Group switching authentication method of machine type communication equipment

Abstract

The invention discloses a group switching authentication method for machine type communication equipment, and relates to the technical field of wireless network security communication. According to the method provided by the invention, the mutual authentication of the target base station and the switching group equipment is realized by executing the two authentication processes of the first switching equipment authentication and the group switching authentication, the switching authentication process is simplified, the number of interaction times and the number of interaction messages are reduced, and the rapid switching authentication of the group equipment is realized. By utilizing the capability of the block chain technology, all security attributes are ensured, meanwhile, the 5G wireless network architecture is kept consistent with the 5G wireless network architecture specified by the 3GPP standard, and the resistance to DoS and DDoS attacks is enhanced.

Description

Technical Field

[0001] The present invention relates to the technical field of wireless network security communication, and in particular to a group switching authentication method for machine type communication equipment. Background Art

[0002] In the existing 5G wireless network, the methods for implementing MTC device authentication can be roughly divided into three categories: (1) Follow the 3GPP standard protocol 5G-AKA, perform handover authentication multiple times, and complete the authentication and key negotiation of a group of MTC devices (MTCDs). (2) Introduce blockchain, deploy blockchain in the system, upload the required authentication information to the blockchain, generate the group key by querying the authentication information on the blockchain during authentication, and implement the authentication and key negotiation of multiple MTC devices in one handover authentication. (3) Use the aggregate message authentication code AMAC or the traditional certificateless aggregate signature method to implement the authentication and key negotiation of multiple MTCDs in one handover authentication.

[0003] However, the 3GPP standard 5G-AKA lacks mutual authentication, insufficient key forward security (KFS) and is highly vulnerable to denial of service (DoS) attacks when handling simultaneous handovers of a group of MTCDs, resulting in security vulnerabilities in the handover authentication process. In addition, due to the ultra-dense nature of 5G networks, with more cellular cells, group handover events are more frequent, resulting in increased signaling when a group of MTCDs are simultaneously switched from a serving base station to a target base station.

[0004] The current way of deploying blockchains uses the characteristics of blockchains as collaborative distributed ledgers to ensure data security and immutability, prevent single point failures and DoS attacks, and deploy private blockchains to enhance data privacy and reduce the risk of data leakage and network attacks. Therefore, by deploying blockchains on edge servers, data security can be significantly improved and some efficiency can be improved. However, the existing blockchain-based solutions have the following problems: (1) Time-consuming operations: The current solution requires query and write operations on the blockchain during authentication, which significantly increases the system's latency and resource consumption, which is not conducive to the 5G wireless network environment with high real-time requirements. (2) Unreasonable system architecture: The existing solution does not explain the location of blockchain deployment and consider the impact of the size of blockchain storage information on efficiency. This cannot meet the needs of actual deployment and increases the complexity of the system architecture and management difficulty.

[0005] The device group switching authentication method using aggregate message authentication code AMAC or traditional certificateless aggregate signature can authenticate multiple MTCDs at a time, significantly improving efficiency. However, the group leader aggregates the message authentication code (MAC) or signature of all group members and sends the aggregate information to the network, which has three weaknesses: the first is the vulnerability to DoS attacks. Only when all members are legitimate can the aggregate information be successfully verified. The attacker can send false aggregate information and deliberately make the entire group verification fail; second, the group leader needs to perform a lot of calculations, and the group leader identity authentication has been ignored by some protocols; third, the delay of the MTCD that first enters the new coverage area is very high because they must wait for the calculation and message exchange of the entire group to end. The traditional certificateless aggregate signature method designs bilinear cryptographic operations, and such computing operations consume a lot of resources and have a certain impact on efficiency.

[0006] The development of 5G networks has promoted the support of large-scale MTC device connections, providing higher data rates, lower latency, larger connection capacity and higher energy efficiency. The introduction of large-scale MTCD enables thousands of devices to interconnect, which is essential for smart cities, smart homes and industrial automation applications that require seamless connection and communication between numerous sensors and actuators. However, the existing large-scale MTCD handover authentication solutions have certain security flaws in 5G networks and are almost ineffective in mitigating DoS or DDoS attacks. In addition, the computational operations involved in handover authentication, such as bilinear mapping, lead to high computational overhead. Summary of the invention

[0007] The present invention provides a group switching authentication method for machine type communication devices to solve the problems of low authentication efficiency, unreasonable system architecture design and security defects in the existing group switching authentication method when facing large-scale device switching in 5G networks.

[0008] The present invention is achieved through the following technical solutions:

[0009] A first aspect of the present invention provides a group switching authentication method for a machine type communication device, which is applied to a decentralized blockchain system, comprising:

[0010] S1, when the first machine type communication device enters the range of the target base station from the original service base station, the first machine type communication device sends a handover request to the original service base station, so that the original service base station sends a handover confirmation message to the target base station through the access management function unit where the original service base station is located;

[0011] The first machine type communication device is the first machine type communication device in the machine type communication device group to enter the range of the target base station from the original serving base station, and the handover confirmation message includes the anonymous identity and group key material of the members of the machine type communication device group;

[0012] S2, the first machine type communication device receives a handover response message to complete mutual authentication and session key negotiation with the target base station, the handover response message being sent by the target base station after verifying the identity of the first machine type communication device;

[0013] S3, sending an aggregate signature request to other members in the machine type communication device group, receiving signatures returned by other members, and calculating an aggregate signature based on the signatures;

[0014] S4, sending the aggregate signature to the target base station, and receiving a member authentication response returned by the target base station after verifying the aggregate signature;

[0015] S5. Forward the member authentication response to other members to complete mutual authentication between other members and the target base station.

