A blockchain-based privacy protection traffic route management method for internet of vehicles

Abstract

The application discloses a blockchain-based privacy protection traffic route management method for Internet of Vehicles, which comprises the following steps: (1) system initialization, which is used for completing the initialization of related entities; (2) registration of participating entities, including registration of vehicles and registration of fog nodes; (3) password login stage, in which a vehicle user inputs a password to log in the vehicle; (4) route request of the fog node; (5) route report of the vehicle, in which the vehicle reports a route to be driven to the fog node; (6) message verification and traffic route aggregation; (7) traffic route management, in which a traffic management center performs relevant management work according to a route set message sent by the fog node; and (8) vehicle revocation and password change. The application adopts a lightweight elliptic curve encryption method and a homomorphic encryption method to encrypt the route of the vehicle, thereby effectively protecting the privacy of the vehicle; and the application also adopts a blockchain technology to effectively manage the key of the vehicle. The application can realize safe privacy protection traffic route management in Internet of Vehicles, and promotes the wide application of the vehicle network.

Description

Technical Field

[0001] This invention relates to vehicle networking and blockchain technology, specifically to a blockchain-based method for vehicle networking privacy protection and traffic route management. Background Technology

[0002] Vehicular Ad Hoc Networks (VANETs) refer to onboard devices in vehicles that utilize wireless communication technology to effectively leverage dynamic information from all vehicles within an information network platform, providing various functional services during vehicle operation. With the rapid growth in the number of vehicles and the continuous development of communication technology, the demand for vehicle safety and privacy protection is becoming increasingly urgent, making VANETs a research hotspot of common interest to governments, research institutions, and vehicle manufacturers. VANETs mainly consist of the following components: Trusted Authority (TA), Roadside Units (RSUs), vehicles, and Traffic Management Centers (TMCs). In VANETs, ​​the two main communication types are vehicle-to-vehicle (V2V) communication and vehicle-to-roadside unit (V2I) communication. In V2V communication, vehicles periodically broadcast traffic-related information such as their speed, location, and route, which can be used to improve driving safety and reduce traffic accidents. In V2I communication, infrastructure such as RSUs is required to provide traffic-related services to nearby vehicles.

[0003] Despite the wide range of applications and significant advantages offered by VANETs, ​​the prevalent security and privacy issues cannot be ignored. Because VANETs utilize public wireless networks in V2V and V2I communications, they are vulnerable to multiple attacks. Without secure communication protection mechanisms, attackers can easily modify messages transmitted via VANETs. For example, driving route information can be maliciously modified to cause traffic congestion, while speed information can be altered to cause traffic accidents. Therefore, traffic-related communications can impact personal safety and property security, making the design of a message authentication scheme suitable for both V2V and V2I communications essential.

[0004] Blockchain technology has been introduced into VANETs environments in recent years, attracting the interest of researchers in the VANETs field because it offers characteristics such as anonymity, decentralization, and immutability in addressing the aforementioned security and performance issues. Specifically, through smart contracts in the blockchain, public information such as public keys, pseudonyms, and certificates can be managed, thereby effectively achieving authentication and revocation. Furthermore, during the authentication process, it only needs to retrieve public information from the blockchain without storing new data on it. Summary of the Invention

[0005] Purpose of the invention: The purpose of this invention is to address the shortcomings of existing technologies and provide a blockchain-based method for privacy protection and traffic route management in the Internet of Vehicles.

[0006] Technical Solution: The present invention provides a blockchain-based method for privacy-preserving traffic route management in the Internet of Vehicles, comprising the following steps:

[0007] Step (1) System initialization: Initialize the relevant entities and obtain the system private key s and system public key P. pub , and the public key (n, g) and private key (λ, μ) for homomorphic encryption; s is a random number;

[0008] Step (2): Relevant participating entities register with the system, including vehicle registration and fog node registration;

[0009] Step (3): The vehicle user enters their password to log in to the vehicle;

[0010] Step (4): The fog node broadcasts a route request message to vehicles within its communication range;

[0011] Step (5) The vehicle reports its upcoming route to the fog node; the vehicle transmits the encrypted route, signature and timestamp to the fog node through a secure channel;

[0012] Step (6), message verification and traffic route aggregation; after receiving the vehicle's message, the fog node first verifies the timestamp and vehicle signature in the message. After successful verification, the fog node aggregates the vehicle's driving route and sends it to the Traffic Management Center (TMC).

