PYCHAIN-IOT: A LIGHTWEIGHT BLOCKCHAIN FRAMEWORK FOR SECURE & SCALABLE INDUSTRIAL IOT AUTOMATION

Industrial Internet of Things (IIoT) deployments require distributed data handling and automation under constrained computing and communication resources. This paper presents PyChain-IoT, a modular Python-based blockchain framework intended for enterprise and IIoT environments. The framework integrates a hash-linked blockchain core, JSON-based persistent transaction storage, WebSocket peer-to-peer communication, validator-based node admission, a lightweight randomized leader-election mechanism, time-triggered smart-contract execution, and a graphical monitoring interface. During each election round, participating nodes generate random values and the node whose value is closest to the arithmetic mean is selected to propose the next block. Node admission uses a configurable supermajority threshold of at least two-thirds of active validators. The current prototype demonstrates transaction persistence, block creation and synchronization, leader election, scheduled contract execution, and real-time visualization. The evaluation is limited to functional behavior under a benign fault model including crash and omission faults; Byzantine-resilient election and large-scale performance evaluation remain future work. PyChain-IoT therefore provides a lightweight experimental platform for studying blockchain-based automation in resource-constrained industrial settings.