Design And Implementation Of A Distributed Oracle For Industrial Internet Of Things

With the advent of the era of Industry 4.0,the integration of the Internet of Things and industry has become an important way to promote the automation and informatization.The Industrial Internet of Things（IIo T）plays an indispensable role in Industry 4.0.The advantage of IIo T is operational efficiency,as well as cost optimization and automatically connecting data.However,it is difficult for IIo T to solve following problems,including data interoperability,data integration and privacy issues.Blockchain technology can realize the collaboration of industrial information without third-party certification and guarantee,which will be a low-cost technical path to realize the information interconnection in the IIo T.Since the blockchain only guarantees the correctness of the data in the chain,there is a defect that the data inside and outside the blockchain could not circulate.Oracle is a solution to solve the problem of interaction and sharing of data off the blockchain,which is the focus of the thesis.The oracle is a set of middleware systems that rely on smart contracts to provide data off the chains.After research,the design elements of the oracle include data sources and trust models and design patterns and interaction methods.There are lack of data source interface and dedicated trust model and design mode and interaction mode,that are still being explored in the oracle.Starting from the scenario of IIo T and focusing on excavating the three requirements of data source interface and privacy protection and data storage,this thesis designs a distributed oracle named DISOC architecture and verifies key technologies.The DISOC has three characteristics as follows.Firstly,The DISOC could obtain three types of offchain data of other private chains,industrial equipment and public chains.Secondly,it is equipped with a security mechanism to ensure the access security and identity privacy of distributed nodes.Thirdly,the data generated in the process of data acquisition supports distributed storage by the chameleon hash technology to reduce the space required for on-chain storage.After analysis and testing,the DISOC can meet the demands,better than schemes listed of the ASTRAEA and ASKE-based oracle.In general,the distributed oracle scheme proposed in this thesis could improve the three aspects of oracle,including data source and privacy protection and storage,which is feasible.