A comprehensive survey on blockchain-based C-ITS applications: Classification, challenges, and open issues

Cooperative Intelligent Transport Systems (C-ITS) aim to improve road safety and provide comfort to both drivers and passengers by enabling vehicles, infrastructure, and other road users to exchange environmental and driving data. Therefore, the accuracy of the information exchanged as well as the authenticity of the entities, effectively affect the efficiency and performance of the system. Blockchain is a new distributed ledger technology that enables secure and transparent information storage and transmission without the control of a central entity. Its inherent features of trust, anonymity, immutability, and data availability offer great potential to solve current C-ITS issues. Recently, several research works are carried out to explore the potential of the blockchain technology in a vehicular environment. In this paper, we present a comprehensive review of the literature related to the application of the blockchain technology in C-ITS. We provide background knowledge on blockchain and the motivations for applying this technology in vehicular networks. Then, we discuss the major challenges that can bring the application of blockchains in a vehicular environment, such as mobility, latency, etc. Next, we review current research and classify it into four main categories. Moreover, a qualitative comparison of the discussed solutions is presented to identify the strengths and the weaknesses of each proposal. Finally, we highlight some open research issues that should be considered in future studies to improve the performance of blockchain-based vehicular systems.