Internet of vehicles security and credible message sharing method based on block chain and trust management

Abstract

The invention belongs to the technical field of blockchain and Internet of Vehicles security management, and relates to an Internet of Vehicles security and credible message sharing method based on blockchain and trust management, comprising: a message providing vehicle records and broadcasts a message, and a message receiving vehicle receives the message, scores the authenticity of the message, and broadcasts the message to a consensus vehicle; the consensus vehicle performs usefulness scoring on each authenticity score s1, i, when the number of high usefulness scores is greater than a threshold value Q, the data (m, s1, i, s2, i, c, t) is uploaded to the accounting node, and s2, i, c are high usefulness scores of the consensus vehicle c on s1, i; the accounting node receives and verifies the data (m, s1, i, s2, i, c, t), packages the verified data into a block and stores the block into a block chain; the RSU calculates the trust value of the vehicle in the area and shares the trust value to an RSU cluster; the RSU cluster makes a trust decision on the vehicle according to the trust value of the vehicle; according to the method, authenticity scoring and usefulness scoring are carried out on the message, the credibility of the shared message in the Internet of Vehicles is improved, and the authenticity and integrity of the message are ensured in combination with the block chain technology.

Description

Technical Field

[0001] The present invention belongs to the technical field of blockchain and Internet of Vehicles security management, and specifically relates to a method for sharing secure and trusted messages in an Internet of Vehicles based on blockchain and trust management. Background Art

[0002] With the continuous development of communication technology, artificial intelligence, big data and other fields, the Internet of Vehicles (IoV) has emerged and has become an important platform for communication, interaction and collaboration between intelligent vehicles. IoV devices are connected through base stations to achieve more efficient vehicle-to-vehicle (V2V) communication, which not only helps vehicles obtain real-time traffic information, but also enhances environmental perception and computing decision-making capabilities. However, the distributed network architecture, high dynamics and high openness of the IoV have brought huge challenges to the message sharing and security between vehicles.

[0003] Current research focuses on establishing secure communication channels and preventing external attacks to ensure the reliability of communication. However, within the Internet of Vehicles, the interaction and collaboration between vehicles is frequent and most of them occur between unfamiliar vehicles, which makes the authenticity and reliability of message sharing questionable. In addition, misleading messages spread by malicious vehicles may cause the receiving vehicle to make wrong decisions, interfere with normal driving, and even cause accidents, threatening personal safety.

[0004] Therefore, in the V2V scenario, improving the authenticity, reliability and security of message sharing between vehicles has become an urgent problem to be solved. Summary of the invention

[0005] To solve the above problems in the prior art, the present invention adopts a secure and trusted message sharing method for the Internet of Vehicles based on blockchain and trust management, including: an Internet of Vehicles message sharing network, the Internet of Vehicles message sharing network including: a vehicle message broadcast layer, a vehicle consensus layer, an accounting layer and a trust decision layer; the vehicle message broadcast layer includes ordinary vehicles, and ordinary vehicles include message providing vehicles and message receiving vehicles; the consensus layer includes consensus vehicles; the accounting layer includes accounting nodes; the trust decision layer includes an RSU cluster composed of roadside units RSU.

[0006] The secure and trusted message sharing method of the Internet of Vehicles includes:

[0007] S1. The message providing vehicle records and broadcasts the message m during driving. The message receiving vehicle i receives the message m, scores the authenticity of the message m, and calculates the authenticity score s. 1,i Broadcast to consensus vehicles;

[0008] S2, consensus vehicle receives message m and authenticity score s 1,i, and give each authenticity score s 1,i Usefulness scoring, when all authenticity scores s 1,i When the number of high usefulness scores is greater than the threshold Q, the authenticity score s 1,i The consensus vehicle c that gives a high usefulness score will send data (m, s 1,i ,s 2,i,c ,t) uploaded to the accounting node; where m is the message, s 2,i,c Score s for the authenticity of consensus vehicle c 1,i The high usefulness score of , t is the current timestamp;

[0009] S3. The accounting node receives and verifies the data uploaded by the consensus vehicle. If the verification is successful, the data uploaded by the consensus vehicle is packaged into blocks and the blocks are stored in the blockchain; otherwise, the data uploaded by the consensus vehicle is discarded;

[0010] S4. RSU calculates the trust value of the vehicle in the area and shares the trust value of the vehicle with the RSU cluster; the RSU cluster makes a trust decision on the vehicle based on the trust value of the vehicle;

[0011] S5. Ordinary vehicles or consensus vehicles that need to request messages send message requests to the blockchain to obtain the required messages.

