Abstract: The prevalence of intelligent vehicles and new energy vehicles has made the structure of vehicle networking system more complex, which has attracted a lot of attention from researchers. The Internet of vehicles cannot be directly applied to the access control of the Internet of Things due to its characteristics such as fast node movement speed, response to security attack, fast change of network topology, short duration of node link and limitation and collision of mobile model in road network topology. The traditional access control of the Internet of vehicles cannot be effectively applied in the current complex Internet of vehicles system. Blockchain technology has natural security. Some scholars have applied blockchain technology to the Internet of vehicles, which can achieve more perfect access control in the current complex Internet of vehicles system. Therefore, comprehensive analysis and research on the solution is urgently needed. Firstly, it gives a brief overview of Internet of vehicles, blockchain and access control of Internet of vehicles. Secondly, it sorts out the limitations of traditional access control of Internet of vehicles, advantages and application scenarios of blockchain access control technology in Internet of vehicles. Then, according to the different access control discrimination methods, the implementation scheme of the existing blockchain access control technology in the Internet of vehicles is elaborated from three perspectives based on trust, location and risk. Then, the common evaluation indexes and experimental environment in the literature are summarized, and the comparative analysis is made. Then it points out the shortcomings of performance, safety and practicability, explains the problems in detail, and gives solutions. Finally, six future research prospects are made for the current research.

Key words: Internet of vehicle（IoV）, access control, blockchain

摘要： 智能汽车和新能源汽车的盛行使车联网系统结构更加复杂，受到研究者的大量关注。车联网因其自身节点移动速度快、应对安全性攻击、网络拓扑变化快、节点链路持续时间短暂和移动模型在路网拓扑中有限制等特点无法直接应用物联网的访问控制，传统车联网访问控制又无法有效应用在当下复杂的车联网系统当中。区块链技术具有天然的安全性，已有学者将区块链技术应用在车联网中，可以在目前复杂的车联网系统中实现更加完善的访问控制，因此亟需对解决方案进行综合分析和研究。对车联网、区块链和车联网访问控制作简要概述，梳理了传统车联网访问控制的局限性，区块链访问控制技术在车联网中的优点和应用场景；根据访问控制判别方式的不同，从基于信任、位置和风险三个角度重点阐述现有区块链访问控制技术在车联网中的实现方案；总结文献中常见评价指标和实验环境，并做对比分析；指出性能、安全性和实用性三方面的不足，对其中问题做更细致的说明，并给出解决思路；对目前研究做出六点未来研究展望。

关键词: 车联网, 访问控制, 区块链