TPM-Based Conditional Privacy-Preserving Authentication Protocol in VANETs

With the establishment of intelligent transportation systems (ITS), research on vehicle ad-hoc networks (VANETs) has played an irreplaceable role in improving traffic safety and efficiency. However, because the deployment of devices based on the IoV is in an open field, the IoV is extremely vulnerable to various attacks without security protection, e.g., remote intrusion, control, trajectory tracking, etc. In order to avoid the above-mentioned attacks and resource abuses, provably secure cryptography primitives are generally considered to guarantee and realize the security of VANETs. This paper proposes a TPM-based conditional privacy-preserving authentication protocol (T-CPPA) which achieves both the integrity and the authenticity of the message/instruct content. The vehicle's privacy is protected by embedding the system master private key into the trust platform module (TPM) which is responsible for generating pseudonyms and signature keys. The authenticity of message content is ensured by calculating message similarity in a cluster-based model. We give the concrete construction of our T-CPPA authentication scheme in symmetric bilinear groups and design a batch validation algorithm to improve efficiency. Security analysis shows that our scheme can resist various traditional attacks in VANETs, and the experimental results indicate that our scheme is efficient and useful in practice.