An adaptive signature and signcryption certificateless privacy protection method for internet of vehicles

Abstract

The present application belongs to the field of vehicle safety communication, and particularly relates to a self-adaptive signature and signcryption vehicle networking certificateless privacy protection method, which comprises: initializing vehicle networking system parameters; a KGC generates a pseudo identity and a partial private key of a corresponding vehicle networking vehicle according to identity information submitted by the vehicle networking vehicle, and sends the pseudo identity and the partial private key to the vehicle networking vehicle terminal through a secure channel; the vehicle networking vehicle terminal generates a private key and a public key based on the received pseudo identity, the partial private key and the system parameters; a first vehicle networking vehicle generates a message tuple by using a self-adaptive signature and signcryption algorithm based on to-be-sent information and privacy requirements, a public key of a second vehicle networking vehicle and system parameters, and sends the message tuple to the second vehicle networking vehicle; after receiving the message tuple, the second vehicle networking vehicle executes a signature and signcryption verification algorithm according to a private key, system parameters and a public key of the first vehicle networking vehicle, restores original information and verifies the correctness of the original information, and realizes efficient message authentication of vehicle networking.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of vehicle-to-everything (V2X) safety communication, and particularly relates to a self-adaptive signature and signcryption V2X certificateless conditional privacy protection method. BACKGROUND

[0002] In V2X, V2X vehicles broadcast basic safety messages to improve traffic efficiency and safety. However, this open broadcast mode makes attackers obtain the privacy information of V2X vehicles, such as location and driving trajectory, through the open wireless communication channel, and then causes the user's privacy to be leaked. At present, the certificateless conditional privacy protection scheme is applied to the message authentication of V2X because it solves the problems of certificate management and key escrow. However, the certificateless conditional privacy protection scheme relies on a single signature mechanism or signcryption mechanism, and does not fully consider that the basic safety message contains both private and non-private information, and cannot adaptively select the signature or signcryption mechanism according to the privacy requirements of the message.

[0003] In addition, the existing certificateless conditional privacy protection scheme based on the signature mechanism or signcryption mechanism often sacrifices the computational overhead or increases the communication overhead in order to ensure security. Since the computing and storage resources of the vehicle-mounted unit are limited, and the communication bandwidth is limited, the performance of message authentication is as important as security and privacy protection. Therefore, in order to provide a secure, efficient and conditional privacy protection message authentication scheme for V2X vehicle communication, a self-adaptive signature and signcryption certificateless conditional privacy protection scheme that can reduce the computational overhead and communication overhead needs to be designed. SUMMARY

[0004] To solve the problems that the existing certificateless conditional privacy protection scheme cannot dynamically select the signature or signcryption mechanism and the message authentication efficiency is not high, the application combines the certificateless signature mechanism and the certificateless signcryption mechanism, ensures the efficiency and security of communication, and integrates the signature and signcryption mechanisms into a parallel algorithm in the communication network between V2X vehicles, thereby greatly improving the flexibility of message authentication.

[0005] A self-adaptive signature and signcryption V2X certificateless conditional privacy protection method comprises the following steps:

[0006] The KGC initializes the V2X system parameters based on system security parameters;

[0007] The KGC generates the pseudo-identity and part of the private key of the V2X vehicle according to the V2X vehicle registration identity information submitted by the V2X vehicle, and sends the generated pseudo-identity and part of the private key to the corresponding V2X vehicle;

[0008] The connected car generates a private key and a public key of the connected car based on a pseudo identity, a partial private key and system parameters, and uploads the public key to the KGC, and the KGC updates a pseudo identity-public key mapping list of the connected car and distributes it to all connected cars in the region;

[0009] The first connected car acquires a connected car message to be sent, determines that the message receiver is a second connected car, retrieves the corresponding public key from the connected car pseudo identity-public key mapping list according to the pseudo identity of the second connected car, and sends the information tuple to the second connected car based on the private key of the first connected car, the connected car message to be sent, the public key of the second connected car and system parameters, according to the privacy requirement of the connected car message, and executes an adaptive signature and encryption algorithm to generate an information tuple;

[0010] The first connected car acquires a connected car message to be sent, determines that the message receiver is a second connected car, retrieves the corresponding public key from the connected car pseudo identity-public key mapping list according to the pseudo identity of the second connected car, and sends the information tuple to the second connected car based on the private key of the first connected car, the connected car message to be sent, the public key of the second connected car and system parameters, according to the privacy requirement of the connected car message, and executes an adaptive signature and encryption algorithm to generate an information tuple;

[0011] The second connected car receives the information tuple, compares the timeliness of the timestamp in the information tuple, and if the timeliness is satisfied, restores the connected car message, and uses the information tuple, the public key of the first connected car and system parameters to judge the correctness of the restored connected car message, and only when the restored connected car message is correct, the second connected car receives the connected car message.

