An intelligent networked vehicle accident evidence storage and liability determination system and retrieval method

Abstract

The application provides a smart networked vehicle accident evidence storage and responsibility determination system and a retrieval method. The system comprises a blockchain network module, an intelligent contract module, a blockchain gateway module, a traffic management department evidence collection module and an SCMS link value query module. The blockchain gateway module is used for obtaining communication messages of a vehicle-mounted unit, forming structured evidence storage data and uploading the data to a blockchain intelligent contract. When an accident occurs, the accident is reported to the blockchain intelligent contract, and an accident evidence collection request is sent to surrounding vehicles. After receiving the request, the surrounding vehicles upload their link values to the intelligent contract. After receiving the reported accident and the link values, the traffic management department transmits the link values into the SCMS system, obtains all the link values of the vehicle being collected within the same time period, combines the link values and the accident time, calculates the retrieval key of all possible messages within the space-time range of the accident, and transmits the retrieval key into the blockchain network through a filter and an on-chain mapping query to retrieve relevant evidence.

Description

Technical Field

[0001] This invention relates to the field of intelligent connected vehicle technology, specifically to an intelligent connected vehicle accident evidence storage and liability determination system and retrieval method. Background Technology

[0002] In recent years, intelligent connected vehicles have gradually emerged, promoting improvements in traffic efficiency and safety. V2X (Vehicle-to-Everything) technology is one of the key technologies for intelligent connected vehicles, serving as their communication foundation. V2X technology allows vehicles to communicate in real time with other vehicles, infrastructure, pedestrians, and cloud services, enabling vehicles to perceive their surroundings and collaborate with other entities to achieve safer, more efficient, and intelligent driving. For example, the Basic Safety Message (BSM) transmitted in V2X includes the vehicle's position, speed, direction, acceleration, and other relevant status data. By sharing this information, vehicles can better perceive their surroundings, predict potential hazards, and take appropriate measures to avoid accidents.

[0003] However, when intelligent connected vehicles are involved in traffic accidents, the interactions and intelligent decision-making between vehicles make the causes of accidents more complex. Traditional methods of determining liability for vehicle accidents, such as dashcams and vehicle event data recording systems, are insufficient to support the determination of liability in complex intelligent connected vehicle accidents. At the same time, the responsible party for the accident is no longer limited to the driver. Related stakeholders may tamper with evidence to evade responsibility. Traditional centralized data storage systems (such as automakers' cloud databases) often cannot prove their innocence. When an accident occurs, it is difficult to obtain accident-related data, and there is no guarantee that the obtained data has not been tampered with, making it difficult to resolve accident disputes fairly and smoothly. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide an intelligent connected vehicle accident evidence storage and liability determination system and retrieval method. By performing on-chain structured encapsulation and key-value pair indexing on V2X messages, an efficient evidence retrieval and privacy protection mechanism is designed to achieve reliable evidence collection of all vehicle-related evidence within the spatiotemporal scope of the accident.

[0005] To solve the above problems, the technical solution of the present invention is as follows:

[0006] A system for evidence preservation and liability determination in intelligent connected vehicle accidents includes a blockchain network module, a smart contract module, a blockchain gateway module, a traffic management department evidence collection module, and an SCMS link value query module. The blockchain gateway module is used to acquire communication messages from the vehicle unit, perform structured encapsulation and key-value pair indexing, and upload the resulting structured evidence data to the blockchain smart contract. When an accident occurs, the system reports the accident to the blockchain smart contract and simultaneously sends an accident evidence collection request to surrounding vehicles. Upon receiving the request, each surrounding vehicle uploads its link value to the smart contract. After receiving the reported accident and link values, the traffic management department transmits the link values ​​to the SCMS system, obtains all link values ​​of the vehicles being investigated within the same time period, and calculates the retrieval keys of all possible messages within the spatiotemporal range of the accident off-chain by combining the link values ​​and the accident time. These keys are then transmitted to the blockchain network for filtering and on-chain mapping queries to retrieve relevant evidence.

