A privacy-enhanced authentication scheme for VANETs based on blockchain and zero-knowledge proof

The rapid development of Intelligent Transportation Systems (ITS) and autonomous driving technologies has made secure authentication and privacy protection of vehicle identities in Vehicular Ad Hoc Networks (VANETs) a hot research issue. Existing solutions typically rely on pseudonym-based approaches. These approaches incur large storage overhead and computational costs, which limit their scalability and efficiency. To address this problem, this paper proposes a novel anonymous authentication scheme in VANETs that synergistically integrates zero-knowledge proof (ZKP) and blockchain technology. An identity-based polynomial commitment is used in the present scheme to achieve privacy-preserving authentication, which ensures the anonymity of the vehicle without revealing sensitive information. Additionally, an identity-based signature algorithm, based on the Gap Diffie-Hellman (GDH) problem, ensures session unlinkability, enhancing connection security. Incorporating the Merkle Patricia Trie (MPT) into the blockchain framework optimizes data retrieval efficiency while minimizing storage and computational burdens on the central server. Blockchain's inherent immutability and transparency further enhance data integrity and security.