Blockchain-Based SDN-Enabled Lightweight Authentication Protocol for IoV Using zk-SNARK

Software-defined networking (SDN), an emerging networking paradigm, has been realized in the internet of vehicles to effectively manage the dynamic nature of vehicles and provide diverse vehicle-to-everything (V2X) services and security. Nevertheless, the lack of authentication mechanisms and malicious behavior of vehicle users has seriously threatened security and privacy concerns in the SDN-based vehicular network (SDVN). Furthermore, in a distributed SDVN, the SDN controllers (SDNCs) are prone to single point of failure (SPoF) due to various potential attack vectors. Such attacks can result in the loss of periodically exchanged vehicular information among SDNCs. To address the aforementioned issues, a novel privacy-preserving lightweight zk-SNARK-based authentication protocol in blockchain-enabled distributed SDVN is presented. To address the SPoF of SDNCs, the proposed network model removes the dependency of a controller on neighboring SDNCs as the authenticated information is validated and stored in the blockchain. As an integral part of the protocol, the vehicles are authenticated by providing succinct and constant size proofs during authentication across SDVN domains. The security and simulation performance analyses confirm the superior performance of the proposed protocol, surpassing state-of-the-art schemes in terms of authentication latency, computation time, and energy efficiency. The proposed protocol has achieved notable improvements of more than 55% in all the metrics considered during the protocol simulation when compared with other protocols.