A Secure Pairing-Free Certificateless Online/Offline Signcryption Scheme With Batch Verification for Edge Computing-Based VANETs

In modern transportation systems, vehicular ad hoc networks (VANETs) provide a solid foundation for improving public transportation. To efficiently realize real-time and secure vehicle communication systems, many certificateless signcryption (CLSC) schemes are proposed in VANETs. However, existing relevant CLSC schemes still have security or efficiency drawbacks. In this paper, we first cryptanalyze Xie et al.’s CLSC scheme (IEEE Trans. Veh. Technol., vol. 72, no. 5, pp. 5642-5653, May. 2023) and demonstrate its vulnerability under public key replacement attacks. Then, we propose a pairing-free CLSC scheme for edge computing-based VANETs, with its security proven in the random oracle model. Our CLSC scheme not only achieves confidentiality and unforgeability in a single logical step, but also avoids costly certificate management and key escrow problems. Meanwhile, our construction leverages online/offline signature (OOS) and batch verification techniques, which significantly reduces communication time-delay and computational overhead. Moreover, our deployment resists multiple prevalent attacks in VANETs, including but not limited to collusion attacks and man-in-the-middle attacks, and provides pseudonym-based conditional privacy for vehicles. Finally, performance results show that our CLSC scheme outperforms existing ones, making it highly practical for VANETs.