Abstract: The mobility of nodes in vehicular cloud, the dynamics of networks, the openness of communication methods, and the non-trustworthiness of vehicles bring more challenges to the security of task scheduling in vehicular cloud. Based on the full consideration of characteristics of vehicular cloud, this article introduces blockchain and proposes a lightweight blockchain architecture suitable for task scheduling in vehicular cloud. Road side units (RSU) are used to construct a blockchain network, and an improved practical Byzantine fault tolerance (PBFT) algorithm is used to complete the consensus. Based on the scheduling delay model of the architecture, the scheduling performance of the architecture is tested and analyzed through experiments. The comparison with Ethereum shows that the proposed architecture not only realizes the non-repudiation of the task scheduling process, avoids the single point failure of the task scheduling server, improves the availability, but also achieves lightweight, that is, no additional computing power or storage space is required, and can reach millisecond-level scheduling delay.

Key words: vehicular cloud, task scheduling, blockchain, practical Byzantine fault tolerance (PBFT), lightweight