SECURE VEHICULAR NETWORKS USING BLOCKCHAIN TECHNOLOGY

Vehicular networks are the communication backbone of connected and autonomous vehicle ecosystems, yet their security posture remains critically underserved. The combination of high node mobility, dynamic topology changes, and reliance on broadcast communication makes traditional centralized security models fundamentally unsuitable for Vehicle-to-Everything (V2X) environments. This paper proposes a blockchain-anchored distributed security framework for vehicular networks that addresses three persistent gaps: absence of tamper-evident message authentication across dynamic node sets, lack of decentralized trust establishment without infrastructure dependency, and insufficient revocation mechanisms for compromised vehicle identities. The proposed architecture integrates a permissioned Hyperledger Fabric ledger as a decentralized trust anchor for vehicle identity management, smart-contract-driven certificate lifecycle enforcement, and a distributed reputation scoring engine that propagates trust metrics across roadside units (RSUs) and onboard units (OBUs) in real time. A cross-node audit mechanism records all V2X message authentication events as immutable ledger transactions, enabling forensic traceability without dependence on any central authority. Experimental evaluation across a simulated 500-vehicle urban corridor demonstrates 96.3% reduction in Sybil attack success rate, message authentication latency of 18.4 ms under peak load, and certificate revocation propagation within 340 ms across the full network—outperforming PKI-based baselines on all security and performance dimensions. The framework aligns with IEEE 1609.2, ETSI ITS, and GDPR pseudonymity requirements.