[0012] Further, the KGC initializes the Internet of Vehicles system parameters based on system security parameters, including:

[0013] The KGC selects an elliptic curve E satisfying the security parameter k, generates partial parameters {P, q, G} of the system, wherein G is an additive cyclic group defined by the elliptic curve E, and P is a generator of the group G with a prime number q as the order;

[0014] The KGC randomly selects a master key s from the multiplicative group of integers modulo q The KGC calculates the master public key of the system based on the master key s and the partial parameter P of the system through elliptic curve scalar multiplication operation;

[0015] The KGC configures a first hash function H0, a second hash function H1, a third hash function H2, a fourth hash function H3 and a function function F: a x {0, 1}→{0, a} of adaptive signature and encryption selection; wherein, F(a, 0) = 0, F(a, 1) = a;

[0016] The KGC generates a system parameter set sp = {G, P, q, P pub ​F, H0, H1, H2, H3.

[0017] Further, the KGC generates the pseudo-identity and the partial private key of the connected car according to the connected car registration identity information submitted by the connected car, comprising:

[0018] The connected car selects a random value from a multiplicative group of integers modulo q , and calculates the partial identity information of the connected car based on an elliptic curve scalar multiplication operation; The connected car sends the real identity of the connected car and the partial identity information to the KGC through a secure channel;

[0019] The KGC obtains the pseudonym identifier and the pseudo-identity through a pseudo-identity generation algorithm based on the received real identity of the connected car, the partial identity information, the system master key, the system master public key, the fourth hash function, and the first hash function;

[0020] The KGC randomly selects a random value from a multiplicative group of integers modulo q , and obtains the partial private key of the connected car through a partial private key generation algorithm based on the random value, the system master public key, the second hash function, and the pseudo-identity.

[0021] Further, the connected car generates the private key and the public key of the connected car based on the pseudo-identity, the partial private key, and the system parameters, comprising:

[0022] The connected car constructs a partial private key discriminant using an elliptic curve scalar multiplication operation according to the pseudo-identity of the connected car, the partial private key of the connected car, and the system parameters, and receives the pseudo-identity and the partial private key of the connected car only when the partial private key discriminant is established;

[0023] Once the partial private key discriminant is established, the connected car selects a random number from a multiplicative group of integers modulo q , and calculates the private key of the connected car through a private key generation algorithm using the random number and the partial private key;

[0024] The connected car calculates the public key of the connected car using an elliptic curve scalar multiplication operation according to the private key of the connected car and the system parameters.

[0025] Further, the first connected car generates an information tuple by executing an adaptive signature and encryption algorithm according to the privacy requirements of the connected car message based on its own private key, the connected car message to be sent, the public key of the second connected car, and the system parameters, comprising:

[0026] The first connected car obtains a random value from a multiplicative group of integers modulo q , and generates a first information value using an elliptic curve scalar multiplication operation according to the random value and the system parameters;

[0027] The first connected vehicle calls a second hash function to calculate a second hash value according to the pseudo identity of the first connected vehicle, the first information value, and the connected vehicle message to be sent;

[0028] The first connected vehicle obtains a second information value by performing a modulo multiplication operation on the private key of the first connected vehicle and the second hash value and then performing a modulo addition operation on the random value.

[0029] The first connected vehicle calls a fourth hash function to calculate a third hash value based on the random value and the public key of the second vehicle, and performs an exclusive OR operation on the third hash value and the message to be sent after calling a function function to obtain a third information value; and generates an information tuple according to the first information value, the second information value, the third information value, and the current timestamp.

[0030] Further, after receiving the information tuple, if the timeliness is satisfied, the second connected vehicle restores the connected vehicle message using a signature and secret verification algorithm, including:

[0031] After receiving the information tuple, the second connected vehicle compares the difference between the timestamp in the information tuple and the current system time with a preset threshold to verify the timeliness: when the difference is less than or equal to the preset threshold, the second connected vehicle restores the connected vehicle message using a signature and secret verification algorithm.

