A V2X Reputation System with Privacy Considerations

Inter-vehicle communications can enable a wide array of novel applications that improve transportation safety and efficiency. However, due to the adversarial environment in which vehicles may operate, it is important to ensure information integrity. To achieve this, we present a blockchain-based reputation mechanism that allows participants to assess the trustworthiness of the received data based on the existing reputation score of the sender. After each data exchange, the receiver rates the sender by uploading an evaluation to the blockchain. To ensure that no tracking of the participants is possible, despite the open nature of the blockchain, we propose an address rotation scheme based on Zero Knowledge Proofs. Vehicles have the capability to change their blockchain address at regular intervals, while at the same time keeping their reputation score. Finally, we conduct experiments and simulations to evaluate our proposed system. The obtained results show that information integrity is ensured even in the presence of large number of adversaries and that privacy protection can be achieved at a reasonable cost.