A blockchain-based vehicle ad hoc network anonymous trust management method

Abstract

The application provides a blockchain-based vehicle network anonymous trust management method, which comprises the following steps: initializing a vehicle network anonymous trust management system, determining system public parameters, generating distributed identities by all entities in the system, and publishing the distributed identities to a blockchain; a vehicle registers at an RA to obtain an initial reputation verifiable certificate, and obtains a corresponding attribute private key from an AA; the vehicle generates a secure event message by using an attribute signature algorithm and broadcasts the secure event message; an RSU verifies the event message and publishes the event message to the blockchain, and meanwhile, updates a vehicle reputation level, and the vehicle obtains a new attribute private key from the AA; the RA tracks malicious vehicles with a reputation level lower than a threshold; the application designs a distributed identity model based on the blockchain in the vehicle network, and realizes non-centralized and conditional privacy protection of vehicle dynamic trust management in combination with attribute signature, and has high security and practicability.

Description

Technical Field

[0001] This invention relates to the technical fields of vehicle network trust management and vehicle privacy protection, specifically to a blockchain-based anonymous trust management method for vehicle networks. Background Technology

[0002] In recent years, with the rapid development of communication and computer technologies, in-vehicle intelligent communication devices have become increasingly powerful, enabling communication between vehicles and with roadside entities. Vehicular ad hoc networks (VANETs) are a type of network composed of numerous neighboring vehicles and roadside units (RSUs). Their purpose is to improve road safety through communication between vehicles and between vehicles and infrastructure, facilitating collaborative road warnings. Applications in VANETs are mainly divided into two categories: non-safety applications and safe applications. Non-safety applications are primarily used for user entertainment, while safe applications are mainly responsible for disseminating road condition information, such as road warnings. For safe applications in VANETs, ​​ensuring the authenticity and reliability of messages is paramount. Although common encryption methods can ensure message security during transmission, the trustworthiness of the message itself cannot be guaranteed. If malicious vehicles in a VANET intentionally spread false information, it would pose a significant threat to traffic safety. In VANETs, ​​to ensure the trustworthiness of information during vehicle communication, trust is typically established between vehicles. This trust is based on direct evaluation of historical interactions and indirect recommendations of information. Existing research proposes introducing trust management mechanisms in vehicular networks to ensure message authenticity. While trust management mechanisms can improve driving efficiency and safety, they also present problems such as over-centralization and vehicle privacy breaches. Overly centralized trust management is vulnerable to attacks and data tampering; for example, internal personnel could privately alter data, or a concentrated attack by hackers could render the service unavailable. Furthermore, the vehicle trust management process often exposes vehicle privacy to some extent, such as vehicle identity or location information, posing a risk of privacy breaches.

[0003] A search revealed the application publication number CN201910554509.3, entitled "A Blockchain-Based Trust Model for Vehicle Network Privacy Protection." This invention uses ring signature technology to enable vehicles to send messages anonymously, preventing them from being tracked by malicious vehicles. It evaluates and filters the messages sent by vehicles through a reputation evaluation mechanism based on blockchain technology, filtering out forged information. Based on the inherent characteristics of blockchain, it ensures that the vehicle's reputation will not be maliciously tampered with and achieves real-time synchronous updates of the vehicle's reputation, further improving the security and ease of use of the vehicle ad hoc network.

[0004] Unlike the inventions mentioned above, this invention designs a blockchain-based distributed identifier model to achieve self-sovereign identity management. Vehicles can generate their own private DID and corresponding public-private key pairs as anonymous and verifiable identities, while the public-private key pairs and pseudonyms of vehicle users in the inventions mentioned above are issued by an authoritative center. Therefore, the vehicle identity in this invention has greater flexibility and security. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention combines the long-term reputation level attribute of a vehicle with attribute signature technology based on the distributed identifier model of blockchain. By designing attribute signatures, verifiable certificates (VCs) are used as the reputation certificate of the vehicle. The reputation level of the vehicle is not directly bound to the identity identifier, realizing decentralized dynamic trust management without exposing the true identity of the vehicle. This provides greater flexibility and provides the additional vehicle recent participation time attribute to participate in the message credibility calculation.