[0016] The present invention utilizes decentralized blockchain for public key management, directly realizes mutual authentication between the target base station and the switching group device, and simplifies the switching authentication process. Specifically, when the first machine type device in the group enters the target base station range from the original service base station, the original service base station sends anonymous information of group members to the target base station through the access management function unit, completes mutual authentication and session key negotiation between the first machine type and the target base station, and then directly completes the group switching authentication with the target base station through the member aggregation signature method, reduces the number of interactions and the number of interactive messages, and realizes fast switching authentication of group devices. Utilizing the capabilities of blockchain technology, the protocol is consistent with the 5G wireless network architecture specified by the 3GPP standard while ensuring all security attributes, and ensures that it is suitable for machine type communication device switching scenarios, has a reasonable system architecture, and realizes key negotiation, anonymity, traceability, perfect forward and backward confidentiality, prevents single point failures, and enhances resistance to DoS and DDoS attacks.

[0017] Furthermore, before step S1, the method further includes: performing handover authentication preparation to obtain group key material; the handover authentication preparation includes:

[0018] The original serving base station sends a neighboring base station list and anonymous identities of group members to the access management function unit where the original serving base station is located;

[0019] The access management function unit calculates a group key material according to the anonymous identity of the group member, and broadcasts the group key material to the original serving base station and the neighboring base station; so that after receiving the group key material, the neighboring base station queries the public key of the group member stored in the blockchain within the group, and stores the query result locally;

[0020] After receiving the group key material, the original serving base station broadcasts it to each group member, and each group member obtains the group key material.

[0021] Furthermore, before the switching authentication preparation, the method further includes: completing system registration to obtain an anonymous identity; the registration method includes:

[0022] The machine type communication device sends its own identity information and public key to the access management function unit, so that the access management function unit requests the anonymous identity of the machine type communication device from the identity authentication service unit, and generates another part of the public key of the machine type communication device according to the anonymous identity;

[0023] The machine type communication device receives the anonymous identity and another part of the public key returned by the access management functional unit, forms a public-private key pair with its own public key, the private key corresponding to its own public key, the other part of the public key, and the private key corresponding to the other part of the public key, and stores the public-private key pair and the anonymous identity; wherein the public key and identity information of the machine type communication device are also stored in the blockchain.

[0024] Furthermore, the method for generating the switching request includes:

[0025] Pick a random number n 1 ∈Z q , and calculate the signature Sig 1 =h 13 msk 1 +n 1 +h 12 psk 1 , where h 12 =H 3 (TID 1 ,TS 1 ,PK 1 ,n 1 ·P), h 13 =H 4 (TID 1 ,n 1 ·P);

[0026] In the above formula, msk 1 The first machine type communication device MTCD 1 A part of its own private key, TID 1 For MTCD 1 Anonymous identity, TS 1 The generation timestamp of the switching request, PK 1 ={mpk 1 ,R 1}, for MTCD 1 The public key parameters, mpk1 is its own public key, R 1 The other part of the public key obtained by registration, P, H 3 , H 4 is the system parameter, P is the generator of the cyclic additive group, H 3 , H 4 is a hash function;

[0027] The anonymous identity TID 1 , Generate timestamp TS 1 , random number n 1 P, and signature Sig 1 Encapsulated as a switch request.

[0028] Further, in step S2, the first machine type communication device receives a handover response message to complete mutual authentication with the target base station, including:

[0029] After receiving the handover response message sent by the target base station, the first machine type communication device verifies the identity of the target base station, and if the verification is successful, generates a session key between the first machine type communication device and the target base station.

[0030] Further, in step S5, sending the member authentication response to other members to complete mutual authentication between other members and the target base station includes:

[0031] After receiving the member authentication response forwarded by the first machine type communication device, the other members verify the identity of the target base station, and if the verification is successful, generate a session key between themselves and the target base station.

[0032] Further, the original serving base station sends a handover confirmation message to the target base station through the access management function unit where the original serving base station is located, including:

[0033] If the original serving base station and the target base station are in the same access management function unit, sending a handover confirmation message to the target base station through the access management function unit;

[0034] If the original service base station and the target base station are in different access management functional units, a switching confirmation message is sent to the access management functional unit where the target base station is located through the access management functional unit, and then the access management functional unit where the target base station is located forwards the switching confirmation message to the target base station.

[0035] A second aspect of the present invention provides a group switching authentication method for a machine type communication device, which is applied to a decentralized blockchain system, wherein the system includes an identity authentication service unit, an access management function unit, a base station, and a machine type communication device group, and the method includes:

[0036] When a first machine type communication device enters a range of a target base station from an original serving base station, sending a handover request to the original serving base station, the first machine type communication device being the first machine type communication device in a group of machine type communication devices to enter a range of the target base station from the original serving base station;

[0037] The original serving base station forwards the handover request to the access management function unit where the original serving base station is located;

[0038] The access management function unit generates a handover confirmation message based on the handover request, and sends the handover confirmation message to the target base station;

[0039] The target base station receives the handover confirmation message, verifies the identity of the first machine type communication device, and sends a handover response message to the first machine type communication device if the verification succeeds;

[0040] The first machine type communication device receives the handover response message and completes mutual authentication with the target base station;

[0041] The first machine type communication device sends an aggregate signature request to other members in the machine type communication device group;

[0042] Each member receives the aggregate signature request, generates its own signature, and sends it to the first machine type communication device;

[0043] The first machine type communication device calculates an aggregate signature according to signatures of each member, and sends the aggregate signature to the target base station;

[0044] The target base station verifies the aggregate signature, and if the verification is successful, sends a member authentication response to the first machine type communication device;

[0045] The first machine type communication device forwards the member authentication response to other members to complete mutual authentication between the other members and the target base station.

[0046] According to a third aspect of the present invention, a machine type communication device is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the group switching recognition method for the machine type communication device as described in any one of the first aspects of the present invention is implemented.

[0047] According to a fourth aspect of the present invention, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the group switching recognition method of a machine type communication device as described in any one of the first aspects of the present invention is implemented.

[0048] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0049] The authentication protocol of the present invention uses blockchain to establish a decentralized public key management system, directly realizes mutual authentication between base stations and machine type communication devices, simplifies the switching authentication process, reduces the number of interactive messages, prevents single point failures, and enhances resistance to DoS and DDoS attacks.

