Revolutionising Vehicular Security: Lightweight Handover Authentication in RIS-Aided VANETs

Vehicular Ad Hoc Networks (VANETs) form the foundational communication framework of intelligent transportation systems, facilitating low-latency, vehicle-to-everything data exchange for enhanced traffic efficiency and safety. Accordingly, ensuring secure, efficient, and scalable authentication is essential to maintain communication trustworthiness, especially in highly dynamic and dense traffic scenarios. While traditional public key cryptography (PKC)-based solutions offer strong security guarantees, they are computationally intensive and struggle to scale under VANET workloads. To address these challenges, this paper proposes a novel lightweight handover authentication scheme that integrates pairing-based cryptography with symmetric key primitives to ensure message integrity, anonymity, and unlinkability. The proposed solution is deployed within a real-world Reconfigurable Intelligent Surface (RIS)-assisted commu- nication environment, enhancing the robustness and feasibility of the authentication process during handover. Furthermore, a comprehensive evaluation is conducted, comparing the computational and communication overhead of the proposed scheme with existing cryptographic protocols. Results demonstrate the superior scalability and efficiency of the proposed approach, making it well-suited for next-generation VANET applications.