ISC-CPPA:Improverd-Security Certificateless Conditional Privacy-preserving Authentication Scheme With Revocation

With the development of Internet of Things, communication and computer technology, the significance of realizing vehicular ad hoc networks (VANETs) become more important. Due to wireless communication, VANETs suffer cyber attacks in practice. Many anonymous authentication schemes have been proposed in the literature. Li et al. proposed an efficient authentication scheme called CL-CPPA. However, the proposed scheme failed to realize the claimed un-linkability and anonymity. In this work, we proposed a new certificateless conditional privacy-preserving authentication scheme with an enhanced security guarantee. Specifically, a random number is selected to encrypt the unique tag to ensure anonymity. And our proposed scheme also realizes un-linkability, ensuring that attackers cannot determine whether different messages are sent by the same vehicle. Besides, we present a detailed and efficient revocation mechanism in the proposed scheme. Each RSU has its own private key, when there is a malicious vehicle, RSU will immediately update the private key of current area. Only legitimate vehicles can get the new private key, and malicious vehicle is efficiently revoked from the network. The experiment results show that the proposed scheme solves the above problems with little additional extra calculations.