryptographic algorithm scheme. The field order of the temporary cryptographic data fields corresponding to each cryptographic algorithm scheme is determined based on the order of the cryptographic algorithm schemes corresponding to each flag bit in the protection scheme identifier.

4. The communication network identifier protection method according to claim 1, characterized in that, The generation of temporary shared keys based on each of the aforementioned cryptographic algorithm schemes includes: For each cryptographic algorithm scheme, a temporary shared key is generated based on the public key of the network element used by the cryptographic algorithm scheme and the key encapsulation mechanism corresponding to the cryptographic algorithm scheme.

5. The communication network identifier protection method according to claim 1, characterized in that, The process of deriving the final key based on each of the temporary shared keys includes: The temporary shared keys are combined to obtain a temporary shared key combination. The temporary shared key combination is input into the key derivation function to derive the final key; The final key includes a temporary encryption key, a temporary integrity protection key, and an initialization key block.

6. The communication network identifier protection method according to any one of claims 1-5, characterized in that, Upon receiving an information update request from the home network element, the method further includes: Based on the information update request, the protection scheme identifier is updated; the information update request is used to instruct the value of the corresponding flag bit in the protection scheme identifier to be updated based on one or more cryptographic algorithm schemes for protecting SUPI that have been redefined.

7. A method for protecting the identifier of a communication network, characterized in that, Applied to home network elements, the method includes: The user equipment receives a user hidden identifier (SUCI) sent by the user equipment. The SUCI includes a protection scheme identifier. The value of the protection scheme identifier is used to indicate a combination of one or more cryptographic algorithm schemes used to protect the SUCI. The protection scheme identifier contains multiple flag bits. Each flag bit corresponds to a specific cryptographic algorithm scheme in the predefined cryptographic algorithm set. The value of each flag bit is used to indicate whether the cryptographic algorithm scheme corresponding to the flag bit is selected. Based on the various cryptographic algorithms used to protect the SUPI, temporary shared keys are generated respectively; Based on the aforementioned temporary shared keys, the final key is derived. The SUCI is decrypted using the final key to obtain the SUPI.

8. The communication network identifier protection method according to claim 7, characterized in that, The SUCI also includes a public key identification information field corresponding to each cryptographic algorithm scheme. The public key identification information field is used to store the identification information of the public key of the network element used by the cryptographic algorithm scheme. The field order of the public key identification information field corresponding to each cryptographic algorithm scheme is determined based on the order of the cryptographic algorithm schemes corresponding to each flag bit in the protection scheme identifier. After receiving the User Hidden Identifier (SUCI) sent by the user equipment, the method further includes: According to the order of the cryptographic algorithm schemes corresponding to each flag bit in the protection scheme identifier, the identification information of the public key of the network element used by each cryptographic algorithm scheme is obtained from the public key identification information field of the SUCI. Based on the identification information of the public key of the network element used by each cryptographic algorithm scheme, the private key of the network element corresponding to each cryptographic algorithm scheme is obtained.

9. The communication network identifier protection method according to claim 8, characterized in that, The SUCI also includes a scheme output field, which includes a temporary cryptographic data field corresponding to each cryptographic algorithm scheme. The temporary cryptographic data field is used to store temporary cryptographic data generated based on the cryptographic algorithm scheme. The field order of the temporary cryptographic data fields corresponding to each cryptographic algorithm scheme is determined based on the order of the cryptographic algorithm schemes corresponding to each flag bit in the protection scheme identifier. After receiving the User Hidden Identifier (SUCI) sent by the user equipment, the method further includes: According to the order of the cryptographic algorithm schemes corresponding to each flag bit in the protection scheme identifier, the temporary cryptographic data generated based on each cryptographic algorithm scheme is obtained from the scheme output field of the SUCI.

10. The communication network identifier protection method according to claim 9, characterized in that, The temporary shared keys are generated based on the various cryptographic algorithms used to protect the SUPI, including: For each cryptographic algorithm scheme, a temporary shared key is generated based on the private key of the network element corresponding to the cryptographic algorithm scheme, the temporary cryptographic data generated based on the cryptographic algorithm scheme, and the key decryption mechanism corresponding to the cryptographic algorithm scheme.

11. The method according to claim 7, characterized in that, The process of deriving the final key based on each of the temporary shared keys includes: The temporary shared keys are combined to obtain a temporary shared key combination. The temporary shared key combination is input into the key derivation function to derive the final key; The final key includes a temporary encryption key, a temporary integrity protection key, and an initialization key block.