[0050] Leveraging the capabilities of blockchain technology, the protocol maintains all security attributes while being consistent with the 5G wireless network architecture specified by the 3GPP standard and ensuring its suitability for MTCD handover scenarios.

[0051] A reliable anti-malicious KGC certificateless aggregate signature algorithm is adopted, and formal evaluation is performed using Burrows-Abadi-Needham (BAN) logic and Scyther tool, which proves that it can achieve mutual authentication with key agreement, anonymity, traceability, perfect forward and backward secrecy, resistance to DoS attacks, and defense against masquerade attacks. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, other relevant drawings can be obtained based on these drawings without creative work. In the drawings:

[0053] Figure 1 is an architecture diagram of a group switching system for machine type communication devices according to an embodiment of the present invention;

[0054] Figure 2 is a registration flow chart of an embodiment of the present invention;

[0055] Figure 3 is a handover authentication preparation flow chart of an embodiment of the present invention;

[0056] Figure 4 is a flow chart of a switching authentication method according to an embodiment of the present invention;

[0057] Figure 5 is a handover authentication flow chart of a first machine type communication device according to an embodiment of the present invention;

[0058] Figure 6 is a group switching authentication flow chart of an embodiment of the present invention;

[0059] Figure 7It is a comparison chart of the authentication overhead experimental results of the method of the present invention and other methods;

[0060] Figure 8 is a diagram showing the experimental results of the system communication overhead of the method of the present invention and other methods;

[0061] Fig. 9 This is a comparison chart of the handover authentication time experimental results of the method of the present invention and other methods;

[0062] Fig.10 It is a comparison chart of energy consumption experimental results of the method of the present invention and other methods. DETAILED DESCRIPTION

[0063] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0064] It should be noted that the terms "including" and "having" and any variations thereof in the specification and claims of the present invention and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to or inherent to other steps or units of the device.

[0065] The terms used in the various embodiments of the application are only used to describe the purpose of specific embodiments and are not intended to limit the various embodiments of the application. As used herein, the singular form is intended to also include the plural form, unless the context clearly indicates otherwise. Unless otherwise limited, all terms used here (including technical terms and scientific terms) have the same meaning as the meanings commonly understood by ordinary technicians in the field of the various embodiments of the application. The terms (such as the terms defined in the dictionary generally used) will be interpreted as having the same meaning as the contextual meaning in the relevant technical field and will not be interpreted as having an idealized meaning or an overly formal meaning, unless clearly defined in the various embodiments of the application.

[0066] An embodiment of the present invention provides a group switching authentication method for machine type communication devices, which is suitable for group switching of a large number of devices in a 5G wireless network, and is beneficial to improving the switching authentication efficiency and ensuring the security of the system.

[0067] For the convenience of expression, in all embodiments of the present invention, the meanings of the following characters are defined as follows: TID is anonymous identity (anonymous identity) information, ID is a permanent identity identifier, GID is a group key, H(msg) is a hash function, K it / K 1tis the session key, TS is the timestamp, MAC is the message authentication code, PK / SK is the public key / private key information, G is the elliptic curve additive group, P / q is the generator of the group / the prime order of the group, {x} k Indicates that the message x is encrypted using the key k.

[0068] The authentication protocol of the present invention uses blockchain to establish a decentralized public key management system, and provides a new group switching authentication method for machine type devices in 5G wireless networks, such as Figure 1 The figure shows a system architecture diagram of the present invention. The system includes an authentication server function unit (AUSF) of a 5G core network, a unified data management server (UDM), an access management function unit (AMF), a 5G base station device (gNB), and a machine type communication device (MTCD). In the figure, the solid line represents a limited connection, and the dotted line represents a wireless connection.

[0069] AUSF provides authentication service functions for devices in the system, responds to authentication requests from requesters, and provides key materials to requesters. UDM stores information such as device identity and key materials, and provides data access and management services. gNB is responsible for wireless access services, supports higher bandwidth and lower latency, and provides faster and more reliable wireless connections. AMF performs registration, connection, reachability, and mobility management, provides session management message transmission channels for base stations and authentication services, and manages groups.

[0070] The development of 5G networks has promoted the support of large-scale machine type communication device connections, providing higher data rates, lower latency, greater connection capacity and higher energy efficiency. The introduction of large-scale machine type communication devices enables thousands of devices to interconnect, which is essential for smart cities, smart homes and industrial automation applications that require seamless connection and communication between numerous sensors and actuators. Existing large-scale MTCD switching authentication solutions have certain security defects in 5G networks and are almost ineffective in mitigating DoS or DDoS attacks. In addition, the computational operations involved in switching authentication such as bilinear mapping will result in high computational overhead. Therefore, the present invention improves the group switching authentication and key negotiation mechanism of machine type communication, reduces the core network signaling overhead, and reduces the server load.

[0071] The group handover authentication method of a machine type communication device of the present invention includes the following parts: A. system initialization and registration; B. initial authentication; C. handover preparation; D. group handover authentication. Steps A to C are necessary preparations for implementing MTCD handover authentication. System initialization and authentication preparation provide necessary materials for authentication. Each part will be described in detail below according to the implementation order.

[0072] A. System initialization and registration.

[0073] This step is completed by the identity authentication server function unit AUSF and the access management function unit AMF in the system.

[0074] Given security parameter 1 K , AMF selects a large prime number q, and sets E(F q ) is a finite field F q Let G be the cyclic additive group generated by generator P, with order q. Define the finite field of hash function as Z q , H 0 ~H 4 Represent different hash functions, H 0 =Z q ×{0,1} * →Z q , H 1 :G×{0,1} * →Z q , H 2 :{0,1} * ×G×{0,1} * ×G×G→Z q , H 3 :{0,1} * ×{0,1} * ×{0,1} * ×{0,1} * ×G×G→Z q , H 4 :{0,1} * ×{0,1} * ×G→Z q , where {0,1} * It represents a set of binary strings of arbitrary length, that is, the hash function can accept binary data of arbitrary length as input. “→” is used to represent the mapping relationship between the input and output of the hash function. 1 When accepting a binary string of arbitrary length as input, it outputs a Z q The elements in , and the representation of other hash functions are similar.