[0007] Preferably, the blockchain network module adopts a consortium blockchain architecture, uses the PBFT consensus algorithm, and is composed of parties involved in the incident.

[0008] Preferably, the smart contract module serves as the blockchain application layer, used for storing V2X messages and collecting accident evidence. The smart contract module includes a message warehouse smart contract, an evidence source index smart contract, an evidence verification smart contract, and a Bloom filter. The message warehouse smart contract, combined with an off-chain cloud database, stores structured and encapsulated V2X messages as evidence. The evidence source index smart contract uses SCMS to locate all vehicles within the spatiotemporal range of the accident for further evidence retrieval. The evidence verification smart contract verifies the source and integrity of data provided in the cloud through on-chain evidence storage. The Bloom filter quickly eliminates keys that absolutely do not exist, thereby reducing the number of on-chain mapping queries.

[0009] Preferably, the blockchain gateway module is embedded in the vehicle to read communication messages from the on-board unit in real time, and uploads the V2X messages to the blockchain after structured encapsulation and key-value pair indexing through the blockchain gateway.

[0010] Preferably, the traffic management department's evidence collection module is used to coordinate various modules, monitor the on-chain accident reporting contract, collect the individual link values ​​reported by vehicles within the accident's time and space range, query all relevant pre-link values ​​from the SCMS system, XOR the link values, combine the accident time, calculate the retrieval keys of all possible messages within the accident's time and space range off-chain, and transmit them to the blockchain network for querying through filters and on-chain mapping to retrieve relevant evidence.

[0011] Preferably, the SCMS link value query module merges message sources through link values, thereby finding all V2X messages sent by the vehicle during the accident period. In SCMS, the registration authority is responsible for verifying the registration certificate of the vehicle unit, and the pseudonym certificate issuing authority will generate a pseudonym certificate for the verified vehicle unit.

[0012] Furthermore, the present invention also provides a method for retrieving evidence of accidents involving intelligent connected vehicles, comprising the following steps:

[0013] The vehicle's blockchain gateway obtains the V2X messages and pseudonym certificates sent by the on-board unit, performs structured encapsulation and key-value pair indexing, and uploads the resulting structured evidence data to the blockchain smart contract.

[0014] After the smart contract receives and stores the structured evidence data, it sends an evidence addition event notification to the blockchain network. After receiving the event notification, the blockchain network node stores the index field in its local filter.

[0015] After an accident occurs, the vehicle that hits the collision reports the accident to the blockchain smart contract after detecting the impact. At the same time, it sends an accident evidence collection request to the surrounding vehicles. After receiving the request, the surrounding vehicles upload their link values ​​to the smart contract.

[0016] After the traffic management department hears the reported accident and link value, it transmits the link value to the SCMS system to obtain all the link values ​​of the vehicle being investigated within the same time period.

[0017] By combining the link value and the time of the incident, the retrieval keys of all possible messages within the spatiotemporal range of the incident are calculated off-chain, and then fed into the blockchain network for querying through filters and on-chain mapping to retrieve relevant evidence.

[0018] Preferably, in the step whereby the traffic management department, after receiving a reported accident and link value, transmits the link value to the SCMS system and obtains all link values ​​of the vehicle being investigated within the same time period, each link value undergoes the following steps:

[0019] The link value is passed to the pseudonym certificate authority, which retrieves the RA-to-PCA pseudonym certificate request hash value from its local private database and sends it to the registration authority.

[0020] The registration authority retrieves the local private database to obtain the corresponding link chain identifiers LCI1 and LCI2, which correspond to the link chains created for the vehicle by LA1 and LA2, respectively, and sends them to LA1 and LA2 respectively.

[0021] After receiving LCI1 and LCI2 respectively, LA1 and LA2 decrypt the initial link seed with their private keys, concatenate it with their own identity ID, calculate the hash, and recursively obtain the link seed for the time period in which the accident occurred. Then, using the link seed as the symmetric key, and the identity ID and pseudonym certificate serial number as plaintext, they encrypt the data using the Davies-Meyer mode, calculate the pre-link value of all pseudonym certificates in sequence, and return it to the traffic management department.