[0032] Further, the signature and secret verification algorithm used to restore the connected vehicle message includes:

[0033] The second connected vehicle calculates a mapping value by performing an elliptic curve scalar multiplication operation on the private key of the second connected vehicle and the first ciphertext, and calculates a fourth hash value by calling a fourth hash function according to the mapping value.

[0034] The second connected vehicle performs an exclusive OR operation on the fourth hash value and the third ciphertext after calling a function function F to obtain the restored connected vehicle message.

[0035] Further, the correctness of the restored connected vehicle message is determined by using the information tuple, the public key of the first connected vehicle, and the system parameters; and only when the restored connected vehicle message is correct, the second connected vehicle receives the connected vehicle message, including:

[0036] When the second connected vehicle only receives one set of information tuple; the second connected vehicle constructs a single message discriminant by performing an elliptic curve scalar multiplication operation on the system parameters, the first information value, the second information value, the public key of the first connected vehicle, and the pseudo identity of the first connected vehicle; and determines whether the restored connected vehicle message is correct according to whether the single message discriminant is established; and only when the restored connected vehicle message is correct, the second connected vehicle receives the connected vehicle message.

[0037] Further, the use information tuple, the public key of the first connected car and the system parameter are used to judge the correctness of the recovered connected car message, and only when the recovered connected car message is correct, the second connected car receives the connected car message, comprising:

[0038] When the second connected car receives multiple information tuples at the same time, the second connected car constructs a batch discriminant according to the system parameter, the first information value, the second information value, the public key of the first connected car and the pseudo-identity of the first connected car through elliptic curve scalar multiplication operation; and according to whether the batch discriminant is established, it is determined whether the recovered connected car message is correct; only when the recovered connected car message is correct, the second connected car receives the connected car message.

[0039] Compared with the prior art, the present application has at least the following beneficial effects:

[0040] The present application combines the certificateless signcryption mechanism and the certificateless signature mechanism, and overcomes the technical defects of the existing certificateless conditional privacy protection scheme which uses only the signature or signcryption mechanism. In view of the limited computing and storage resources of the vehicle unit, the present application designs a certificateless conditional privacy protection scheme which adaptively selects signature and signcryption, realizes lightweight message authentication, dynamically maintains the mapping list of the pseudo-identity-public key of the connected car by KGC using OTA technology, and constructs distributed storage between distributed connected car nodes, which can effectively resist public key tampering attacks. Under the premise of ensuring security and privacy protection, compared with the existing certificateless conditional privacy protection scheme, the present application reduces the computing and communication overheads, realizes the optimization balance of security, privacy protection and message authentication efficiency, and can meet the efficient authentication requirements of the vehicle unit, and provides reliable technical support for the secure communication of the intelligent transportation system. BRIEF DESCRIPTION OF DRAWINGS

[0041] In order to more clearly illustrate the technical solutions and advantages of the embodiments of the present application or the prior art, the drawings needed in the following embodiment or prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can obtain other drawings according to these drawings without creative labor.

[0042] Fig. 1 The flowchart of the present application;

[0043] Fig. 2 The system model diagram of the present application. DETAILED DESCRIPTION

[0044] In order to further illustrate the technical means and effects taken by the present application to achieve the predetermined inventive objectives, the specific implementation, structure, features and effects of the technical solutions according to the present application are described in detail below in combination with the drawings and preferred embodiments. The specific features, structures or characteristics in one or more embodiments can be combined in any suitable form. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present application belongs.

[0045] Referring to Figs. 1-2 The present application provides a self-adaptive signature and signcryption certificateless conditional privacy protection method for Internet of Vehicles, comprising:

[0046] S1: KGC initializes the Internet of Vehicles system parameters based on system security parameters.

[0047] S2: KGC generates the pseudo-identity and partial private key of the connected car according to the connected car registration identity information submitted by the connected car, and sends the generated pseudo-identity and partial private key to the corresponding connected car.

[0048] S3: The connected car generates the private key and public key of the connected car based on the pseudo-identity, partial private key and system parameters, and uploads the public key to KGC, KGC updates the connected car pseudo-identity-public key mapping list and distributes it to all connected cars in the region.

[0049] S4: The first connected car obtains the connected car message to be sent, determines that the message receiver of the connected car is the second connected car, retrieves the corresponding public key from the connected car pseudo-identity-public key mapping list according to the pseudo-identity of the second connected car.