[0012] Authenticity scoring of message m includes: the message receiving vehicle calculates the distance to the location where message m occurs and predicts the upcoming route. If the distance between the message receiving vehicle and the location where message m occurs is greater than a distance threshold, or the location where message m occurs is on the upcoming route predicted by the message receiving vehicle, then an authenticity score is performed on message m; otherwise, no authenticity score is performed.

[0013] The consensus vehicle performs usefulness scoring on the authenticity score, including: the consensus vehicle predicts the path to be traveled, and if the message corresponding to the authenticity score is located on the path to be traveled by the consensus vehicle, the authenticity score is scored for usefulness; otherwise, no usefulness scoring is performed.

[0014] In step S2, the threshold Q is When all authenticity scores s 1,i The number of high usefulness scores H that satisfies When all the authenticity scores of message m are s 1,i Re-evaluate the usefulness; when all authenticity ratings s 1,i The number of high usefulness scores H that satisfies , the message m is deemed invalid and discarded; where V is the number of consensus vehicles and L is the number of authenticity scores of message m.

[0015] The accounting layer also includes: a reward and punishment mechanism, which includes a trust threshold; the accounting node uses the reward and punishment mechanism to adjust the trust value of the consensus vehicle, and automatically replaces the consensus vehicle with a trust value less than the trust threshold with the vehicle with the highest trust value among ordinary vehicles.

[0016] The accounting node uses the reward and punishment mechanism to adjust the trust value of the consensus vehicle, including: in step S2, when all authenticity scores s 1,i When the number of high usefulness scores is greater than the threshold Q, the accounting node increases the trust value of the consensus vehicle with high usefulness scores and reduces the trust value of the consensus vehicle with low usefulness scores through the smart contract.

[0017] The RSU calculates the trust value of the vehicle in the area including: the RSU calculates the trust evidence of the vehicle in the area, and calculates the trust value of the vehicle based on the trust evidence; the trust value of the vehicle calculated based on the trust evidence includes:

[0018]

[0019] Among them, T j (k) represents the trust value of vehicle j at time k, w C Cooperation degree C j The weight of (k), w F Familiarity F ij The weight of (k), is the weight of the authenticity score s1(k), is the weight of the usefulness score s2(k), C j (k) is the cooperation degree of vehicle j at time k, F oj (k) is the familiarity of vehicle j at time k, s1(k) is the authenticity score of the received message by vehicle j at time k, s2(k) is the usefulness score of the received authenticity score by vehicle j at time k, and o is the evaluation vehicle of vehicle j, which can be any vehicle in the Internet of Vehicles message sharing network.

[0020] The RSU cluster includes a weighted adjustment mechanism; sharing the trust value of the vehicle to the RSU cluster includes: when the vehicle enters the area of ​​another new RSU from one RSU area in the RSU cluster, the new RSU inherits the trust value of the vehicle and uses the weighted adjustment mechanism to weighted adjust the trust value of the vehicle to obtain the adjusted trust value.

[0021] The weighted adjustment mechanism is used to adjust the trust value of the vehicle by weighted adjustment, including:

[0022] ω=α×ω net +β×ω v +γ×ω trust

[0023] T new =ωT historical

[0024] Among them, ω represents the weighting factor, α, β, and γ are the weight coefficients of different factors, α+β+γ=1, ω net ,ω v ,ω trust They are the status factor of the Internet of Vehicles message sharing network, the dynamic factor of vehicle behavior, and the stability factor of vehicle trust value, T new represents the adjusted trust value of the vehicle, T historical Represents the trust value of the vehicle before adjustment.

[0025] The RSU cluster makes trust decisions on vehicles based on the trust value of the vehicles, including: RSU allows vehicles with high trust values ​​to communicate normally in the Internet of Vehicles message sharing network; RSU restricts vehicles with low trust values ​​from communicating in the Internet of Vehicles message sharing network, and monitors vehicles with low trust values.

