Cross-domain authentication method and system under vehicle-mounted ad hoc network

Abstract

The invention relates to the technical field of network security communication, and particularly discloses a cross-domain authentication method and system under a vehicle-mounted ad hoc network, the method is realized based on the cross-domain authentication system under the vehicle-mounted ad hoc network, and the cross-domain authentication system comprises a key generation center and a trusted authorization mechanism in at least one domain corresponding to each region, a plurality of roadside units and vehicles in each area; the method comprises the steps of system initialization, vehicle initialization, roadside unit initialization, threshold group signature construction, identity updating, intra-domain identity authentication, inter-domain identity authentication, illegal user identification, illegal user logout and the like. According to the cross-domain authentication method provided by the invention, the problems of privacy protection, cross-domain equipment cooperation, malicious entity tracking and the like in a vehicle-mounted network are effectively solved, and rapid development of smart traffic is promoted.

Description

Technical Field

[0001] The present invention relates to the field of network security communication technology, and in particular to a cross-domain authentication method in a vehicle-mounted ad hoc network. Background Art

[0002] With the continuous development of mobile communication networks and autonomous driving technologies, Internet of Vehicles (IoV) technology has significantly improved the safety and efficiency of road traffic with its unique functions and applications, and is gradually becoming one of the fields with the greatest industrial potential. However, when Internet of Vehicles (IoV) networks are deployed on a large scale, users face a series of threats to information security and privacy leakage. In order to ensure and improve the security of IoV user data interaction, the efficiency of IoV systems in vehicle communication and rapid data collection has been improved.

[0003] The communication environment of the Internet of Vehicles is inherently vulnerable because it uses public wireless communication technology. The high mobility of vehicles and the volatility of the environment increase the risk of malicious attacks during the communication process. Malicious attackers may intercept and eavesdrop on messages in transit, and may perform various security attacks on these messages, such as modification, identity forgery, disguise or replay. This not only threatens the integrity and confidentiality of data, but may also lead to traffic accidents.

[0004] During cross-domain communication, devices in different domains often rely on their own independent authentication mechanisms to communicate. This diversified authentication system may have problems of distrust and operability between domains during cross-domain interaction, exacerbating the security challenges of protecting data privacy and identity authentication. In addition, the complexity of cross-domain communication further amplifies the risk of user privacy leakage, while placing higher requirements on achieving solid and secure identity authentication. These factors together constitute the key challenges of cross-domain authentication in the Internet of Vehicles. Traditional authentication methods increase the workload of the authentication center, and single-node servers face the risk of service paralysis when failures or attacks occur.

[0005] In summary, the Internet of Vehicles system needs a new authentication solution that can achieve efficient, secure and reliable cross-domain authentication while protecting user privacy, so as to cope with the complex security challenges in the IoV environment. Summary of the invention

[0006] In view of the technical problems in the prior art, the present invention provides a cross-domain authentication method and system in a vehicle-mounted ad hoc network.

[0007] In a first aspect, a cross-domain authentication method in a vehicle-mounted ad hoc network of the present invention is implemented based on a cross-domain authentication system in a vehicle-mounted ad hoc network, wherein the cross-domain authentication system includes a key generation center, a trusted authorization authority in at least one domain corresponding to each area, and a plurality of roadside units and vehicles in each area; the method includes the following steps:

[0008] System initialization: the trusted authority generates system parameters within the domain;

[0009] Vehicle initialization: the trusted authorization agency generates a pseudo-identity of the vehicle according to the system parameters in the domain and sends it to the vehicle through a secure channel. The vehicle verifies the pseudo-identity, obtains the corresponding public key and private key, and stores them;

[0010] Roadside unit initialization: the trusted authority generates a key message for the roadside unit according to the system parameters in the domain and sends it to the corresponding roadside unit through a secure channel. The roadside unit verifies the key message, obtains the key corresponding to it and stores it;

[0011] Constructing a threshold group signature: constructing a threshold group, the threshold group consisting of a number of vehicles and roadside units as members; any vehicle in the threshold group generates a signature of a traffic message and broadcasts it, and the roadside unit or other vehicles receive the signature message and verify whether the signature is legal;

[0012] Identity update: Before performing intra-domain identity authentication, the trusted authorization agency updates the user whose identity has expired by calling the update algorithm;

[0013] Intra-domain identity authentication: The trusted authorization agency in the domain authenticates the vehicle's identity. After successful identity authentication, the vehicle establishes a communication connection with other vehicles in the domain;

[0014] Inter-domain identity authentication: A vehicle in the first domain initiates an inter-domain connection request, which is forwarded by a trusted authority in the first domain and authenticated by a trusted authority in the second domain. If the authentication is successful, the vehicle in the first domain establishes a communication connection with the vehicle in the second domain.

[0015] Identify illegal users: The trusted authorization agency authenticates the users in the domain and identifies illegal users;

[0016] Deregistering illegal users: The trusted authorization agency establishes a revocation tree on the blockchain. When there are illegal users, the trusted authorization agency deregisters the registration information of the illegal users.