[0006] A blockchain-based anonymous trust management method for vehicular networks includes: constructing a blockchain-based anonymous trust management system for vehicular networks, comprising a regulatory body (RA), an attribute authority (AA), a roadside unit (RSU), vehicles, and a blockchain-based self-sovereign identity management model; and the process of anonymously trusting vehicles through the blockchain-based anonymous trust management system includes:

[0007] S1: Initialize the blockchain-based vehicle network anonymous trust management system, determine the system's public parameters, and generate distributed identities for regulatory agencies (RA), attribute authorities (AA), roadside units (RSU), and vehicles in each region and publish them to the blockchain;

[0008] S2: The vehicle registers with the RA to obtain an initial reputation verifiable credential and obtains the corresponding attribute private key from the AA. The corresponding attributes include the initial reputation level, timestamp, and serial number.

[0009] S3: The vehicle generates a security event message using an attribute signature algorithm and broadcasts it.

[0010] S4: RSU verifies the event message and publishes it to the blockchain, while updating the vehicle's reputation rating. The vehicle obtains a new attribute private key from AA.

[0011] S5:RA tracks malicious vehicles with a reputation rating below a threshold.

[0012] Preferably, the initialization of a blockchain-based anonymous trust management system for vehicular networks, determining system public parameters, and the process by which regulatory agencies (RA), attribute authorities (AA), roadside units (RSU), and vehicles in each region generate distributed identities and publish them to the blockchain includes:

[0013] S11: Regulatory Authority (RA) generates public identity identifier Did RA And obtain a public-private key pair (PK). RA SK RA ), PK the public key information RA and using SK RA Signature to identity identifier Did RA Digital signatures are placed in the DID document Doc RA It is then published to the blockchain to generate a public identity identifier (Did) for the Attribute Authority (AA) and Roadside Unit (RSU) of the area under its jurisdiction. AA,i and Did RSU,i The system contains multiple independent regulatory agencies, and different regions are managed by different independent regulatory agencies (RAs).

[0014] S12: The attribute authority AA inputs the security parameter λ into the system, defines a multiplicative cyclic group G of prime order p, the generator g of group G, and the bilinear mapping e: G1×G1→G2; and obtains the system's public parameter Params and master key Msk through the attribute signature initialization algorithm.

[0015] S13: Attribute Authority AA generates a public-private key pair (PK). AA SK AA ), PK the public key information AA The public parameters (Params) and digital signature are placed in the AA's DID document Doc. AA In, and put the DID document Doc AA Published to the blockchain;

[0016] S14: The Roadside Unit (RSU) generates a public-private key pair (PK). RSU SK RSU ), and PK the public key information AA And digital signatures are placed in the DID document Doc RSU And publish it to the blockchain;

[0017] S15: Vehicle users generate n identity identifiers {Did v,1 Did v,2 ,...,Did v,n} and a corresponding public-private key pair (PK) v,i SK v,i ), i∈n, use the public key PK v,i The digital signature of the DID document content is placed in the corresponding DID document Doc. i It is then published to the blockchain.

[0018] Preferably, the process of a vehicle registering with the RA to obtain an initial reputation-verifiable credential and obtaining the corresponding attribute private key from the AA includes:

[0019] S21: Vehicle owners submit a DID document set (DIDSet) to the regulatory agency RA. v Registering with its real identity (Tid) and verifying the vehicle's DID document set (DIDSet) using RA. v Digital signatures in;

[0020] S22: If verification is successful, the regulatory agency RA generates an initial verifiable credential IniVC and issues it to the vehicle user, along with the vehicle's true identity Tid and vehicle identification {Did}. v,1 Did v,2 ,...,Did v,n The mapping relationship is placed in the identity mapping table. Tid If verification fails, registration will fail.

[0021] S23: The vehicle user presents the Initial Credible Verifiable Certificate (IniVC) to the Attribute Authority (AA) to apply for the Attribute Private Key;

[0022] S24: Attribute Authority (AA) verifies the initial reputation verifiable credential IniVC. If verification is successful, AA generates a serial number sn for the vehicle and obtains the vehicle's attribute Attr based on the initial reputation verifiable credential IniVC. v = {level, time, sn}, where level is the vehicle's reputation level and time is the timestamp of the vehicle's most recent involvement in a road event;

[0023] S25: Attribute Authority AA based on vehicle attribute Attr v The corresponding attribute private key SK is generated through the attribute signature algorithm. attr and the attribute private key SK attr Securely sent to the vehicle user.