[0026] Beneficial effects:

[0027] 1. The present invention scores the authenticity and usefulness of messages through a multi-layer trust management mechanism, and combines blockchain technology to improve the credibility of shared messages in the Internet of Vehicles, ensuring the authenticity and integrity of messages; 2. The present invention incentivizes the provision of high-quality messages and punishes the propagation of low-quality messages through trust value calculation and trust value reward and punishment mechanism, thereby optimizing the utilization efficiency of system resources; 3. The present invention stores valid messages and scores through blockchain to prevent data tampering and unauthorized access, while improving the efficiency of cross-regional message interaction, shortening the message response time, and enhancing the collaborative working ability of the Internet of Vehicles system; 4. The present invention shares the trust values ​​of vehicles in each RSU area through the RSU cluster, thereby improving the efficiency of cross-regional vehicle trust assessment, and uses a weighted adjustment mechanism to adjust the trust values ​​of cross-regional vehicles, so that the RSU can more reasonably assess the trust status of cross-domain vehicles and avoid misjudgments that may be caused by the transmission of a single trust value. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a specific flow chart of the secure and trusted message sharing method of the Internet of Vehicles based on blockchain and trust management of the present invention;

[0029] Figure 2 This is a scenario diagram of the secure and trusted message sharing method for Internet of Vehicles based on blockchain and trust management of the present invention. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] like Figure 1 , Figure 2 As shown, the present invention adopts a secure and reliable message sharing method for the Internet of Vehicles based on blockchain and trust management, including: an Internet of Vehicles message sharing network, the network including: a vehicle message broadcast layer, a vehicle consensus layer, an accounting layer and a trust decision layer; the vehicle message broadcast layer includes ordinary vehicles, the ordinary vehicles include message providing vehicles (Message providing vehicle, MPV) and message receiving vehicles (Message Receiving Vehicle, MRV), the consensus layer includes consensus vehicles (Consensus vehicle, CV), the accounting layer includes accounting nodes, and the trust decision layer includes an RSU cluster composed of RSUs;

[0032] The secure and trusted message sharing method of the Internet of Vehicles includes:

[0033] S1. The message providing vehicle records and broadcasts valuable event messages m encountered on the road during driving. The message receiving vehicle receives the message m, scores the authenticity of the broadcasted message m based on its own observations, and broadcasts the authenticity score to the consensus vehicle;

[0034] The message providing vehicle (MPV) actively selects and broadcasts messages, which can cover a variety of categories, such as traffic conditions, road information, infrastructure information, services and facilities, and emergency events. The specific message classification is shown in Table 1. The broadcasting behavior of MPV can deliver important information to surrounding vehicles in a timely manner, improving the efficiency of information sharing.

[0035] Table 1 Message classification

[0036]

[0037]

[0038] The authenticity score of the message receiving vehicle (MRV) is based on a scale of 1 to 5, where 1-2 points indicate that the message is unreliable and is a false message; 3 points indicate that the authenticity of the message needs further verification; 4-5 points indicate that the message is authentic and reliable. The premise of the score is that the location of the message is near the MRV or on its upcoming driving path. Therefore, the MRV can score the authenticity of the message based on actual observations. The MRV broadcasts these scores to the consensus vehicle nodes, providing basic data for subsequent trust evaluation.

[0039] MRV's authenticity score mainly solves the "authenticity" problem of the message, that is, whether the message is consistent with the actual situation. Since MRV is near the area where the message occurs, it can provide the most direct observation results based on the current environment, road conditions or events, thereby evaluating the authenticity of the message. In other words, the authenticity score relies on MRV's direct observation of the current environment to ensure that the message is consistent with the actual situation.

[0040] Method for determining whether the location where the message is sent is near the MRV: In the Internet of Vehicles, vehicles are usually equipped with GPS or other positioning systems; when the MPV broadcasts a message, it will include the latitude and longitude information of the message; the MRV can calculate the distance to the location where the message is sent based on its own GPS position; if the distance is within the matrix threshold range of the default value (for example, within 300 meters), it is considered that the message is sent near the MRV.

[0041] Method for determining whether the location of the message is on the path that the MRV is about to travel: The MRV can predict its possible future travel path based on its current speed and direction combined with the driving route of the navigation system. If the location of the message is on the MRV's expected driving path, the MRV can consider that the message is related to its own driving, and thus conduct further authenticity assessment.

