A multi-chain-based trusted reputation evaluation and management system and method for internet of vehicles

Abstract

The application discloses a kind of based on multi-chain Internet of Vehicles trusted credit evaluation and management system, method, belongs to intelligent traffic safety field.The application applies identity information chain to carry out vehicle registration and authentication, eliminates the dependence on third-party CA agency;Event chain and reputation chain are introduced respectively to improve storage and query efficiency, wherein the event chain is used to store event information to realize the accountability to malicious vehicle, and the reputation chain stores vehicle reputation value to limit the Internet of Vehicles activity of low-reputation vehicle.The application designs an improved Bayesian inference algorithm based on multi-factor measurement to calculate alarm credibility, to improve the reliability of the reputation evaluation process, while using a voting system to mitigate malicious vehicle collusion attacks.The application can effectively improve the scalability and security of the blockchain-based Internet of Vehicles credit system, improve the real-time performance of the alarm, and thus improve the safety and efficiency of the intelligent transportation system.

Description

Technical Field

[0001] This invention relates to the field of intelligent transportation safety, specifically to a multi-chain-based vehicle network trusted reputation assessment and management system and method, which addresses the problem that malicious vehicles may spread a large number of false alarms to deceive other vehicles, thereby posing a great threat to the safety and reliability of road traffic. Background Technology

[0002] Vehicle-to-everything (V2X) technology is a typical application scenario for the Internet of Things (IoT). Leveraging next-generation information and communication technologies and the rapid development of various high-tech devices equipped in intelligent vehicles, such as GPS, radar, and in-vehicle equipment, vehicle nodes can connect to everything through various types of networks (V2X) to build Intelligent Transportation Systems (ITS) and realize the vision of smart cities. In V2X, complex and dynamic data generated by vehicles, humans, and the environment are transmitted and processed in real time. This data includes traffic conditions, traffic accidents, road construction, congestion, and more. Reliable information can help vehicles find the fastest route and avoid collisions. Unreliable information can even lead to serious traffic accidents.

[0003] In their 2018 presentation at the 17th IEEE International Conference on Trust, Security and Privacy in Computing and Communications / 12th IEEE International Conference on Big Data Science and Engineering, Zhaojun Lu et al. proposed a blockchain-based Anonymous Reputation System (BARS) for anonymous authentication and trusted communication in connected vehicles. Vehicles are authenticated using two blockchains (CerBC and RevBC), with authentication based on proofs of existence and non-existence. Furthermore, the public key serves as a pseudonym for anonymous communication, eliminating the linkability between the real identity and the public key to protect vehicle privacy. On the other hand, all broadcast information is recorded in MesBC as persistent evidence to assess each vehicle's reputation. A reputation management algorithm is designed to prevent the spread of false information and incentivize vehicles to expose misconduct.

[0004] In 2023, Zhou Hao et al. published a paper titled "Blockchain-Assisted Emergency Message Trust Assessment Scheme in the Internet of Vehicles" in the Journal of Xi'an University of Electronic Science and Technology. This scheme proposes a blockchain-assisted emergency message trust assessment method for the Internet of Vehicles. First, the authors utilize blockchain technology to distribute vehicle trust data, achieving reliable data storage. Then, they propose two caching strategies: a pre-caching strategy and a query-based caching strategy. Finally, based on the proposed query algorithm, they introduce historical vehicle trust values ​​and combine them with vehicle location and message freshness as reference factors for emergency message trust assessment, achieving low-latency and highly accurate trust assessment. However, the proposed caching strategies significantly increase storage space overhead, and caching a large amount of information in the RSU (Remote State Unit) poses a significant security risk.

[0005] In published literature, most authors use blockchain systems to store reputation, while some authors have not yet considered the storage of alert events. Those authors who have considered storing alert events have not considered the problems of storage chaos and low query efficiency. Summary of the Invention

[0006] To address the shortcomings of existing research, this invention proposes a multi-chain-based trusted reputation assessment and management system and method for vehicle networks, in order to solve several problems mentioned in the background section.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: a multi-chain-based vehicle network trusted reputation assessment and management system, comprising:

[0008] Vehicle nodes, each vehicle is equipped with an on-board unit (OBU) to support communication between vehicles and between vehicles and road infrastructure units (RSUs). Vehicles interact with the blockchain through the management platform's API interface, which includes multiple functions such as joining the blockchain network, reporting alarms, verifying alarms, and post-event accountability.