[0024] Preferably, the process by which the vehicle generates and broadcasts a security event message using an attribute signature algorithm includes:

[0025] S31: Vehicle users generate a reputation-verifiable credential (RLVC) using an attribute signature algorithm. The formula for generating the RLVC is as follows:

[0026] CreateRLVC("RL",Did v,i ,issDate RL ,expDate RL ,Info Attr SK attr →RLVC

[0027] Here, CreateRLVC represents the method for generating reputation-verifiable credentials, "RL" indicates that the credential type is a reputation credential, and Did... v,iIssDate indicates the vehicle's identification. RL expDate indicates the creation time. RL Indicates the expiration time, Info Attr SK represents the set of attributes and attribute signature strategy for vehicle users. attr The private key representing the vehicle's attributes;

[0028] S32: Vehicle Owner Replacement Identification Did v,j Participating in road event activities, a verifiable safety message (TrafVP) is generated based on traffic information (TrafMess) and the reputation-verifiable credential (RLVC). The formula for generating a TrafVP is:

[0029] CreateTrafVP("Traf",Did v,j ,issDate Traf TrafMess, RLVC, SK v,j →TrafVP

[0030] Here, CreateTrafVP represents the method for generating verifiable safety messages, "Traf" indicates that the safety message type is a road event message, and Did... v,j IssDate indicates the vehicle's identification. Traf Indicates creation time, SK v,j This represents the vehicle's private key;

[0031] S33: Vehicle users broadcast TrafVP to roadside units (RSUs) and nearby vehicles.

[0032] Preferably, the RSU verifies the event message and publishes it to the blockchain, while simultaneously updating the vehicle's reputation rating. The process of the vehicle obtaining a new attribute private key from the AA includes:

[0033] S41: The digital signature in the Roadside Unit (RSU) verification security message TraVP and the attribute signature in the reputation-verifiable credential RLVC;

[0034] S42: If the verification passes, the Roadside Unit (RSU) calculates the credibility of the message based on the vehicle's reputation rating attribute, the most recent participation timestamp attribute, and the content of the road event published by the vehicle in the Reputable Verifiable Credential (RLVC), and publishes the event message to the blockchain. If the verification fails, the message is discarded.

[0035] S43: The Roadside Unit (RSU) updates the vehicle's reputation level and activity timestamp based on the reliability of road messages. If the vehicle's message is reliable, the reputation level is increased by one level; if the message is unreliable, it is decreased by one level. A Reputation Update Verifiable Certificate (UpdVC) is generated and issued to the vehicle user. The formula for generating UpdVC is:

[0036] CreateUpdVC("Upd",Did RSU Did v,j ,issDate Upd ,expDate Upd A new SK RSU )

[0037] →UpdVC

[0038] Here, CreateUpdVC represents the method for generating reputation update verifiable credentials, "Upd" indicates that the type of verifiable credential is reputation update, and Did... RSU The ID representing the creator RSU, Did v,j IssDate indicates the vehicle's identity. Upd expDate indicates the creation time. Upd Indicates the expiration date, A new ={level new ,time new} indicates the vehicle's new reputation level attribute. new and the activity timestamp attribute time new ;

[0039] S44: The vehicle user presents the Reputation Update Verifiable Certificate UpdVC to the Attribute Authority AA to apply for a new attribute private key. The Attribute Authority AA verifies the Reputation Update Verifiable Certificate UpdVC.

[0040] S45: If verification is successful, publish the vehicle serial number sn to the blockchain to revoke the vehicle's attribute private key and generate a new serial number sn for the vehicle. new Based on the reputation update verifiable credential UpdVC, the new set of vehicle attributes {level} is obtained. new ,time new ,sn new} and generate a new attribute private key SK by attribute signing. new The application is issued to the vehicle user; if verification fails, the application is invalid.

[0041] Preferably, the process by which the regulatory agency (RA) tracks malicious vehicles with a reputation rating below a threshold includes: if the RA discovers that a vehicle user's reputation rating is below a threshold T, it marks the vehicle user as a malicious vehicle and looks up the identity mapping table Table based on the vehicle user's identity identifier. Tid The vehicle's true identity (Tid) will be made public to prevent malicious vehicle users from participating in road activities.

[0042] The beneficial effects of this invention are:

[0043] This invention designs a blockchain-based self-sovereign identity model for in-vehicle networks. Based on the needs of vehicle trust management, it uses blockchain technology combined with DIDs (Distributed Identity Registries) specifications to design self-sovereign identities for entities in the system, realizing self-sovereign identities for entities in vehicle trust management. Vehicles can autonomously generate private DIDs as anonymous verifiable identities to protect privacy. Based on the self-sovereign identity model, this invention designs attribute-signature-based verifiable certificates (VCs) as vehicle reputation certificates, achieving decentralized dynamic trust management without exposing the vehicle's true identity. Attached Figure Description

[0044] Figure 1 This is a system model diagram of the present invention;

[0045] Figure 2 This is a flowchart of the blockchain-based anonymous trust management method for in-vehicle networks according to the present invention. Detailed Implementation

[0046] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] A blockchain-based anonymous trust management method for vehicular networks includes: a blockchain-based anonymous trust management system for vehicular networks, which includes a regulatory body (RA), an attribute authority (AA), a roadside unit (RSU), vehicles, and a blockchain-based self-sovereign identity management model.

