An Efficient and Adaptive Privacy-Preserving Authentication Scheme for VANETs

Vehicular Ad-Hoc Networks (VANETs) are essential for assisting vehicle operations and enhancing driving safety. However, due to the mobility and openness of VANETs, they face a range of question, including vehicle privacy protection, message authentication, limitations in computational and storage capacity, and constrained network bandwidth. To tackle these issues, we introduce a certificateless efficient adaptive authentication scheme that preserves privacy. When acquiring reputation values of drivers and vehicles from an external trust system, our scheme enables vehicles with varying reputation levels to achieve different degrees of privacy protection. We adopts a certificateless mechanism to resolve the issue of key escrow. Additionally, pseudonyms for vehicles are generated through hash chains, effectively reducing storage overhead. We avoids complex bilinear pairings and supports batch authentication, thereby enhancing authentication efficiency. It also considers the many-to-one relationship between drivers and vehicles, allowing the tracking center to hold both vehicles and drivers accountable. The security analysis demonstrates that the proposed scheme attains existential unforgeability within the framework of the random oracle model. In terms of performance analysis, the scheme demonstrates superior performance compared to existing solutions.