A Cross-domain Data Sharing Scheme for VANETs Based on Blockchain

With the continuous development of the Vehicular Ad Hoc Network (VANET), cross-domain sharing of vehicle data has become a significant concern. The Ciphertext-Policy Attribute-Based Encryption (CP-ABE) algorithm plays a key role in data sharing as it can achieve “one-to-many” transmission. In this paper, we propose a cross-domain data sharing scheme based on unpaired CP-ABE in VANETs, utilizing the blockchain and InterPlanetary File System (IPFS) system. The blockchain network is composed of trusted authorities (TAs) from different domains. Due to the high-speed movement characteristics of vehicles, we divide vehicle attributes into two categories: static and dynamic. we design a cross-domain data verification contract based on attribute bloom filter (ABF) for decryption testing. Vehicles that pass the test will receive dynamic attribute decryption keys generated by TAs in the data sharing domain to achieve cross-domain access. In addition, we design an outsourced decryption scheme to reduce the computational overhead during vehicle decryption and propose a direct permission revocation mechanism to ensure the flexibility and security of the system. The simulation experiment results show that our scheme optimizes the efficiency of cross-domain data access significantly compared with other approaches.