[0017] Furthermore, system initialization includes:

[0018] Let F P represents a finite field of order p, over which the trusted authority constructs an elliptic curve E;

[0019] Choose a generator P from E, a cyclic group G of order large prime number q;

[0020] The trusted authority randomly selects As the private key SK GA , the public key is obtained by calculation is a finite field;

[0021] Defining a secure hash function The common system parameters are {G,q,P,P pub ,H0,H1,H2},P pub is the system public key;

[0022] The vehicle initialization includes:

[0023] The vehicle generates a random number Calculate K i =k i P, then sends a registration request {Register||ID i ,K i ,t i}, where ID i Vehicle i The real identity information, t i Indicates the current timestamp of the registration request;

[0024] The trusted authority selects a random number Calculating pseudonyms R i =r i P,h0=H0(PID i ,K i ,R i ),as well as s n It is the system private key;

[0025] Generate identity certificate cert i =(Acc i ||ID i ||PID i ||gpk||t i ||T i ); Acc i is a blockchain account, gpk is a vehicle i The group public key of the domain, T i It is cert i Validity period;

[0026] Generate a pseudo-identity message {Response||cert i ||y i ||R i} and sent to the vehicle through a secure channel i ;

[0027] The vehicle i By calculating y i P=R i +H0(PID i ,K i ,R i ) pub , verify the pseudo identity; if the verification is successful, then (cert i ,K i ,k i ,R i ,y i ) is stored on the blockchain within the domain, and the public key and private key of the vehicle are vpk i =K i , vsk i =k i ;

[0028] The roadside unit initialization includes:

[0029] The roadside unit generates a random number Calculate K j =k j P, and get the current time T j ∈{0,1} * , the message {Register||ID j ,K j ,T j} is sent to the trusted authority; wherein, ID j is the identity information of the roadside unit;

[0030] After receiving the message, the trusted authority generates a random number Calculate R j =r j P, h1 = H1 (ID j ,K j )as well as

[0031] Generate key message {Response||gpk,R j ,y j ,T j}, and sent to the roadside unit via a secure channel;

[0032] The roadside unit is calculated by Verify the key message; if the verification is successful, {k j ,K j ,r j ,R j} is stored on the blockchain within the domain; the public key and private key of the roadside unit are vpk j =K j , vsk j =k j .

[0033] Furthermore, the construction threshold group includes:

[0034] A threshold group signature scheme of (t,n) is used, where t is the threshold value and the threshold group is a set of n members, represented by M = {m1,m2,…,m t}(t≤n); The members of the threshold group include at least: group administrator GA, group member m i , signature verifier GV, θ is the traffic message that needs to be signed;

[0035] The group administrator GA randomly selects a secret value And calculate pk i =κ i P, where κ i =sk i ; Then secretly select a t-1 degree polynomial where a iz ∈[1,p-1](z=0,1,…,t-1);

[0036] Calculate the group private key of the threshold group as sk gi =f i (0) = a i0 , calculate the group public key of the threshold group as pk gi =f i (0)P=a i0 P;

[0037] Group Members i Randomly choose a secret value Calculate pk i =v i P, and generate a temporary pseudonym ζ i ;

[0038] Any of the vehicles in the threshold group generates a signature of a traffic message and broadcasts it, including:

[0039] Group Members i Through the private key sk i Sign traffic messages i =sk i I i +h i (θ)ν i modp, where h i (θ) is the hash value of the traffic message;

[0040] Group Members i Broadcasting the signature of the traffic message;

[0041] The roadside unit or other vehicle receives the signed message and verifies whether the signature is legitimate, including:

[0042] Single message authentication: via public user pseudonym PID i Computation I i And the hash value h of the traffic message i (θ), and by calculating ν i h i (θ) = s i P-pk i I i To verify whether the signature is legitimate;

[0043] And / or, batch message verification: When the group administrator GA receives N different signed messages, it calculates and verification message The threshold signature (S, V) and the verification message Y are broadcast to the signature verifier GV in the group. When N ≥ t, SP is calculated to verify whether the signature is legal; where:

[0044]

[0045] Furthermore, identity updates include:

[0046] Vehicle inspection identity certificate cert i Whether it is expired, if it is expired, submitting an update request {IDUpData} to the trusted authority through the roadside unit;

[0047] The trusted authorization agency calls the update algorithm to complete the identity update of the vehicle;

[0048] The roadside unit submits the user's blockchain account Acc to the trusted authority i , group public key gpk and T i Perform identity updates;

[0049] The trusted authority verifies the validity of the signature through gpk. If it is valid, Time = T i new ;

[0050] Output T i new , gpk updates user identity information.

[0051] Furthermore, the intra-domain identity authentication includes:

[0052] The vehicle will send the identity certificate i Send to the current roadside unit through a secure channel;

[0053] After receiving the T i If valid, the consistency of the group public key gpk is verified. If they are the same, the authentication is successful.

