Research And Application Of Trusted Data Exchange Technology Based On Blockchain Smart Contract

With the rapid development of information technology such as cloud computing and Internet of Things,big data has swept the society in all walks of life.Massive data has increasingly become a core asset,with the potential to subvert the lifestyle of modern society,and the key to tapping this potential is the sharing,exchange and fusion of multi-party data.However,the traditional data exchange generally relies on a centralized platform,and the privacy data of users are easily backed up by the platform and the user side,resulting in the loss of data ownership by the sharing party and the difficulty in prosecuting privacy data disclosure.Therefore,how to build a trusted data exchange technology solution between the sharing party and the user side to ensure the data security of the sharing party while satisfying the data requirements of the user side is an urgent problem to be solved.Blockchain,as a decentralized trust system,has the characteristics of untouchable modification,traceability and security of data on the chain.Combining with smart contract technology and cryptography technology,it can provide a new solution to the problem of data privacy protection in the process of data trusted exchange.Aiming at the drawbacks of existing data exchange,this thesis proposes the research and application of trusted data exchange technology based on blockchain smart contract by using blockchain technology,smart contract technology and encryption cryptography.The main research work of this thesis is as follows:(1)This thesis proposes and implements a trusted data exchange technology scheme based on blockchain smart contract.The design idea of the scheme is as follows.Firstly,considering the limited storage space of the blockchain,only the data catalogues that the users are willing to share are stored on the chain,and the data release records are saved as evidence of traceability and certification.Secondly,the sharer encrypts the data according to the homomorphic encryption key pair negotiated with the requester,and the data can be analyzed and calculated without the decryption by homomorphic encryption.The exchange process does not expose the original data,and guarantees the ownership of the data of the sharer.Then,the sharer uses the ECDSA-secp256k1 algorithm to sign the data and store the data into chains to ensure reliable data sources.Decentralized platform verifies data signature through smart contract technology,controls access and execution rights of encrypted data,and the encrypted data is burned after using.The ciphertext results can only be decrypted and used by the user.The platform only has the execution right of the data,and realizes the "separation of powers" and restricts each other.Finally,the thesis tests the technical scheme of the design.(2)According to the technical scheme proposed in this thesis,a trusted data exchange platform based on smart contract of blockchain is implemented.Based on Truffle and Ganache,a private chain development environment and framework for ethereum is built.Smart contracts are developed using Solidity to control data security and access rights.JavaScript technologies such as web3.js are used to process data to be exchanged,and secure interaction between local nodes and data on the chain is realized.The research results and platform test results of this thesis shows that the trusted data exchange platform based on blockchain smart contract can solve the privacy data leakage,data oligopoly and data ownership rights and other points in the process of data sharing of traditional platform under the premise of satisfying the functions of data encryption and decryption,traceability authentication and secure exchange.The platform designed in this thesis does not disclose the shared data,and the platform and user data are not backed up.It realizes the separation of ownership,execution and use of data in practical sense,and provides a new way of thinking and solution for highly trusted data exchange.