CRT-Paillier Homomorphic Privacy Protection Scheme Based on BLS Signatures in Mobile Vehicular Networks

Vehicular Ad-hoc Networks (VANETs) serve as an integral component within Intelligent Transportation Systems (ITS), designed to augment traffic fluidity and ensure a secure, comfortable driving environment for both drivers and passengers. In this system, real-time data exchange between vehicles, Road Side Units (RSUs), and other infrastructure is essential. However, this process can potentially lead to serious data privacy issues due to the large-scale data exchange. This paper proposes an edge-assisted homomorphic privacy protection scheme in VANETs, based on BLS signatures for homomorphic authentication and group signatures to address the conflicting requirements of participant identity verification and anonymity. By utilizing the Chinese Remainder Theorem (CRT)-optimized Paillier encryption algorithm, it allows for homomorphic addition operations on encrypted data, aiming to support secure data aggregation in ciphertext states while ensuring data transmission and aggregation security. The incorporation of CRT decomposes the modulo operation in the Paillier algorithm into operations with smaller moduli, further enhancing the efficiency of the Paillier algorithm in handling large-scale datasets, and reducing computational complexity and time costs. Experimental results demonstrate that with a global precision of 1024 bits in gmpy2, for a 2048-bit key length CRT-Paillier encryption algorithm, the encryption time is 91.30 ms, and the decryption time is 9.96 ms. The proposed scheme significantly enhances data security and operational efficiency within the VANET domain.