ECPB: Efficient Conditional Privacy-Preserving Authentication Scheme Supporting Batch Verification for VANETs

In this paper, we introduce an efficient Conditional Privacy-Preserving authentication scheme(ECPB) based on group signature for vehicular ad hoc networks (VANETs). Although group signature is widely used in VANETs for security requirements, the existing schemes based on group signatures suffer longer computational delays in the certificate revocation list (CRL) checking and in the signature verification process, leading to lower verification efficiency. In our scheme, membership validity (a validity period) is required when a vehicle applies for a group member and this validity is used to check whether the vehicle is still a group member or not, which can be used as a substitute for the CRL checks. Neglecting the CRL checks will sharply decrease the costs incurred in the signatures verification. In addition, our proposed scheme also supports batch verification. Experimental analysis proves that our proposed scheme exhibit improved efficiency over the existing schemes, in terms of verification delay and average delay.