SecretCharge: A Blockchain-Based and Privacy-Preserving Scheme for Payment Information of Intelligent Connected Vehicles

In the development of urban transportation, Intelligent Connected Vehicle (ICV) technology has become a key force in promoting intelligence, sustainability, and efficiency. In particular, the rapid development of electric vehicles (EVs) has led to a growing demand for charging. However, this process risks exposing the private payment information of EV users, including the location of charging stations, the moment of charging, and users' identities. Our paper proposes a blockchain-based distributed privacy-preserving payment scheme named “SecretCharge”, designed to protect users' private information for ICV payment service scenarios. To meet the demands of large-scale applications of ICV, we propose an efficient group signature scheme based on the ElGamal signature, achieving high efficiency in key generation, signing, and verification algorithms. To conceal the payment information of EV users, we sign the data using our group signature scheme and use it as input for a zero-knowledge proof, ensuring that the information can be verified without being disclosed. To eliminate the dependence on third-party billing entities in traditional centralized schemes, we process system payments on the blockchain, achieving decentralization. Finally, our scheme is tested on Ethereum. The experimental results demonstrate our scheme's efficiency and usability, achieving privacy protection for user payment information in ICV.