[0013] Step (7): Traffic Management Center (TMC) manages traffic routes: After receiving the fog node message, the TMC first verifies the timestamp and fog node signature. If the verification is successful, the vehicle's driving route is decrypted and restored.

[0014] Step (8), Vehicle Removal and Password Change: The Trust Center triggers a smart contract to remove vehicles with malicious behavior or invalid public keys. Removed vehicles need to obtain a new login password.

[0015] Furthermore, the detailed process of step (1) is as follows:

[0016] Step (1-1): The Trusted Center TA generates the elliptic curve E: y 2 =x 3 +ax+b mod p, then TA chooses the elliptic curve group G with generator order q for generator P;

[0017] Step (1-2): TA selects a random number s as the system private key and calculates the system public key P. pub =s·P;

[0018] Steps (1-3): TA selects a one-way hash function h(·);

[0019] Steps (1-4): The Traffic Management Center (TMC) randomly selects two prime numbers p1 and p2 and a random number g, calculates n = p1·p2, λ = 1 / cm(p1, p2), and μ = (L(g) / (p1, p2)). λ mod n 2 )) -1 mod n, based on homomorphic encryption, generates a public key (n, g) and a private key (λ, μ).

[0020] Furthermore, the specific process of registering vehicles and fog nodes in step (2) is as follows:

[0021] Step (2-1): The user selects vehicle V. i Login password PW i and one's own identity UID i Use identity UID i Encrypt the login password to obtain UPW i =h1(UID) i ||PW i Then, the registration request {ID} is sent via a secure channel. i UPWi} is sent to the Trusted Center (TA);

[0022] Among them, UID i This refers to the identity, ID of the i-th user. i This refers to the identity of the i-th vehicle; PW i It is the user's login password, UPW i It is the result of encrypting the user's login password;

[0023] Step (2-2): After receiving the user's registration request, the Trusted Center (TA) first checks the user's status. If the user has already been registered or is on the blacklist, the TA will reject the user's registration request; otherwise, it will proceed to step (2-3).

[0024] Steps (2-3): Trusted Center (TA) randomly selects... Calculate sk i =h2(ID) i ||s||k i Use this as the vehicle's private key, and then calculate vehicle V. i pseudonym Vehicle public key VPK=sk i ·P; Simultaneously calculate parameters C i =h3(A i ||UPW i );

[0025] sk i It refers to the private key of the i-th vehicle, t i It is the corresponding timestamp, A i B i and C i These are the relevant safety parameters;

[0026] Step (2-4), TA will {B i C i ,sk i PID i , (n, g)} is transmitted to vehicle V through a secure channel i At the same time, TA will {PID i Upload the VPK to the smart contract;

[0027] Steps (2-5), Fog Node F j Personal ID j Transmitted to TA; ID via secure channel j This refers to the identity of the j-th fog node;

[0028] Step (2-6): TA obtains fog node F j After receiving the registration request, the TA first checks the status of the fog node. If the status is invalid, the TA rejects the fog node's registration request; otherwise, it continues to execute steps (2-7).

[0029] Steps (2-7), TA selection Used as the private key for the fog node, and used to compute the fog node F. j Public key PK j =sk j ·P;

[0030] Among them, sk j This refers to the private key of the j-th fog node;

[0031] Step (2-8), TA will {sk j , pk j The registration process is completed by transmitting the data to the fog node via a secure channel.

[0032] Furthermore, the specific process of step (3) where the user enters a password to log in to the vehicle is as follows:

[0033] Step (3-1): Vehicle user input {ID} i PW i UID i Login vehicle V i Onboard unit (OBU);

[0034] Step (3-2), Vehicle V i Calculate UPW i=h1(UID) i ||PW i ), Then check equation C. i =h3(A i ||UPW i Check if the equation is true. If it is true, the login is successful; otherwise, the login fails.

[0035] Among them, UID i This refers to the identity, ID of the i-th user. i This refers to the identity of the i-th vehicle; PW i It is the user's login password, UPW i It is the result of encrypting the user's login password; A i B i and C i These are the relevant safety parameters. The order of appearance is required.

[0036] UPW is calculated twice in this invention. i and A i The first step is to calculate the user's login information, and the second step is to calculate the user's login information to verify whether the user meets the login requirements.

