An Unlinkable Authenticated Key Agreement With Collusion Resistant for VANETs

Anonymous authentication is an important step to protect vehicular privacy and security in VANETs. To improve the efficiency of anonymous authentication in multiple security domains, VANETs integrated with blockchain attracts extensive attention. However, the existing blockchain-based authentication schemes cannot effectively achieve anonymity because colluded RSUs or vehicles can achieve linkability via the same retrieved record to destroy anonymity. To address the issue, we propose an unlinkable authenticated key agreement with collusion resistant for VANETs. For the unlinkability of V2R, firstly, a trusted authority generates multiple tickets that hide the vehicle's identity and shares them by the blockchain network. Then, vehicle generates different pseudonyms by homomorphic encryption, and RSU uses different tickets to authenticate them. Meanwhile, in view of the unlinkability of the V2V, anonymous authenticated key agreement based on homomorphic properties is designed to enable vehicles to achieve authentication without retrieving any vehicular information. Security analysis and performance evaluation show that our scheme has strict unlinkability and enhanced anonymity as well as improves the efficiency of V2R and V2V by 10% and 50%, respectively.

Automated summary

The paper introduces an unlinkable authenticated key agreement with collusion resistance for VANETs, which enhances security and efficiency by generating multiple hidden identities and shared tickets by a trusted authority for vehicles and RSUs to conduct anonymous authentication.