[0042] S2, consensus vehicle receives message m and authenticity score s 1,i , and give each authenticity score s 1,i Usefulness scoring, when all authenticity scores s 1,i When the number of high usefulness scores is greater than the threshold Q, the authenticity score s 1,i The consensus vehicle c that gives a high usefulness score will send data (m, s 1,i ,s 2,i,c ,t) uploaded to the accounting node; where m is the message, s 2,i,c Score s for the authenticity of consensus vehicle c 1,i , t is the current timestamp; preferably, the threshold Q is V is the number of consensus vehicles, and L is the number of authenticity scores of message m.

[0043] The main tasks of the consensus vehicle CV are as follows:

[0044] Receiving messages: CV is responsible for receiving event messages sent from MPV and authenticity scores sent from MRV.

[0045] Usefulness score: CV will evaluate the usefulness of the authenticity score sent by MRV to ensure the authenticity of the message and reduce the possibility of tampering during the message transmission. If an authenticity score can provide effective help to other vehicles, CV will give a high usefulness score (4-5 points); if an authenticity score does not match the actual situation and has a negative impact on other vehicles, CV will give a low usefulness score (1-3 points). In order to ensure the relevance of the usefulness score, CV only evaluates the authenticity score of the message that occurs on the route it is about to travel.

[0046] CV's usefulness score focuses on the "usefulness" of the message, that is, whether the message can provide effective assistance to vehicles that are about to enter the area. CV is not always located at the place where the message occurs, but evaluates its future value based on the content of the message and the driving route. The evaluation at this stage ensures the practicality and importance of the message to the vehicle's decision-making and prevents the message from interfering with other vehicles. In other words, the usefulness score is designed to evaluate whether the message is helpful to vehicles on the future driving route, so CV will evaluate the message based on the message on its upcoming route to ensure the practicality of the message.

[0047] In one embodiment, the usefulness scoring method includes: CV can combine the authenticity scores of all MRVs for a total judgment: if all other MRVs report the congestion of a certain road section, and a certain MRV gives an inconsistent authenticity score, then CV will consider the score to be inaccurate and give a low usefulness score.

[0048] In one embodiment, the usefulness scoring method includes: CV determines whether MRV is in the area where the message occurs based on the latitude and longitude of the message and the position of MRV; CV matches the time when the message occurs and the time when MRV sends the authenticity score, and determines whether the message and its authenticity score are received within a reasonable time range. If MRV is not in the area where the message occurs, or the consensus vehicle CV does not receive the message and its authenticity score within a reasonable time range, then CV may consider that the authenticity score of the MRV does not match the actual situation, and thus give a low usefulness score; otherwise, a high usefulness score is given.

[0049] Reaching consensus: When all authenticity scores s 1,i The number of high usefulness scores is greater than the threshold , the message is deemed valid and the authenticity score is s 1,i The consensus vehicle c that gives a high usefulness score will send data (m, s 1,i ,s2,i,c ,t) upload to the accounting node; otherwise, if the consensus vehicles fail to reach a consensus on the message, the message will not be recognized as a valid message, and the subsequent processing includes the following points:

[0050] When all authenticity scores s 1,i The number of high usefulness scores H that satisfies When all the authenticity scores of message m are s 1,i Re-rating the usefulness.

[0051] The same message is evaluated only three times. If the proportion of high usefulness scores is still between 1 / 2 and 2 / 3 during the third evaluation, the message will no longer be evaluated and will be considered invalid and discarded.

[0052] When all authenticity scores s 1,i The number of high usefulness scores H that satisfies When the message is received, it is directly deemed invalid and discarded.

[0053] For messages that are considered invalid, the consensus vehicle will broadcast a notification that the message is invalid. When other vehicles receive the notification, they will also discard the message, further preventing the spread of unreliable messages.

[0054] S3. The accounting node receives and verifies the data uploaded by the consensus vehicle. If the verification is successful, the data uploaded by the consensus vehicle is packaged into blocks and the blocks are stored in the blockchain; otherwise, the data uploaded by the consensus vehicle is discarded.

[0055] At the accounting layer, RSU serves as the accounting node, which is responsible for selecting consensus vehicles, replacing consensus vehicles, verifying and packaging data, and executing reward and punishment mechanisms.

[0056] Select consensus vehicles: The accounting node selects vehicles with high reliability, abundant resources and slow status changes as consensus vehicles through trust value evaluation.