[0054] The first vehicle is established to communicate with another second vehicle in the domain, the process comprising:

[0055] The first vehicle uses the private key vsk i Sign the request message And send a request to establish communication to the second vehicle through the secure channel {request||σ i};

[0056] After the second vehicle receives the identity certificate, j Extract the group public key gpk from the , and verify the signature. If the verification is successful, it proves that the two belong to the same domain;

[0057] The second vehicle uses the private key vsk j Sign the response message And send a response to the communication request {response||σ j};

[0058] After the first vehicle is received, the identity certificate cert i Extract the group public key gpk pair σ j Verification is performed, and if the verification is successful, the first vehicle and the second vehicle establish a communication connection.

[0059] Furthermore, the inter-domain identity authentication includes:

[0060] The first vehicle in the first domain calculates l=g H(ID) , choose a random number calculate C=H(l,w),u=r ID - C·l, forwarding the connection request π=(l, C, u) from the trusted authority in the first domain to the trusted authority in the second domain through a secure channel;

[0061] After receiving the connection request, the trusted authority in the second domain calculates w′=g u ·g C·l , w′=g u ·g C·l, calculate C′=H(l,w′), and verify whether the equation C′=C holds. If so, the identity verification is successful;

[0062] If a first vehicle in the first domain wants to establish a communication connection with a second vehicle in the second domain, the first vehicle initiates a transaction tr={Acc i ,Acc j ,Re,coin i}, where Acc i For the payer, Acc j is the payee, Re is the transaction information, coin i The transaction amount; if the inter-domain blockchain verifies and reaches a consensus, the transaction is written into a new block and the transaction identifier is returned to the payer Acc i ; Payee Acc j After receiving the transfer, contact the payer Acc i Communicate as needed, otherwise, terminate the communication.

[0063] Further, the identifying of illegal users includes:

[0064] The trusted authorization agency executes the Open algorithm Open(gmsk,m,σ)→(ID / ⊥), and takes the group owner's private key gmsk, the message m and the signature σ as the input of the Open algorithm. If the output is ⊥, the user is an illegal user; if the user is a member of the group, the real identity information of the member is output.

[0065] Furthermore, the deregistration of illegal users includes:

[0066] The trusted authority generates a system parameter SP and a master key mk of a revocation tree;

[0067] According to the algorithm BuildTree(SP,mk,t,Acc), the node account information Acc of the tree is output. The master key mk is used to sign the child nodes of the tree, and the timestamp t is used to limit the validity period of the node.

[0068] According to the algorithm Addnode(Acc i ,t i ,sk i ) Output any node node i The child node Acc i And the key sk corresponding to the child node i , if and only if the child node contains the timestamp t i When the timestamp t of the parent node is newer, the child node is valid;

[0069] According to the algorithm Deletenode(Ac i c, i ′t,si k) Delete the child node Acc of a node i , generate a new timestamp t′ to update the node node i ,Since the time of the child node is older than that of the parent node, the child node is invalid;

[0070] When the number of vehicles with expired identities meets the preset conditions, the Deletenode(Acc i ,t i ′,sk i ) algorithm updates the node t′ and cancels the account information Acc of the illegal user i .

[0071] Furthermore, the method also includes:

[0072] Generate a blacklist: The trusted authority in each domain generates and maintains a blacklist based on the identified illegal users, and updates the users whose identities have expired in combination with the blacklist when the identities are updated.

[0073] In the second aspect, the present invention provides a cross-domain authentication system under a vehicle-mounted ad hoc network, the cross-domain authentication system includes a key generation center, a trusted authorization agency in at least one domain corresponding to each area, and a number of roadside units and vehicles in each area, the vehicle is provided with an on-board unit for communicating with other vehicles and roadside units; the cross-domain authentication system is used to implement the above method.

[0074] The cross-domain authentication method and system under the vehicle-mounted ad hoc network of the present invention are implemented based on the cross-domain authentication system under the vehicle-mounted ad hoc network. The cross-domain authentication system includes a key generation center, a trusted authorization agency in at least one domain corresponding to each area, and a plurality of roadside units and vehicles in each area; the method includes the steps of system initialization, vehicle initialization, roadside unit initialization, construction of threshold group signature, identity update, intra-domain identity authentication, inter-domain identity authentication, identification of illegal users, cancellation of illegal users, etc. The present invention provides a cross-domain authentication method, which uses intra-domain private chains and inter-domain alliance chains to deploy blockchain networks, eliminates the incomplete trust problem between domains in the cross-domain authentication process, and ensures the trust barrier of cross-domain users. In addition, non-interactive zero-knowledge proof is used to authenticate the identity of vehicle users, and the user identity is authenticated without leaking the user's privacy. The revocation mechanism based on the tree structure can realize the identity revocation of some malicious users with destructive behavior and expired users in the domain, reduce system storage redundant storage, and perform real-time monitoring when a new user submits an authentication request or a vehicle performs cross-domain authentication to detect whether it is a malicious user, thereby ensuring the long-term, safe and stable operation of the blockchain network. BRIEF DESCRIPTION OF THE DRAWINGS