[0037] Furthermore, in step (4), the fog node F j The specific process of requesting a route is as follows:

[0038] Step (4-1): The fog node selects a random number x. j Calculate X j =x j ·P, then generate the current signature σ of the fog node. F1 =sk j +x j ·h2(ID j ||RS||T j1 )mod q, then the fog node sends the message M1={ID} j X j , σ F1 RS, T j1 Broadcast to all vehicles within communication range;

[0039] T j1 It is the current timestamp; sk j This refers to the private key of the j-th fog node; RS is the route request that the fog node wants to query, and X... j These are safety parameters;

[0040] Step (4-2), Vehicle V i Upon receiving message M1, first check the validity of the timestamp. If the timestamp is expired, reject the message; otherwise, proceed with the vehicle verification equation σ.F1 ·P=pk j +X j h2(ID j ||RS||T j1 If the equation is true, then proceed to step (5); otherwise, discard the message and do not proceed to the next step.

[0041] pk j It is fog node F j public key, ID j It refers to F j His identity.

[0042] Furthermore, the specific process of step (5), in which the vehicle reports its upcoming route to the fog node, is as follows:

[0043] Step (5-1), Vehicle V i Convert the route to be traveled into binary form, which is of the form {F1(V), F2(V), ..., F...}. m (V)};

[0044] Step (5-2): Select a random number for the vehicle. Then encrypt its driving route. At the same time, the vehicle selects a random number. And calculate D i =d i ·P, Next, vehicle V i Generate its signature σ vi =sk i +d i ·β i mod q;

[0045] Step (5-3): The vehicle transmits the message through the secure channel. Transmitted to fog nodes; σ vi , D i PID i T i1 These refer to vehicle V. i The signature, the encrypted vehicle route, V i The pseudonym, current timestamp; F m (V) is the binary representation of the vehicle's travel route. It is r i The nth power (n = p1·p2), D i These are safety parameters.

[0046] Furthermore, the specific process of step (6) verification and traffic route aggregation is as follows:

[0047] Step (6-1): The fog node receives the vehicle's message. First, check the timestamp T. i1 To verify the validity of the timestamp, if it is valid, the fog node sends a query transaction to the blockchain to retrieve the vehicle's public key; after obtaining the vehicle's public key, the fog node calculates... To check the equation Check if the condition is met. If not, the message is rejected; if it is met, proceed to step (6-2).

[0048] σ vi , D i PID i T i1 These refer to vehicle V. i The signature, the encrypted vehicle route, D i It is a safety parameter, V i The pseudonym and the current timestamp;

[0049] Step (6-2): After verifying the messages sent by the vehicle, the fog node aggregates the k driving routes of the vehicle and sends them to the Traffic Management Center (TMC).

[0050] Aggregation route as follows:

[0051]

[0052] Then, the fog node selects a random number. Calculate Y j =y j ·P, and generate the current signature of the fog node. Fog nodes will send messages Send it to the Traffic Management Center (TMC) via a secure channel;

[0053] Among them, Y j These are safety parameters. These are the calculation parameters of the decryption formula in homomorphic encryption, and the random number. Used for encryption.

[0054] Furthermore, the specific method for the Traffic Management Center (TMC) to manage traffic routes in step (7) is as follows:

[0055] Step (7-1): The Traffic Management Center (TMC) receives the message sent by the fog node. First, check the timestamp T. j2 If the equation is valid, then continue to verify its validity. Check if the equation is true; if it is false, reject the message.

[0056] Step (7-2): TMC uses the private key (λ, μ) to calculate... Decryption

[0057] Where, μ=(L(g) λ mod n 2 )) -1 mod n, L(x) = (x-1) / n;

[0058] The final route information recovered is as follows:

[0059] Furthermore, the specific process of step (8) vehicle cancellation and password change is as follows:

[0060] Step (8-1): When a fog node detects malicious behavior by a vehicle, it encapsulates a voting transaction to trigger a smart contract on the blockchain. Once the number of votes (VoteCount) is greater than or equal to the threshold (Thre), the Trusted Center (TA) sends a reversal transaction to trigger the smart contract DeletePK to remove the vehicle's public key. In addition, the TA periodically checks the validity of the vehicle's public key. If it is invalid, the TA sends a reversal transaction to trigger the smart contract DeletePK to remove the vehicle's public key.

[0061] Step (8-2): The user enters {UID} into the vehicle. i ID i PW i} and a new password

[0062] Step (8-3), Vehicle calculation user login password UPW i =h1(uID) i ||PW i ), Then check equation C. i =h1(UID) i ||PW i Are they equal?

