Design And Implementation Of Blockchain Data Trading System

With the rapid development of information technology and the Internet of Things,data is being generated at an unprecedented rate and the value of data is increasingly recognized by the public.From the current data market,the data resources owned by various organizations or individuals are independent of each other.In order to solve the problem of"data islands",many data trading platforms at home and abroad have emerged.However,the existing data trading platforms are used as a centralized third party to manage the trading process of both parties.This method has the disadvantages of easy data leakage,high transaction cost,unfairness and inefficient trading process.Blockchain technology has the characteristics of decentralization,non-tampering,openness and anonymity.Micropayment technology has the characteristics of simple transaction process and low transaction cost.The combination of these two technologies can perfectly solve the problems of existing data trading platforms.In the off-blockchain environment,both parties conduct efficient and low-cost transactions through the use of micro-payment technology.In the blockchain environment,blockchain and smart contracts ensure the security and fairness of transactions.The entire transaction process does not require the participation of any third party other than the parties to the transaction,effectively avoiding data leakage.The data trading system implemented in this thesis is divided into two modules:the off-blockchain trading module and the blockchain module.In order to improve transaction efficiency while ensuring transaction security,we made improvements on the micropayment scheme PayWord[1]proposed by Rivest and Shamir,and developed the consensus mechanism and smart contract on the blockchain based on the Ethereum.The content of this thesis mainly has the following four points:(1)By analyzing the problems existing in the data trading platforms,the research objectives of this thesis are obtained,and the necessity of implementing a blockchain-based data trading platform is emphasized.(2)Introduced peer-to-peer communication,consensus mechanism,blockchain related technology and micropayment technology,and then elaborated their characteristics and implementation principles.(3)Conducted a comprehensive demand analysis on the data trading system,determined the system architecture.and completed the code design of each module while completing the design of the off-blockchain trading modlule and the blockchain module.(4)Tested the off-blockchain module and the blockchain module,and gave test cases.