Lattice-Based Certificateless Aggregate Authentication Scheme With Conditional Privacy-Preserving for VANET

Vehicular ad hoc network (VANET) is a key infrastructure of Intelligent Transportation Systems (ITS). As VANET is inherently exposed to wireless channels, numerous identity authentication schemes have been proposed to ensure the security and privacy of data transmission. However, existing schemes still suffer some limitations. First, most existing schemes are based on classical cryptographic assumptions, making them inadequate in the post-quantum era. Meanwhile, the limited number of quantum-resistant authentication schemes still suffer from efficiency issues and even security vulnerabilities. To address above challenges, we propose a novel Lattice-based Certificateless Aggregate Authentication scheme (L-CLAA) with conditional privacy-preserving for VANET. By leveraging lattice trapdoors and Schnorr-like signature techniques to reconstruct the Certificateless Aggregate Signature (CLAS) framework, we achieve a rigorous and concise lattice-based signature construction, which can efficiently complete signature generation, verification and aggregated verification. Both secure and practical dynamic pseudonym mechanism have been combined with together in this signature construction. It enables the L-CLAA scheme to authenticate pseudonym legitimacy with low computational and communication cost without revealing the real identity. Rigorous security analysis demonstrates that the L-CLAA scheme provides key security features such as unforgeability, conditional traceability and quantum resistance, meeting the security and privacy requirements of VANET. Performance evaluation and applicability analysis demonstrate that the L-CLAA scheme achieves more efficient and well-balanced performance compared with existing representative lattice-based schemes, with sufficient practical applicability for VANET, particularly in the post-quantum era.