An improved efficient authentication scheme for vehicular ad hoc networks with batch verification using bilinear pairings

Research related to the authentication schemes in vehicular ad hoc networks (VANETs) still becomes a hot issue to discuss. In 2019, Cui and Tu proposed an efficient authentication scheme for vehicular ad hoc networks (VANETs) with batch verification using bilinear pairings. Their scheme was designed to improve the utilisation of the double-secret key in the identity-based batch signature (IBS) scheme published by Jianhong et al. and Bayat et al. Unfortunately, we found that Cui and Tu's identity-based conditional privacy-preserving authentication (IBCPPA) scheme is also insecure against non-repudiation attack. By those defects, a malicious user can broadcast some wrong messages to mislead the roadside unit (RSU) and deny its behaviour when a trusted authority (TA) traces it. In this article, we address the issue and give our improvement to withstand the above security threat.