Efficient Distributed Admission and Revocation Using Blockchain for Cooperative ITS

Cooperative Intelligent Transportation System (C- ITS) enables inter-networking of vehicles for alerts exchanging in order to improve road safety. While this technology is about to enter the market in the upcoming years, critical questions related to the communication security continue to be challenging research concerns. Current solutions to secure inter-vehicle communication depend mainly on the use of digital certificates for authentication. However, such an approach imposes significant overhead on vehicles since it is computationally demanding and requires validation of the certificate within a limited period. In addition, relying on a central node for deciding on issuing and revoking certificates introduces a single point of failure and could even risk the safety of motorists. In this paper, we propose the use of Blockchain to keep track of the certificate of each vehicle (valid or revoked) in distributed and immutable records. In essence we replace certificate verification with a lightweight blockchain-based authentication approach. In addition, we propose a fully distributed vehicle admission/revocation scheme. We show that our scheme could alleviate the computation overhead and enhance the response time while improving the overall system security.