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SMChain: a scalable blockchain protocol for secure metering systems in distributed industrial plants

Metering is a critical process in large-scale distributed industrial plants, which enables multiple plants to collaborate to offer mutual services without outside interference. When distributed plants measure the data from a shared common source, e.g., flow metering in an oil pipeline, trustworthiness and immutability must be guaranteed among them. In this paper, we propose a hierarchical and scalable blockchain-based secure metering system, SMChain, to provide strong security, trustworthy guarantee, and immutable services. SMChain adopts a two-layer blockchain structure, consisting of independent local blockchains stored at individual plants and one state blockchain stored in the cloud. To deal with the scalability issues within each plant, we propose a novel scalable Byzantine Fault Tolerance (BFT) consensus protocol based on (k, n)-threshold signature scheme to deal with the Byzantine faults and reduce the intra-plant communication complexity from O(n2) to O(n). For the state blockchain, we use a cloud-based service to synchronize and integrate the local blockchains into one state blockchain, which can further be distributed back to each plant.