[0022] After obtaining all the pre-link values ​​of the vehicle being investigated within the same time period, the traffic management department obtains the corresponding link value through an XOR operation.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] 1. This invention is based on blockchain technology and combines on-chain and off-chain data collaborative design to effectively collect and integrate V2X messages sent by intelligent connected vehicles, providing relevant credible evidence of all vehicles within the spatiotemporal range for accident liability determination, thereby comprehensively reconstructing the accident process and promoting accident liability determination.

[0025] 2. This invention combines the link value mechanism of the SCMS communication architecture to perform on-chain structured encapsulation and key-value pair indexing of V2X, thereby achieving efficient retrieval of post-accident message evidence while protecting the identity privacy of the vehicle being investigated.

[0026] 3. This invention effectively solves the problem of evidence preservation and liability determination in intelligent connected vehicle accidents, providing reliable and fine-grained evidence from all vehicles within the spatiotemporal range of the accident and its corresponding efficient retrieval mechanism, while protecting the identity and privacy of the vehicles whose evidence is collected. Attached Figure Description

[0027] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0028] Figure 1 This is a diagram of the intelligent connected vehicle accident evidence storage and liability determination system of the present invention;

[0029] Figure 2 This is a flowchart of the intelligent connected vehicle accident evidence retrieval method of the present invention;

[0030] Figure 3 This is a flowchart of the accident-related information evidence retrieval and verification process for the present invention. Detailed Implementation

[0031] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0032] Specifically, this invention provides a blockchain-based intelligent connected vehicle accident evidence storage and liability determination system, such as... Figure 1 As shown, the system includes a blockchain network module, a smart contract module, a blockchain gateway module, a traffic management department evidence collection module, and an SCMS link value query module.

[0033] The blockchain network module adopts a consortium blockchain architecture and uses the PBFT consensus algorithm, composed of parties involved in the accident. The consensus nodes are fixed by a small number of institutions with high credibility and strong storage and computing capabilities (such as traffic management departments, insurance companies, vehicle networking service providers, and vehicle manufacturers). Other users do not participate in consensus calculations, but only synchronously store block header data. Post-accident evidence verification is conducted using Simplified Payment Verification (SPV), thereby ensuring the fair rights of all parties.

[0034] The smart contract module, serving as the blockchain application layer, aims to implement basic system functions such as storing V2X messages and collecting accident evidence. This layer includes: a Message Repository smart contract (MR contract), an Evidence Source Index smart contract (ESI contract), an Evidence Verification smart contract (EV contract), and a Bloom filter. The MR contract, combined with an off-chain cloud database, stores structured V2X messages as evidence. It employs an on-chain data structure using MsgID as the retrieval key to achieve efficient evidence retrieval and reduce on-chain storage burden. Considering the massive volume of V2X messages, evidence retrieval can be time-consuming; therefore, a fast retrieval mechanism combining off-chain preprocessing with on-chain queries based on Bloom filters is designed. The ESI contract aims to locate all vehicles within the spatiotemporal range of the accident using the SCMS (Security Credential Management System) for further evidence retrieval, while protecting the privacy of the vehicles being investigated. The EV contract is specifically built for automatically verifying the integrity and source of retrieved evidence, verifying the source and integrity of data provided in the cloud through on-chain storage. Through these smart contracts, automated collaboration can be achieved in V2X message storage and accident evidence collection tasks. Bloom filters are a probabilistic data type that offers faster query efficiency compared to mapping data types due to their compact data structure and query processing method. A Bloom filter uses multiple hash functions to map elements to multiple positions in a bit array; to check if an element exists, it simply verifies whether the bits in those positions are 1. In this embodiment, when V2X message structured processing data is uploaded to the blockchain, the blockchain node adds the retrieval key MsgID to a locally maintained Bloom filter. Setting up a Bloom filter in the blockchain node helps to quickly retrieve evidence when a traffic management department receives an evidence retrieval query request. During evidence retrieval, the Bloom filter can quickly exclude some keys that absolutely do not exist, thereby reducing the number of on-chain mapping queries.

