Secure and Energy-Aware Key Management for Intelligent Buildings using Particle Swarm Optimization and Blockchain

This work proposes Intelligent Building Dynamic Key Management System (IBDKEY), a new dynamic key management approach for smart building energy management through Wireless Sensor Networks (WSNs) and blockchain. IBDKEY addresses the issue of secure, lightweight, and scalable blockchain-based key distribution with respect to blockchain's decentralized and tamper-evident nature in addition to PKSO's optimization feature. The protocol maintains dynamically calculated cryptographic keys in terms of private key parameters and dynamic computation cost optimization with enhanced randomness, security, and adaptability to network dynamics. The protocol uses blockchain for open storage, verifiability, and revocation of keys regardless of centralized control. The algorithm ensures dynamic rekeying, communication overhead optimal, and node compromise and replay attack evasions. Experimental outcomes indicate that IBDKEY performs superiorly compared to other conventional methods such as TSK, RKP, and ECKM in terms of key performance indicators. It delivers the highest average entropy (119.6 bits) and fitness score (114.3), accompanied by an equally satisfactory generation time of 5.3 ms. It also provides higher revocation accuracy (96.4%) with the minimum rate of false revocation (1.1%), demonstrating its efficiency in identifying compromised nodes. From the resource efficiency point of view, IBDKEY minimized communication overhead (2.1 KB/node) and power consumption (15.2 mJ) in order to support low-power sensor networks. Combination of swarm intelligence and blockchain provides a secure, energy-efficient, and resilient key management system. In summary, IBDKEY fills the gap between energy efficiency and security with a scalable and effective cryptographic solution for future smart buildings and smart grids.