ASCON-Based Pairing-Free Certificateless Authentication and Key Agreement Protocol for IoV

The increased deployment of vehicles with advanced on-board units has facilitated intelligent transportation services using communication with roadside units. However, such communication is conducted over open channels; hence, transmitted messages are vulnerable to security threats, necessitating secure and efficient authentication protocols. Recently, an authentication protocol for the Internet of Vehicles. This paper presents a detailed cryptanalysis of the protocol and demonstrates that the protocol is vulnerable to session key disclosure, man-in-the-middle, and vehicle-capture attacks, and fails to ensure vehicle untraceability. To overcome these security weaknesses, we propose an ASCON-based pairing-free certificateless authentication and key agreement protocol for the IoV. We employ ASCON to offer lightweight confidentiality and integrity protection and adopt certificateless authentication based on elliptic curve cryptography. Moreover, it supports efficient batch authentication of multiple vehicles to reduce authentication delay under high-density traffic conditions. We validate the security of the proposed protocol through informal and formal security analyses and evaluate its practicality through computation and communication cost comparisons, as well as network simulator 3 and simulation of urban mobility experiments. The results demonstrate that the proposed protocol provides secure and low-latency authentication suitable for dynamic IoV environments.