[0035] Blockchain Gateway Module: In the Internet of Vehicles (IoV), vehicles interact with people, vehicles, roads, and the cloud via V2X. Communication information includes vehicle status and collaborative data, which can be used for accident liability determination. The blockchain gateway module is embedded in the vehicle and reads communication messages from the On-Board Unit (OBU) in real time. To minimize on-chain storage, it is not suitable to directly store the full V2X communication data on the blockchain. The blockchain gateway performs structured encapsulation and key-value pair indexing of V2X messages before uploading them to the blockchain, while simultaneously uploading the original complete information to a distributed cloud storage database. On-chain data is organized using a mapping data type: the key is a hash, and the mapping value is structured V2X data. The key is a hash value that identifies the information, including message time, linkage value, and type, i.e., MsgID = hash(alignedTime||linkageValue||messageType). Since the Basic Security Message (BSM) of V2X has a sampling frequency of 10Hz, the alignment time (alignedTime) is recommended to be set to 0.1 seconds. Furthermore, if necessary, milliseconds can be further obtained from the mapping value structure data. The mapped value structure `Evidence` contains milliseconds, location, message hash, digital signature, and the message's cloud storage address. The message hash and digital signature are used to verify message integrity and ensure non-repudiation of origin. The message's cloud storage address is designed for on-chain EV contracts to retrieve the original, complete information and corresponding pseudonymous certificates from the cloud. This specific on-chain data structure is designed for rapid evidence retrieval from large volumes of connected vehicle messages and supports the following on-chain automated evidence verification.

[0036] The traffic management department's evidence collection module is used to coordinate various modules, monitor the on-chain accident reporting contract, collect the individual link values ​​reported by vehicles within the accident's time and space range, query all relevant pre-link values ​​from the SCMS system, XOR the link values, combine the accident time, calculate the retrieval keys of all possible messages within the accident's time and space range off-chain, and transmit them to the blockchain network for querying through Bloom filters and on-chain mapping to retrieve relevant evidence.

[0037] SCMS Link Value Query Module: SCMS provides privacy protection for vehicle identity in accident evidence collection. It uses link values ​​to merge message sources, thereby identifying all V2X messages sent by the vehicle during the accident period. In SCMS, the Registration Authority (RA) is responsible for verifying the registration certificate of the On-Board Unit (OBU), and the Certificate Authority (PCA) generates a pseudonym certificate for the verified OBU. When providing a pseudonym certificate, a "link value" is calculated and embedded into the pseudonym certificate, improving the efficiency of revoking pseudonym certificates. Within a specific time period, the link value is collision-resistant; that is, there is a one-to-one correspondence between the link value and the pseudonym certificate within a certain period. This relationship is used to serve as the vehicle identifier for the source of the connected vehicle message, aiding in evidence retrieval. To prevent linking to the pseudonym certificate of a single device, two independent linking authorities (LA1 and LA2) generate pre-link values, which are calculated using an XOR operation.

[0038] The specific working process of the blockchain-based intelligent connected vehicle accident evidence storage and liability determination system of this invention is as follows:

[0039] Vehicles are equipped with blockchain gateways to obtain V2X messages such as BSM and pseudonymous certificates sent by the On-Board Unit (OBU) in real time. These messages are then structured, encapsulated, and indexed using key-value pairs. The resulting structured evidence data is uploaded to the blockchain MR contract. Simultaneously, all raw data is uploaded to a public distributed cloud server for storage, providing detailed data for accident liability determination. The structured evidence data based on link values ​​allows for efficient retrieval and verification of all V2X message evidence within the spatiotemporal scope of the accident, while protecting vehicle identity privacy and trajectory security. When an accident occurs, the colliding vehicle immediately reports the accident to the blockchain ESI contract upon detecting the impact, and simultaneously sends an accident evidence collection request to surrounding vehicles. Upon receiving the request, each surrounding vehicle uploads a link value to the ESI contract. The traffic management department, upon receiving the reported accident and link values, transmits the link values ​​to the SCMS system to obtain all link values ​​from the vehicles being investigated within the same time period. Then, combining the link values ​​and the accident time, all possible evidence retrieval keys are calculated off-chain. A Bloom filter eliminates keys that are definitely non-existent, and the filtered keys are then transmitted to the blockchain to query the MR contract for their existence. If the evidence exists, the EV contract retrieves the original data from the cloud based on the mapping value of the on-chain evidence data, and verifies its integrity and origin. Ultimately, the retrieval and verification of vehicle evidence within the spatiotemporal range of the accident is completed.