[0075] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0076] Figure 1 A flowchart of a cross-domain authentication method in a vehicle ad hoc network according to an embodiment of the present invention;

[0077] Figure 2 A schematic diagram of a cross-domain authentication method in a vehicle ad hoc network according to an embodiment of the present invention;

[0078] Figure 3 A schematic flow chart of a cross-domain authentication method in a vehicle ad hoc network according to another embodiment of the present invention;

[0079] Figure 4 A schematic diagram of a revocation tree structure in a cross-domain authentication method in a vehicle-mounted ad hoc network according to an embodiment of the present invention. DETAILED DESCRIPTION

[0080] The following will be combined with the accompanying drawings in the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the protection scope of the present invention.

[0081] A cross-domain authentication method under a vehicle-mounted ad hoc network in an embodiment of the present invention is implemented based on a cross-domain authentication system under a vehicle-mounted ad hoc network. The cross-domain authentication system includes a key generation center, a trusted authorization agency in at least one domain corresponding to each area, and several roadside units and vehicles in each area. In the system of the embodiment of the present invention, vehicle users enjoy specific resources in the domain, and after authentication, they access the resources of a specific domain on demand. Each vehicle is equipped with a vehicle-mounted unit, which is responsible for simple communications and tasks. The roadside unit, as an intermediate entity with certain storage and computing capabilities, broadcasts traffic alarms, collects basic safety information of nearby vehicles, and communicates with the vehicle. As an intermediary between vehicles and larger communication infrastructure, roadside units promote data exchange, traffic management, and connection with a wider network, improving the overall communication efficiency and security of the vehicle network. There are two types of blockchains in this application, namely intra-domain blockchains and inter-domain blockchains, both of which are alliance chains. The intra-domain blockchain mainly maintains the identity registration information of vehicle users, and the inter-domain blockchain is mainly oriented to authorized nodes, solving the untrusted communication between different domains, and ensuring the validity and legitimacy of the data in the chain by regularly updating the registration information of vehicle users.

[0082] like Figures 1 to 4 As shown, the cross-domain authentication method in a vehicle ad hoc network according to an embodiment of the present invention includes the following steps:

[0083] Step S10: System initialization: The trusted authority generates system parameters within the domain.

[0084] Specifically: Let F P Representing a finite field of order p, the trusted authority constructs an elliptic curve E over the field;

[0085] Choose a generator P from E, a cyclic group G of order large prime number q;

[0086] Trusted authority random selection As the private key SK GA , the public key is obtained by calculation is a finite field;

[0087] Defining a secure hash function The common system parameters are {G,q,P,P pub ,H0,H1,H2},P pub The system public key.

[0088] Step S20: Vehicle initialization: The trusted authorization agency generates a pseudo-identity for the vehicle based on the system parameters within the domain and sends it to the vehicle through a secure channel. The vehicle verifies the pseudo-identity, obtains the corresponding public key and private key, and stores them.

[0089] Specifically: the vehicle generates a random number Calculate K i =k i P, then sends a registration request {Register||ID i ,K i ,t i}, where ID i Vehicle i The real identity information, t i Indicates the current timestamp of the registration request;

[0090] Trusted authority selects random number Calculating pseudonyms R i =r i P,h0=H0(PID i ,K i ,R i ),as well as s n It is the system private key;

[0091] Generate identity certificate cert i =(Acc i ||ID i ||PID i ||gpk||t i ||T i ); Acc i is a blockchain account, gpk is a vehicle i The group public key of the domain, T i It is cert i Validity period;

[0092] Generate a pseudo-identity message {Response||cert i ||y i ||R i} and sent to the vehicle through a secure channel i ;

[0093] Vehicle i By calculating y i P=R i +H0(PID i ,K i ,R i ) pub , verify the pseudo identity; if the verification is successful, then (cert i ,K i ,k i ,R i ,y i) is stored on the blockchain within the domain, and the public key and private key of the vehicle are vpk i =K i , vsk i =k i .

[0094] Step S30: Roadside unit initialization: The trusted authorization agency generates a key message for the roadside unit according to the system parameters in the domain and sends it to the corresponding roadside unit through a secure channel. The roadside unit verifies the key message, obtains the corresponding key and stores it.

[0095] Specifically: The roadside unit generates a random number Calculate K j =k j P, and get the current time T j ∈{0,1} * , the message {Register||ID j ,K j ,T j} is sent to a trusted authority; where ID j It is the identity information of the roadside unit;

[0096] After receiving the message, the trusted authority generates a random number Calculate R j =r j P, h1 = H1 (ID j ,K j )as well as

[0097] Generate key message {Response||gpk,R j ,y j ,T j} and sent to the roadside unit via a secure channel;

[0098] Roadside units are calculated by Verify the key message; if the verification is successful, {k j ,K j ,r j ,R j} is stored on the blockchain within the domain; the public key and private key of the roadside unit are vpk j =K j , vsk j =k j .