[0050] S5: The first connected car executes the self-adaptive signature and signcryption algorithm to generate an information tuple based on its own private key, the connected car message to be sent, the public key of the second connected car and the system parameters according to the privacy requirement of the connected car message, and sends the information tuple to the second connected car.

[0051] S6: After receiving the information tuple, the second connected car compares the timeliness of the timestamp in the information tuple, and if the timeliness is satisfied, restores the connected car message, and uses the information tuple, the public key of the first connected car and the system parameters to judge the correctness of the restored connected car message, and only when the restored connected car message is correct, the second connected car receives the connected car message.

[0052] The above steps are described in detail as follows:

[0053] S1: KGC initializes the Internet of Vehicles system parameters based on system security parameters.

[0054] A KGC (key generation center) generates system parameters of the Internet of Vehicles, and issues the system parameters and a pseudo-identity-public key mapping list of the Internet of Vehicles to a registered connected vehicle. As shown in Fig. 2 The Internet of Vehicles includes three entities of the connected vehicle, the roadside unit and the KGC, and the KGC updates the pseudo-identity-public key mapping list of the connected vehicle through an OTA update technology.

[0055] The KGC generates system parameters of the Internet of Vehicles, including:

[0056] S11: The KGC selects an elliptic curve E satisfying a security parameter k, and generates partial parameters {p, q, G} of the system, wherein G is an additive cyclic group defined by the elliptic curve E, and P is a generator of the group G with a prime number q as the order;

[0057] S12: The KGC randomly selects a system master key s from an integer module q multiplicative group , wherein and calculates a system master public key P based on the system master key s and the partial parameter P through an elliptic curve scalar multiplication operation. pub , wherein P pub =sP;

[0058] S13: The KGC configures four cryptographic hash functions and an adaptive selection signature and signature function F: a x {0, 1}→{0, a}; wherein, F(a, 0)=0, F(a, 1)=a;

[0059] The four cryptographic hash functions include a first hash function H0, a second hash function H1, a third hash function H2 and a fourth hash function H3, namely:

[0060] H0:{0,1} π →G;

[0061]

[0062] H3:G→{0,1} n ;

[0063] , wherein H0:{0,1} π →G represents that a string with a length of π bits is mapped to a point in the elliptic curve G; represents that a point on the elliptic curve G is mapped to a value in ; represents that a point on the elliptic curve G and a string with a length of n bits are mapped to a value in ; H3:G→{0,1} n represents that a point on the elliptic curve G is mapped to a string with a length of π bits.

[0064] The adaptive selection signature and sign function F: a x {0, 1} -> {0, a} includes: when the information transmitted by the connected car is non-private information about the speed, gear state, heading angle, steering wheel angle, four-axis acceleration and brake state of the connected car, b = 0, F(a, b) = 0; when the information transmitted by the connected car is private information about the position or historical trajectory of the connected car, b = 1, F(a, b) = a.

[0065] S14: The KGC generates a system parameter set sp = {G, P, q, P pub , F, H0, H1, H2, H3} based on the four hash functions, the partial parameters {P, q, G} and the function F through a system parameter generation algorithm.

[0066] S2: The KGC generates the pseudo-identity and partial private key of the connected car according to the connected car registration identity information submitted by the connected car, and sends the generated pseudo-identity and partial private key to the corresponding connected car.

[0067] The KGC generates the pseudo-identity and partial private key of the connected car according to the connected car registration identity information submitted by the connected car, and sends the generated pseudo-identity and partial private key to the corresponding connected car.

[0068] S21: The connected car selects a random value from the multiplicative group of integers modulo q , and calculates the partial identity information AID i,1 of the connected car based on elliptic curve scalar multiplication operation; the connected car sends the real identity ID i of the connected car and the partial identity information AID i,1 together to the KGC through a secure channel;

[0069] The partial identity information AID i,1 of the connected car includes:

[0070]

[0071] S22: The KGC obtains the pseudonym identifier PID i and the pseudo-identity AID i,1 of the connected car through a pseudo-identity generation algorithm based on the received real identity ID pub of the connected car, the partial identity information AID i of the connected car, the system master key s, the system master public key P i , the fourth hash function H3 and the first hash function H0.

[0072] The pseudonym identifier PID i of the connected car includes:

[0073]

[0074] The pseudo-identity AID of the connected car i include:

[0075] AID i =H0(ID) i )+p i,1 ;

[0076] S23: KGC from the multiplication group modulo q Randomly select a random number k i And based on this random number k i System Master Public Key P pub The second hash function H1, and the pseudo-identity AID of connected vehicles. i A partial private key for a connected vehicle is obtained through a partial private key generation algorithm.