[0040] Furthermore, the present invention also provides a method for retrieving evidence of accidents involving intelligent connected vehicles, such as... Figure 2 and Figure 3 As shown, the method includes the following steps:

[0041] S1: The vehicle's blockchain gateway obtains the V2X messages and pseudonym certificates sent by the on-board unit, performs structured encapsulation and key-value pair indexing, and uploads the resulting structured evidence data to the blockchain smart contract.

[0042] Specifically, the vehicle's blockchain gateway obtains V2X messages such as BSM and pseudonym certificates sent by the OBU in real time, performs structured encapsulation and key-value pair indexing, and uploads the resulting structured evidence data to the blockchain MR contract; at the same time, it uploads all the original data to a public distributed cloud server for storage, providing detailed data for accident liability determination.

[0043] The MR contract provides a repository of on-chain structured evidence storage data and offers interfaces for adding and querying evidence storage data.

[0044] The specific fields of the on-chain structured evidence storage data are as follows:

[0045]

[0046] MsgID=Hash(alignedTime||linkageValue||messageType),

[0047] Struct Evidence={millisecondTime,positionPoint,messageHash,digitalSignature,cloudAddress},

[0048] Among them, alignedTime is the alignment time based on 0.1 seconds, linkageValue is the link value embedded in the pseudonym certificate, messageType is the specific type of V2X message, millisecondTime, positionPoint, messageHash, and digitalSignature are the millisecond time, position, message hash value, and digital signature in the V2X message, respectively, and cloudAddress is the storage location of the original data (V2X message and vehicle pseudonym certificate) in the cloud.

[0049] S2: After the smart contract receives and stores the structured evidence data, it sends an evidence addition event notification to the blockchain network. After receiving the event notification, the blockchain network node stores the index field in the local filter.

[0050] Specifically, after receiving and storing the structured evidence data, the MR contract sends an evidence addition event notification to the blockchain network. Upon receiving the event notification, the blockchain network node stores the index field msgID in a local Bloom filter for quickly excluding msgIDs that definitely do not exist during subsequent evidence retrieval, thereby accelerating evidence retrieval.

[0051] event EvidenceAdded(bytes32 indexed msgID, string millisecondTime, string positionPoint, bytes32 messageHash, bytes digitalSignature, stringcloudAddress).

[0052] S3: After an accident occurs, the vehicle that hits the collision detects the impact and reports the accident to the blockchain smart contract. At the same time, it sends an accident evidence collection request to the surrounding vehicles. After receiving the request, the surrounding vehicles upload their link values ​​to the smart contract.

[0053] Specifically, after an accident occurs, the vehicle that struck the object detects the impact and reports the accident to the blockchain ESI contract. The specific data field is the accident time and location string, along with its own link value. At the same time, it sends an accident evidence collection request to surrounding vehicles, with the specific field being the accident time and location string. Upon receiving the request, each surrounding vehicle uploads its own link value to the corresponding accident time and location string to the ESI contract.

[0054] The ESI contract provides an index of accident evidence sources (all vehicles within the spatiotemporal scope of the accident). This index contains only a single link value for each vehicle. Because vehicles may use multiple link values ​​interchangeably within the same time period, a single link value cannot retrieve all messages from a vehicle within that time period. However, all link values ​​can be securely obtained from a single link value through the SCMS system, allowing for the retrieval of all message evidence. The data stored in the ESI contract is as follows:

[0055] The `Mapping(Accident Time&Location String=>Linkage Values ​​Array)` method uses `Accident Time&Location String` to uniquely identify the time and location of the accident, and `Linkage Values ​​Array` to be a collection of indexed link values.

