A Lightweight Blockchain-Enabled Trust Management Model for Secure Vehicular Communication

Vehicular Ad Hoc Networks (VANETs) are emerging as a pivotal component in intelligent transportation systems, offering safety-critical and comfort-related information to drivers and passengers. The effectiveness of VANETs relies on the timely exchange of messages between vehicles and roadside units (RSUs), where the trustworthiness of shared data is paramount. Traditional centralized trust models, though efficient in information validation, suffer from single points of failure, limited scalability, and vulnerability to insider threats. This has driven a paradigm shift toward decentralized architectures, with blockchain technology standing out due to its immutable, transparent, and distributed nature. This study presents a comprehensive review of existing centralized and decentralized trust management models in VANETs, analyzing their methodologies, strengths, and limitations. By examining trust metrics, validation schemes, and message verification strategies across the literature, it identifies critical gaps in scalability, response time, and resistance to malicious behavior. Addressing these limitations, we propose a novel blockchain-based trust model named CB-RTM (Consortium Blockchain for RSU-Assisted Trust Management), an intelligent framework designed to ensure secure, verifiable, and real-time dissemination of safety messages in VANETs. The CB-RTM model integrates consortium blockchain with RSU-based validation and a Proof-of-Authority (PoA) consensus mechanism to filter and authenticate event messages using location certificates and trust scores. Unlike existing approaches, the model localizes trust updates and block propagation to geographically bounded regions, enhancing scalability and latency performance. Experimental evaluation demonstrates that the proposed CB-RTM outperforms state-of-the-art models across key metrics. The model achieves a trust accuracy of 96.2%, a latency of 0.42 seconds, and a throughput of 245 messages per second, while maintaining a manageable communication overhead of 11.2%. These results confirm that CB-RTM is a robust, scalable, and efficient solution for trust management in real-time VANET environments