[0077] The private key for the connected vehicle includes:

[0078] W i =k i P pub ;

[0079] h 1i =H1(AID) i +W i );

[0080] p i =(k i +(s -1 h 1i modq))modq;

[0081] Among them, connected cars V i Part of the private key is PSK i ={p i W i}. Among them, W i Indicating connected car V i The first part of the private key value, p i Indicating connected car V i The second part of the private key value, h 1i This represents the first hash value.

[0082] S3: Based on the pseudo-identity, partial private key, and system parameters, the connected vehicle generates its private and public keys. The connected vehicle uploads the pseudo-identity and public key to KGC, and KGC updates the pseudo-identity-public key mapping list of connected vehicles and distributes it to all connected vehicles in the region.

[0083] The connected vehicle generates its private and public keys based on a pseudo-identity, partial private keys, and system parameters, including:

[0084] S31: The connected vehicle uses elliptic curve scalar multiplication to construct a partial private key discriminant based on the pseudo identity, partial private key and system parameters. The connected vehicle receives the pseudo identity and partial private key of the connected vehicle if and only if the partial private key discriminant is true.

[0085] The partial private key discriminant includes:

[0086] p i P pub =W i +h 1i P;

[0087] Among them, h 1i Indicating connected car V i via h 1i =H1(AID) i +W i The first hash value obtained by calculation, W i Indicating connected car V i The first part of the private key value, p i Indicating connected car V i The second part of the private key value.

[0088] S32: Once the partial private key discriminant is valid, the connected vehicle uses a multiplication group of integers modulo q. Select a random number μ from the middle i And using random number μ i The private key of the connected vehicle is calculated using a private key generation algorithm, along with a portion of the vehicle's private key.

[0089] The private key of the connected vehicle includes:

[0090] sk i =(μ i +p i )mod q;

[0091] Among them, sk i Indicating connected car V i private key, μ i Indicates from A random number, p, is selected. i Indicating connected car V i The second part of the private key value.

[0092] S33: The connected vehicle calculates its public key using elliptic curve scalar multiplication based on its private key and system parameters.

[0093] The public key for the connected vehicle includes:

[0094] PK i =sk i P;

[0095] Among them, PK i Indicating connected car V i public key, dk i Indicating connected car V i The private key, P represents the generator of the cyclic additive group G.

[0096] The connected vehicle pseudo-identity-public key mapping list is stored using a hash table data structure, where the pseudo-identity identifier is used as the key and the public key is used as the value.

[0097] Connected vehicles upload their pseudo-identities and public keys to KGC through a secure channel, write them into the connected vehicle pseudo-identity-public key mapping list, and use OTA (Over-The-Air) technology to distribute the updated connected vehicle pseudo-identity-public key mapping list to the on-board units of all connected vehicles in the region.

[0098] S4: First Connected Car V i Get the connected vehicle message to be sent m i The message recipient's connected vehicle is identified as the second connected vehicle V. j Based on the pseudo-identity of the second connected vehicle, the corresponding public key is retrieved from the pseudo-identity-public key mapping list of connected vehicles.

[0099] All connected vehicles are connected vehicles in the Internet of Vehicles (IoV). The first connected vehicle is the message sender, and the second connected vehicle is the message receiver. The connected vehicle messages include: information obtained by the connected vehicle through the electronic unit, and messages sent to the first connected vehicle by other connected vehicles or roadside units.

[0100] S5: The first connected vehicle uses its own private key and the connected vehicle message to be sent. i The public key and system parameters of the second connected vehicle, based on the connected vehicle message m i To meet privacy requirements, an adaptive signature-cryptography algorithm is executed to generate an information tuple, which is then sent to the second connected vehicle.

[0101] The first connected car uses its own private key and the connected car message to be sent. i The public key and system parameters of the second connected vehicle, based on the connected vehicle message m i To meet privacy requirements, the adaptive signature-signaling algorithm generates information tuples including:

[0102] S51: The first connected car uses a multiplication group modulo q. Obtain the random value ηi , according to a random value η i and system parameters, an elliptic curve scalar multiplication operation is performed to generate a first information value.

[0103] The first information value includes:

[0104] B i = η i P;

[0105] Wherein, B i represents the first information value, η i represents a random number selected from .