[0009] The Road Facility Unit (RSU) is used to communicate with vehicles and other RSUs. The Road Facility Unit (RSU) is an authoritative node and can directly participate in the block generation and verification process.

[0010] The blockchain layer includes the identity information chain, the event chain, and the reputation chain, which are used to store various types of information and execute corresponding smart contracts. The identity information chain is responsible for storing vehicle information and digital certificates, and executing smart contracts for identity registration and verification. The event chain stores the content of events sent by vehicles and executes smart contracts for querying emergency event content. The reputation chain is responsible for storing vehicle reputation and executing smart contracts for querying vehicle reputation values.

[0011] A multi-chain-based trusted reputation assessment and management method for vehicle-to-everything (V2X) networks includes the following steps:

[0012] Step 1: Use blockchain to register and authenticate identities to eliminate the limitations of third-party CA institutions and ensure information security. When a vehicle enters the system, it first needs to register on the identity information chain to join the blockchain network.

[0013] Step 2: When an alarm needs to be sent, the vehicle requests to send an alarm from the Road Infrastructure Unit (RSU) through the management platform. The RSU sends the information that needs to be authenticated to the identity information chain. After verification, the result is returned to the RSU. The RSU queries the vehicle's reputation value in the reputation chain based on the information in the identity information chain, and decides whether to receive the alarm based on the vehicle's reputation value. If the vehicle's reputation value is greater than a preset threshold, the alarm is received by the RSU. If the RSU receives n alarms about the accident ε, the RSU will use a Bayesian inference algorithm based on multi-factor measurement to calculate the credibility of these n alarms. If the alarm credibility is greater than the preset trust threshold, the alarm is broadcast; if it is less than the trust threshold, the alarm is discarded. After the alarm is broadcast, the alarm content is uploaded to the event chain.

[0014] When post-incident accountability is required, the vehicle applies for accountability from the Road Infrastructure Unit (RSU) through the management platform. The RSU sends the required authentication information to the identity information chain. After verification, the result is returned to the RSU, which then uses the vehicle identifier V... ID Query the events reported by vehicles in the event chain;

[0015] Step 3: When a vehicle receiving an alert passes through the area where an emergency occurs (ε), it submits a verification request to the nearest Road Infrastructure Unit (RSU). To prevent collusion attacks by malicious vehicles, the RSU uses a voting system to mitigate collusion after receiving a certain number of votes. Based on the voting results, the RSU updates the reputation value of the alerted vehicle and uploads it to the reputation chain.

[0016] Specifically, joining the blockchain network as described in the first step refers to:

[0017] Whenever a vehicle applies to join the blockchain network, a vehicle registration request identifier V is first generated. R V R Includes basic information related to the vehicle, namely the vehicle identifier V. ID Vehicle age V age and sensor list V sensor Subsequently, the V RThe request will be sent to the nearest Road Infrastructure Unit (RSU). If the vehicle is no more than 15 years old and has all the necessary sensors to join the network, the RSU will generate a unique Session identifier to effectively register the vehicle to the blockchain network. Each Session identifier includes a request identifier V. R The current timestamp T and the identifier RSU of the Road Infrastructure Unit (RSU) where the registered vehicle is located. ID And generate a secure and unique hash value representing the session information using the hash function h:

[0018] Session = h(V R ,T,RSU ID (1)

[0019] While creating a session, the Road Infrastructure Unit (RSU) also performs the following tasks: generating a key pair and assigning a public key Pk to the vehicle. vj and a private key Sk vj It also provides the vehicle with a digital certificate (Cert) and a public key (Pk). vj This serves as a pseudo-identity for the vehicle within the blockchain network, ensuring the vehicle's privacy within the network. The content of the blocks in the identity information chain is shown in (2):

[0020] {V ID V age V sensor ,Session,Pk vj ,Cert} (2)

[0021] The management platform sends the vehicle's ID to the identity information chain to request the vehicle's identity information. After receiving the request signed by the management platform, the identity information chain verifies the signed request and searches for the relevant vehicle's identity information certificate on the blockchain. The queried identity information certificate is sent to the smart contract for verification.

[0022] If a vehicle is joining the network for the first time, its initial reputation will be set to Rep, which is a parameterizable variable that reflects the vehicle's minimum reliable reputation value. The system will lower the reputation of vehicles that spread false information and gradually increase the reputation of vehicles that spread true information.