[0057] The specific selection process is as follows:

[0058] First, in the early stages of the network, when the network has not been attacked, all vehicle nodes are in a trusted state. Therefore, the accounting node selects the consensus vehicle based on the vehicle's driving status (computing resources, network connection stability, driving route, vehicle status change frequency, etc.).

[0059] Secondly, during the network operation period, the accounting node calculates the trust value of the vehicle based on its behavior (see step S4 for specific calculation) and determines its driving status based on the collected vehicle status information.

[0060] Replacement of consensus vehicle: When the trust value of a consensus vehicle is less than the trust threshold, the accounting node will automatically cancel its consensus qualification, downgrade it to an ordinary vehicle, and replace it with the vehicle with the highest trust value among ordinary vehicles. The trust value ranges from 0 to 1, where 0 indicates maliciousness and 1 indicates trustworthiness. Because the trust value of a consensus vehicle needs to be maintained at a high level, the trust threshold is set to 0.6. When the trust value of a consensus vehicle is lower than 0.6, it will be replaced.

[0061] Verify and package data: The accounting node receives and verifies the messages and scores submitted by the consensus vehicle; the verified data will be packaged into blocks and uploaded to the blockchain to ensure the integrity and traceability of the data.

[0062] The specific verification process is as follows:

[0063] Step 1: Format verification: The accounting node checks whether the uploaded data complies with the predetermined format specifications (such as data type, field integrity, etc.) to ensure that the data has not been tampered with during transmission.

[0064] Step 2: Timestamp verification: Confirm the timestamp of the uploaded data to ensure that the data is submitted within a reasonable time range to avoid the impact of outdated information. The reasonable time range is that the difference between the timestamp of the message upload and the current time should be between 5 and 30 seconds to ensure the timeliness of the information.

[0065] Step 3: Consensus vehicle score consistency check: Check whether the received data has more than 2 / 3 of the consensus vehicles uploaded. If so, determine whether the uploaded usefulness scores are similar. If so, the data can be considered credible and the check passed.

[0066] When the verification is passed, the average value of the uploaded authenticity score and the average value of the uploaded usefulness score are calculated, and the message, the average value of the authenticity score, the average value of the usefulness score and the current timestamp are stored in the blockchain as a record.

[0067] Execute reward and punishment mechanism: In order to ensure the fairness and transparency of the system, the accounting nodes execute reward and punishment measures through smart contracts. 1,i When the number of high usefulness scores is greater than the threshold Q, the accounting node increases the trust value of the consensus vehicle with high usefulness scores and reduces the trust value of the consensus vehicle with low usefulness scores through the smart contract.

[0068] S4. In the trust decision layer, RSU calculates the trust value of vehicles in the area and shares the trust value of the vehicle to the RSU cluster to achieve trust evaluation of vehicles across regions. Finally, the RSU cluster makes trust decisions on the vehicle based on the trust value; the vehicles in the RSU area include ordinary vehicles and consensus vehicles.

[0069] It is implemented in four steps: vehicle trust evidence calculation, vehicle trust value calculation in the region, RSU cluster sharing trust information and trust decision-making.

[0070] Step 1: Collect vehicle data and calculate relevant trust evidence. There are four types of trust evidence, namely the degree of cooperation and familiarity between vehicle nodes, and the authenticity and usefulness scores of messages given by vehicles. The following is an explanation of these four trust evidences.

[0071] Cooperation degree: measures the frequency and closeness of interaction between the evaluated vehicle and other vehicles in the network. Specifically, the cooperation degree reflects the degree to which the evaluated vehicle cooperates with other vehicles in the network over a period of time, that is, it evaluates the cooperation activity of a vehicle in the entire network. The formula is shown below.

[0072]

[0073] Among them, C j (k) represents the cooperation degree of the evaluated car j at time k; N j (k) represents the set of neighbor vehicles that interact with the evaluated vehicle j at time k, and N represents the total number of vehicles in the network.

[0074] Familiarity: Select any vehicle as the evaluation vehicle. The evaluation vehicle refers to the vehicle responsible for trust evaluation of other vehicles (evaluated vehicles) in the Internet of Vehicles. It can be any vehicle in the network with evaluation capabilities; it measures the proportion of common neighbors that the evaluation vehicle and the evaluated vehicle have in the network. Specifically, familiarity reflects the strength of the relationship between the evaluation vehicle and the evaluated vehicle and the frequency of common contact, that is, it evaluates the familiarity and trust basis between two specific vehicles. High familiarity indicates that the two vehicles have more common neighbors and may know and trust each other better. The formula is shown below.