[0075] AUSF from the hash function set Zq Choose a random element α∈Z q , and calculate the corresponding public key P pub =α·P, where P is the generator of the cyclic additive group G. AMF selects a random element β∈Z q , and calculate the corresponding public key T pub =β·P, where P is the generator of the cyclic additive group G. Finally, AMF will publish system parameters params=(P,q,G,P pub ,T pub ,H 0 ,H 1 ,H 2 ,H 3 ,H 4 ).

[0076] To protect identity privacy, each MTCD and gNB should first register with the system to obtain their own anonymous identity. i MTCD i As an example, the specific registration process is described. The registration process occurs before authentication preparation and switching authentication. After the system is initialized, registration is allowed. Figure 2 As shown in the registration flow chart, the registration method of MTCD is as follows.

[0077] First, MTCD sends its own identity information and public key to AMF, so that AMF requests the anonymous identity of the machine type communication device from AUSF. After AMF obtains the anonymous identity, it generates another part of the public key of MTCD based on the anonymous identity. Then MTCD receives the anonymous identity and another part of the public key returned by AMF, forms a public-private key pair with its own public key, the private key corresponding to its own public key, another part of the public key, and the private key corresponding to the other part of the public key, and stores the public-private key pair and anonymous identity locally. Please refer to the following steps for more detailed process.

[0078] Step 1: MTCD i Send its own identity information and public key to AMF.

[0079] Each machine type communication device has a unique identity. The system obtains the real identity of each device, distributes an anonymous identity to each device, and stores their real identity information in the blockchain.

[0080] Specifically, MTCD i Choose a random number msk i ∈Z q As its secret value, and calculate part of its public key mpk according to the formula i =msk i ·P. Then calculate δ=H 0 (mski ·T pub ) as the symmetric encryption key for the identity ID i and the public key mpk i Encrypt and get the ciphertext {ID i ,mpk i} δ , and send the message {mpk i ,{ID i ,mpk i} δ}Send to AMF.

[0081] In the above formula, T pub , H 0 , Z q , P is the system parameter, T pub is the public key of AMF, H 0 is the hash function, Z q Hash set, P is the generator of the cyclic additive group G, mpk i For MTCD i The public key, ID i For MTCD i real identity information.

[0082] Step 2: AMF receives MTCD i After the message, check MTCD i identity, and MTCD i ID i And part of the public key mpk i Forward to AUSF to request MTCD from AUSF i Anonymous identity.

[0083] Step 3: After AUSF receives the anonymous identity generation request from AMF, it i Real ID i And part of the public key mpk i Generate the corresponding anonymous identity TID i , send the anonymous identity to MTCD via AMF i , and MTCD i Real ID i Forwarded to UDM for storage.

[0084] Among them, the formula for AUSF to generate anonymous identity is: Where α is the AUSF from the hash function set Z q Choose a random element from Z, α∈Z q ,mpk i For MTCD i A part of the public key, H1 is a system parameter, representing a hash function, It is an XOR operation.

[0085] Step 4: AMF receives MTCD returned by AUSF i Anonymous ID TID i , for MTCD i Generate a secret key and the corresponding public key.

[0086] Specifically, AMF selects a random number r i ∈Z q , calculate R i =r i P as another part of the public key, h i1 =H 2 (TID i ,mpk i ,R i ,T pub ) and psk i =r i +β·h i1 As another part of the private key of MTCD, then calculate δ = H 0 (β·mpk i ) as the symmetric encryption key, and the message {TID i ,mpk i ,psk i ,R i} is encrypted, and finally the encrypted message {TID i ,mpk i ,psk i ,R i} δ Forward to MTCD i .

[0087] Step 5: MTCD i Receive the registration response message and store the anonymous identity TID i , according to the received message {TID i ,mpk i ,psk i ,R i} can calculate h i1 =H 2 (TID i ,mpk i ,R i ,T pub ), and verify psk i p=R i +h i1 ·T pubIf the verification is successful, the other part of the private key and public key in the received message are stored together with the private key and public key of the user to obtain the public key parameter pair PK. i ={mpk i ,R i} and private key parameter pair SK i ={msk i ,psk i}.

[0088] Thus MTCD i Complete the registration in the system through AMF and obtain the complete public and private key pair parameters. All MTCD devices perform the same registration method. i The public key is sent to all base stations gNB. After receiving it, gNB uploads the public key to the blockchain for storage and management.

[0089] B. MTCD, AUSF and UDM perform initial authentication.

[0090] In the scheme of the present invention, all MTCDs, AUSFs and UDMs perform initial authentication according to the 5G-AKA scheme. The gNB and AMF monitor the movement trajectory of each MTCD to determine whether there are some MTCDs that can group users based on historical data from the serving base station gNB, and then regroup users based on the changes in the signal to interference and noise ratio (SINR) from the serving base station gNB and the neighboring base station gNB. The algorithm supports the mathematical correlation required to form the MTCD group. If such correlation is found, these MTCDs will be regarded as a group.

[0091] C. Preparation before switching authentication.

[0092] This step is performed before switching authentication to provide the necessary key material for the authentication process. Figure 3 In the handover authentication preparation flow chart shown in the figure, the handover authentication step is performed by the base station and the access management functional unit. Before the first machine type communication device enters the target base station range from the original service base station, before the handover authentication, the original service base station s-gNB sends the neighboring base station list and the anonymous identity of the group member to the AMF where it is located. The AMF calculates the group key material based on the anonymous identity of the group member and broadcasts it to the original service base station and the neighboring base station t-gNB; after the neighboring base station t-gNB receives the group key material, it queries the public key of the group member stored in the blockchain within the group and stores the query result locally. After receiving the group key material, the original service base station broadcasts it to each group member so that each group member can obtain the group key material. The detailed steps are as follows.

