A study on a privacy preservation method for VANETs based on certificateless anonymous authentication and non-interactive zero-knowledge proof

As a core component of intelligent transportation systems, the security authentication and privacy protection mechanisms in Vehicular Ad Hoc Networks (VANETs) are of paramount importance. To address key security issues in VANETs, such as the vulnerability of identity privacy to leakage, the complexity of certificate management, the high risk of key escrow, and the challenge of balancing authentication efficiency with security, the paper proposes a privacy-preserving identity authentication and key agreement method based on certificateless public key cryptography (CL-PKC) and non-interactive zero-knowledge proofs (NIZK). This method utilizes a composite identity identifier and combines it with Pedersen commitments to propose a dynamic anonymous identity generation mechanism. It stores static commitments containing identity information on the blockchain, and generates one-time dynamic identities through re-randomization in each authentication process, thereby solving the certificate management issue and achieving anonymity. Furthermore, the method designs an authentication protocol based on CL-PKC and Schnorr NIZK, integrating private key validity verification with dynamic identity verification. A vehicle only needs to construct a single zero-knowledge proof to complete both verifications simultaneously, eliminating the risk of key escrow and improving authentication efficiency and security. For experimental evaluation, the paper constructs a simulation environment based on standard elliptic curve cryptography (ECC) and the Ganache blockchain testnet, utilizing benchmark testing data to conduct a comprehensive performance comparison between the proposed method and existing typical authentication methods. Security analysis and experimental evaluation demonstrate that the proposed method satisfies security requirements such as conditional anonymity, unlinkability, and forward security, effectively reduces the system's computational and communication overhead, and is applicable to highly dynamic and resource-constrained VANET environments.