[0023] If an emergency occurs within a 500-meter coverage radius of a Road Facilities Unit (RSU), denoted as ε, then nearby vehicles, such as V... j (j∈1,...,n), an emergency is detected by the OBU and converted into an alarm with a fixed format. As shown in (3):

[0024]

[0025] Among them, Pk vj The public key assigned to the Road Facilities Unit (RSU). Indicates the time of the incident (obtained via the TEE's built-in clock). This indicates the location where the accident ε occurred (obtained via a coordinate extraction algorithm called by the TEE). Indicates vehicle V j A detailed description of the incident ε is then provided, followed by the calculation of an alarm using a hash algorithm. hash value Get the current time from TEE. and current position coordinates Use signature algorithm Generate a signature with timestamp and location stamp. As shown in (4):

[0026]

[0027] Finally, vehicle V j Generate alarm And send it to the Road Facilities Unit (RSU), as shown in (5):

[0028]

[0029] Specifically, the improved Bayesian inference algorithm based on multi-factor measurement described in the second step is as follows:

[0030] In calculating alarm credibility At the same time, the impact of two key factors on the credibility of this communication alert is considered: the reputation value (CW) of the alerting vehicle. j and Environmental Trust Value (CW) env As shown in (6):

[0031]

[0032] Where parameters α and β represent the weights of the broadcast vehicle reputation value and environmental trust value in the credibility of this alarm, respectively, α + β = 1, and the environmental trust value is CW. env This reflects the actual situation of the alarm broadcast by the vehicle that issued the alarm during this communication. Considering that the environmental trust value is affected by the freshness of the alarm and the distance between the alarm generation location and the accident location, specifically, the longer the interval between the alarm generation time and the accident occurrence time, the lower the environmental trust value; and the farther the distance between the alarm generation location and the accident location, the lower the environmental trust value will be. env As shown in (7):

[0033] CW env =CWf / 2+CW l / 2 (7)

[0034] Among them, CW f and CW l These represent alert freshness and alert generation location, respectively. (CW) f and CW l Environmental Trust Value (CW) env Both have an impact, define t Th and d Th Assuming effective time and effective distance thresholds for alarms, the Road Facilities Unit (RSU) can [access these thresholds]. Obtain the time of the accident Location of the accident Alarm generation time and alarm generation location The alarm freshness Δt and the distance Δd between the alarm generation location and the accident occurrence location are calculated using formulas (8) and (9), respectively.

[0035]

[0036]

[0037] Alert Freshness CW f and alarm generation location CW l Calculate using formulas (10) and (11) respectively;

[0038]

[0039]

[0040] Here, γ is a preset parameter used to adjust CW. f and CW l rate of change, Δt-t Th Δd-d represents the difference between alarm freshness and alarm validity time threshold. Th This represents the difference between the distance between the alarm generation location and the accident occurrence location and the alarm effective distance threshold;

[0041] Suppose that the Road Facilities Unit (RSU) receives n alerts about an accident ε, then the RSU will calculate the confidence level of these n alerts. To obtain the alarm confidence set regarding accident ε Finally, based on the alarm credibility set C ε The aggregation confidence of the occurrence of the accident ε is calculated using the Bayesian inference formula. The calculation process is shown in (12):

[0042]

[0043] Where P(ε) is the prior probability of event ε occurring. It is the negation of ε. A trust threshold T is pre-set. Th If P(ε|C) ε )≥T Th If the alarm is credible, then it is considered reliable; otherwise, it is considered unreliable.

[0044] Specifically, the voting system described in step three is as follows:

[0045] When a vehicle receiving an alert passes through the area where an emergency occurred (ε), it submits a verification request to the nearest Road Facilities Unit (RSU). After receiving a certain number of votes, the RSU integrates the received approval votes (Ack). j and opposition to Nack j The number of [trust levels] is used to calculate the trust level, known as TR.

[0046]

[0047] After receiving a certain number of votes, the Road Facilities Unit (RSU) will combine the voting results. If a reasonable percentage of vehicles verify the authenticity of the alarm event, the event is considered a real event, and the reputation score of the alarming vehicle will increase. However, if a minimum percentage of vehicles verify the authenticity of the alarm, it will be considered a false event, and the vehicle's reputation score will decrease. If the total number of vehicles that verify the event as a real event is close to the total number of vehicles that verify the event as a false event, it will be considered undefined, and the vehicle's reputation value will not change.