[0075]

[0076] Among them, F oj (k) represents the familiarity between the evaluation car o and the evaluated car j at time k, N o (k) represents the set of neighbor vehicles of the evaluation vehicle o at time k. The neighbor vehicles of the evaluation vehicle o usually refer to other vehicles in the Internet of Vehicles that are close to the evaluation vehicle and can communicate directly with it. N j (k) represents the set of neighboring vehicles of the evaluated vehicle j at time k; N o (k)∩N j (k) represents the set of common neighbors of the evaluating car o and the evaluated car j at time k.

[0077] Authenticity score: refers to the authenticity score of the received message by MRV. The formula is as follows.

[0078]

[0079] The purpose of authenticity scoring is to quickly filter out false news and improve the initial credibility of the news.

[0080] Usefulness score: refers to the usefulness score assigned by the consensus vehicle to the authenticity score issued by the MRV.

[0081]

[0082] The purpose of usefulness scoring is to ensure the authenticity and reliability of the message during dissemination through secondary verification.

[0083] The trust value of each vehicle is calculated based on the above trust evidence. The trust value calculation formula is as follows:

[0084]

[0085] Among them, T j (k) represents the trust value of vehicle j at time k, w C Cooperation degree C j The weight of (k), w F Familiarity F ij The weight of (k), is the weight of the authenticity score s1(k), is the weight of the usefulness score s2(k),

[0086] In order to deal with the problem of delayed trust value update caused by the dynamic movement of vehicles in different areas, the RSU in the new area needs to collect evidence again to calculate the trust value of the vehicle, which may bring network security risks. Therefore, the present invention adopts the sharing of vehicle trust information in the RSU cluster. When the vehicle moves to the new RSU coverage area, the new RSU can immediately access the trust data of the vehicle in other areas, thereby avoiding the trust evaluation from scratch, effectively shortening the response time of trust classification, and improving the real-time performance and reliability of the system. However, considering that the network environment, vehicle behavior pattern and malicious node distribution of different RSU areas may be quite different, simply transferring the trust value when the vehicle crosses the area may lead to deviation in the evaluation result. Therefore, a weighted adjustment mechanism can be adopted, that is, when the vehicle enters the new RSU area, the new RSU not only inherits the trust value, but also makes appropriate weighted adjustments to it. The weighting factor of the weighted adjustment mechanism is calculated by the new RSU based on factors such as the current network status, vehicle behavior and stability of the trust value. Through this mechanism, the RSU can more reasonably evaluate the trust status of cross-domain vehicles and avoid the misjudgment that may be caused by the transfer of a single trust value.

[0087] Specifically, the process of weighted adjustment of the trust value of the vehicle using the weighted adjustment mechanism is as follows:

[0088] Network status evaluation: The new RSU evaluates the current network status, including network delay, bandwidth, signal strength, etc. For example, in the case of poor network conditions, the weight of the trust value may be reduced because an unstable network may lead to unreliable information transmission; in one embodiment, the network delay time, network bandwidth, and signal strength are weighted and normalized to obtain a network status factor.

[0089] Dynamic analysis of vehicle behavior: RSU monitors the behavior patterns of vehicles in the new area, including their driving speed and interactions with other vehicles. If a vehicle exhibits abnormal behavior in the new area (such as sudden stops, sudden lane changes, etc.), its trust value may be reduced; in one embodiment, the vehicle's driving speed and the number of interactions with other vehicles are weighted and normalized to obtain a dynamic behavior factor.

[0090] Trust value stability assessment: RSU analyzes the stability of the trust value to determine whether it has remained consistent over the past time period or whether there have been drastic fluctuations; if the trust value does not change much and remains at a high level, it means that the vehicle is relatively reliable, otherwise its trust value needs to be lowered; in one embodiment, the variance or standard deviation of the trust value over the past time period is calculated and normalized to obtain a stability factor.

