<p>Vehicular ad-hoc networks play a crucial role in intelligent transportation systems by enabling secure and efficient communication between vehicles and roadside units. However, the dynamic and open nature of these networks introduces significant challenges in terms of security, privacy, and key management. To address these challenges, we propose a blockchain-assisted conditional privacy-preserving authentication scheme based on identity-based ring signcryption, which leverages the fundamental principles of identity-based cryptosystems and ring signatures to ensure conditional privacy. Moreover, blockchain guarantees tamper-proof storage and decentralized management of vehicle identities and public keys, thereby enhancing trust and transparency. Additionally, the scheme reduces computational and communication overhead through batch verification. Security analysis and performance evaluations show that the proposed scheme provides various security properties, including confidentiality, verifiability, replay attack resistance, anonymity, unforgeability, and traceability, all while maintaining low computational and communication overhead. These features make it a promising solution for future vehicular networks.</p>