[0048] After the voting process, if the event is confirmed as genuine, the reputation score of the vehicle that issued the alert will increase. The calculation process is shown in (14):

[0049]

[0050] The current credit rating of the vehicle that issued the alarm. This refers to the vehicle's new reputation;

[0051] If the incident is determined to be a false alarm, the reputation score of the vehicle that issued the alert will be lowered. The calculation process is shown in (15):

[0052]

[0053] EAF refers to the number of times a vehicle sends an erroneous alert within a given time window;

[0054] Vehicles are encouraged to send verification alerts; vehicles that correctly verify their alerts to the Road Facilities Unit (RSU) will have their reputation score increased. The calculation process is shown in (16):

[0055]

[0056] θ is a value in the range [0,1], representing a parameterizable gain constant.

[0057] The beneficial effects of this invention are as follows: First, it proposes a multi-chain interaction model for vehicle-to-everything (V2X) networks to solve the problems of storage chaos and low query efficiency. Second, it designs an identity information chain for identity registration and authentication, thereby eliminating the limitations of third-party CA institutions. Third, it designs an improved Bayesian inference algorithm based on multi-factor measurement to calculate alarm credibility; if the alarm credibility is lower than a preset threshold, the alarm will not be issued. Fourth, it designs a voting system to mitigate the problem of malicious vehicle collusion attacks, calculating the reputation value of the vehicle that issued the alarm; when the vehicle's reputation value is lower than a preset threshold, its subsequent network activities will be rejected. Attached Figure Description

[0058] Figure 1 This is a diagram of the vehicle network architecture of the present invention;

[0059] Figure 2 This is a diagram illustrating the consensus process of the PoA consensus algorithm of this invention.

[0060] Figure 3 This is the multi-chain interaction model of the present invention;

[0061] Figure 4 A flowchart is added to ensure the trustworthiness of blockchain nodes in this invention. Detailed Implementation

[0062] To provide a more detailed description of the present invention and to facilitate understanding by those skilled in the art, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. The embodiments in this section are for illustrative purposes and are not intended to limit the present invention.

[0063] Example 1: A multi-chain-based vehicle network trusted reputation assessment and management system, comprising the following parts:

[0064] Please see Figure 1 The framework is divided into four layers from bottom to top: the vehicle layer, the network layer, the blockchain layer, and the application layer. System components include vehicle nodes, road infrastructure units (RSUs), blockchain, and a management platform. These mobile nodes and infrastructure communicate with each other through communication methods such as DSRC (Dedicated Short Range Communication), LTE (Long Term Evolution), 4G, and 5G to achieve data sharing.

[0065] Vehicle Layer and Network Layer: Vehicle Nodes: Each vehicle is equipped with an Onboard Unit (OBU) to support communication between vehicles and between vehicles and infrastructure. The OBU communicates wirelessly with other vehicles' OBUs and roadside infrastructure (such as roadside units), and has some computing power to perform simple calculations, including detecting and reporting various road condition events. The OBU plays a crucial role in vehicle-to-everything (V2X) communication, transmitting traffic information, assisting vehicles in intelligent driving, improving road safety, and supporting a range of vehicle-to-vehicle communication and services. It typically includes components such as wireless communication modules, location awareness technology, a Trusted Execution Environment (TEE), processors, and storage devices to enable effective communication between vehicles and between vehicles and infrastructure. Road Infrastructure Units (RSUs): Devices installed at road edges or intersections to communicate with vehicles and other RSUs. RSUs play a vital infrastructure role in V2X, supporting communication between vehicles and between vehicles and infrastructure. RSUs are typically equipped with wireless communication devices, such as Wi-Fi or cellular communication modules, to communicate with moving vehicles and other RSUs. They possess sufficient computing power, network communication capabilities, and storage space, and are equipped with TEEs. The Road Infrastructure Unit (RSU), acting as a relay station between vehicle nodes and the application layer, is responsible for event collection and reporting, reputation updates and management, and the coordination of event chain and reputation chain block production. This invention assumes that the Road Infrastructure Unit (RSU) is completely trustworthy.