12. The communication network identifier protection method according to any one of claims 7-11, characterized in that, The method further includes: If it is necessary to modify the SUPI encryption strategy, an information update request is sent to the user equipment; the information update request is used to instruct the value of the corresponding flag bit in the protection scheme identifier to be updated based on one or more cryptographic algorithm schemes for protecting SUPI that have been redefined.

13. A communication network identification protection device, characterized in that, Applied to user equipment, including: The protection scheme determination module is used to determine one or more cryptographic algorithm schemes for protecting the user identity identifier SUPI, wherein the one or more cryptographic algorithm schemes are selected from a predefined set of cryptographic algorithms; The first key generation module is used to generate temporary shared keys based on each of the aforementioned cryptographic algorithm schemes; The first key derivation module is used to derive the final key based on each of the temporary shared keys; The SUCI generation module is used to protect the SUPI based on the final key to obtain the user hidden identifier SUCI; The SUCI includes a protection scheme identifier. The value of the protection scheme identifier is used to indicate a combination of one or more cryptographic algorithm schemes used to protect the SUCI. The protection scheme identifier contains multiple flag bits, each flag bit corresponding to a specific cryptographic algorithm scheme in the predefined cryptographic algorithm set. The value of each flag bit is used to indicate whether the cryptographic algorithm scheme corresponding to the flag bit is selected.

14. A communication network identification protection device, characterized in that, Applied to home network elements, including: The SUCI receiving module is used to receive the User Hidden Identifier (SUCI) sent by the user equipment. The SUCI includes a protection scheme identifier, the value of which is used to indicate a combination of one or more cryptographic algorithm schemes used to protect the SUCI. The protection scheme identifier contains multiple flag bits, each flag bit corresponding to a specific cryptographic algorithm scheme in the predefined cryptographic algorithm set. The value of each flag bit is used to indicate whether the cryptographic algorithm scheme corresponding to the flag bit is selected. The second key generation module is used to generate temporary shared keys based on the various cryptographic algorithm schemes used to protect the SUPI. The second key derivation module is used to derive the final key based on each of the temporary shared keys; The decryption module is used to decrypt the SUCI based on the final key to obtain the SUPI.

15. A user equipment, characterized in that, Includes memory, transceiver, and processor; A memory for storing computer programs; a transceiver for sending and receiving data under the control of the processor; and a processor for reading the computer programs from the memory and performing the following operations: Determine one or more cryptographic algorithm schemes for protecting the user identity identifier SUPI, wherein the one or more cryptographic algorithm schemes are selected from a predefined set of cryptographic algorithms; Based on each of the aforementioned cryptographic algorithm schemes, temporary shared keys are generated respectively; Based on the aforementioned temporary shared keys, the final key is derived. Based on the final key, the SUPI is protected to obtain the user-hidden identifier SUCI; The SUCI includes a protection scheme identifier. The value of the protection scheme identifier is used to indicate a combination of one or more cryptographic algorithm schemes used to protect the SUCI. The protection scheme identifier contains multiple flag bits, each flag bit corresponding to a specific cryptographic algorithm scheme in the predefined cryptographic algorithm set. The value of each flag bit is used to indicate whether the cryptographic algorithm scheme corresponding to the flag bit is selected.

16. A home network element, characterized in that, Includes memory, transceiver, and processor; A memory for storing computer programs; a transceiver for sending and receiving data under the control of the processor; and a processor for reading the computer programs from the memory and performing the following operations: The user equipment receives a user hidden identifier (SUCI) sent by the user equipment. The SUCI includes a protection scheme identifier. The value of the protection scheme identifier is used to indicate a combination of one or more cryptographic algorithm schemes used to protect the SUCI. The protection scheme identifier contains multiple flag bits. Each flag bit corresponds to a specific cryptographic algorithm scheme in the predefined cryptographic algorithm set. The value of each flag bit is used to indicate whether the cryptographic algorithm scheme corresponding to the flag bit is selected. Based on the various cryptographic algorithms used to protect the SUPI, temporary shared keys are generated respectively; Based on the aforementioned temporary shared keys, the final key is derived. The SUCI is decrypted using the final key to obtain the SUPI.

17. An electronic device comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that, When the processor executes the computer program, it implements the communication network identifier protection method as described in any one of claims 1-6 or 7-12.

18. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the communication network identifier protection method as described in any one of claims 1-6 or 7-12.

19. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the communication network identifier protection method as described in any one of claims 1-6 or 7-12.

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