CoCoChain: A Concept-Aware Consensus Protocol for Secure Sensor Data Exchange in Vehicular Ad Hoc Networks

Area of Science:

• Computer Science
• Network Security
• Distributed Systems

Background:

• Vehicular Ad Hoc Networks (VANETs) require low-latency, reliable V2X communication for safety and traffic optimization.
• Traditional blockchain consensus mechanisms (BFT-style) face challenges with high message overhead and latency in VANETs, hindering integrity and auditability.

Purpose of the Study:

• To introduce CoCoChain, a novel concept-aware consensus mechanism designed to address the limitations of conventional BFT consensus in VANETs.
• To enhance the efficiency and performance of blockchain-based V2X communication by reducing message overhead and latency.

Main Methods:

• CoCoChain utilizes a sparse autoencoder (SAE) to encode raw message payloads into low-dimensional concept vectors.
• Only the top-k activations (semantic digests) are broadcast during consensus, integrated into a practical BFT workflow with semantic checks.
• Simulations were conducted using OMNeT++/SUMO in urban, highway, and multi-hop broadcast scenarios, including adversarial attacks and cross-layer stress.

Main Results:

• CoCoChain reduced consensus message overhead by up to 25% and confirmation latency by 20%.
• The mechanism maintained data integrity with up to 20% Byzantine participants.
• Information freshness, measured by Age of Information (AoI), improved under high channel load.

Conclusions:

• CoCoChain offers an efficient and secure consensus mechanism tailored for VANETs, improving performance and information timeliness.
• The semantic-aware approach effectively balances security, overhead, and latency in V2X communication systems.