[0066] Blockchain Layer: The framework comprises three chains: the identity information chain, the event chain, and the reputation chain. All three chains in this system employ the Proof-of-Agent (PoA) consensus algorithm. Please refer to [link / reference]. Figure 2 The diagram illustrates the consensus process of the PoA consensus algorithm. Road Facility Units (RSUs) act as validator nodes, while vehicles are ordinary nodes. When a vehicle reports a new alert, the nearest authority node (RSU) is designated to receive it. Upon receiving the alert, the RSU performs calculations and reaches a consensus among authority nodes based on the time order of the RSU calculation results to determine the next block generator. Subsequently, the authority node generates a new block and signs its contents with its private key. The digital signature is added to the newly generated block, and the block header includes a field storing the generator's digital signature. The new block is broadcast to the network, and other authority nodes obtain it and verify the validity of the digital signature using the generator's public key. If the digital signature verification passes, the other authority nodes accept the new block and add it to their local blockchain.

[0067] Application layer: Includes a management platform with multiple modules, such as joining the blockchain network, reporting alerts, verifying alerts, and post-event accountability.

[0068] Please see Figure 3 The above describes a multi-chain interaction model.

[0069] Please see Figure 4 The above is a flowchart of the trusted joining process for blockchain nodes.

[0070] Whenever a vehicle applies to join the blockchain network, a vehicle registration request identifier V is first generated. R V R Includes basic information related to the vehicle, namely the vehicle identifier V. ID Vehicle age V age and sensor list V sensor Subsequently, the V R The request will be sent to the nearest Road Infrastructure Unit (RSU). If the vehicle is no more than 15 years old and has all the necessary sensors to join the network, the RSU will generate a unique session identifier to effectively register the vehicle into the network. Each session includes a request identifier V. R The current timestamp T and the identifier of the RSU to which the registered vehicle belongs. ID It then generates a secure and unique hash value representing the session information using a hash function h.

[0071] Session = h(V R ,T,RSU ID (1)

[0072] While creating a session, the Road Infrastructure Unit (RSU) also performs the following tasks: generating a key pair and assigning a public key Pk to the vehicle. vj and a private key Sk vj It also provides a digital certificate (Cert) for the vehicle and a public key (Pk). vj This serves as a pseudo-identity for the vehicle within the blockchain network, ensuring the vehicle's privacy within the network. The content of the blocks in the identity information chain is shown in (2):

[0073] {V ID V age V sensor ,Session,Pk vj ,Cert} (2)

[0074] The Road Infrastructure Unit (RSU) sends the vehicle's ID to the Identity Information Chain, requesting the vehicle's identity information. Upon receiving the request signed by the RSU, the Identity Information Chain verifies the signature and searches the blockchain for the relevant vehicle's identity certificate. The queried identity certificate is then sent to a smart contract for verification.

[0075] If a vehicle is joining the network for the first time, its initial reputation is set to Rep, a parameterizable variable reflecting the vehicle's minimum reliable reputation value. The system lowers the reputation of vehicles spreading false information and gradually increases the reputation of vehicles spreading true information.

[0076] If an emergency occurs within a 500-meter coverage radius of a Road Facilities Unit (RSU) (denoted as ε), then nearby vehicles, such as V... j (j∈1,...,n), an emergency is detected by the OBU and converted into an alarm with a fixed format. As shown in (3):

[0077]

[0078] Among them, Pk vj The public key assigned to the Road Facilities Unit (RSU). Indicates the time of the incident (obtained via the TEE's built-in clock). Indicates the location of the accident (obtained via TEE calling a coordinate extraction algorithm). Indicates vehicle V j A detailed description of the incident ε. Then, an alarm is calculated using a hash algorithm. hash value Get the current time from TEE. and current position coordinates ( Use signature algorithm Generate a signature with timestamp and location stamp. As shown in (4):

[0079]

[0080] Finally, vehicle V j Generate alarm And send it to the RSU, as shown in (5):

[0081]

[0082] When an alarm needs to be sent, the vehicle requests it from the Road Infrastructure Unit (RSU) through the management platform. The RSU sends the required authentication information to the identity information chain. After verification, the result is returned to the RSU. The RSU then queries the vehicle's reputation value in the reputation chain based on the information in the identity information chain and decides whether to send an alarm based on the vehicle's reputation value. If the vehicle's reputation value is greater than a preset threshold, an alarm is sent to the RSU.

[0083] If a Road Facilities Unit (RSU) receives n alerts about an accident ε, the RSU will calculate the confidence level of these n alerts. If the confidence level of an alert is greater than a preset confidence threshold, the alert will be broadcast; otherwise, the alert will be discarded.

