Blockchain-driven distributed key management for strengthening Industrial Internet of Things security

The Industrial Internet of Things (IIoT) enhances manufacturing through large-scale device connectivity but remains vulnerable to key compromise and dynamic node attacks. Centralized key management systems suffer from scalability and single-point failure issues. To address these challenges, this study introduces a novel blockchain-driven distributed key management scheme that enables secure, scalable, and decentralized communication across IIoT networks. The proposed framework introduces a hierarchical node classification–ordinary, meta-, and new nodes–to achieve adaptive and autonomous key distribution without reliance on a central authority. A three-tier blockchain architecture integrating device, edge, and cloud layers ensures decentralized trust, tamper-proof verification, and rapid consensus. The scheme’s unique polynomial-based key generation mechanism allows meta-nodes to collaboratively generate asymmetric bivariate polynomials, whose shares are validated through on-chain Kate commitments for secure pairwise and group communication. The novelty of this work lies in its dynamic threshold switching mechanism, which maintains communication security during node additions or removals, and its hybrid blockchain deployment, which merges on-chain validation with off-chain computation to optimize latency and resource utilization. Security analysis confirms strong resilience against Sybil, replay, and Byzantine attacks, while experimental results demonstrate enhanced key recoverability, communication integrity, and reduced computational overhead compared to traditional centralized approaches.