Abstract: To resolve the difficulties of forensics and determination of responsibility for traffic accidents, a blockchain-based e-forensics scheme under Internet Of Vehicles (IOV) communications architecture was proposed. In this scheme, the remote storage of digital evidence was implemented by using the decentralized storage mechanism of blockchain, and the fast retrieval of digital evidence and effective tracing of related evidence chain were realized by using the smart contracts. The access control of data was performed by using the token mechanism to protect the privacy of vehicle identities. Meanwhile, a new consensus mechanism was proposed to meet real-time requirements of IOV for forensics. Simulation results show that the new consensus algorithm in this proposed scheme has higher efficiency compared with the traditional Delegated Proof Of Stake (DPOS) consensus algorithm and the speed of forensics meets the requirements of IOV environment, which ensures the characteristics of electronic evidence such as non-tampering, non-repudiation and permanent preservation, so as to realize the application of blockchain technology in judicial forensics.

Key words: Internet Of Vehicles (IOV), blockchain, e-forensics, consensus algorithm, smart contract

摘要： 针对车辆交通事故取证困难、责任归属难以判定等问题，提出一种车联网（IOV）通信架构下基于区块链的电子取证方案。该方案利用区块链去中心化存储机制实现电子证据的远程存储，并利用智能合约机制完成电子证据的快速检索和相关证据链的有效追溯；而为有效保护车辆身份的隐私，提出一种令牌机制来对数据进行访问控制；同时，为满足IOV的实时取证要求，提出了一种高效批量共识机制。实验仿真表明，所提方案中的新型共识算法效率优于传统委托权益证明（DPOS）共识算法，且取证速度满足IOV环境的需求，保证了电子证据的不可篡改、不可否认及永久保存等特性，实现了区块链技术在司法存取证方面的应用。

关键词: 车联网, 区块链, 电子取证, 共识算法, 智能合约