[0093] Step 1: The s-gNB sends a handover request to the AMF. The handover request contains the list of neighboring t-gNBs of the s-gNB and the anonymous identifiers TID of all existing group members. i .

[0094] Step 2: AMF obtains the anonymous identity TID of all group members i After that, the group key GID is calculated and the timestamp TS f Encrypted with the group key, the encrypted ciphertext {GUD,TS f} δ , calculate the verification code MAC = H(GID||TS f ), generate a handover response {{TID 1 ||…||TID 1},{GUD,TS f} δ ,MAC}, broadcasts the handover response to s-gNB and neighboring base stations. After receiving the message, t-gNB queries the public key information of group members stored in the blockchain within the group and stores the queried information locally.

[0095] Specifically, the calculation method of the group key is: Among them, TDI i For each MTCD in the group i The anonymous identity of , n represents the number of group members.

[0096] Step 3: The s-gNB sends the handover confirmation message {{GUD,TS f} δ , MAC} broadcast to all MTCDs in the group i .

[0097] Each MTCD i Decrypt the switching confirmation message to obtain the group key GID and verify the timestamp TS of the received message f and verification code MAC to determine its authenticity.

[0098] Through this preparation, before the handover authentication, the neighboring base station t-gNB obtains the anonymous identity of the group member of the base station s-gNB currently requesting the handover, and the group members, the base station s-gNB requesting the handover, and the neighboring base stations all obtain the group key information.

[0099] D. MTCD group switching authentication.

[0100] Implementing group switching authentication includes two steps: the first MTCD 1 Switch authentication, and the second is group switch authentication. Figure 4As shown in the group handover authentication method flow chart, when the first MTCD in the group enters the target base station from the original serving base station, the first MTCD executes 1 After the first authentication is completed, such as steps S1-S2, the handover authentication of the group is performed, such as steps S3-S5. The execution subject of the following steps is the first MTCD. 1 .

[0101] S1, first machine type communication device MTCD 1 When entering the range of the target base station from the original service base station, a switching request is sent to the original service base station, so that the original service base station sends a switching confirmation message to the target base station through the access management function unit where it is located.

[0102] Among them, MTCD 1 It is the first machine type device in the machine type communication device group to enter the target base station range from the original serving base station, and the handover confirmation message includes the anonymous identity and group key material of the members of the machine type communication device group.

[0103] S2, MTCD 1 Receive a handover response message to complete mutual authentication with the target base station. The handover response message is sent by the target base station to the MTCD. 1 Issued after identity verification.

[0104] S3, MTCD 1 Send an aggregate signature request to other members in the machine type communication device group, receive signatures returned by other members, and calculate an aggregate signature based on the signatures;

[0105] S4, MTCD 1 Sending the aggregate signature to the target base station, and receiving a member authentication response returned by the target base station after verifying the aggregate signature;

[0106] S5, MTCD 1 The member authentication response is sent to other members to complete mutual authentication between other members and the target base station.

[0107] The following will be explained in more detail in conjunction with the interaction between the devices in the two handover authentications. Figure 5 Shown is the first MTCD 1 The switching authentication process includes the following steps.

[0108] Step 1: When the first MTCD in the group 1 When entering the coverage area of ​​the base station t-gNB, MTCD 1 Send a handover request to the original serving base station s-gNB.

[0109] A method of generating a handover request includes: MTCO 1 Pick a random number n 1 ∈Z q , and calculate its signature Sig 1 =h 13 msk 1 +n 1 +h 12 psk 1 , where h 12 =H 3 (TID 1 ,TS 1 ,PK 1 ,n 1 ·P), h 13 =H 4 (TID 1 ,n 1 ·P).

[0110] In the above formula, msk 1 For MTCD 1 A part of the private key, that is, the private key selected by itself, TID 1 For MTCD 1 Anonymous identity, TS 1 The generation timestamp of the switching request, PK 1 ={mpk 1 ,R 1}, for MTCD 1 The public key parameters, mpk 1 The public key chosen for itself, R 1 To register and obtain the public key, P, H 3 , H 4 is the system parameter, P is the generator of the cyclic additive group, H 3 , H 4 is a hash function.

[0111] MTCD 1 TID 1 , Generate timestamp TS 1 , random number n 1 P, and signature Sig 1 Encapsulated in the handover request and sent to the original serving base station s-gNB.

[0112] Step 2: The original serving base station s-gNB checks the timestamp TS in the received handover request 1 , if valid, the switching request will be forwarded to the s-AMF where it is located.

[0113] Step 3: After receiving the handover request, s-AMF sends a handover request confirmation message to t-gNB, including the anonymous identifiers TID of all group members. 1 …TID i , and the group key GID, and forward the random number n in the handover request 1 P and signature Sig 1 to t-gNB.

[0114] Step 4: After receiving the handover request confirmation message from s-AMF, t-gNB queries MTCD on the blockchain 1 The public key of the MTCD is obtained and the signature is verified. If the verification is successful, a handover response is generated and sent to the MTCD. 1 send.

[0115] Specifically, t-gNB calculates h 11 =H 2 (TID 1 ,mpk 1 ,R 1 ,T pub ),h 12 =H 3 (TID 1 ,TS 1 ,PK 1 ,n 1 ·P) and h 13 =H 4 (TID 1 ,n 1 ·P).

[0116] In the above, TID 1 For MTCD 1 Anonymous identity, mpk 1 , R 1 TS 1 The generation timestamp of the switching request, PK 1 =, n 1 P is, T pub , H 2 , H 3 , H 4 is the system parameter, P is the generator of the cyclic additive group, H 2 , H 3 , H 4 is a hash function.

[0117] Then verify the formula Sig 1 P = h 13 ·mpk 1 +n 1 ·P+h 12 ·R 1 +h 11 ·h12 ·T pub Is it true? If the equation is true, then MTCD 1 The signature is successfully verified. The t-gNB then selects a random number n t ∈Z q , and generate the session key Sig t =H 0 (GID,TID t ,TS t ,n t P), calculate the group key And to MTCD 1 Send these messages.