[0106] S52: The first connected car calls a second hash function H2 to calculate a second hash value according to the pseudo-identity of the first connected car, the first information value and the connected car message to be sent.

[0107] The second hash value includes:

[0108] h 2,i = H2((B i + ADI i ), m i );

[0109] Wherein, h 2,i represents the second hash value, B i represents the first information value, AID i represents the pseudo-identity of the first connected car, and m i represents the connected car message to be sent.

[0110] S53: The first connected car obtains a second information value after performing a modulo operation between the private key of the first connected car and the second hash value and adding a random number η i .

[0111] The second information value includes:

[0112] c 2,i = (η i + (h 2,i sk i ) mod q) mod q;

[0113] Wherein, c 2,i represents the second information value, h 2,i represents the second hash value, η i represents a random number selected from , sk i represents the private key of the first connected car V i , and q represents a large prime number.

[0114] S54: The first connected vehicle calls a fourth hash function H3 based on the random number η i and the public key of the second connected vehicle, calculates a third hash value, and calls a function function based on the third hash value and does XOR operation with the message to be sent to obtain a third information value; generates an information tuple according to the first information value, the second information value, the third information value and the current timestamp.

[0115] The third hash value includes:

[0116] h 3,i =H3(η i PK j );

[0117] Wherein, h 3,i represents the third hash value, η i represents a random number selected from , and PK j represents the public key of the second connected vehicle V i .

[0118] The third information value includes:

[0119]

[0120] Wherein, c 1,i represents the third information value, h 3,i represents the third hash value, m i represents the message to be sent, and F represents the function function of adaptive signature or signcryption.

[0121] The information tuple includes:

[0122] σ i ={B i ,c 1,i ,c 2,i ,t i};

[0123] Wherein, B i represents the first information value, c 1,i represents the third information value, c 2,i represents the second information value, and t i represents the timestamp when the information tuple is generated.

[0124] S6: After receiving the information tuple, the second connected vehicle compares the timeliness of the timestamp in the information tuple, and if the timeliness is satisfied, the connected vehicle message is recovered, and the information tuple, the public key of the first connected vehicle and the system parameter are used to judge the correctness of the recovered connected vehicle message. Only when the recovered connected vehicle message is correct, the second connected vehicle receives the connected vehicle message.

[0125] After receiving the information tuple, the second connected vehicle compares the difference between the time stamp in the information tuple and the current system time with the preset threshold to verify the timeliness: when the difference is less than or equal to the preset threshold, the second connected vehicle uses a signature and cipher verification algorithm to recover the connected vehicle message, and uses the information tuple, the public key of the first connected vehicle and the system parameters to judge the correctness of the message, and the second connected vehicle receives the connected vehicle message m only when the recovered connected vehicle message is correct i .

[0126] The second connected vehicle uses a signature and cipher verification algorithm to recover the connected vehicle message, including:

[0127] S61: The second connected vehicle calculates a mapping value by elliptic curve scalar multiplication operation according to the private key of the second connected vehicle and the first ciphertext, and calculates a fourth hash value by calling a fourth hash function H3 according to the mapping value.

[0128] The fourth hash value includes:

[0129] h 4,i =H3(sk j B i );

[0130] Wherein, h 4,i represents the fourth hash value, sk j represents the private key of the second connected vehicle, and B i represents the first information value.

[0131] S62: The second connected vehicle performs XOR operation with the third ciphertext after calling the function function F according to the fourth hash value, to obtain the recovered connected vehicle message.

[0132] The recovered connected vehicle message includes:

[0133]

[0134] Wherein, m′ i represents the recovered connected vehicle message, h 4,i represents the fourth hash value, and c 1,i represents the third information value.

[0135] Using the information tuple, the public key of the first connected vehicle and the system parameters to judge the correctness of the recovered connected vehicle message includes:

[0136] S621: When the second connected car only receives one set of information tuples; the second connected car constructs a single message discriminant according to the system parameters, the first information value, the second information value, the public key of the first connected car and the pseudo identity of the first connected car through the elliptic curve scalar multiplication operation; and determines whether the original connected car message is correct according to whether the single message discriminant is established; if the single message discriminant is established, it is determined that the recovered connected car message is correct; if the single message discriminant is not established, the recovered connected car message is incorrect, and an error message is returned.

[0137] The single message discriminant includes:

[0138] c 2,i P=B i +H2((B i +AID i ),m′ i )PK i ;

[0139] Wherein, c 2,i represents the second information value, P represents the generator of the elliptic curve, B i represents the first information value, AID i represents the pseudo identity of the first connected car, and PK i represents the public key of the first connected car.

