A General Framework for Intelligent IoT Data Acquisition and Sharing in an Untrusted Environment Based on Blockchain

Traditional IoT systems suffer from high equipment management costs and difficulty in trustworthy data sharing caused by centralization. Blockchain provides a feasible research direction to solve these problems. The main challenge at this stage is to integrate the blockchain from the resourceconstrained IoT devices and ensure the data of IoT system is credible. We provide a general framework for intelligent IoT data acquisition and sharing in an untrusted environment based on the blockchain, where gateways become Oracles. A distributed Oracle network based on Byzantine Fault Tolerant algorithm is used to provide trusted data for the blockchain to make intelligent IoT data trustworthy. An aggregation contract is deployed to collect data from various Oracle and share the credible data to all on -chain users. We also propose a gateway data aggregation scheme based on the REST API event publishing/subscribing mechanism which uses SQL to achieve flexible data aggregation. The experimental results show that the proposed scheme can alleviate the problem of limited performance of IoT equipment, make data reliable, and meet the diverse data needs on the chain.