Review of Certificateless Authentication Scheme for Vehicular Ad Hoc Networks

Vehicular networks play an integral role in Intelligent Transportation Systems (ITS) by facilitating real-time communication between vehicles, roadside infrastructure, and cloud-based services. But this inherent characteristics on mobility, decentralization, and open wireless broadcast nature makes security threats a big target to them with impersonation attacks, Sybil attacks, data breaches and unauthorized access. PKI-based authentication methods, on the other hand, do not fit our objective, given the high computational overhead, certificate management issues, and centralization risk involved in V2V authentication protocols. Certificateless authentication has been proposed to avoid the challenges and costs associated with certificate-based security infrastructures by providing a lightweight and efficient alternative solution. Based on authentication models, cryptographic techniques, privacy-preserving mechanisms, emerging technologies and security properties, this survey presents a systematic classification of certificateless authentication schemes. It encompasses an investigation of emerging cryptographic solutions like lattice-based encryption, blockchain-supported authentication/credential management, AI-empowered security, and considers their impact on VANET security, scalability, and real-time constraints. Moreover, this study considers the application of 5G networks, edge computing, and post-quantum cryptography in VANET authentication. To ensure privacy-preserving and secure vehicular communication systems that could be scaled for infrastructural networks, the results highlight the shortcomings of existing vehicular authentication methods, and the need for hybrid authentication models, standardization, and interoperability.