[0056] Meanwhile, the ESI contract provides an event notification mechanism that notifies the blockchain network when a new incident is reported or a new link value is added.

[0057] S4: After the traffic management department hears the reported accident and link value, it transmits the link value to the SCMS system to obtain all the link values ​​of the vehicle being investigated within the same time period.

[0058] Specifically, after the traffic management department receives a reported accident and the link value, it transmits the link value to the SCMS system. Each link value goes through the following steps:

[0059] The link value is passed to the pseudonym certificate authority, which retrieves the RA-to-PCA pseudonym certificate request hash value from its local private database and sends it to the registration authority.

[0060] The registration authority retrieves the local private database to obtain the corresponding link chain identifiers LCI1 and LCI2, which correspond to the link chains created for the vehicle by LA1 and LA2, respectively, and sends them to LA1 and LA2 respectively.

[0061] After receiving LCI1 and LCI2 respectively, LA1 and LA2 decrypt the initial link seed with their private keys, concatenate it with their own identity ID, calculate the hash, and recursively obtain the link seed for the time period in which the accident occurred. Then, using the link seed as the symmetric key, and the identity ID and pseudonym certificate serial number as plaintext, they encrypt the data using the Davies-Meyer mode, calculate the pre-link value of all pseudonym certificates in sequence, and return it to the traffic management department.

[0062] After obtaining all the pre-link values ​​of the vehicle being investigated within the same time period, the traffic management department obtains the corresponding link value through an XOR operation.

[0063] S5: Combining the link value and the time of the incident, calculate the retrieval keys of all possible messages within the spatiotemporal range of the incident off-chain, and pass them into the blockchain network for querying through filters and on-chain mapping to retrieve relevant evidence.

[0064] Specifically, the traffic management department uses the accident time as a benchmark, expands forward and backward to form the accident time period, and selects integer multiples of 0.1 seconds from the time period to obtain the set of aligned time points. The link value set and the set of aligned time points are combined with the message type to be retrieved and arranged to calculate the set of all possible search keys MsgID within the spatiotemporal range of the accident.

[0065] The traffic management department first uses a local Bloom filter on the blockchain node to quickly eliminate search keys MsgID that are definitely non-existent. Then, the Bloom-filtered search key MsgID is passed to the blockchain network to query the MR contract for its existence. If it exists, the EV contract retrieves the original data from the cloud based on the mapping value of the on-chain evidence data and verifies its integrity and origin. Ultimately, the retrieval and verification of vehicle evidence within the spatiotemporal range of the accident is completed.

[0066] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A smart connected vehicle accident evidence storage and liability determination system, characterized in that, The system includes a blockchain network module, a smart contract module, a blockchain gateway module, a traffic management department evidence collection module, and an SCMS link value query module. The blockchain gateway module is used to acquire communication messages from the vehicle-mounted unit, perform structured encapsulation and key-value pair indexing, and upload the resulting structured evidence data to the blockchain smart contract. When an accident occurs, the system reports the accident to the blockchain smart contract and simultaneously sends an accident evidence collection request to surrounding vehicles. Upon receiving the request, the surrounding vehicles each upload their link values ​​to the smart contract. After receiving the reported accident and link values, the traffic management department transmits the link values ​​to the SCMS system, obtains all link values ​​of the vehicles being investigated within the same time period, and, combining the link values ​​and the accident time, calculates the retrieval keys of all possible messages within the spatiotemporal range of the accident off-chain. These keys are then transmitted to the blockchain network for filtering and on-chain mapping queries to retrieve relevant evidence.

2. The intelligent connected vehicle accident evidence storage and liability determination system according to claim 1, characterized in that, The blockchain network module adopts a consortium blockchain architecture, uses the PBFT consensus algorithm, and is composed of parties involved in the incident.