[0063] If the equation is false, it means the user entered an incorrect password, and the process will terminate; otherwise, the vehicle calculation...

[0064] Step (8-4), Secret Storage of Vehicles This refers to the encrypted value of the new login password.

[0065] Beneficial effects: To reduce the frequent occurrence of traffic congestion and traffic accidents, the technical solution of this invention uses homomorphic encryption to encrypt the driving route of vehicles, and then sends the encrypted information to the fog node; the traffic management center (TMC) decrypts the received ciphertext by the fog node and performs traffic management based on the decrypted data, without knowing the individual route of each vehicle, thus effectively protecting the privacy of vehicles; at the same time, blockchain is used to manage the public keys of vehicles.

[0066] Compared with the prior art, the present invention has the following advantages:

[0067] (1) This invention uses elliptic curve cryptography instead of bilinear pairing operations, resulting in lower computational and communication overhead. Simultaneously, it employs homomorphic encryption, ensuring that the traffic management center only knows the total number of vehicles on each road segment, not the individual route of each vehicle, effectively protecting vehicle privacy.

[0068] (2) This invention uses blockchain technology to record the anonymous public key of the vehicle. Based on smart contract technology, the public key of the vehicle recorded on the blockchain can be updated, queried, and deleted. In addition, during the identity verification process, it does not require a trusted authority (TA) to be online, thus reducing the workload of the TA.

[0069] This invention implements more functional features, such as batch authentication, vehicle revocation, and password modification. Furthermore, the security of this cryptographic protocol is evaluated through formal security analysis and it is resistant to various types of attacks, exhibiting stronger security compared to other related schemes. Attached Figure Description

[0070] Figure 1 This is a system model diagram of the present invention;

[0071] Figure 2 This is a block structure diagram of the blockchain in this invention;

[0072] Figure 3 This is a comparison chart of computational overhead in one embodiment of the present invention;

[0073] Figure 4 This is a comparison diagram of communication overhead in one embodiment of the present invention. Detailed Implementation

[0074] The technical solution of the present invention will be described in detail below, but the scope of protection of the present invention is not limited to the embodiments described.

[0075] To address the privacy and traffic safety issues in existing vehicle network communication technologies, this invention is based on lightweight encryption technology. Each vehicle uses homomorphic encryption to encrypt its driving route and transmits the ciphertext to a fog node. The fog node aggregates all vehicle routes and transmits the aggregated routes (not the routes of individual vehicles) to the TMC (Traffic Management Controller). The TMC then decrypts the ciphertext, thus receiving the total number of vehicles on each road segment without knowing the individual routes of each vehicle. The TMC can then perform traffic management accordingly. This invention also employs blockchain technology for vehicle key management, effectively solving problems related to key management and malicious vehicle revocation; it effectively addresses the privacy and security protection and traffic route management issues existing in VANETs.

[0076] like Figure 1 As shown in this embodiment, the blockchain-based vehicle network privacy-preserving traffic route management method mainly involves the following entities: Trusted Center (TA), Traffic Management Center (TMC), vehicles, fog nodes, and the blockchain network. The Trusted Center (TA) possesses sufficient computing, storage, and communication capabilities; it is responsible for the initialization of the entire system and provides registration services for vehicles and fog nodes. Furthermore, only the TA can track the true identity of malicious vehicles; it is assumed that the TA is a completely trustworthy and uncompromising entity. Each Traffic Management Center (TMC) is responsible for managing traffic conditions within its management area and can promptly guide vehicles in the event of traffic congestion or accidents. In this invention, the TMC can decrypt the route aggregation content transmitted from the fog nodes, providing timely route guidance to vehicles. Each vehicle is equipped with an On-Board Unit (OBU) and a Tamper-Proof Device (TPD). The OBU can communicate with other vehicles or infrastructure, while the TPD can store elements and perform encryption and decryption operations. Fog nodes are responsible for broadcasting route request information, verifying vehicle identities, and aggregating vehicle driving routes. Fog nodes are also responsible for receiving and analyzing messages and performing decisions such as real-time traffic warnings and traffic data aggregation.