[0118] Step 5: MTCD 1 Receive the handover response, verify the identity of t-gNB, and if the verification is successful, generate the session key. 1 Authenticate t-gNB using the following method.

[0119] First generate the signature Sig′ t =H 0 (GID,TID t ,TS t ,n t ·P), verify Sig′ t =Sig t If the equation is true, it means that the t-gNB identity authentication is successful. 1 Generate session key K 1t =n 1 ·n t ·P.

[0120] So far, MTCD 1 Mutual authentication and key negotiation with t-gNB are completed.

[0121] Furthermore, when the original serving base station s-gNB and the target base station t-gNB are in the same AMF, the handover confirmation message is sent directly to the target base station through the AMF. If they are not in the same AMF, after the s-AMF receives the handover request message forwarded by the original serving base station s-gNB, it forwards the message to the t-AMF where the target base station t-gNB is located, and the t-AMF performs the handover confirmation. Similarly, the t-AMF will send the anonymous identity identifiers TIDs of all group members to the t-gNB. 1 …TID i , and the group key material GID as a response, it then sends n 1 P and Sig 1After receiving the message, t-gNB continues to verify the information in the same way as in step 4. If the verification is successful, a handover response is generated and sent to MTCD. 1 Send.MTCD 1 After receiving the switching response, the processing steps are the same as step S5.

[0122] Complete the first MTCD 1 After mutual authentication and key agreement with t-gNB, the group handover authentication process is performed. Figure 6 As shown, the specific steps include the following steps.

[0123] Step 1: MTCD 1 Send MTCD to other group members i Initiate an aggregate signature request and broadcast the anonymous identity TID of the base station t-gNB t ,MTCD 1 Also send your own anonymous identity TID t and group key material GID 1 ,

[0124] Step 2: MTCD of other members in the group i Receive the aggregate signature request and verify that GID = GID 1 +H(TID 1 ) is established to verify MTCD 1 identity.

[0125] Specifically, verify MTCD 1 The identity method is to select a random number n i ∈Z q , generate their respective signatures Sig i , and send the aggregate signature response to MTCD 1 The response information includes its own anonymous identity TIDi and the time when the response information was generated TS i , secret parameter ni·P and signature Sig i .

[0126] Among them, the signature calculation is: Sig i =h i3 msk i +n i +h i2 psk i .

[0127] Step 3: MTCD 1 After receiving the signatures of all group members, calculate the aggregate signature for the group And send the aggregate signature to t-gNB.

[0128] Step 4: t-gNB verifies the aggregate signature. If the verification is successful, it generates a group authentication response and sends it to MTCD 1 .

[0129] Furthermore, t-gNB first pre-authenticates all group members. If the authentication is successful, it authenticates all MTCDs. Specifically, using the formula Pre-authenticate all group members. If the formula is established, t-gNB authenticates the identity of the group member by verifying the signature of the group member. If the identity authentication is successful, since it has been connected to MTCD 1 After mutual authentication, t-gNB sends the timestamp TS t , random number n t P, and your own signature Sig t =H 0 (GID,TID t ,TS t ,n t P) sent to MCTD 1 ,.

[0130] Step 5: MCTD 1 Forward the group authentication response to the member MTCD i .

[0131] Step 6: MTCD i Receive MTCD 1 After receiving the authentication response message, the identity of the target base station t-gNB is verified. Generate the signature Sig′ t =H 0 (GID,TID t ,TS t ,n t ·P), if Sig′ t =Sig t , it means that the t-gNB identity authentication is successful. If the authentication is successful, MTCD i Generate MTCD i Session key K between t-gNB it =n i ·n t ·P.

[0132] At this point, member MTCD i Mutual authentication and key negotiation with t-gNB are completed.

[0133] As a complete application embodiment, the present invention also provides a group switching authentication method for machine type communication devices applied to the system, which uses a decentralized blockchain system to manage public keys. The system includes an identity authentication service unit, an access management function unit, a base station and a machine type communication device group. The authentication switching process includes the following process.

[0134] 1. When a first machine type communication device enters a range of a target base station from an original serving base station, the first machine type communication device sends a handover request to the original serving base station. The first machine type communication device is the first machine type communication device in a group of machine type communication devices to enter a range of the target base station from the original serving base station.

[0135] 2. The original serving base station forwards the switching request to the access management functional unit where it is located.

[0136] 3. The access management function unit generates a handover confirmation message based on the handover request, and sends the handover confirmation message to the target base station.

[0137] 4. The target base station receives the handover confirmation message, verifies the identity of the first machine type communication device, and sends a handover response message to the first machine type communication device if the verification succeeds;

[0138] 5. The first machine type communication device receives the handover response message and completes mutual authentication with the target base station.

[0139] 6. The first machine type communication device sends an aggregate signature request to other members in the machine type communication device group.

[0140] 7. Each member receives the aggregate signature request, generates its own signature, and sends it to the first machine type communication device.

[0141] 8. The first machine type communication device calculates an aggregate signature according to the signatures of each member, and sends the aggregate signature to the target base station.

[0142] 9. The target base station verifies the aggregate signature, and if the verification is successful, sends a member authentication response to the first machine type communication device.

[0143] 10. The first machine type communication device forwards the member authentication response to other members, completing mutual authentication between the other members and the target base station.

[0144] The above is an authentication interaction process between devices. It can be understood that the interaction between the devices in the system also includes interaction processes such as initialization registration and authentication preparation. The execution method of the specific steps can refer to the aforementioned embodiment and will not be repeated here.

[0145] An embodiment of the present invention further provides a machine type communication device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the group switching authentication method for machine type communication devices of the present invention is implemented.

[0146] The memory is a computer-readable storage medium that can be used to store software programs, computer executable programs, and modules. The processor executes various functional applications and data processing of the electronic device by running the software programs, instructions, and modules stored in the memory to implement the group switching authentication method of the machine type communication device of any of the above embodiments of the present invention.

