Towards Privacy-Preserving Decentralized Reputation Management for Vehicular Crowdsensing

The reputation of a vehicle is a critical role in most vehicular crowdsensing applications, which incentivizes vehicles to perform crowdsensing tasks by submitting high-quality data and getting remunerated accordingly. Unfortunately, existing centralized reputation systems are vulnerable to collusion attacks, and decentralized approaches are susceptible to Sybil attacks. What’s worse, both of them have privacy leakage and fairness problems. To address these issues, we take advantage of various cryptographic primitives and the blockchain technology to present a privacy-preserving decentralized reputation management system. Specifically, a compact traceable ring signature is proposed to provide identity privacy protection and resist Sybil attacks. To ensure fairness, the quantification of data quality is fulfilled by combining the rating feedback mechanism with comprehensive updating factors. Additionally, our system allows the reputation update automatically through smart contracts deployed on the consortium blockchain. The authenticity of the reputation can be verified by a zero-knowledge proof when a vehicle shows its reputation. Finally, a proof-of-concept prototype system by Parity Ethereum is presented. Extensive security analysis and implementations demonstrate the feasibility and efficiency of the proposed system.