[0077] The specific steps of this embodiment are as follows:

[0078] Step (1) System initialization: Initialize the relevant entities and obtain the system private key s and system public key P. pub , and the public key (n, g) and private key (λ, μ) for homomorphic encryption; s is a random number;

[0079] Step (1-1): The Trusted Center TA generates the elliptic curve E: y 2 =x 3 +ax+b mod p, then TA chooses the elliptic curve group G with generator order q for generator P;

[0080] Step (1-2): TA selects a random number s as the system private key and calculates the system public key P.pub =s·P;

[0081] Steps (1-3): TA selects a one-way hash function h(·);

[0082] Steps (1-4): The Traffic Management Center (TMC) randomly selects two prime numbers p1 and p2 and a random number g, calculates n = p1·p2, λ = 1 / cm(p1, p2), and μ = (L(g) / (p1, p2)). λ mod n 2 )) -1 mod n, based on homomorphic encryption, generates a public key (n, g) and a private key (λ, μ);

[0083] Step (2): Relevant participating entities register with the system, including vehicle registration and fog node registration;

[0084] Step (2-1): The user selects vehicle V. i Login password PW i and one's own identity UID i Use identity UID i Encrypt the login password to obtain UPW i =h1(UID) i ||PW i Then, the registration request {ID} is sent via a secure channel. i UPW i Send to the Trusted Center (TA);

[0085] Among them, UID i This refers to the identity, ID of the i-th user. i This refers to the identity of the i-th vehicle;

[0086] Step (2-2): After receiving the user's registration request, the Trusted Center (TA) first checks the user's status. If the user has already been registered or is on the blacklist, the TA will reject the user's registration request; otherwise, it will proceed to step (2-3).

[0087] Steps (2-3): Trusted Center (TA) randomly selects... Calculate sk i =h2(ID) i ||s||k i Use this as the vehicle's private key, and then calculate vehicle V. i pseudonym Vehicle public key VPK=sk i ·P; Simultaneously calculate parameters C i =h3(A i ||UPW i );

[0088] ski It refers to the private key of the i-th vehicle, t i It is the corresponding timestamp, A i B i and C i These are the relevant safety parameters;

[0089] Step (2-4), TA will {B i C i ,sk i PID i , (n, g)} is transmitted to vehicle V through a secure channel i At the same time, TA will {PID i Upload the VPK to the smart contract;

[0090] Steps (2-5), Fog Node F j Personal ID j Transmitted to TA; ID via secure channel j This refers to the identity of the j-th fog node;

[0091] Step (2-6): TA obtains fog node F j After receiving the registration request, the TA first checks the status of the fog node. If the status is invalid, the TA rejects the fog node's registration request; otherwise, it continues to execute steps (2-7).

[0092] Steps (2-7), TA selection Used as the private key for the fog node, and used to compute the fog node F. j Public key PK j =sk j ·P;

[0093] Among them, sk j This refers to the private key of the j-th fog node;

[0094] Step (2-8), TA will {sk j , pk j The registration process is completed by transmitting the data to the fog node via a secure channel.

[0095] Step (3): To verify the legitimacy of the vehicle user, the vehicle user enters a password to log in to the vehicle;

[0096] Step (3-1): Vehicle user input {ID} i PW i UID i Login vehicle V i Onboard unit (OBU);

[0097] Step (3-2), Vehicle V i Calculate UPW i =h1(UID)i ||PW i ), Then check equation C. i =h3(A i ||UPW i Check if the equation is true. If it is true, the login is successful; otherwise, the login fails.

[0098] Step (4): The fog node broadcasts a route request message to vehicles within its communication range;

[0099] Step (4-1): The fog node selects a random number x. j Calculate X j =x j ·P, then generate the current signature σ of the fog node. F1 =sk j +x j ·h2(ID j ||RS||T j1 )mod q, then the fog node sends the message M1={ID} j X j , σ F1 RS, T j1 Broadcast to all vehicles within communication range;

[0100] T j1 It is the current timestamp; sk j This refers to the private key of the j-th fog node;

[0101] Step (4-2), Vehicle V i Upon receiving message M1, first check the validity of the timestamp. If the timestamp is expired, reject the message; otherwise, proceed with the vehicle verification equation σ. F1 ·P=pk j +X j h2(ID j ||RS||T j1 If the equation is true, then proceed to step (5); otherwise, discard the message and do not proceed to the next step.