[0147] The memory may mainly include a program storage area and a data storage area, wherein the program storage area may store an operating system and at least one application required for a function; the data storage area may store data created according to the use of the terminal, etc. In addition, the memory may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other non-volatile solid-state storage device. In some instances, the memory may further include a memory remotely arranged relative to the processor, and these remote memories may be connected to the electronic device via a network.

[0148] An embodiment of the present invention further provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the group switching authentication method for a machine type communication device according to any embodiment of the present invention is implemented.

[0149] According to a fifth aspect of the present invention, a computer program product is provided. When the computer program product is run on a computer, the computer executes the group switching authentication method for a machine type communication device according to any one of the above embodiments of the present invention.

[0150] In addition, a device equipped with a 3.50GHz Intel(R)Core(TM)i7-12700H processor and 16GB RAM is used to evaluate the computational cost of the two stages of handover authentication of the present invention. In the comparison of different indicators, the abbreviation used in this scheme is BSPGH; the comparison schemes are A privacy-preserving handover authentication protocol for a group of MTC devices in 5G networks (PPHAP), a novel authentication scheme supporting multiple user access for 5G and beyond (NASS), and 3GPP TS23.501R16 (5G-AKA).

[0151] The cryptographic library used to perform the cryptographic operations required for the proposed scheme is C / C++ OPENSSL, for the selected protocols, each of which uses different cryptographic functions and has unique key size requirements. In order to fully and fairly evaluate their performance at the same security level, we follow NIST's recommendation and use 256-bit equivalent key strength throughout the simulation. Therefore, for all ECC-based operations, we choose secp256k1 as the default elliptic curve. Each cryptographic function is run 10,000 times to measure its average execution time.

[0152] The measurement results are as follows: dot product T PM 0.201 milliseconds, click T PA 0.001 milliseconds, modular exponentiation T E 0.665 milliseconds, Rivest-Shamir-Adleman (RSA) signature and verification T RV The hash operation time is 1.445 milliseconds. H The symmetric encryption / decryption operation T is 0.021 milliseconds. A The XOR, multiplication and arithmetic operations are ignored.

[0153] The data access latency in the blockchain was evaluated, and the measurement results are as follows: Figure 7As shown. First, a blockchain prototype was created. The blockchain contains many blocks, each of which is 1MB in size. Each block is stored as a file and contains multiple transaction records. Each transaction record is a subscription record for a device. In order to reduce the storage overhead of the blockchain, this size should be adjusted according to the preferences of the network operator. All transactions in the blockchain are indexed using Python dictionaries. In order to compare the performance difference between blockchain and traditional databases, another centralized database was also built using MariaDB v10.4.14. The read operation T of the blockchain BC.read The write operation T is 0.2914 milliseconds. BC.write is 0.0434 milliseconds, while for the centralized database, the read and write operations T DB Both are 0.4956 milliseconds.

[0154] In addition, the present invention evaluates the communication cost including the propagation time and the transmission time, and the measurement results are as follows: Figure 8 The propagation time is determined by the distance between the transmitter and the receiver and the propagation speed on the wireless communication channel and is approximately 3×10 8 m / s. Assuming the cell radius is 200 m, the MTCD sends data packets at a rate of 3×10 8 It takes 200 meters for the data to propagate at a speed of meters per second to the gNB. According to the 3GPP standard for 5G communications, the downlink data rate in general urban areas is 50Mbps and the uplink data rate is 25Mbps.

[0155] The robustness of the scheme is estimated in 30 MTCDs, and the authentication time comparison between different protocols is shown in Fig. 9 As shown in the scheme, the group switching authentication process may be forced to stop and restart when encountering an unknown attack. It is assumed that each step of the group switching authentication may be subject to an unknown attack, and the probability of an unknown attack occurring is uniform. The average time for successful authentication is calculated as follows:

[0156]

[0157] Among them, T, T success 、T failed are the average time for successful authentication, the total time for successful authentication, and the total time for failed authentication, respectively. success is the number of successful authentications, p is the number of unknown percentage attacks, n is the number of steps in the protocol, and t failed represents the total time cost before the attack occurs in step i, t success Indicates the time it takes for a successful authentication before an attack can occur.

[0158] Since mobile devices such as MTCDs have limited battery life, security protocols that provide the highest security features with the least energy consumption are always preferred. To evaluate the energy consumption of MTCDs, two factors should be considered, including the energy required for data transmission and the energy consumed to perform cryptographic functions. For the energy used for data transmission, the energy consumption evaluation follows the data transmission power model. The transmission energy cost for uplink and downlink is calculated as follows:

[0159] E ul =(α u t udr +β)·t ul

[0160] E dl =(α d t ddr +β)·t dl

[0161] Among them, α u =438.39mW / Mbps, α d =51.97mW / Mbps, β =1288.04mW, t udr =25Mbps, t ddr =50Mbps. udr represents the uplink throughput, t ddr represents the downlink throughput, t ul is the uplink transmission time, t dl is the downlink transmission time.

[0162] An energy cost approximation is used for the energy used to execute cryptographic functions. All experiments are performed using a battery-powered Compaq iPAQ H3670 PDA equipped with an Intel SA-1110 StrongARM processor running at 206MHz, 64MB RAM, and 16MB FlashROM for evaluation. The energy cost of a single AES encryption or decryption operation is 7.87+1.21bμJ, where b is the number of bytes in the plaintext. The energy cost of a SHA-1 hash operation is 1.21bμJ, where b is the number of bytes in the plaintext. H The energy cost per byte is 0.76 μJ. Considering that the energy cost of generating an ECDH public key is 276.7 mJ and the energy cost of deriving an ECDH public key is 163.5 mJ, a single scalar multiplication operation E PM The energy consumption of a single RSA operation is estimated to be 220.1 mJ. RV The energy consumption of using cryptographic primitives is 832.6mJ. The energy consumption of using cryptographic primitives is derived from the cryptographic operations used in the protocol, thus deriving the theoretical energy cost. Finally, the energy consumption comparison between different protocols is as follows Fig.10 shown.