[0099] Step S40: construct threshold group signature: construct a threshold group, which is composed of several vehicles and roadside units as members; any vehicle in the threshold group generates a signature of the traffic message and broadcasts it, and the roadside unit or other vehicles receive the signed message and verify whether the signature is legal.

[0100] In this step, constructing a threshold group includes:

[0101] A threshold group signature scheme of (t,n) is used, where t is the threshold value and the threshold group is a set of n members, represented by M = {m1,m2,…,m t}(t≤n); The members of the threshold group include at least: group administrator GA, group member m i , signature verifier GV, θ is the traffic message that needs to be signed;

[0102] The group administrator GA randomly selects a secret value And calculate pk i =κ i P, where κ i =sk i ; Then secretly select a t-1 degree polynomial where a iz ∈[1,p-1](z=0,1,…,t-1);

[0103] Calculate the group private key of the threshold group as sk gi =f i (0) = a i0 , calculate the group public key of the threshold group as pk gi =f i (0)P=a i0 P;

[0104] Group Members i Randomly choose a secret value Calculate pk i =v i P, and generate a temporary pseudonym ζ i ;

[0105] In this step, any vehicle in the threshold group generates a signature of the traffic message and broadcasts it, including:

[0106] Group Members i Through the private key sk i Sign traffic messages i =sk i I i +h i (θ)ν i modp, where h i (θ) is the hash value of the traffic message;

[0107] Group Members i Broadcasting the signature of the traffic message;

[0108] In this step, the roadside unit or other vehicle receives the signed message and verifies whether the signature is legitimate, including:

[0109] Single message authentication: via public user pseudonym PID i Computation I i And the hash value h of the traffic message i (θ), and by calculating ν i h i (θ) = s i P-pk i I i To verify whether the signature is legitimate;

[0110] And / or, batch message verification: When the group administrator GA receives N different signed messages, it calculates and verification message The threshold signature (S, V) and the verification message Y are broadcast to the signature verifier GV in the group. When N ≥ t, SP is calculated to verify whether the signature is legal; where:

[0111]

[0112] Step S50: Identity update: Before performing intra-domain identity authentication, the trusted authorization agency updates the user's expired identity by calling an update algorithm.

[0113] Specifically include: Vehicle inspection identity certificate cert i Whether it is expired. If it is expired, submit an update request {IDUpData} to the trusted authority through the roadside unit;

[0114] The trusted authority calls the update algorithm to complete the vehicle identity update;

[0115] The roadside unit submits the user's blockchain account Acc to the trusted authority i , group public key gpk and T i Perform identity updates;

[0116] The trusted authority verifies the validity of the signature through gpk. If it is valid, Time = T i new ;

[0117] Output T i new , gpk updates user identity information.

[0118] Step S60: Intra-domain identity authentication: A trusted authorization agency in the domain authenticates the vehicle identity. After successful identity authentication, the vehicle establishes a communication connection with other vehicles in the domain.

[0119] Specifically include: the vehicle will be the identity certificate cert i Send to the current roadside unit through a secure channel;

[0120] After receiving the roadside unit, it first verifies T i If valid, the consistency of the group public key gpk is verified. If they are the same, the authentication is successful.

[0121] The first vehicle is established to communicate with another second vehicle in the domain, the process comprising:

[0122] The first vehicle uses the private key vsk i Sign the request message And send a request to establish communication to the second vehicle through the secure channel {request||σ i};

[0123] After the second vehicle receives the identity certificate, j Extract the group public key gpk from the , and verify the signature. If the verification is successful, it proves that the two belong to the same domain;

[0124] The second vehicle uses the private key vsk j Sign the response message And send a response to the communication request {response||σ j};

[0125] After the first vehicle is received, the identity certificate cert i Extract the group public key gpk pair σ j Verification is performed, and if the verification is successful, the first vehicle and the second vehicle establish a communication connection.

[0126] Step S70: inter-domain identity authentication: The vehicle in the first domain initiates an inter-domain connection request, which is forwarded by a trusted authorization agency in the first domain and authenticated by a trusted authorization agency in the second domain. If the authentication is successful, the vehicle in the first domain establishes a communication connection with the vehicle in the second domain.

[0127] This step specifically includes: calculating l=g for the first vehicle in the first domain: H(ID) , choose a random number calculate C=H(l,w),u=r ID- C·l, forwarding the connection request π=(l, C, u) from the trusted authority in the first domain to the trusted authority in the second domain through a secure channel;

[0128] After receiving the connection request, the trusted authority in the second domain calculates w′=g u ·g C·l , w′=g u ·g C·l , calculate C′=H(l,w′), and verify whether the equation C′=C holds. If so, the identity verification is successful;

[0129] If a first vehicle in the first domain wants to establish a communication connection with a second vehicle in the second domain, the first vehicle initiates a transaction tr={Acc i ,Acc j ,Re,coin i}, where Acc i For the payer, Acc j is the payee, Re is the transaction information, coin i The transaction amount; if the inter-domain blockchain verifies and reaches a consensus, the transaction is written into a new block and the transaction identifier is returned to the payer Acc i ; Payee Acc j After receiving the transfer, contact the payer Acc i Communicate as needed, otherwise, terminate the communication.

