WOTS-based Conditional Privacy-preserving Authentication Protocol for VANETs

With the development of quantum computing, the present asymmetric crypto schemes could be significantly harmed by quantum algorithms. Hence, we propose a conditional privacy-preserving authentication (CPPA for short) protocol for vehicular ad hoc networks (VANETs for short) based on Winternitz-type one-time signature (WOTS for short). In the proposed protocol, a vehicle or a roadside unit can verify the validity of a received message, and any third party cannot retrieve the real identity of the vehicle except the trusted authority. Our proposed CPPA can not only ensure privacy but also achieve related security in VANETs, including authentication, non-repudiation, conditional privacy, un-linkability, resistance to quantum analysis, resistance to impersonation attacks, resistance to modification attacks, resistance to replay attacks, resistance to man-in-the-middle attacks, resistance to stolen verifier table attacks, etc. due to adopting WOTS, our proposed protocol achieves the smaller verification key size and the smaller signature size.