BAKP: A Blockchain-Assisted Anonymous Authentication and Key Agreement Protocol for Secure Internet of Vehicle

Authentication in the Internet of Vehicles (IoV) is challenged by significant communication delays and risks of attacker intrusion, attributed to the high mobility of vehicles. Current authentication schemes often fail to fully address the reliability of Road Side Units (RSUs) and typically overlook issues related to single points of failure. Additionally, these schemes do not adequately consider secure and efficient handover authentication during vehicle access, leading to increased computational and communication costs. To overcome these limitations, we introduce BAKP, a blockchain-assisted anonymous authentication and key agreement protocol designed specifically for IoV contexts. BAKP enables secure access authentication for vehicles connecting to network services, even in scenarios where RSUs are semi-trusted. When the vehicles re-request network services, the RSUs bypass the authentication center and directly query the blockchain-recorded authentication results, thereby streamlining the handover process. The protocol also supports the revocation of pseudo-identities and enhances the transparency in tracing malicious entities. We performed a provable security analysis of BAKP using the Standard Model, along with formal security evaluations employing Colored Petri Nets (CPN) and the DolevYao attacker model. Our results confirm that BAKP is robust against all relevant attacks and demonstrate its efficiency through comprehensive performance evaluations.