On the Security of a Secure Batch Verification with Group Testing for VANET

Vehicular communication networking can provide well-suited traffic messages, emergency warning messages and infotainment dissemination, and improve driving condition for drivers. The authentication of these information is particularly important in VANET since the wrong traffic information may result in traffic accident and traffic jam. And VANET requires short verifying delay to response messages. To identify invalid messages and reduce verifying delay, a lot of schemes have been proposed to verify the information of VANET by batch verification technique. Recently, Lee et al.' proposed an improved authentication scheme with batch verification based on bilinear pairing to make VANET more secure, efficient, and more suitable for practical use. Unfortunately, their scheme is shown to be insecure and cannot achieve re-play attacking, tracing and non-repudiation of message. Finally, to overcome the above flaws, an improved authentication scheme is proposed. And the security proof and performance analysis are presented. By comparing with Lee et al.s' scheme and Zhang et al.'s scheme in terms of verifying delay, our scheme is more efficient than Zhang et al.'s scheme. And Batch verification time in our scheme is more 0.6ms than that of Lee et al.'s scheme, however, Lee et al.'s is insecure.