[0048] like Figure 1 As shown, there are four entities in this invention, including regulatory agency RA, attribute authority AA, roadside unit RSU, and vehicle.

[0049] The regulatory body, RA, is a trusted authority that assigns publicly known attributes to Attribute Authority (AA) and Roadside Unit (RSU) for authentication and is responsible for vehicle registration and tracking of malicious vehicles. Different geographic areas are managed by different RAs, but these RAs do not participate in the vehicle reputation management process.

[0050] The Attribute Authority (AA) is responsible for initializing attribute signatures, publishing public parameters for attribute signatures, and issuing private keys for the corresponding reputation level attributes to vehicles. There are multiple AAs in the system, and they are independent of each other.

[0051] Roadside Units (RSUs) are trusted infrastructure located beside roads that directly participate in vehicle reputation management. They are responsible for collecting vehicle reputation management-related messages, evaluating messages to determine vehicle reputation update parameters, issuing verifiable credentials (VCs) for vehicle reputation updates, participating in consensus within the blockchain, and maintaining the operation of the blockchain system.

[0052] Vehicles autonomously create their own identity identifier (DID) and continuously update their credit rating by participating in vehicle-to-everything (V2X) credit management activities.

[0053] A blockchain-based anonymous trust management method for in-vehicle networks, such as... Figure 2 As shown, it includes:

[0054] S1: Initialize the blockchain-based vehicle network anonymous trust management system, determine the system's public parameters, and generate distributed identities for regulatory agencies (RA), attribute authorities (AA), roadside units (RSU), and vehicles in each region and publish them to the blockchain;

[0055] S2: The vehicle registers with the RA to obtain an initial reputation verifiable credential and obtains the corresponding attribute (initial reputation level, timestamp, serial number) private key from the AA;

[0056] S3: The vehicle generates a security event message using an attribute signature algorithm and broadcasts it.

[0057] S4: RSU verifies the event message and publishes it to the blockchain, while updating the vehicle's reputation rating. The vehicle obtains a new attribute private key from AA.

[0058] S5:RA tracks malicious vehicles with a reputation rating below a threshold.

[0059] The process of initializing a blockchain-based anonymous trust management system for vehicular networks, determining system public parameters, and generating distributed identities for regulatory agencies (RA), attribute authorities (AA), roadside units (RSU), and vehicles in each region and publishing them to the blockchain includes:

[0060] S11: Regulatory Authority (RA) generates public identity identifier Did RA Obtain a public-private key pair (PK). RA SK RA ), and its DID document Doc RA On-chain, Doc RA ={Did RA PK RA Subject, σ RA}, where Did RA PK represents the identity identifier of RA. RA σ represents the public key, Subject represents the public information, and σ represents the public key. RAThis indicates that the DID document content is digitally signed using the RSA algorithm, and a public identity identifier (DID) is generated for each attribute authority (AA) and roadside unit (RSU) within the area. AA,i and Did RSU,i ;

[0061] S12: Attribute authority AA inputs security parameter λ, defines the global attribute set U for attribute element u∈Zp, and d-1 default attribute sets. Define a multiplicative cyclic group G1 of prime order p, a generator g of group G1, a bilinear mapping e: G1 × G1 → G2, and two hash functions H1: {0, 1}. * →G1,H2:{0,1} * →G1, select a random number Calculate g1 = g s Select random element g2∈G1, calculate Z=e(g1,g2), and obtain the public parameter Params=(g,g1,g2,Z,d,H1,H2) and the master key Msk=s;

[0062] S13: Attribute Authority AA's Identity Identifier Did AA Issued by RA, the attribute authority AA generates a public-private key pair (PK). AA SK AA Add the common parameter Params to the AA's DID document Doc. AA In the middle, Doc AA ={Did AA Did RA PK AA Params, σ AA}, where Did AA Indicates AA's identity identifier, Did RA Indicates Did AA The actual controller is Did RA PK AA This represents the public key, Params represents the public parameters, and σ represents the public key. AA This indicates that the DID document content is digitally signed using the RSA algorithm, and the DID document Doc... AA Published to the blockchain;

