Lightweight Conditional Privacy-Preserving Scheme for VANET Communications

As a crucial component of intelligent transportation systems, VANETs are essential for enhancing road safety and enabling efficient traffic management. To ensure secure communication, vehicles often use pseudonyms to protect their identity privacy. However, unconditional anonymity can hinder accountability, making it very necessary to provide conditional privacy protection for vehicles. The conditional privacy-preserving technology not only protects the identity privacy of legitimate vehicles, but also can trace the real identity of malicious vehicles. Some existing schemes lack conditional privacy protection or have large computation and communication costs, which makes them unsuitable for resource-constrained VANETs environments. Hence, we improve the current schnorr-based aggregate signature by eliminating bilinear pairing operations, optimizing the aggregation procedure for batch verification and propose a lightweight certificateless-based aggregate signature scheme (ECPP-CLAS) for VANETs. In our scheme, the aggregation enables multiple signatures to be compressed into an aggregated signature and verified simultaneously, thereby reducing communication consumption, trusted entity generates the pseudonym for the corresponding vehicle through special construction to meet the conditional privacy-preserving requirement. The security analysis and performance evaluation show that our proposed scheme can meet the expected security objectives and lightweight requirements.