A Blockchain-based Hierarchical Trust Management Scheme for IoT

The diverse and resource-constrained nature of Internet of Things (IoT) nodes presents challenges in terms of storage, computing capacity, scalability, and privacy. Effective trust management is crucial for gathering reliable data, enhancing privacy, and detecting and mitigating malicious nodes within the IoT ecosystem. However, traditional trust management mechanisms are vulnerable to security attacks, such as central node failures, and often neglect the unique constraints of IoT nodes. This paper introduces a blockchain-based hierarchical trust management framework aimed at addressing the limitations of conventional trust management systems for IoT. The proposed framework evaluates node reputation and organizational trust across two levels: intra-organizational and inter-organizational. At the intra-organizational level, a lightweight blockchain calculates trust and records node reputations. Upon reaching the local blockchain's length threshold, node reputation values are aggregated and inscribed in the global blockchain. In contrast, the global blockchain calculates and records organizational trust. Inter-organizational trust is assessed through direct and indirect trust methodologies. The proposed approach is assessed via a confusion matrix, demonstrating its efficacy in identifying and eliminating low-resource malicious nodes with minimal computational overhead.