[0163] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A group switching authentication method for a machine type communication device, characterized in that: Applied to decentralized blockchain systems, including: S1, when the first machine type communication device enters the range of the target base station from the original service base station, the first machine type communication device sends a handover request to the original service base station, so that the original service base station sends a handover confirmation message to the target base station through the access management function unit where the original service base station is located; The first machine type communication device is the first machine type device in the machine type communication device group to enter the range of the target base station from the original serving base station, and the handover confirmation message includes the anonymous identity and group key material of the members of the machine type communication device group; S2, the first machine type communication device receives a handover response message to complete mutual authentication with the target base station, the handover response message being sent by the target base station after verifying the identity of the first machine type communication device; S3, sending an aggregate signature request to other members in the machine type communication device group, receiving signatures returned by other members, and calculating an aggregate signature based on the signatures; S4, sending the aggregate signature to the target base station, and receiving a member authentication response returned by the target base station after verifying the aggregate signature; S5. Forward the member authentication response to other members to complete mutual authentication between other members and the target base station.

2. The group switching authentication method of a machine type communication device according to claim 1, characterized in that: Before step S1, the method further includes: performing handover authentication preparation to obtain group key material; the handover authentication preparation includes: The original serving base station sends a neighboring base station list and anonymous identities of group members to the access management function unit where it is located; so that the access management function unit calculates a group key material according to the anonymous identities of the group members, and broadcasts the group key material to the original serving base station and the neighboring base stations; After receiving the group key material, the neighboring base station queries the public key of the group member stored in the blockchain within the group, and stores the query result locally; After receiving the group key material, the original serving base station broadcasts it to each group member, and each group member obtains the group key material.

3. The group switching authentication method of a machine type communication device according to claim 2, characterized in that: Before the switching authentication preparation, the method further includes: completing system registration to obtain an anonymous identity; the registration method includes: The machine type communication device sends its own identity information and public key to the access management function unit, so that the access management function unit requests the anonymous identity of the machine type communication device from the identity authentication service unit, and generates another part of the public key of the machine type communication device according to the anonymous identity; The machine type communication device receives the anonymous identity and another part of the public key returned by the access management functional unit, forms a public-private key pair with its own public key, the private key corresponding to its own public key, the other part of the public key, and the private key corresponding to the other part of the public key, and stores the public-private key pair and the anonymous identity; wherein the public key and identity information of the machine type communication device are also stored in the blockchain.

4. The group switching authentication method of a machine type communication device according to claim 1, characterized in that: The method for generating the switching request includes: Pick a random number n1∈Z q , and calculate the signature Sig1 = h 13 msk1+n1+h 12 psk1, where h 12 =H3(TID1,TS1,PK1,n1·P),h 13 =H4(TID1,n1·P); In the above formula, msk1 is a part of the private key of the first machine type communication device MTCD1 itself, TID1 is the anonymous identity of MTCD1, TS1 is the generation timestamp of the switching request, PK1 = {mpk1, R1}, is the public key parameter of MTCD1, mpk1 is its own public key, R1 is another part of the public key obtained by registration, P, H3, H4 are system parameters, P is the generator of the cyclic addition group, H3, H4 are hash functions; The anonymous identity TID1, the generated time stamp TS1, the random number n1·P, and the signature Sig1 are encapsulated as a switching request.

5. The group switching authentication method of a machine type communication device according to claim 1, characterized in that: In step S2, the first machine type communication device receives a handover response message to complete mutual authentication with the target base station, including: After receiving the handover response message sent by the target base station, the first machine type communication device verifies the identity of the target base station, and if the verification is successful, generates a session key between the first machine type communication device and the target base station.

6. The group switching authentication method of a machine type communication device according to claim 1, characterized in that: In step S5, sending the member authentication response to other members to complete mutual authentication between other members and the target base station includes: After receiving the member authentication response forwarded by the first machine type communication device, the other members verify the identity of the target base station, and if the verification is successful, generate a session key between themselves and the target base station.

7. The group switching recognition method of a machine type communication device according to claim 1, characterized in that: The original serving base station sends a handover confirmation message to the target base station through the access management function unit where the original serving base station is located, including: If the original serving base station and the target base station are in the same access management function unit, sending a handover confirmation message to the target base station through the access management function unit; If the original service base station and the target base station are in different access management functional units, a switching confirmation message is sent to the access management functional unit where the target base station is located through the access management functional unit, and then the access management functional unit where the target base station is located forwards the switching confirmation message to the target base station.

8. A group switching authentication method for a machine type communication device, characterized in that: A decentralized blockchain system is applied, the system comprising an identity authentication service unit, an access management function unit, a base station and a machine type communication device group, the method comprising: When a first machine type communication device enters a range of a target base station from an original serving base station, sending a handover request to the original serving base station, the first machine type communication device being the first machine type communication device in a group of machine type communication devices to enter a range of the target base station from the original serving base station; The original serving base station forwards the handover request to the access management function unit where the original serving base station is located; The access management function unit generates a handover confirmation message based on the handover request, and sends the handover confirmation message to the target base station; The target base station receives the handover confirmation message, verifies the identity of the first machine type communication device, and sends a handover response message to the first machine type communication device if the verification succeeds; The first machine type communication device receives the handover response message and completes mutual authentication with the target base station; The first machine type communication device sends an aggregate signature request to other members in the machine type communication device group; Each member receives the aggregate signature request, generates its own signature, and sends it to the first machine type communication device; The first machine type communication device calculates an aggregate signature according to signatures of each member, and sends the aggregate signature to the target base station; The target base station verifies the aggregate signature, and if the verification is successful, sends a member authentication response to the first machine type communication device; The first machine type communication device forwards the member authentication response to other members to complete mutual authentication between the other members and the target base station.

9. A machine type communication device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the group switching recognition method of the machine type communication device according to any one of claims 1 to 7 is implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the group switching recognition method of the machine type communication device according to any one of claims 1 to 7 is implemented.

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