An Anonymous Signature-Based Authentication and Key Agreement Scheme for Vehicular Ad Hoc Networks

Anonymous authentication is a critical step in safeguarding vehicle privacy and security in VANETs. VANETs connected with blockchain are gaining popularity as a means to increase the effectiveness of anonymous authentication across many security domains. However, present blockchain-assisted authentication systems cannot successfully achieve anonymity since colluding RSUs or vehicles may acquire linkability via the same retrieved record, hence destroying anonymity. To solve the problem, the proposed work offers an unlinkable anonymous signature-based authentication for VANET to ensure collusion resistance. To provide V2R unlinkability, a trusted authority issues anonymous parameters that conceal the vehicle's identification from RSUs and other vehicles in the VANET system. The vehicle user produces anonymous signatures, and RSUs validate them during anonymous authentication. Moreover, the proposed authentication methods are based on an anonymous certificateless signature (ACS) approach that is computationally more efficient and provably safe against eternal forgery in the random oracle model. Additionally, the proposed work guarantees that neither an RSU nor a vehicle has the authority to divulge users’ true identities. Hence, the proposed system has stringent unlinkability and better anonymity, and it enhances the efficiency of V2R and V2V communications considerably according to security analysis and performance assessment.