Misbehavior Detection in Vehicular Ad Hoc Networks Based on Privacy-Preserving Federated Learning and Blockchain

Abstract

As an irreversible trend, connected vehicles have become increasingly more popular. They depend on the generation and sharing of data between vehicles to improve safety and efficiency of the transportation system. Due to the open feature of the vehicular ad hoc network (VANET), it is possible for dishonest and misbehaving vehicles to disrupt traffic by transmitting false information. In recent years, misbehavior detection systems have been developed to detect the malicious behaviour, and machine learning methods have been employed to make the detection more accurately. However, existing misbehavior detection systems typically require a single entity (e.g., a central server) for centralized data collection and training. Model updates are restricted due to data privacy and high overhead of data communication, which reduces the defensive capability of misbehavior detection systems. In this paper, we propose a blockchain-based federated learning scheme to detect misbehavior, which is trained collaboratively by coordinating multiple distributed edge devices while ensuring data security and privacy. In addition, to further protect the privacy of the model on the blockchain, differential privacy with the Gaussian mechanism is leveraged to provide strict privacy protection. Common data falsification attacks are studied in this paper. The experimental results show that our proposed scheme is feasible and effective, and demonstrate that our scheme achieves satisfied accuracy and efficiency.