[0084] In calculating alarm credibility In this study, the method considers the impact of two key factors on the credibility of the communication alert: the reputation value (CW) of the alerting vehicle. j and Environmental Trust Value (CW) env As shown in (6):

[0085]

[0086] Here, parameters α and β represent the weights of the broadcast vehicle reputation value and environmental trust value in the credibility of this alarm, respectively, with α + β = 1. Environmental trust value CW env This reflects the actual situation of the alarm broadcast by the vehicle that issued the alert during this communication. The environmental trust value is considered to be affected by the freshness of the alarm and the distance between the alarm generation location and the accident location. Specifically, the longer the interval between the alarm generation time and the accident occurrence time, the lower the environmental trust value; and the greater the distance between the alarm generation location and the accident location, the lower the environmental trust value will also be. CW env As shown in (7):

[0087] CW env =CW f / 2+CW l / 2 (7)

[0088] Among them, CW f and CW l These represent alert freshness and alert generation location, respectively. (CW) f and CW l Environmental Trust Value (CW) env Both have an impact. Define t Th and d Th The effective time threshold and effective distance threshold for the alarm. The RSU can [access the alarm from...]. Obtain the time of the accident from the middle. Location of the accident Alarm generation time and alarm generation location The alarm freshness Δt and the distance Δd between the alarm generation location and the accident location are calculated using formulas (8) and (9), respectively.

[0089]

[0090]

[0091] Alert Freshness CW f and alarm generation location CW l Calculate using formulas (10) and (11) respectively.

[0092]

[0093]

[0094] Here, γ is a preset parameter used to adjust CW. f and CW l The rate of change of Δt-t Th Δd-d represents the difference between alarm freshness and alarm validity time threshold. Th This represents the difference between the distance between the alarm generation location and the accident location and the alarm effective distance threshold.

[0095] Suppose that the Road Facilities Unit (RSU) receives n alerts about an accident ε, then the RSU will calculate the confidence level of these n alerts. To obtain the alarm confidence set regarding accident ε Finally, based on the alarm credibility set C ε The aggregation confidence of the occurrence of the accident ε is calculated using the Bayesian inference formula. The calculation process is shown in (12):

[0096]

[0097] Where P(ε) is the prior probability of event ε occurring. It is the negation of ε. This solution pre-sets a trust threshold T. Th If P(ε|C) ε )≥T Th If the alarm is credible, then it is considered reliable. Otherwise, the alarm is considered unreliable.

[0098] Once the broadcast alarm is completed, the alarm content is uploaded to the event chain.

[0099] When a vehicle receiving an alert passes through the area where an emergency occurred (ε), it will submit a verification request to the nearest Road Facilities Unit (RSU). After receiving a certain number of votes, the nearest Road Facilities Unit (RSU) will consolidate the approved (Ack) votes. j and opposition to Nack j The number of [trust levels] is used to calculate the trust level, known as TR.

[0100]

[0101] After receiving a certain number of votes, the Road Facilities Unit (RSU) merges the votes. If a reasonable percentage of vehicles verify the authenticity of the alarm event, the event is considered genuine, and the reputation score of the alarming vehicle increases. However, if a minimum percentage of vehicles verify the alarm's authenticity, it is considered a false alarm, and the vehicle's reputation score decreases. If the total number of vehicles verifying the event as genuine is close to the total number of vehicles verifying it as false, it is considered undefined, and the vehicle's reputation value remains unchanged.

[0102] After the voting process, if the event is confirmed as genuine, the reputation score of the vehicle that issued the alert will increase. The calculation process is shown in (14):

[0103]

[0104] The current credit rating of the vehicle that issued the alarm. Refers to the vehicle's new reputation.

[0105] If the incident is determined to be a false alarm, the reputation score of the vehicle that issued the alert will be lowered. The calculation process is shown in (15):

[0106]

[0107] EAF refers to the number of times a vehicle sends an erroneous alert within a given time window.

[0108] Vehicles are encouraged to send verification alerts. Vehicles that correctly verify their alerts to the Road Facilities Unit (RSU) will have their reputation score increased. The calculation process is shown in (16):

[0109]

[0110] θ is a value in the range [0,1], representing a parameterizable gain constant.

[0111] The Road Facilities Unit (RSU) updates the reputation value of alert vehicles based on the voting results and uploads it to the reputation chain.