[0063] S14: Identification of Roadside Unit (RSU) Did RSU Issued by the regulatory body RA, the roadside unit (RSU) generates a public-private key pair (PK). RSU SK RSU ), and the DID document Doc RSU Published to the blockchain, Doc RSU ={Did RSU DidRA PK RSU PubInfo,σ RSU}, where Did RSU Indicates the identity of the RSU, Did RA Indicates Did RSU The actual controller is Did RA PK RSU This represents the public key, PubInfo represents public information, and σ represents the public key. RSU This indicates that the DID document content has been digitally signed using the RSA algorithm;

[0064] S15: Vehicle users generate n identity identifiers {Did v,1 Did v,2 ,...,Did v,n}, obtain a corresponding public-private key pair (PK) v,i SK v,i ), i∈n, use the public key PK v,i The digital signature of the DID document content is placed in the corresponding DID document Doc. v,i Doc is published to the blockchain. v,i ={Did v,i PK v,i ,VPub,σ v,i}, where Did v,i PK is an identifier representing a vehicle user. v,i This represents the public key, VPub represents the vehicle's public information, and σ... v,i This represents a digital signature of the DID document content.

[0065] The process of a vehicle registering with the RA to obtain an initial verifiable reputation credential and obtaining the corresponding attribute (initial reputation level, timestamp, serial number) private key from the AA includes:

[0066] S21: Vehicle users submit a collection of DID documents to the regulatory agency RA. v,i}, i∈n, and its real identity Tid are registered, and RA verifies the digital signature of the vehicle DID document;

[0067] S23: If verification fails, registration fails; if verification succeeds, the regulatory agency RA issues the Initial Credential Verifiable Certificate (IniVC) to the vehicle user and places the mapping relationship between the vehicle's true identity tid and the vehicle's identity identifier into the identity mapping table Table. Tid The formula for generating the initial reputation-verifiable credential IniVC is:

[0068] CreateIniVC("Initial",Did RA Didv,1 ,issDate Ini ,expDate Ini IniInfo, SK RA →IniVC

[0069] Where CreateIniVC represents the method for generating initial reputation-verifiable credentials, IniVC =

[0070] {"Initial",Did RA Did v,1 ,issDate Ini ,expDate Ini IniInfo,σ Ini}, "Initial" indicates that the type of verifiable credentials is the initial reputation type, Did RA The identity identifier of the creator's regulatory body, RA, Did v,1 IssDate indicates the vehicle's identification. Ini expDate indicates the creation time. Ini IniInfo = {level, time} represents the vehicle user's credit rating (level) and the timestamp of their most recent road activity (time). σ indicates the expiration time. Ini This indicates the use of the RSA algorithm to digitally sign an initially trustworthy and verifiable credential.

[0071] S24: The vehicle user applies for the attribute private key from the attribute authority AA based on the initial reputation verifiable credential IniVC;

[0072] S25: The Attribute Authority (AA) verifies the digital signature in the Initial Trustworthy Verifiable Certificate (IniVC) using the RSA verification algorithm and determines whether the issuer in RegVC1 is the regulatory body (Did). RA Is the owner the vehicle user? v,1 Is the IniVC issued by a regulatory body? RA Is the owner the vehicle user? v,1 The expiration time is greater than or equal to the current time (CurrentTime), as shown in the following formula:

[0073]

[0074] If all the above verifications and judgments are satisfied and pass, the verification is successful. AA generates a serial number sn for the vehicle and obtains the vehicle's attribute Attr based on the initial reputation verifiable credential IniVC. v= {level, time, sn}, where level represents the vehicle's reputation level, time represents the timestamp of the vehicle's most recent participation in a road event, and sn represents a unique serial number;

[0075] S26: Attribute Authority AA is based on the vehicle's attribute Attr. v Generate the attribute private key SK using the attribute signature algorithm. attr Randomly select a d-1 order polynomial q(x) = a0 + a1x + a2x 2 +...+a d-1 x d-1 Let q(0) = s, and generate a new attribute set A' = Attr v ∪Ω, for each attribute i∈A', randomly select a random number r i ∈Zp, and calculate and Finally, output the private key SK. attr =(d i0 ,d i1 ),i∈A', and the attribute private key SK attr Securely sent to the vehicle user.

