A Privacy-Preserving Charging Scheme for Electric Vehicles Using Blockchain and Fog Computing

A distributed charging system based on the Internet of Things can provide important supports to ensure the safe and sustainable operation of electric vehicles (EVs). Usually, drivers prefer to use local charging piles by querying the remote cloud server. Frequent communication with the cloud server will not only produce an unnecessary communication overhead but also increase the latency of response. More seriously, the cloud-based centralized management mode is vulnerable to cyber-attacks, which usually leads to privacy leakage. However, previous studies seldom focus on the privacy issue of the charging system for EVs. In this article, a decentralized and privacy-preserving charging scheme for EVs is proposed, which is based on blockchain and fog computing. In this scheme, fog computing is introduced to provide local computing with low latency. Specifically, a fog computing network, which is composed of fog computing nodes (FCNs), is used to provide localized services. Besides, a flexible consortium blockchain architecture is proposed. The blockchain system is deployed on the distributed FCNs, providing a decentralized and secure storage environment. By combining mutual authentication, smart contract, and blockchain-based storage, the security of privacy in the charging process can be ensured. The theoretical analysis and experiments demonstrate the advantages of the proposed scheme.