[0091] Weighted factor calculation: Based on the above evaluation, RSU calculates a weighted factor for the trust value, the formula is as follows:

[0092] ω=α×ω net +β×ω v +γ×ω trust

[0093] Among them, ω represents the weighting factor, α, β, and γ are the weight coefficients of different factors, α+β+γ=1, ω net ,ω v ,ω trust They are the status factor of the Internet of Vehicles message sharing network, the behavior dynamic factor of the vehicle, and the stability factor of the vehicle trust value. The range of the network status factor, behavior dynamic factor, and stability factor is between 0 and 1.

[0094] Trust value adjustment: Use the weighting factor ω to adjust the trust value, as follows:

[0095] T new =ωT historical

[0096] Among them, T new represents the adjusted trust value, T historical Represents the trust value before adjustment.

[0097] RSU makes trust decisions for all vehicles in the area based on the trust value of the vehicle. For vehicles with high trust values, RSU will allow them to continue to communicate and interact normally in the network; for vehicles with low trust values ​​or suspected malicious intent, RSU may take security measures such as restricting communication and monitoring their behavior to ensure that messages in the network can be reliably transmitted and effectively maintain the overall security and stability of the Internet of Vehicles; among them, a trust value greater than the trust threshold is a high trust value, and a trust value less than the trust threshold is a low trust value.

[0098] S5. Ordinary vehicles or consensus vehicles that need to request messages send message requests to the blockchain to obtain the required messages.

[0099] If the event message has been recorded in the blockchain, the requesting vehicle can retrieve the credible message through the blockchain. In addition, in order to improve the retrieval efficiency, the requesting vehicle can narrow the search scope according to the timestamp, message category, etc., so as to locate the relevant message in the blockchain. After successfully obtaining the required message, the requesting vehicle can apply the message to its own formal decision-making and actual scenarios, further improving its safety, decision-making accuracy and user experience during driving.

[0100] The above embodiments further illustrate the purpose, technical solutions and advantages of the present invention in detail. It should be understood that the above embodiments are only preferred implementation modes 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 in the protection scope of the present invention.

Claims

1. A secure and reliable message sharing method for Internet of Vehicles based on blockchain and trust management, characterized in that: include: The Internet of Vehicles message sharing network includes: vehicle message broadcast layer, vehicle consensus layer, accounting layer and trust decision layer; the vehicle message broadcast layer includes ordinary vehicles, ordinary vehicles include message providing vehicles and message receiving vehicles; the consensus layer includes consensus vehicles; the accounting layer includes accounting nodes; the trust decision layer includes an RSU cluster composed of roadside units RSU; The secure and trusted message sharing method of the Internet of Vehicles includes: S1. The message providing vehicle records and broadcasts the message m during driving. The message receiving vehicle i receives the message m, scores the authenticity of the message m, and calculates the authenticity score s. 1,i Broadcast to consensus vehicles; S2, consensus vehicle receives message m and authenticity score s 1,i , and give each authenticity score s 1,i Usefulness scoring, when all authenticity scores s 1,i When the number of high usefulness scores is greater than the threshold Q, the authenticity score s 1,i The consensus vehicle c that gives a high usefulness score will send data (m, s 1,i ,s 2,i,c ,t) uploaded to the accounting node; where m is the message, s 2,i,c Score s for the authenticity of consensus vehicle c 1,i The high usefulness score of , t is the current timestamp; S3. The accounting node receives and verifies the data uploaded by the consensus vehicle. If the verification is successful, the data uploaded by the consensus vehicle is packaged into blocks and the blocks are stored in the blockchain; otherwise, the data uploaded by the consensus vehicle is discarded; S4. RSU calculates the trust value of the vehicle in the area and shares the trust value of the vehicle with the RSU cluster; the RSU cluster makes a trust decision on the vehicle based on the trust value of the vehicle; S5. Ordinary vehicles or consensus vehicles that need to request messages send message requests to the blockchain to obtain the required messages.

2. The method for sharing secure and reliable messages in Internet of Vehicles based on blockchain and trust management according to claim 1 is characterized in that: Authenticity scoring of message m includes: the message receiving vehicle calculates the distance to the location where message m occurs and predicts the upcoming route. If the distance between the message receiving vehicle and the location where message m occurs is greater than a distance threshold or the location where message m occurs is on the upcoming route predicted by the message receiving vehicle, an authenticity score is performed on message m; otherwise, no authenticity score is performed.

