An effective cross-domain identity authentication based on blockchain and certificateless cryptography for internet of vehicles

To address identity forgery and privacy leakage in Internet of vehicles (IoV) within intelligent transportation systems, we propose an efficient cross-domain identity authentication (IA) scheme based on blockchain and certificateless cryptography. However, existing IA schemes often suffer from high computational overhead, limited scalability, or inadequate support for cross-domain scenarios. First, a distributed authentication architecture is designed, and an off-chain storage mechanism combining blockchain and distributed hash table (DHT) to reduce storage costs. Second, a key generation scheme based on certificateless cryptography is designed to address key escrow problem. Third, a conditional privacy protection mechanism is proposed to achieve both anonymity and traceability of vehicle identities. A formal privacy evaluation is provided based on k-anonymity quantifies anonymity level under realistic adversary models. Finally, performance evaluations are conducted in terms of authentication delay, throughput, and success rate, demonstrating that the proposed scheme improves authentication efficiency while enhancing the system security and privacy.