[0130] Step S80: Identify illegal users: The trusted authorization agency authenticates the users in the domain and identifies illegal users.

[0131] This step specifically includes: the trusted authorization agency executes the Open algorithm Open(gmsk,m,σ)→(ID / ⊥), and uses the group owner's private key gmsk, the message m and the signature σ as the input of the Open algorithm. If the output is ⊥, the user is an illegal user; if the user is a member of the group, the real identity information of the member is output.

[0132] Step S90: Deregister illegal users: The trusted authorization agency establishes a revocation tree on the blockchain. When there are illegal users, the trusted authorization agency deregisters the registration information of the illegal users.

[0133] This step specifically includes: the trusted authority generates the system parameters SP and the master key mk of the revocation tree;

[0134] According to the algorithm BuildTree(SP,mk,t,Acc), the node account information Acc of the tree is output. The master key mk is used to sign the child nodes of the tree, and the timestamp t is used to limit the validity period of the node.

[0135] According to the algorithm Addnode(Acc i ,t i ,sk i ) Output any node node i The child node Acc i And the key sk corresponding to the child node i , if and only if the child node contains the timestamp t i When the timestamp t of the parent node is newer, the child node is valid;

[0136] According to the algorithm Deletenode(Acc i ,t i ′,sk i ) Delete the child node Acc of a node i , generate a new timestamp t′ to update the node node i ,Since the time of the child node is older than that of the parent node, the child node is invalid;

[0137] When the number of vehicles with expired identities meets the preset conditions, the Deletenode(Acc i ,t i ′,sk i ) algorithm updates the node t′ and cancels the account information Acc of the illegal user i .

[0138] In another embodiment of the present invention, it also includes:

[0139] Step S100: Generate a blacklist: The trusted authority in each domain generates and maintains a blacklist based on the identified illegal users, and updates the users whose identities have expired in combination with the blacklist when the identities are updated.

[0140] In this embodiment, each domain needs to jointly maintain a blacklist, which is counted by the trusted authorization agency of each domain and collected and reported by the roadside unit. The information of malicious users tracked by the system will be uploaded to the list. Before a new user is updated, the list will be queried to ensure system security.

[0141] A cross-domain authentication system in a vehicle-mounted ad hoc network according to an embodiment of the present invention includes a key generation center, a trusted authorization agency in at least one domain corresponding to each area, and a number of roadside units and vehicles in each area. The vehicle is provided with an on-board unit for communicating with other vehicles and roadside units; the cross-domain authentication system is used to implement the above method embodiment, and the specific process will not be repeated here.

[0142] The cross-domain authentication method and system under the vehicle-mounted ad hoc network of the present invention are implemented based on the cross-domain authentication system under the vehicle-mounted ad hoc network. The cross-domain authentication system includes a key generation center, a trusted authorization agency in at least one domain corresponding to each area, and a plurality of roadside units and vehicles in each area; the method includes the steps of system initialization, vehicle initialization, roadside unit initialization, construction of threshold group signature, identity update, intra-domain identity authentication, inter-domain identity authentication, identification of illegal users, cancellation of illegal users, etc. The present invention provides a cross-domain authentication method, which uses intra-domain private chains and inter-domain alliance chains to deploy blockchain networks, eliminates the incomplete trust problem between domains in the cross-domain authentication process, and ensures the trust barrier of cross-domain users. In addition, non-interactive zero-knowledge proof is used to authenticate the identity of vehicle users, and the user identity is authenticated without leaking the user's privacy. The revocation mechanism based on the tree structure can realize the identity revocation of some malicious users with destructive behavior and expired users in the domain, reduce system storage redundant storage, and perform real-time monitoring when a new user submits an authentication request or a vehicle performs cross-domain authentication to detect whether it is a malicious user, thereby ensuring the long-term, safe and stable operation of the blockchain network.

[0143] The present invention is further described above with the aid of specific embodiments. However, it should be understood that the specific description here should not be construed as limiting the essence and scope of the present invention. Various modifications made to the above embodiments by ordinary technicians in the field after reading this specification are all within the scope of protection of the present invention.

