Abstract
As urban centers transition toward smart mobility frameworks, autonomous vehicle (AV) fleets require decentralized, secure, and latency-sensitive identity management systems to ensure resilient coordination and prevent Sybil or impersonation attacks. Traditional centralized Public Key Infrastructure (PKI) models suffer from single points of failure, administrative friction, and severe communication overhead in dynamic Vehicle-to-Everything (V2X) environments. This paper proposes a lightweight, consensus-driven Self-Sovereign Identity (SSI) framework tailored for AV fleet management utilizing a Byzantine Fault Tolerant (BFT) directed acyclic graph (DAG) blockchain architecture. Our model integrates W3C-compliant decentralized identifiers (DIDs) with zero-knowledge proofs (ZKPs) to enable verifiable credential verification while strictly preserving vehicle operational and location privacy. Through extensive simulation of 1,000 AV nodes operating within a high-density urban grid scenario, the proposed architecture achieved a 64% reduction in identity verification latency compared to conventional Ethereum-based state channels, while maintaining a 99.98% transaction validation success rate under heavy network stress. Furthermore, the protocol demonstrates robust resistance against rogue node insertion and identity spoofing attacks. These findings indicate that integrating DAG-based consensus mechanisms with zero-knowledge decentralized identity constructs provides a scalable, privacy-preserving foundation for real-time AV fleet coordination in next-generation smart cities.
