An Efficient Lightweight Mutual Authentication and Key Exchange Protocol for Roaming Vehicle

Intelligent vehicles and their infrastructure have been a booming topic that requires attention towards grooming security services and providing a safe-secure drive experience to users worldwide. Authentication of these vehicles within and away from the home network plays an essential role in maintaining seamless service access, especially for users moving away from the home network. Traditional schemes are centralized and primarily focus on vehicle authentication within a home network. Very few studies have been conducted on vehicle authentication during roaming. The trusted authority (TA) must authenticate its vehicle along with the one in roaming, which increases the communication and computational load on the TA as scalability increases. This article presents a lightweight authentication scheme, especially for roaming vehicles, and focuses on sharing the authentication load. A vehicle, along with its home TA (HTA) identity, sends an authentication request to a nearby roadside unit (RSU) during roaming. After receiving an authentication request from the RSU, the foreign TA (FTA) connects to the HTA. Vehicle authenticity was confirmed as a session key generated for communication with a roaming vehicle, ensuring seamless service access. The proposed scheme was tested against standard BAN logic to prove that it meets the required security standards and authentication requirements. Furthermore, the communication and computation cost analysis proves that this scheme is lightweight compared with other traditional schemes. Security analysis proves that the proposed scheme can successfully prevent major attacks, such as anonymity, unlinkability, replay attack, message tampering, and malicious vehicle tracking.