[0112] This invention designs an improved Bayesian inference algorithm based on multi-factor measurement to calculate alarm credibility, thereby enhancing the reliability of the reputation assessment process. It also employs a voting system to mitigate malicious vehicle collusion attacks. This invention effectively improves the scalability and security of blockchain-based vehicle-to-everything (V2X) reputation systems, enhances the real-time performance of alarms, and ultimately improves the safety and efficiency of intelligent transportation systems.

[0113] The above description is merely a specific idea of ​​the present invention to facilitate understanding by researchers in the field. However, the implementation of the present invention is not limited to the above description. Those skilled in the art can make improvements or modifications based on the present invention, and all improvements or modifications utilizing the concept of the present invention are considered to be within the scope of protection of the present invention.

Claims

1. A multi-chain-based trusted reputation assessment and management method for vehicle-to-everything (V2X) networks, characterized in that: Includes the following steps: Step 1: Use blockchain to register and authenticate identities. When a vehicle enters the system, it first needs to register on the identity information chain to join the blockchain network. Step 2: When an alarm needs to be sent, the vehicle requests an alarm from the Road Infrastructure Unit (RSU) through the management platform. The RSU sends the required authentication information to the identity information chain. After verification, the result is returned to the RSU. The RSU then queries the vehicle's reputation value in the reputation chain based on the information in the identity information chain and decides whether to receive the alarm based on the vehicle's reputation value. If the vehicle's reputation value is greater than a preset threshold, the alarm is received by the RSU. The RSU receives n alarms related to the accident. If an alarm is triggered, the RSU will use a Bayesian inference algorithm based on multi-factor measurement to calculate the confidence level of these n alarms. If the alarm confidence level is greater than the preset trust threshold, the alarm will be broadcast; if it is less than the trust threshold, the alarm will be discarded. After the alarm is broadcast, the alarm content is uploaded to the event chain. When post-incident accountability is required, the vehicle applies for post-incident accountability from the Road Infrastructure Unit (RSU) through the management platform. The RSU sends the required authentication information to the identity information chain. After verification, the result is returned to the RSU, which then uses the vehicle identifier... Query the events reported by vehicles in the event chain; Step 3: When the vehicle receiving the alarm passes through the emergency... In the area where the alarm occurs, the alarm is submitted for verification to the nearest Road Infrastructure Unit (RSU). After receiving a certain number of votes, the RSU uses a voting system to mitigate collusion, updates the reputation value of the alarm vehicle based on the voting results, and uploads it to the reputation chain.

