It is a challenging issue to provide a secure and conditional anonymous authentication scheme in vehicle ad hoc networks (VANETs) with low storage space and computational cost. In 2008, Lu et al. proposed a conditional privacy preservation scheme called efficiency conditional privacy preservation (ECPP) protocol. The ECPP protocol provides conditional privacy preservation to vehicles in VANETs. That is, on one hand vehicles can achieve anonymous authentication in the network, on the other hand, allow to be traced and revoked if necessary. However, ECPP scheme suffers from high computational cost and large storage. In this scheme, an improved protocol based on the concept of ECPP protocol has been proposed to achieve more efficiency conditional privacy preservation (MECPP) scheme in VANETs. Comparing with ECCP, the computational cost of the proposed scheme has been decreased by about 54 % while the communication overhead has been reduced by about 10 % . At the same time, a lot of storage space has been saved.
A Novel Anonymous Authentication Scheme in Ad Hoc Networks