Abstract
In Collaborative Intelligent Transportation System (C-ITS), vehicles send collaborative awareness messages (CAMs) carrying information such as speed, position, and identity, to interact with other vehicles, and thus, obtain transportation services. However, CAMs are broadcasted in plaintext over the unsafe network, which causes the leakage of vehicle's sensitive information when maliciously intercepted. At present, there is less scheme for encryption and anonymous authentication CAMs that is suitable for the actual scenario. In this paper, we propose a revocable zone encryption scheme with anonymous authentication. When vehicles enter the zone, the zone manager first completes the anonymous authentication according to the vehicle-generated join request containing a self-delegated certificate. Then, vehicles encrypt CAMs with the session key by symmetric encryption and wrap the session key with the zone key for secure communication. Besides, we use the complete subtree method to satisfy the revocation of the vehicle and zone key management respectively. Finally, simulation experiments and analysis show that our scheme provides stronger privacy-preserving compared with proposals that only support anonymous authentication. Differing from the similar scheme that tries to encrypt CAMs, our scheme not only satisfies more security requirements but also our key management is more feasible.