Abstract: With the increase of traffic problems,various applications of vehicular Ad hoc networks(VANEh) arc pro- posed. And their security is receiving increasing attention. This paper proposed a secure vehicl}to-infrastructure com- munication protocol based on certificateless public key cryptosystem. The proposed protocol combines the advantages of the protocol based on traditional public key cryptosystem(no key escrow) and that based on II}PKC(implicit authenti- canon). Compared with a certificate based protocol at the same security level, the efficiency of the proposed approach is

Key words: Certificateless public key cryptosystem, Vehicular ad hoc network, Implicit authentication