[0076] The process by which a vehicle generates and broadcasts a security event message using an attribute signature algorithm includes:

[0077] S31: Vehicle user changes identity identifier, using identity identifier Did v,2 The Reliable Verifiable Credential (RLVC) is generated using an attribute signature algorithm. The expression for generating the RLVC is:

[0078] CreateRLVC("RL",Did v,2 ,issDate RL ,expDate RL ,Info Attr SK attr →RLVC

[0079] Wherein, "RL" indicates that the type of voucher is a credit voucher, Did v,2 IssDate represents the identity identifier of the creator's vehicle. RL expDate indicates the creation time. RL Indicates the expiration time, Info Attr =(Attr v |Γ v ) represents the set of attributes of a vehicle. v and attribute signature access strategy Γ v =(level∩time∩sn),RLVC=

[0080] {Attr v |Γ v Did v,2 ,issDate RL ,expDate RL ,σ attr} represents a reputation-verifiable credential. CreateRLVC represents the method for generating a reputation-verifiable credential, including processing the credential content M. RLVC =

[0081] {Attr v Did v,2 ,issDate RL ,expDate RL The attribute signature of}, the vehicle user inputs the attribute private key SK attr Attr signature attribute set v and signature strategy Γ v Threshold value k = 3, from attribute set Attr v Selecting k attributes from the data yields the attribute set. Due to |Attr v |=k, therefore A k =Attr v Select a subset of size dk from the default attribute set Ω. Select d random numbers r′ i ∈Zp, i∈A k ∪Ω', select a random number r∈Zp, calculate σ0; finally output the attribute-based signature σ. attr =(σ0,{σ i},σ′0),i∈A k ∪Ω', and the signature of the attribute σ attr Place it into the verifiable credential RLVC; the expression for calculating σ0 is:

[0082]

[0083]

[0084] σ′0=g r

[0085] S32: The vehicle user generates a verifiable security message TrafVP based on the traffic information TrafMess and the reputation verifiable credential RLVC. The expression for generating the verifiable security message TrafVP is:

[0086] CreateTrafVP("Traf",Did v,2 ,issDate TrafTrafMess, RLVC, SK v,2 →TrafVP

[0087] Where CreateTrafVP represents the method for generating verifiable security messages, TrafVP = {"Traf", Did} v,2 ,issDate Traf ,TrafMess,RLVC,σ Traf}, "Traf" indicates that it is a road event message type, Did v,2 IssDate is a vehicle identification number. Traf Indicates the publication time, TrafMess indicates a road event message, σ Traf This indicates the use of the RSA algorithm to create a digital signature for a verifiable secure message;

[0088] S33: Vehicle users broadcast TrafVP to roadside units (RSUs) and nearby vehicles.

[0089] The RSU verifies the event message and publishes it to the blockchain, while simultaneously updating the vehicle's reputation rating. The process of the vehicle obtaining a new attribute private key from the AA includes:

[0090] S41: The Roadside Unit (RSU) verifies the digital signature in the security message TraVP and verifies the attribute-based signature σ in the reputation-verifiable credential RLVC. attr According to the content of the verifiable credential M RLVC The set of attributes possessed by a vehicle (Attr) v , public parameters Params and attribute-based signature σ attr Calculate the following equations.

[0091]

[0092] If the equation holds true, the Trustworthy Verifiable Credentials (RLVC) verification is successful, and it is determined whether the issuer of the TraVP is the vehicle user (Did). v,2 Was the publisher of RLVC the vehicle user Did? v,2 The expiration time of RLVC is greater than or equal to the current time (CurrentTime), as shown in the following formula:

[0093]

[0094] If all the above verifications and judgments are true, the verification passes; otherwise, the verification fails.

[0095] S42: If the verification passes, the Roadside Unit (RSU) calculates the credibility of the message based on the vehicle user's reputation level (level), the most recent participation timestamp attribute (time), and the content of the road event published by the vehicle in the Reputable Verifiable Credentials (RLVC). If the verification fails, the message is discarded.

[0096] S43: The Roadside Unit (RSU) updates the vehicle's reputation level and activity timestamp based on the reliability of road messages. If the vehicle's message is reliable, the reputation level is increased by one level; if the message is unreliable, it is decreased by one level. A Reputation Update Verifiable Certificate (UpdVC) is generated and issued to the vehicle user. The formula for generating UpdVC is:

[0097] CreateUpdVC("Upd",Did RSU Did v,2 ,issDate Upd ,expDate Upd A new SK v,2 )

[0098] →UpdVC

[0099] Where CreateUpdVC represents the method for generating reputation-updating verifiable credentials, UpdVC =

[0100] {"Upd",Did RSU Did v,2 Attr new ,issDate Upd ,expDate Upd ,σ Upd}, "Upd" indicates that the verifiable credential type is a reputation update type, Did RSU Did represents the creator's identity. v,i IssDate indicates the vehicle's identity. Upd expDate indicates the creation time. Upd Indicates the expiration date.