2. The method for trustworthy reputation assessment and management of vehicle-to-everything (V2X) networks based on multi-chain as described in claim 1, characterized in that, The first step of joining the blockchain network specifically refers to: Whenever a vehicle applies to join the blockchain network, a vehicle registration request identifier is first generated. , Includes basic information related to the vehicle, namely the vehicle identifier. Vehicle age and sensor list Subsequently, the The message will be sent to the nearest Road Infrastructure Unit (RSU). If the vehicle is no more than 15 years old and has all the sensors required to join the network, the RSU will generate a unique session identifier. To effectively register vehicles to the blockchain network, each session identifier Including request identifier The current timestamp T and the identifier of the Road Facilities Unit (RSU) where the registered vehicle is located. And generate a secure and unique hash value representing the session information using the hash function h: （1） While creating a session, the Road Infrastructure Unit (RSU) also performs the following tasks: generating a key pair and assigning a public key to the vehicle. and a private key and provide digital certificates for vehicles. Public key As the vehicle's pseudo-identity in the blockchain network, the content of the block in the identity information chain is shown in (2): （2） The management platform sends the vehicle's ID to the identity information chain to request the vehicle's identity information. After receiving the request signed by the management platform, the identity information chain verifies the signed request and searches for the relevant vehicle's identity information certificate on the blockchain. The queried identity information certificate is sent to the smart contract for verification. If a vehicle is joining the network for the first time, its initial reputation will be set to Rep, which is a parameterizable variable that reflects the vehicle's minimum reliable reputation value. The system will lower the reputation of vehicles that spread false information and gradually increase the reputation of vehicles that spread true information. If an emergency occurs within the coverage radius of a Road Facilities Unit (RSU), it is represented as Then the nearby vehicles V j (j∈1,...,n) The OBU detects an emergency and converts it into a fixed-format alarm. As shown in (3): （3） in, The public key assigned to the Road Facilities Unit (RSU). Indicates the time of the accident, ( , ) indicates an accident Location of occurrence, Indicates vehicle V j For the accident A detailed description is then provided, and an alarm is calculated using a hash algorithm. The hash value H( ), and retrieve the current time from the TEE. and current position coordinates ( , ), using signature algorithm Generate a signature with timestamp and location stamp. D ， As shown in (4): D （4） Finally, the vehicle Generate alarm And send it to the Road Facilities Unit (RSU) as shown in (5): （5）。 3. The method for trustworthy reputation assessment and management of vehicle-to-everything (V2X) networks based on multi-chain as described in claim 2, characterized in that, The improved Bayesian inference algorithm based on multi-factor measurement described in the second step is as follows: In calculating alarm credibility At the same time, the impact of two key factors on the credibility of this communication alert is considered: the reputation value of the alerting vehicle. j and environmental trust value As shown in (6): （6） Among them, parameters and These represent the weights of the broadcast vehicle's reputation value and the environment's trust value in the credibility of this alert, respectively. Environmental Trust Value This reflects the actual situation of the alarm broadcast by the vehicle that issued the alarm during this communication. The longer the interval between the alarm generation time and the accident occurrence time, the lower the environmental trust value; and the farther the distance between the alarm generation location and the accident occurrence location, the lower the environmental trust value will also be. As shown in (7): （7） in, and These represent the alert freshness and the alert generation location, respectively. and Trust value for the environment Both have an impact, definition and Assuming effective time and effective distance thresholds for alarms, the Road Facilities Unit (RSU) can [access these thresholds]. Obtain the time of the accident Location of the accident ( , ) Alarm generation time and alarm generation location ( , ) Alert freshness and the distance between the alarm generation location and the accident location d is calculated using formulas (8) and (9) respectively; （8） d= （9） Alert Freshness and alarm generation location Calculate using formulas (10) and (11) respectively; （10） （11） in, It is a preset parameter used for adjustment. and rate of change, This represents the difference between alarm freshness and the alarm validity period threshold. This represents the difference between the distance between the alarm generation location and the accident occurrence location and the alarm effective distance threshold; Suppose the Road Facilities Unit (RSU) receives n reports about an accident. If an alarm is triggered, the Road Facilities Unit (RSU) will calculate the confidence level of these n alarms. (i∈1,...,n) to obtain information about the accident Alarm credibility set ={ , ,…, Finally, based on the alarm credibility set Accidents are calculated using Bayesian inference formulas. The calculation process for the aggregation confidence level is shown in (12): （12） in ( ) is an event The prior probability of occurrence, , yes The negation event, , A trust threshold T is pre-set. Th ,if If the alarm is credible, then it is considered reliable; otherwise, it is considered unreliable.

4. The method for trustworthy reputation assessment and management of vehicle-to-everything (V2X) networks based on multi-chain as described in claim 1, characterized in that, The voting system described in step three is as follows: When the vehicle receiving the alarm passes through the emergency... The area where the incident occurred will be submitted for verification to the nearest Road Infrastructure Unit (RSU). After receiving a certain number of votes, the nearest Road Infrastructure Unit (RSU) will integrate the votes received. and opposition The number of [trust levels] is used to calculate the trust level, known as TR. （13） After receiving a certain number of votes, the Road Facilities Unit (RSU) will combine the votes. If a reasonable percentage of vehicles verify the authenticity of the alarm event, the event is considered a real event, and the reputation score of the alarming vehicle will increase. However, if a minimum percentage of vehicles verify the authenticity of the alarm, it will be considered a false event, and the vehicle's reputation score will decrease. If the total number of vehicles that verify the event as a real event is close to the total number of vehicles that verify the event as a false event, it will be considered undefined, and the vehicle's reputation value will not change. After the voting process, if the event is confirmed as genuine, the reputation score of the vehicle that issued the alert will increase. The calculation process is shown in (14): （14） The current credit rating of the vehicle that issued the alarm. This refers to the vehicle's new reputation; If the incident is determined to be a false alarm, the reputation score of the vehicle that issued the alert will be lowered. The calculation process is shown in (15): （15） This refers to the number of times a vehicle sends an error alert within a given time window; Vehicles are encouraged to send verification alerts to the Road Facilities Unit (RSU). Vehicles that correctly verify their alerts to the RSU will have their reputation score increased. The calculation process is shown in (16): （16） It is a value in the range [0,1], representing a parameterizable gain constant.

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