[0140] S622: When the second connected car receives multiple sets of information tuples at the same time; the second connected car constructs a batch discriminant according to the system parameters, the first information value, the second information value, the public key of the first connected car and the pseudo identity of the first connected car through the elliptic curve scalar multiplication operation; and determines whether the original connected car message is correct according to whether the batch discriminant is established. If the batch discriminant is established, the recovered connected car message is correct; if the batch discriminant is not established, the recovered connected car message is incorrect, and an error message is returned.

[0141] The batch discriminant includes:

[0142]

[0143] Wherein, c 2,i represents the second information value, P represents the generator of the elliptic curve, B i represents the first information value, AID i represents the pseudo identity of the first connected car, m′ i represents the recovered original connected car message, and PK i represents the public key of the first connected car.

[0144] The above examples are only used to illustrate the technical solutions of the present application, but not limit the present application; although the present application has been described in detail with reference to the foregoing examples, those ordinarily skilled in the art should understand: the technical solutions recorded in the foregoing examples can still be modified, or some technical features can be replaced equivalently; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A method for protecting certificate-free privacy in vehicle-to-everything (V2X) networks using adaptive signature and signature encryption, characterized in that: include: KGC initializes the vehicle-to-everything (V2X) system parameters based on system safety parameters. KGC generates a pseudo identity and a partial private key for the connected vehicle based on the registered identity information submitted by the connected vehicle, and sends the generated pseudo identity and partial private key to the corresponding connected vehicle. Based on the pseudo-identity, partial private key, and system parameters, the connected vehicle generates a private key and a public key, and uploads the public key to KGC. KGC updates the pseudo-identity-public key mapping list of connected vehicles and distributes it to all connected vehicles in the region. The first connected vehicle obtains the connected vehicle message to be sent, determines that the connected vehicle receiving the message is the second connected vehicle, and retrieves the corresponding public key from the connected vehicle pseudo-identity-public key mapping list based on the pseudo-identity of the second connected vehicle. The first connected vehicle, based on its own private key, the connected vehicle message to be sent, the public key of the second connected vehicle, and system parameters, performs an adaptive signature-cryptography algorithm to generate an information tuple according to the privacy requirements of the connected vehicle message, and sends the information tuple to the second connected vehicle. After receiving the information tuple, the second connected vehicle compares the timeliness of the timestamp in the information tuple. If the timeliness is satisfied, it restores the connected vehicle message and uses the information tuple, the public key of the first connected vehicle, and system parameters to determine the correctness of the restored connected vehicle message. The second connected vehicle receives the connected vehicle message if and only if the restored connected vehicle message is correct. Specifically, the first connected vehicle, based on its own private key, the connected vehicle message to be sent, the public key of the second connected vehicle, and system parameters, generates an information tuple by executing an adaptive signature-cryptography algorithm according to the privacy requirements of the connected vehicle message, including: The first connected car starts from integer modulus multiplication group A random value is obtained from the system parameters, and an elliptic curve scalar multiplication operation is used to generate a first information value based on the random value and the system parameters. The first connected vehicle uses the pseudo identity, first information value, and connected vehicle message to be sent to call the third hash function to calculate the second hash value. The first connected vehicle obtains the second information value by performing a modular multiplication operation on the private key and the second hash value, followed by a modular addition with the random value. The first connected vehicle uses a random value and the public key of the second connected vehicle to call the fourth hash function to calculate the third hash value. Based on the third hash value, it calls the function and performs an XOR operation with the message to be sent to obtain the third information value. Based on the first information value, the second information value, the third information value, and the current timestamp, an information tuple is generated.

2. The method for protecting certificate-free privacy in vehicle networking based on adaptive signature and signature encryption as described in claim 1, characterized in that, The KGC initializes the vehicle-to-everything (V2X) system parameters based on system security parameters, including: KGC selects options that meet safety parameters. Elliptic curve Generate some parameters of the system ,in It is composed of elliptic curves Defined addition cyclic group, It is a prime number. group Generators; KGC from integer modulo multiplication group Randomly select the master key ,in And based on the system's master key and some parameters The master public key of the system is calculated using elliptic curve scalar multiplication. KGC configures the first hash function. Second hash function Third hash function Fourth hash function And an adaptive function for selecting signature and signature encryption. ;in, ; KGC is based on the first hash function. Second hash function Third hash function Fourth hash function Some parameters and function A system parameter set is generated through a system parameter generation algorithm. .

