Blockchain-Based Exchange of Control Information in Decentralised IIoT

Sammanfattning

This thesis investigates a decentralised protocol for exchanging and logging control-related information between Master Terminal Units (MTUs) in smart grid environments. Traditional SCADA architectures rely on centralised coordination, which limits trust, accountability, and cross-domain transparency. At the same time, resource-constrained field-layer components such as RTUs and PLCs, and connected field devices such as sensors and actuators cannot support complex decentralised mechanisms. To address this, a protocol is proposed in which MTUs collaborate through a permissioned blockchain. Control-related events are submitted as structured records and immutably stored in a shared ledger, providing tamper-evident logging and traceability without requiring direct blockchain participation from field devices. A proof-of-concept implementation was developed using Hyperledger Fabric and evaluated in a controlled laboratory environment. Performance tests were conducted across network configurations ranging from 2 to 16 peers, measuring throughput, latency, and resource usage. The results show that the system maintains low and stable latency under load, while throughput decreases as the number of peers increases due to endorsement and replication overhead. The append-only design eliminates concurrency conflicts and ensures consistent event recording across participants. The study concludes that decentralised MTU-level coordination with blockchain-based logging is feasible as a laboratory proof-of-concept and can support improved accountability in smart grid systems. However, the results do not demonstrate production-level fault tolerance, adversarial resilience, or large-scale deployment readiness.