Blockchain-Enabled Secure Data Sharing for Autonomous Vehicle Swarms in 6G V2X Networks

Abstract

The evolution toward fully autonomous vehicle swarms operating in 6G Vehicle-to
Everything (V2X) networks necessitates unprecedented levels of secure, real-time
data exchange for cooperative perception and navigation. However, existing
centralized trust authorities introduce single points of failure and latency
bottlenecks, while decentralized approaches struggle with Byzantine behavior
among untrusted vehicles. This paper proposes ChainGuard-V2X, a hybrid
blockchain architecture optimized for low-latency, high-throughput data sharing in
autonomous vehicle networks. Our framework implements a practical Byzantine
Fault Tolerant (pBFT) consensus mechanism modified with reputation-based voting
weights, where vehicles earn trust scores based on historical data validity. We
introduce a novel "proof-of-trajectory" validation scheme that cryptographically
verifies the physical plausibility of shared sensor data using digital signatures from
roadside units (RSUs). A two-layer sharding design separates high-frequency
operational data (processed off-chain) from critical security events (recorded on
chain). Simulation using SUMO traffic models integrated with OMNeT++ network
emulation demonstrates that ChainGuard-V2X achieves consensus within 120ms
under 6G millimeter-wave conditions, supporting 500+ vehicles per shard with
99.94% data integrity. Compared to Ethereum-based solutions, our approach reduces
latency by 78% and increases transaction throughput to 2,800 TPS while maintaining
resistance to 33% malicious nodes. Energy consumption analysis shows only 8.2%
overhead compared to non-blockchain V2X communication, making it feasible for
electric vehicle deployments.