[0102] pk j It is fog node F j public key, ID j It refers to F j identity;

[0103] Step (5) The vehicle reports its upcoming route to the fog node; the vehicle transmits the encrypted route, signature and timestamp to the fog node through a secure channel;

[0104] Step (5-1), Vehicle V iConvert the route to be traveled into binary form, which is of the form {F1(V), F2(V), ..., F...}. m (V)};

[0105] Step (5-2): Select a random number for the vehicle. Then encrypt its driving route. At the same time, the vehicle selects a random number. And calculate Next, vehicle V i Generate its signature σ vi =sk i +d i ·β i mod q;

[0106] Step (5-3): The vehicle transmits the message through the secure channel. Transmitted to fog nodes;

[0107] σ Vi , D i PID i T i1 These refer to vehicle V. i The signature, the encrypted vehicle route, V i The pseudonym and the current timestamp;

[0108] Step (6), message verification and traffic route aggregation; after receiving the vehicle's message, the fog node first verifies the timestamp and vehicle signature in the message. After successful verification, the fog node aggregates the vehicle's driving route and sends it to the Traffic Management Center (TMC).

[0109] Step (6-1): The fog node receives the vehicle's message. First, check the timestamp T. i1 To verify the validity of the timestamp, if it is valid, the fog node sends a query transaction to the blockchain to retrieve the vehicle's public key; after obtaining the vehicle's public key, the fog node calculates... To check the equation Check if the condition is met. If not, the message is rejected; if it is met, proceed to step (6-2).

[0110] σ vi , D i PID i T i1 These refer to vehicle V. i The signature, the encrypted vehicle route, V i The pseudonym and the current timestamp;

[0111] Step (6-2): After verifying the messages sent by the vehicle, the fog node aggregates the k driving routes of the vehicle and sends them to the Traffic Management Center (TMC).

[0112] Aggregation route as follows:

[0113]

[0114] Then, the fog node selects a random number. Calculate Y j =y j ·P, and generate the current signature of the fog node. Fog nodes will send messages Send it to the Traffic Management Center (TMC) via a secure channel;

[0115] Step (7): Traffic Management Center (TMC) manages traffic routes: After receiving the fog node message, the TMC first verifies the timestamp and fog node signature. If the verification is successful, the vehicle's driving route is decrypted and restored.

[0116] Step (7-1): The Traffic Management Center (TMC) receives the message sent by the fog node. First, check the timestamp T. j2 If the equation is valid, then continue to verify its validity. Check if the equation is true; if it is false, reject the message.

[0117] Step (7-2): TMC uses the private key (λ, μ) to calculate... Decryption

[0118] Where, μ=(L(g) λ mod n 2 )) -1 mod n, L(x) = (x-1) / n;

[0119] The final route information recovered is as follows:

[0120] Step (8), Vehicle Removal and Password Change: The Trust Center triggers a smart contract to remove vehicles with malicious behavior or invalid public keys. Removed vehicles need to obtain a new login password.

[0121] Step (8-1): When a fog node detects malicious behavior by a vehicle, it encapsulates a voting transaction to trigger a smart contract on the blockchain. Once the number of votes (VoteCount) is greater than or equal to the threshold (Thre), the Trusted Center (TA) sends a reversal transaction to trigger the smart contract DeletePK to remove the vehicle's public key. In addition, the TA periodically checks the validity of the vehicle's public key. If it is invalid, the TA sends a reversal transaction to trigger the smart contract DeletePK to remove the vehicle's public key.

[0122] Step (8-2): The user enters {UID} into the vehicle. i ID i PW i} and a new password

[0123] Step (8-3), Vehicle calculation user login password UPW i =h1(UID) i ||PW i ), Then check equation C. i =h1(UID) i ||PW i Are they equal?

[0124] If the equation is false, it means the user entered an incorrect password, and the process will terminate; otherwise, the vehicle calculation...

[0125] Step (8-4), Secret Storage of Vehicles

[0126] To facilitate understanding of the technical solution in this embodiment, the meanings of the relevant variables are explained first, as detailed in Table 1.

[0127] Table 1

[0128]

[0129] Example:

[0130] The blockchain used in this embodiment is as follows: Figure 2 As shown, a block in this blockchain consists of a block header and a block body. The block header contains the hash of the previous block and the root of a Merkle tree, in which a large amount of complex data is recorded.

[0131] The computational overhead of the technical solution of this invention in actual application is compared with that of other solutions, and the results are as follows: Figure 3As shown, this invention (rightmost in the figure) has significant advantages in terms of computational overhead at the vehicle end, roadside unit / fog node end, TA / TMC / CSO end, and total overhead.