3. The method for sharing secure and reliable messages in Internet of Vehicles based on blockchain and trust management according to claim 1 is characterized in that: The consensus vehicle performs usefulness scoring on the authenticity score, including: the consensus vehicle predicts the path to be traveled, and if the message corresponding to the authenticity score is located on the path to be traveled by the consensus vehicle, the authenticity score is scored for usefulness; otherwise, no usefulness scoring is performed.

4. The method for sharing secure and reliable messages in Internet of Vehicles based on blockchain and trust management according to claim 1 is characterized in that: In step S2, the threshold Q is When all authenticity scores s 1,i The number of high usefulness scores H that satisfies When all the authenticity scores of message m are s 1,i Re-evaluate the usefulness; when all authenticity ratings s 1,i The number of high usefulness scores H that satisfies , the message m is deemed invalid and discarded; where V is the number of consensus vehicles and L is the number of authenticity scores of message m.

5. The method for sharing secure and reliable messages in Internet of Vehicles based on blockchain and trust management according to claim 1 is characterized in that: The accounting layer also includes: a reward and punishment mechanism, which includes a trust threshold; the accounting node uses the reward and punishment mechanism to adjust the trust value of the consensus vehicle, and automatically replaces the consensus vehicle with a trust value less than the trust threshold with the vehicle with the highest trust value among ordinary vehicles.

6. The method for sharing secure and reliable messages in Internet of Vehicles based on blockchain and trust management according to claim 5 is characterized in that: The accounting node uses the reward and punishment mechanism to adjust the trust value of the consensus vehicle, including: in step S2, when all authenticity scores s 1,i When the number of high usefulness scores is greater than the threshold Q, the accounting node increases the trust value of the consensus vehicle with high usefulness scores and reduces the trust value of the consensus vehicle with low usefulness scores through the smart contract.

7. The method for sharing secure and reliable messages in Internet of Vehicles based on blockchain and trust management according to claim 1 is characterized in that: The RSU calculates the trust value of the vehicle in the area including: the RSU calculates the trust evidence of the vehicle in the area, and calculates the trust value of the vehicle based on the trust evidence; the trust value of the vehicle calculated based on the trust evidence includes: Among them, T j (k) represents the trust value of vehicle j at time k, w C Cooperation degree C j The weight of (k), w F Familiarity F ij The weight of (k), is the weight of the authenticity score s1(k), is the weight of the usefulness score s2(k), C j (k) is the cooperation degree of vehicle j at time k, F oj (k) is the familiarity of vehicle j at time k, s1(k) is the authenticity score of the received message by vehicle j at time k, s2(k) is the usefulness score of the received authenticity score by vehicle j at time k, and o is the evaluation vehicle of vehicle j, which can be any vehicle in the Internet of Vehicles message sharing network.

8. The method for sharing secure and reliable messages in Internet of Vehicles based on blockchain and trust management according to claim 1 is characterized in that: The RSU cluster includes a weighted adjustment mechanism; sharing the trust value of the vehicle to the RSU cluster includes: when the vehicle enters the area of ​​another new RSU from one RSU area in the RSU cluster, the new RSU inherits the trust value of the vehicle and uses the weighted adjustment mechanism to weighted adjust the trust value of the vehicle to obtain the adjusted trust value.

9. The method for sharing secure and reliable messages in Internet of Vehicles based on blockchain and trust management according to claim 8 is characterized in that: The weighted adjustment mechanism is used to adjust the trust value of the vehicle in a weighted manner, including: ω=α×ω net +β×ω v +γ×ω trust T new =ωT historical Among them, ω represents the weighting factor, α, β, and γ are the weight coefficients of different factors, a+β+γ=1, ω net ,ω v ,ω trust They are the status factor of the Internet of Vehicles message sharing network, the dynamic factor of vehicle behavior, and the stability factor of vehicle trust value, T new represents the adjusted trust value of the vehicle, T historical Represents the trust value of the vehicle before adjustment.

10. The method for sharing secure and reliable messages in Internet of Vehicles based on blockchain and trust management according to claim 1 is characterized in that: The RSU cluster makes trust decisions on the vehicle based on the trust value of the vehicle, including: RSU allows vehicles with high trust values ​​to communicate normally in the Internet of Vehicles message sharing network; RSU restricts vehicles with low trust values ​​from communicating in the Internet of Vehicles message sharing network, and monitors vehicles with low trust values.

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