Lightweight Vehicular Ad-Hoc Network Conditional Privacy-Preserving Authentication Based on Blockchain

Conditional Privacy-Preserving Authentication (CPPA) effectively supports secure communication in Vehicular Ad-hoc Network (VANET). To address the issues of inefficient message authentication and adversarial threats to data privacy in VANETs, a lightweight blockchain-based CPPA scheme is proposed. The proposed scheme utilizes an improved noninteractive Schnorr signature algorithm based on elliptic curve cryptography in the message verification phase, which avoids time-consuming cryptographic operations. The scheme employs entity-generated short pseudonyms for anonymous communication and introduces a consortium blockchain into the system architecture. The sender's identity is automatically verified during the message verification process using smart contract technology, thereby reducing the communication overhead of the scheme. Security analysis shows that the proposed scheme is secure against forgery under an adaptive chosen-message attack in the Random Oracle Model (ROM) while satisfying the requirements of conditional privacy preservation. Performance analysis measures the execution time of the proposed scheme and the existing CPPA scheme using cryptographic operations with the MIRACL cryptographic library. A Hyperledger Caliper is used to evaluate the transaction latency and throughput of the blockchain test network. The results demonstrate that the proposed scheme achieves lightweight computation and communication overhead in the signature generation and single-message verification phases and effectively supports batch message verification.