[0132] The communication overhead of the technical solution of this invention in actual application is compared with the communication overhead of other solutions, and the results are as follows: Figure 4 As shown, the communication overhead of the technical solution of the present invention is low.

Claims

1. A blockchain-based method for privacy-preserving traffic route management in the Internet of Vehicles (IoV), characterized in that: Includes the following steps: Step (1): System initialization, performing entity initialization work and obtaining the system private key. System public key and the public key for homomorphic encryption. and private key ; It is a random number; Step (2): Entities register with the system, including vehicle registration and fog node registration; Step (3): The vehicle user enters their password to log in to the vehicle; Step (4): The fog node broadcasts a route request message to vehicles within its communication range; Step (5) The vehicle reports its upcoming route to the fog node; The vehicle transmits the encrypted driving route, signature, and timestamp to the fog node via a secure channel; Step (6), message verification and traffic route aggregation; after receiving the vehicle's message, the fog node first verifies the timestamp and vehicle signature in the message. After successful verification, the fog node aggregates the vehicle's driving route and sends it to the Traffic Management Center (TMC). Step (7): Traffic Management Center (TMC) manages traffic routes: After receiving the fog node message, the TMC first verifies the timestamp and fog node signature. If the verification is successful, the vehicle's driving route is decrypted and restored. Step (8), Vehicle Removal and Password Change: The Trust Center triggers a smart contract to remove vehicles with malicious behavior or invalid public keys. Removed vehicles need to obtain a new login password.

2. The blockchain-based vehicle network privacy protection traffic route management method according to claim 1, characterized in that, The detailed process of step (1) is as follows: Step (1-1): The Trusted Center (TA) generates an elliptic curve. : Then TA selects the generator. Generation order is Elliptic curve group ; Step (1-2): TA selects a random number. Used as the system private key, and used to calculate the system public key. ; Steps (1-3): TA selects a one-way hash function. ; Steps (1-4): The Traffic Management Center (TMC) randomly selects two prime numbers p1 and p2 and a random number. Calculate n=p 1· p2, =lcm(p 1, p 2) , Public keys are generated based on homomorphic encryption. and private key .

3. The blockchain-based vehicle network privacy protection traffic route management method according to claim 2, characterized in that, The specific process of registering vehicles and fog nodes in step (2) is as follows: Step (2-1): User selects vehicle login password and one's own identity Using identity Encrypt the login password to obtain Then, the registration request is sent through a secure channel. Send to the Trusted Center (TA); Hash functions; Indicates a connection operation; in, This refers to the identity of the i-th user. This refers to the identity of the i-th vehicle; It is the user's login password. It is the result of encrypting the user's login password; Step (2-2): After the Trusted Center (TA) receives the user's registration request, it first checks the user's status. If the user has already been registered or is on the blacklist, the TA will reject the user's registration request; otherwise, it will proceed to step (2-3). Steps (2-3): Trusted Center (TA) randomly selects... ,calculate Used as the vehicle's private key, then calculate the vehicle's private key. pseudonym Vehicle public key Simultaneously calculate parameters , , ; It refers to the private key of the i-th vehicle. It is the corresponding timestamp. , and These are the relevant safety parameters; and Hash functions; Indicates the XOR operation; Steps (2-4), TA will Transmitted to the vehicle via a secure channel At the same time, TA will Upload to smart contract; Steps (2-5), Fog Node his own identity Transmitted to TA via a secure channel; This refers to the identity of the j-th fog node; Steps (2-6): TA obtains fog nodes. After receiving the registration request, the TA first checks the status of the fog node. If the status is invalid, the TA rejects the fog node's registration request; otherwise, it continues to execute steps (2-7). Steps (2-7), TA selection Used as the private key for fog nodes, and used to calculate fog node values. Public Key ; in, This refers to the private key of the j-th fog node; Steps (2-8), TA will The registration process is completed by transmitting the data to the fog node via a secure channel.

4. The blockchain-based vehicle network privacy protection traffic route management method according to claim 3, characterized in that, The specific process of step (3) where the user enters a password to log in to the vehicle is as follows: Step (3-1), User input for the vehicle Login vehicle Onboard unit (OBU); Step (3-2), Vehicle calculate , Then check the equation. Check if the equation is true. If it is true, the login is successful; otherwise, the login fails. Hash functions; Indicates a connection operation; Indicates the XOR operation; This refers to the identity of the i-th user. This refers to the identity of the i-th vehicle; It is the user's login password. It is the result of encrypting the user's login password; , and These are the relevant safety parameters.