Claims

1. A cross-domain authentication method in a vehicle-mounted ad hoc network, characterized in that: The method is implemented based on a cross-domain authentication system under a vehicle-mounted ad hoc network, and the cross-domain authentication system includes a key generation center, a trusted authorization agency in at least one domain corresponding to each area, and a number of roadside units and vehicles in each area; The method comprises the following steps: System initialization: the trusted authority generates system parameters within the domain; Vehicle initialization: the trusted authorization agency generates a pseudo-identity of the vehicle according to the system parameters in the domain and sends it to the vehicle through a secure channel. The vehicle verifies the pseudo-identity, obtains the corresponding public key and private key, and stores them; Roadside unit initialization: the trusted authority generates a key message for the roadside unit according to the system parameters in the domain and sends it to the corresponding roadside unit through a secure channel. The roadside unit verifies the key message, obtains the key corresponding to it and stores it; Constructing a threshold group signature: constructing a threshold group, the threshold group consisting of a number of vehicles and roadside units as members; any vehicle in the threshold group generates a signature of a traffic message and broadcasts it, and the roadside unit or other vehicles receive the signature message and verify whether the signature is legal; Identity update: Before performing intra-domain identity authentication, the trusted authorization agency updates the user whose identity has expired by calling the update algorithm; Intra-domain identity authentication: The trusted authorization agency in the domain authenticates the vehicle's identity. After successful identity authentication, the vehicle establishes a communication connection with other vehicles in the domain; Inter-domain identity authentication: A vehicle in the first domain initiates an inter-domain connection request, which is forwarded by a trusted authority in the first domain and authenticated by a trusted authority in the second domain. If the authentication is successful, the vehicle in the first domain establishes a communication connection with the vehicle in the second domain. Identify illegal users: The trusted authorization agency authenticates the users in the domain and identifies illegal users; Deregistering illegal users: The trusted authorization agency establishes a revocation tree on the blockchain. When there are illegal users, the trusted authorization agency deregisters the registration information of the illegal users.

2. A cross-domain authentication method in a vehicle ad hoc network as claimed in claim 1, characterized in that: System initialization includes: Let F P represents a finite field of order p, over which the trusted authority constructs an elliptic curve E; Choose a generator P from E, a cyclic group G of order large prime number q; The trusted authority randomly selects As the private key SK GA , the public key is obtained by calculation is a finite field; Defining a secure hash function The common system parameters are {G,q,P,P pub ,H0,H1,H2},P pub is the system public key; The vehicle initialization includes: The vehicle generates a random number Calculate K i =k i P, then sends a registration request {Register||ID i ,K i ,t i }, where ID i Vehicle i The real identity information, t i Indicates the current timestamp of the registration request; The trusted authority selects a random number Calculating pseudonyms R i =r i P,h0=H0(PID i ,K i ,R i ),as well as s n It is the system private key; Generate identity certificate cert i =(Acc i ||ID i ||PID i ||gpk||t i ||T i ); Acc i is a blockchain account, gpk is a vehicle i The group public key of the domain, T i It is cert i Validity period; Generate a pseudo-identity message {Response||cert i ||y i ||R i } and sent to the vehicle through a secure channel i ; The vehicle i By calculating y i P=R i +H0(PID i ,K i ,R i ) pub , verify the pseudo identity; if the verification is successful, then (cert i ,K i ,k i ,R i ,y i ) is stored on the blockchain within the domain, and the public key and private key of the vehicle are vpk i =K i , vsk i =k i ; The roadside unit initialization includes: The roadside unit generates a random number Calculate K j =k j P, and get the current time T j ∈{0,1} * , the message {Register||ID j ,K j ,T j } is sent to the trusted authority; wherein, ID j is the identity information of the roadside unit; After receiving the message, the trusted authority generates a random number Calculate R j =r j P, h1 = H1 (ID j ,K j )as well as Generate key message {Response||gpk,R j ,y j ,T j }, and sent to the roadside unit via a secure channel; The roadside unit is calculated by Verify the key message; if the verification is successful, {k j ,K j ,r j ,R j } is stored on the blockchain within the domain; the public key and private key of the roadside unit are vpk j =K j , vsk j =k j .

3. A cross-domain authentication method in a vehicle ad hoc network as claimed in claim 2, characterized in that: The construction threshold group includes: A threshold group signature scheme of (t,n) is used, where t is the threshold value and the threshold group is a set of n members, represented by M = {m1,m2,…,m t }(t≤n); The members of the threshold group include at least: group administrator GA, group member m i , signature verifier GV, θ is the traffic message that needs to be signed; The group administrator GA randomly selects a secret value And calculate pk i =κ i P, where κ i =sk i ; Then secretly select a t-1 degree polynomial Among them, a iz ∈[1,p-1](z=0,1,…,t-1); Calculate the group private key of the threshold group as sk gi =f i (0) = a i0 , calculate the group public key of the threshold group as pk gi =f i (0)P=a i0 P; Group Members i Randomly choose a secret value Calculate pk i =v i P, and generate a temporary pseudonym ζ i ; Any of the vehicles in the threshold group generates a signature of a traffic message and broadcasts it, including: Group Members i Through the private key sk i Sign traffic messages i =sk i I i +h i (θ)ν i mod p, where h i (θ) is the hash value of the traffic message; Group Members i Broadcasting the signature of the traffic message; The roadside unit or other vehicle receives the signed message and verifies whether the signature is legitimate, including: Single message authentication: via public user pseudonym PID i Computation I i And the hash value h of the traffic message i (θ), and by calculating ν i h i (θ) = s i P-pk i I i To verify whether the signature is legitimate; And / or, batch message verification: When the group administrator GA receives N different signed messages, it calculates and verification message The threshold signature (S, V) and the verification message Y are broadcast to the signature verifier GV in the group. When N ≥ t, SP is calculated to verify whether the signature is legal; where:

4. A cross-domain authentication method in a vehicle ad hoc network as claimed in claim 3, characterized in that: Identity updates include: Vehicle inspection identity certificate cert i Whether it is expired, if it is expired, submitting an update request {IDUpData} to the trusted authority through the roadside unit; The trusted authorization agency calls the update algorithm to complete the identity update of the vehicle; The roadside unit submits the user's blockchain account Acc to the trusted authority i , group public key gpk and T i Perform identity updates; The trusted authority verifies the validity of the signature through gpk. If it is valid, Time = T i new ; Output T i new , gpk updates user identity information.

5. A cross-domain authentication method in a vehicle ad hoc network as claimed in claim 4, characterized in that: The intra-domain identity authentication includes: The vehicle will send the identity certificate i Send to the current roadside unit through a secure channel; After receiving the T i If valid, the consistency of the group public key gpk is verified. If they are the same, the authentication is successful. The first vehicle is established to communicate with another second vehicle in the domain, the process comprising: The first vehicle uses the private key vsk i Sign the request message And send a request to establish communication to the second vehicle through the secure channel {request||σ i }; After the second vehicle receives the identity certificate, j Extract the group public key gpk from the , and verify the signature. If the verification is successful, it proves that the two belong to the same domain; The second vehicle uses the private key vsk j Sign the response message And send a response to the communication request {response||σ j }; After the first vehicle is received, the identity certificate cert i Extract the group public key gpk pair σ j Verification is performed, and if the verification is successful, the first vehicle and the second vehicle establish a communication connection.

6. A cross-domain authentication method in a vehicle ad hoc network as claimed in claim 5, characterized in that: The inter-domain identity authentication includes: The first vehicle in the first domain calculates l=g H(ID) , choose a random number Calculate w = g rID ,C=H(l,w),u=r ID - C·l, forwarding the connection request π=(l, C, u) from the trusted authority in the first domain to the trusted authority in the second domain through a secure channel; After receiving the connection request, the trusted authority in the second domain calculates w′=g u ·g C·l , w′=g u ·g C·l , calculate C′=H(l,w′), and verify whether the equation C′=C holds. If so, the identity verification is successful; If a first vehicle in the first domain wants to establish a communication connection with a second vehicle in the second domain, the first vehicle initiates a transaction tr={Acc i ,Acc j ,Re,coin i }, where Acc i For the payer, Acc j is the payee, Re is the transaction information, coin i The transaction amount; if the inter-domain blockchain verifies and reaches a consensus, the transaction is written into a new block and the transaction identifier is returned to the payer Acc i ; Payee Acc j After receiving the transfer, contact the payer Acc i Communicate as needed, otherwise, terminate the communication.

7. A cross-domain authentication method in a vehicle ad hoc network as claimed in claim 6, characterized in that: The identification of illegal users includes: The trusted authorization agency executes the Open algorithm Open(gmsk,m,σ)→(ID / ⊥), and takes the group owner's private key gmsk, the message m and the signature σ as the input of the Open algorithm. If the output is ⊥, the user is an illegal user; if the user is a member of the group, the real identity information of the member is output.

8. A cross-domain authentication method in a vehicle ad hoc network as claimed in claim 7, characterized in that: The cancellation of illegal users includes: The trusted authority generates a system parameter SP and a master key mk of a revocation tree; According to the algorithm BuildTree(SP,mk,t,Acc), the node account information Acc of the tree is output. The master key mk is used to sign the child nodes of the tree, and the timestamp t is used to limit the validity period of the node. According to the algorithm Addnode(Acc i ,t i ,sk i ) Output any node node i The child node Acc i And the key sk corresponding to the child node i , if and only if the child node contains the timestamp t i When the timestamp t of the parent node is newer, the child node is valid; According to the algorithm Deletenode(Ac i c, i ′t,s i k) Delete the child node Acc of a node i , generate a new timestamp t′ to update the node node i ,Since the time of the child node is older than that of the parent node, the child node is invalid; When the number of vehicles with expired identities meets the preset conditions, the Deletenode(Acc i ,t i ′,sk i ) algorithm updates the node t′ and cancels the account information Acc of the illegal user i .

9. A cross-domain authentication method in a vehicle ad hoc network as claimed in claim 8, characterized in that: The method also includes: Generate a blacklist: The trusted authority in each domain generates and maintains a blacklist based on the identified illegal users, and updates the users whose identities have expired in combination with the blacklist when the identities are updated.

10. A cross-domain authentication system in a vehicle-mounted ad hoc network, characterized in that: The cross-domain authentication system includes a key generation center, a trusted authorization agency in at least one domain corresponding to each area, and a number of roadside units and vehicles in each area. The vehicle is provided with an on-board unit for communicating with other vehicles and roadside units; the cross-domain authentication system is used to implement the method described in any one of claims 1 to 9.

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