3. The intelligent connected vehicle accident evidence storage and liability determination system according to claim 1, characterized in that, The smart contract module, serving as the blockchain application layer, is used to store V2X messages and collect accident evidence. This module includes a message warehouse smart contract, an evidence source index smart contract, an evidence verification smart contract, and a Bloom filter. The message warehouse smart contract, integrated with an off-chain cloud database, stores structured, encapsulated V2X messages as evidence. The evidence source index smart contract uses SCMS to locate all vehicles within the spatiotemporal range of the accident for further evidence retrieval. The evidence verification smart contract verifies the source and integrity of data provided in the cloud through on-chain evidence storage. The Bloom filter quickly eliminates keys that absolutely do not exist, thereby reducing the number of on-chain mapping queries.

4. The intelligent connected vehicle accident evidence storage and liability determination system according to claim 1, characterized in that, The blockchain gateway module is embedded in the vehicle to read communication messages from the on-board unit in real time. The V2X messages are then structured, indexed using key-value pairs, and uploaded to the blockchain.

5. The intelligent connected vehicle accident evidence storage and liability determination system according to claim 1, characterized in that, The traffic management department's evidence collection module is used to coordinate various modules, monitor the on-chain accident reporting contract, collect the individual link values ​​reported by vehicles within the accident's time and space range, query all relevant pre-link values ​​from the SCMS system, XOR the link values, combine the accident time, calculate the retrieval keys of all possible messages within the accident's time and space range off-chain, and transmit them to the blockchain network for filtering and on-chain mapping queries to retrieve relevant evidence.

6. The intelligent connected vehicle accident evidence storage and liability determination system according to claim 1, characterized in that, The SCMS link value query module merges message sources through link values, thereby finding all V2X messages sent by the vehicle during the accident period. In SCMS, the registration authority is responsible for verifying the registration certificate of the on-board unit, and the pseudonym certificate issuing authority will generate a pseudonym certificate for the verified on-board unit.

7. A method for retrieving evidence of accidents involving intelligent connected vehicles, characterized in that, The method includes the following steps: The vehicle's blockchain gateway obtains the V2X messages and pseudonym certificates sent by the on-board unit, performs structured encapsulation and key-value pair indexing, and uploads the resulting structured evidence data to the blockchain smart contract. After the smart contract receives and stores the structured evidence data, it sends an evidence addition event notification to the blockchain network. After receiving the event notification, the blockchain network node stores the index field in its local filter. After an accident occurs, the vehicle that hits the collision reports the accident to the blockchain smart contract after detecting the impact. At the same time, it sends an accident evidence collection request to the surrounding vehicles. After receiving the request, the surrounding vehicles upload their link values ​​to the smart contract. After the traffic management department hears the reported accident and link value, it transmits the link value to the SCMS system to obtain all the link values ​​of the vehicle being investigated within the same time period. By combining the link value and the time of the incident, the retrieval keys of all possible messages within the spatiotemporal range of the incident are calculated off-chain, and then fed into the blockchain network for querying through filters and on-chain mapping to retrieve relevant evidence.

8. The method for retrieving evidence of intelligent connected vehicle accidents according to claim 7, characterized in that, After the traffic management department receives the reported accident and link value, it transmits the link value to the SCMS system. In the process of obtaining all link values ​​of the vehicle being investigated within the same time period, each link value goes through the following steps: The link value is passed to the pseudonym certificate authority, which retrieves the RA-to-PCA pseudonym certificate request hash value from its local private database and sends it to the registration authority. The registration authority retrieves the local private database to obtain the corresponding link chain identifiers LCI1 and LCI2, which correspond to the link chains created for the vehicle by LA1 and LA2, respectively, and sends them to LA1 and LA2 respectively. After receiving LCI1 and LCI2 respectively, LA1 and LA2 decrypt the initial link seed with their private keys, concatenate it with their own identity ID, calculate the hash, and recursively obtain the link seed for the time period in which the accident occurred. Then, using the link seed as the symmetric key, and the identity ID and pseudonym certificate serial number as plaintext, they encrypt the data using the Davies-Meyer mode, calculate the pre-link value of all pseudonym certificates in sequence, and return it to the traffic management department. After obtaining all the pre-link values ​​of the vehicle being investigated within the same time period, the traffic management department obtains the corresponding link value through an XOR operation.

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