5. The blockchain-based vehicle network privacy protection traffic route management method according to claim 3, characterized in that, The fog node in step (4) The specific process of requesting a route is as follows: Step (4-1): Select a random number for the fog node. ,calculate Then generate the current signature of the fog node. Then the fog node will send the message Broadcast to all vehicles within communication range; It is a generator; It is the current timestamp; This refers to the private key of the j-th fog node; This is the route request that the fog node wants to query. These are safety parameters; Indicates a connection operation; Step (4-2), Vehicle Once the message is received First, check the validity of the timestamp; if the timestamp is expired, reject the message. Otherwise, the vehicle verification equation If the equation is true, then proceed to step (5); otherwise, discard the message and do not proceed with the subsequent steps. Fog node public key, It means His identity.

6. The blockchain-based vehicle network privacy protection traffic route management method according to claim 5, characterized in that, The specific process of the vehicle reporting its upcoming route to the fog node in step (5) is as follows: Step (5-1), Vehicle Convert the route it wants to travel into binary form, which is in the form of: ; Step (5-2): Select a random number for the vehicle. Then encrypt its driving route. At the same time, the vehicle selects a random number. and calculate , Next, the vehicle Generate its signature ; Indicates a connection operation; Step (5-3): The vehicle transmits the message through the secure channel. Transmitted to fog nodes; They refer to vehicles The signature, the encrypted vehicle route, The pseudonym and the current timestamp; It is the binary representation of the vehicle's travel route. yes to the power of n, These are safety parameters.

7. The blockchain-based vehicle network privacy protection traffic route management method according to claim 6, characterized in that, The specific process of verification and traffic route aggregation in step (6) is as follows: Step (6-1): The fog node receives the vehicle's message. First, check the timestamp. If the timestamp is valid, the fog node sends a query transaction to the blockchain to retrieve the vehicle's public key. After retrieving the vehicle's public key, the fog node computes... To check the equation Check if the condition is met. If not, the message is rejected; if it is met, proceed to step (6-2). These are safety parameters; yes The katakana; They refer to vehicles The signature, encrypted vehicle route, security parameters, The pseudonym and the current timestamp; Step (6-2): After verifying the messages sent by the vehicles, the fog nodes aggregate the vehicles' messages. The driving route is then sent to the Traffic Management Center (TMC). Aggregation route as follows: ； Then, the fog node selects a random number. ,calculate And generate the current signature of the fog node. Fog nodes will send messages Send it to the Traffic Management Center (TMC) via a secure channel; Indicates the current timestamp; in, These are safety parameters. These are the calculation parameters of the decryption formula in homomorphic encryption, and the random number. Used for encryption.

8. The blockchain-based vehicle network privacy protection traffic route management method according to claim 7, characterized in that, The specific method for the Traffic Management Center (TMC) to manage traffic routes in step (7) is as follows: Step (7-1): The Traffic Management Center (TMC) receives the message sent by the fog node. First, check the timestamp. If the equation is valid, then continue to verify its validity. Check if the equation is true; if it is false, reject the message. Indicates a connection operation; Indicates the current timestamp; Step (7-2): TMC uses the private key Through calculation Decryption ; in, , ; The final route information recovered is as follows: .

9. The blockchain-based vehicle network privacy protection traffic route management method according to claim 8, characterized in that, The specific process for step (8), vehicle cancellation and password change, is as follows: Step (8-1): When the fog node detects malicious behavior from a vehicle, it encapsulates a voting transaction to trigger a smart contract on the blockchain. Once the vote count is reached... The Trusted Center (TA) then sends a reversal transaction to trigger the smart contract to remove the vehicle's public key. In addition, the TA periodically checks the validity of the vehicle's public key. If it becomes invalid, the TA sends a reversal transaction to trigger the smart contract to remove the vehicle's public key. Step (8-2): The user inputs information into the vehicle. And a new password ; in, This refers to the identity of the i-th user; It is the identity of the i-th vehicle; It is the vehicle's login password; Step (8-3): Calculate the user login password for the vehicle. , Then check the equation. Are they equal? This refers to a one-way hash function; Indicates the XOR operation; If the equation is false, it means the user entered an incorrect password, and the process will terminate; otherwise, the vehicle calculation... , ; Indicates a connection operation; Step (8-4), Secret Storage of Vehicles , This refers to the encrypted value of the new login password.

Images