[0101] A new ={level new ,time new} indicates the vehicle's new reputation level. new and participation timestamp time new , σ Upd It is a digital signature of the reputation update verifiable credential UpdVC using the RSA algorithm.

[0102] S44: The vehicle user applies for a new attribute private key from the attribute authority AA based on the reputation update verifiable credential UpdVC. The attribute authority AA verifies the digital signature in the reputation update verifiable credential UpdVC.

[0103] S45: If verification fails, the application is invalid; if verification succeeds, a new serial number sn is generated for the vehicle. new The vehicle's old serial number (sn) is uploaded to the blockchain to revoke the vehicle's original attributes. Based on the reputation update verifiable credential UpdVC, the new set of vehicle attributes ({level) is obtained. new ,time new ,sn new} and generate a new attribute private key SK using the method for generating attribute private keys in the attribute signature algorithm in S3. new Issued to vehicle users.

[0104] The process by which the RA tracks malicious vehicles with reputation ratings below a threshold includes: the regulatory body RA discovers the reputation rating of the vehicle user. v If the vehicle's value is below the threshold T, the vehicle user is marked as a malicious vehicle, and the identity mapping table Table is consulted based on the vehicle user's identity identifier. Tid The vehicle's true identity (Tid) will be made public to prevent malicious vehicle users from participating in road activities.

[0105] The above-described embodiments further illustrate the purpose, technical solution, and advantages of the present invention. It should be understood that the above-described embodiments are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made to the present invention within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A blockchain-based anonymous trust management method for in-vehicle networks, characterized in that, include: A blockchain-based anonymous trust management system for vehicular networks is constructed. This system includes a regulatory body (RA), an attribute authority (AA), a roadside unit (RSU), the vehicle, and a blockchain-based self-sovereign identity management model. The process of anonymous trust management for vehicles through this blockchain-based vehicular network anonymous trust management system includes: S1: Initialize the blockchain-based vehicle network anonymous trust management system, determine the system's public parameters, and generate distributed identities for regulatory agencies (RA), attribute authorities (AA), roadside units (RSU), and vehicles in each region and publish them to the blockchain; S2: The vehicle registers with the RA to obtain an initial verifiable reputation credential and retrieves the corresponding attribute private key from the AA. These attributes include the initial reputation level, timestamp, and serial number; specifically: S21: Vehicle owners submit a collection of DID documents to the regulatory agency RA. And register with its real identity TID, RA verifies the vehicle DID document collection. Digital signatures in; S22: If verification is successful, the regulatory agency RA generates an initial credibility-verifiable credential IniVC and issues it to the vehicle user, thus verifying the vehicle's true identity. and vehicle identification The mapping relationship is put into the identity mapping table. If verification fails, registration will fail. S23: The vehicle user presents the Initial Credible Verifiable Certificate (IniVC) to the Attribute Authority (AA) to apply for the Attribute Private Key; S24: Attribute Authority (AA) verifies the Initial Reputation Verifiable Certificate (IniVC). If verification is successful, AA generates a serial number (sn) for the vehicle and obtains the vehicle's attributes based on the Initial Reputation Verifiable Certificate (IniVC). Where level is the vehicle's reputation level and time is the timestamp of the vehicle's most recent involvement in a road event; S25: Attribute Authority AA based on vehicle attributes Generate the corresponding attribute private key through the attribute signature algorithm. and the attribute private key Securely sent to the vehicle user; S3: The vehicle generates and broadcasts a security event message using an attribute signature algorithm; specifically including: S31: Vehicle users generate a reputation-verifiable credential (RLVC) using an attribute signature algorithm. The formula for generating the RLVC is as follows: ； in, This describes the method for generating trustworthy and verifiable credentials. This indicates that the type of document is a credit document. This indicates the identification of the vehicle being released. Indicates the creation time. Indicates the expiration date. This represents the set of attributes and attribute signature strategy for vehicle users. The private key representing the vehicle's attributes; S32: Vehicle user changes identification Participate in road incident activities, based on road condition information. Verifiable credentials Generate verifiable security messages ,generate The formula is: ； in, This indicates the method for generating verifiable security messages. This indicates that the safety message type is a road event message. This indicates the identification of the vehicle being released. Indicates the creation time. This represents the vehicle's private key; S33: Vehicle users will The broadcast was made to the roadside RSU unit and nearby vehicles; S4: RSU verifies the event message and publishes it to the blockchain, while updating the vehicle's reputation rating. The vehicle obtains a new attribute private key from AA; specifically including: S41: The digital signature in the Roadside Unit (RSU) verification security message TraVP and the attribute signature in the reputation-verifiable credential RLVC; S42: If the verification passes, the Roadside Unit (RSU) calculates the credibility of the message based on the vehicle's reputation rating attribute, the most recent participation timestamp attribute, and the content of the road event published by the vehicle in the Reputable Verifiable Credential (RLVC), and publishes the event message to the blockchain. If the verification fails, the message is discarded. S43: The Roadside Unit (RSU) updates the reputation level and activity timestamp of vehicles based on the credibility of road messages. If the message posted by the vehicle is credible, the reputation level is increased by one level; if the message is unreliable, the reputation level is decreased by one level, and a verifiable credential for reputation update is generated. Issued to vehicle users, generating The formula is: ; in, This describes the method for generating and updating verifiable credibility credentials. This indicates that the type of verifiable credential is a reputation update type. This represents the identity identifier of the creator, RSU. It indicates the vehicle's identity. Indicates the creation time. Indicates the expiration date. This indicates the vehicle's new reputation rating attribute. and activity timestamp attribute ; S44: The vehicle user presents the Reputation Update Verifiable Certificate UpdVC to the Attribute Authority AA to apply for a new attribute private key. The Attribute Authority AA verifies the Reputation Update Verifiable Certificate UpdVC. S45: If verification is successful, publish the vehicle serial number (sn) to the blockchain to revoke the vehicle's attribute private key and generate a new serial number for the vehicle. Based on the reputation update verifiable credential UpdVC, a new set of vehicle attributes is obtained. And generate a new attribute private key through attribute signing. Issued to the vehicle user; if verification fails, the application is invalid. S5:RA tracks malicious vehicles with a reputation rating below a threshold.

