A secure group-based authentication protocol for IoVT in 5G-enabled smart transportation and road safety systems

The Internet of Vehicular Things (IoVT) is evolving rapidly, connecting vehicles, infrastructure, and other smart systems via the Internet. This connectivity enhances safety, efficiency, and data-driven services but also introduces significant security and privacy risks. To tackle these challenges, this paper proposes a lightweight, group-based authentication and key agreement (AKA) protocol tailored for 5G-enabled IoVT networks. The protocol achieves essential security goals, including mutual authentication, key confirmation, forward and backward secrecy, subscriber privacy, and session unlinkability. Its security has been formally validated using the AVISPA tool and BAN logic, showing strong resistance against common cryptographic attacks. Performance evaluations indicate that the proposed protocol can reduce signaling overhead by up to 47.3%, lower bandwidth consumption by up to 32.3%, and significantly decrease computational costs compared to the standard EPS-AKA protocol. Overall, these results highlight a secure, efficient, and scalable solution suitable for next-generation 5G-based IoVT systems.