3. The method for protecting certificate-free privacy in vehicle networking based on adaptive signature and signature encryption according to claim 2, characterized in that, The KGC generates a pseudo identity and partial private key for the connected vehicle based on the registered identity information submitted by the connected vehicle, including: Connected vehicles from integer modulo multiplication group Select random values It calculates some identity information of connected vehicles based on elliptic curve scalar multiplication; the connected vehicle sends its real identity and some identity information to KGC through a secure channel; Based on the received real identity, partial identity information, system master key and system master public key, fourth hash function and first hash function, KGC obtains pseudo-identity and pseudo-identity through pseudo-identity generation algorithm; KGC from integer modulo multiplication group A random value is randomly selected from the system, and based on the random value, the system's master public key, the second hash function, and the pseudo-identity, a partial private key for the connected vehicle is obtained through a partial private key generation algorithm.

4. The method for protecting certificate-free privacy in vehicle networking based on adaptive signature and signature encryption according to claim 1, characterized in that, The connected vehicle generates its private and public keys based on a pseudo-identity, partial private keys, and system parameters, including: Based on the false identity of the connected vehicle, a portion of the private key of the connected vehicle, and system parameters, the connected vehicle uses elliptic curve scalar multiplication to construct a partial private key discriminant. The connected vehicle receives the false identity and partial private key of the connected vehicle if and only if the partial private key discriminant is true. Once the partial private key discriminant is valid, the connected vehicle will switch from integer modulo... multiplication group Select random numbers And using the random number Partial private key, calculated using a private key generation algorithm for connected vehicles; The public key of a connected vehicle is calculated using elliptic curve scalar multiplication based on the vehicle's private key and system parameters.

5. The method for protecting certificate-free privacy in vehicle networking based on adaptive signature and signature encryption according to claim 1, characterized in that, After receiving the information tuple, if the timeliness requirement is met, the second connected vehicle uses a signature-verification algorithm to recover the connected vehicle message, including: After receiving the information tuple, the second connected vehicle compares the difference between the timestamp in the information tuple and the current system time with a preset threshold to verify the timeliness: when the difference is less than or equal to the preset threshold, the second connected vehicle uses a signature-encryption verification algorithm to recover the connected vehicle message.

6. The method for protecting certificate-free privacy in vehicle networking based on adaptive signature and signature encryption as described in claim 5, characterized in that, Recovering connected vehicle messages using a signature-signature verification algorithm includes: The second connected vehicle calculates the mapping value using elliptic curve scalar multiplication based on its private key and the first ciphertext, and then calls the fourth hash function to calculate the fourth hash value based on the mapping value. The second connected vehicle calls the function based on the fourth hash value. Then, an XOR operation is performed with the third ciphertext to obtain the recovered connected car message.

7. The method for protecting certificate-free privacy in vehicle networking based on adaptive signature and signature encryption according to claim 6, characterized in that, The process of using information tuples, the public key of the first connected vehicle, and system parameters to determine the correctness of the recovered connected vehicle message, and the second connected vehicle receiving the connected vehicle message if and only if the recovered connected vehicle message is correct, includes: When the second connected vehicle receives only one set of information tuples, it constructs a single-message discriminant using elliptic curve scalar multiplication based on system parameters, the first information value, the second information value, the public key of the first connected vehicle, and the pseudo-identity of the first connected vehicle. It then determines whether the recovered connected vehicle message is correct based on whether the single-message discriminant is valid. The second connected vehicle receives the connected vehicle message only if and only if the recovered connected vehicle message is correct.

8. The method for protecting certificate-free privacy in vehicle networking based on adaptive signature and signature encryption according to claim 6, characterized in that, The process of using information tuples, the public key of the first connected vehicle, and system parameters to determine the correctness of the recovered connected vehicle message, and the second connected vehicle receiving the connected vehicle message if and only if the recovered connected vehicle message is correct, includes: When the second connected vehicle receives multiple sets of information tuples simultaneously, the second connected vehicle constructs a batch discriminant based on system parameters, the first information value, the second information value, the public key of the first connected vehicle, and the pseudo-identity of the first connected vehicle through elliptic curve scalar multiplication. Based on whether the batch discriminant is valid, it determines whether the recovered connected vehicle message is correct. The second connected vehicle receives the connected vehicle message if and only if the recovered connected vehicle message is correct.

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