ESGA: Efficient and Secure Geo-Aware Certificate Revocation for Blockchain-Based Multi-Domain VANETs

In vehicular ad-hoc networks (VANETs), certificate revocation is a critical technique to synchronize the invalid vehicle information accurately and timely across the network, especially in scenarios involving multiple edge domains. In order to achieve efficient and privacy-preserving certificate revocation list (CRL) synchronization, we propose ESGA, an efficient and secure geo-aware certificate revocation scheme for blockchain-based multi-domain VANETs. Since invalid vehicles are driving within specific edge domains during certain time periods, we design a hierarchical Geo-CRL structure comprising a blockchain-based global CRL and geographically distributed local CRLs. Furthermore, we design an adaptive geo-aware synchronization mechanism which enables timely local CRLs update, while ensuring periodic or event-driven updates of the global CRL on the blockchain. Finally, to protect the CRL information from pseudonym linking attacks, we design linkage values chain-based certificate revocation method for privacy preservation. The experimental results demonstrate that ESGA can significantly improve CRL synchronization efficiency with lower CRL query latency and storage overhead, and to protect the privacy of certificate revocation in blockchain-based multi-domain VANETs.