DBVA: Double-layered blockchain architecture for enhanced security in VANET vehicular authentication

Vehicular ad-hoc networks (VANET) are crucial for improving road safety and traffic management in Intelligent Transportation Systems (ITS). However, these networks face significant security and privacy challenges due to their dynamic and decentralized nature. Traditional authentication methods, such as Public Key Infrastructure (PKI) and centralized systems, struggle with scalability, single points of failure, and privacy issues. To address these issues, this paper introduces DBVA, a Double-Layered Blockchain Architecture that integrates private and consortium blockchains to create a robust and scalable authentication framework for VANET. The DBVA framework segregates public transactions, such as traffic data, from private transactions, such as identity and location information, into separate blockchain layers, preserving privacy and enhancing security. Additionally, DBVA introduces strict access control smart contracts for the decentralized revocation of unauthorized vehicle privileges, minimizing communication risks and enhancing system resilience. A dynamic pseudonym identity generation mechanism with periodic updates further strengthens privacy by segregating real and pseudonymous identities into separate blockchain layers. Comprehensive performance evaluations reveal that DBVA significantly enhances computational efficiency, reducing the computational cost to 18.34 ms, lowering communication overhead to 992 bits per message, and minimizing storage requirements to just 50 units, making it competitive among contemporary schemes. Extensive security analysis and formal proof confirm that DBVA effectively meets all essential privacy and security requirements, making it a robust, reliable, and scalable solution for enhancing the security, privacy, and resilience of VANET.