An Efficient, Identifiable and Abortable Multi-Party Signature Scheme for VANETs

Vehicular ad-hoc networks (VANETs) are networks based on short-range wireless communication technology, mainly used for direct communication between vehicles and interaction with roadside infrastructures. The emergence of VANETs has improved the efficiency and safety of vehicle travel. However, malicious vehicles may intentionally send incorrect messages to mislead other vehicles for personal gain, and this behavior cannot be identified yet. To address this issue, we propose an efficient, identifiable, and abortable multi-party signature scheme for VANETs. Specifically, we utilize the property of zero-knowledge proofs to design a method that can efficiently identify malicious vehicles during the signature process, and define a strategy to quickly locate false proofs. Additionally, the message signing key in the proposed scheme is jointly generated by multiple entities, which avoids the security issues of key escrow and single point failure. Through rigorous security analysis, it is demonstrated that the proposed scheme satisfies essential security requirements for VANETs, including message unforgeability and authentication, vehicle anonymity, malicious traceability, collusion resistance, replay attack resistance, identifiable abort, and forward security of signing private key. Performance analysis shows that our scheme reduces the total aggregation verification time by up to 80% compared to existing schemes, and maintains a lower packet loss rate ($< $0.6%) at higher vehicle densities. Therefore, our scheme is suitable for large-scale VANETs deployments.