2. The blockchain-based anonymous trust management method for vehicle networks according to claim 1, characterized in that, The process of initializing a blockchain-based anonymous trust management system for vehicular networks, determining system public parameters, and generating distributed identities for regulatory agencies (RA), attribute authorities (AA), roadside units (RSU), and vehicles in each region and publishing them to the blockchain includes: S11: Regulatory Authority (RA) generates public identity identifiers. And obtain a public-private key pair ( ), public key information and use Signature as an identifier Digital signatures are placed in the DID document It is then published to the blockchain to generate public identity identifiers for the Attribute Authority (AA) and Roadside Unit (RSU) of the area under its jurisdiction. and The system contains multiple independent regulatory agencies, and different regions are managed by different independent regulatory agencies (RAs). S12: Attribute Authority (AA) inputs security parameters to the system. Define a multiplicative cyclic group G of prime order p, a generator g of group G, and a bilinear mapping. The system's public parameters Params and master key Msk are obtained through the attribute signature initialization algorithm. S13: Attribute Authority AA generates a public-private key pair ( ), pass the public key information The public parameters Params and digital signature are placed in the AA's DID document. In, and the DID document Published to the blockchain; S14: The Roadside Unit (RSU) generates a public-private key pair. ), and public key information And digital signatures are placed in the DID document And publish it to the blockchain; S15: Vehicle users generate n identity identifiers. and a corresponding public / private key pair ∈n, public key The digital signature of the DID document content is placed in the corresponding DID document. It is then published to the blockchain.

3. The blockchain-based anonymous trust management method for vehicle networks according to claim 1, characterized in that, The formula for generating initial reputation-verifiable credentials in IniVC is: ； in, This describes the method for generating initial, verifiable credentials. This indicates that the type of verifiable credentials is the initial reputation type. This represents the identity identifier of the creator, RA. This indicates the vehicle's identification. Indicates the creation time. Indicates the expiration date. Indicates the vehicle's credit rating and the most recent time stamp of participation in road activities , This represents the private key of the regulatory body, RA.

4. The blockchain-based anonymous trust management method for vehicle networks according to claim 1, characterized in that, The process by which the RA tracks malicious vehicles with reputation ratings below a threshold includes: the regulatory body RA discovering the reputation rating of the vehicle user. If the vehicle's value is below the threshold T, the vehicle user is marked as a malicious vehicle, and the identity mapping table is consulted based on the vehicle user's identity identifier. The vehicle's true identity (Tid) will be made public to prevent malicious vehicle users from participating in road activities.

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