Research And Application Of Tokenization Method Of Trusted Data Based On Blockchain Technology

As a valuable resource with great potential,data has attracted more and more attention.Especially after the era of big data and the advancement of the Internet technology,data has been infiltrated into all aspects of people's daily life.Faced with the explosive growth of data,the use of big data not only brings convenience to human beings,but also brings many problems such as the data ownership which is difficult to determine;data can easily be falsified while cannot be shared efficiently.And,as a large amount of data is closely related to users' behavior,the privacy of user data is difficult to protect.Consequently,these problems urgently need to be solved.As an emerging and rapidly developing information technology in recent years,blockchain technology has realized a decentralized distributed data ledger in a truth-less environment.Born with the features such as decentralization,tamper-proof,traceability and high reliability,the blockchain has unique advantages and broad application prospects in data ownership assertion,storage,sharing,privacy protection and tokenization,etc.Focusing on how to improve the credibility and security of data,as well as speed up the sharing efficiency of data,this dissertation studies the trusted data tokenization model based on the blockchain technology.On the one hand,the proposed hybrid blockchain model is used to determine data ownership,record and protect the privacy of the original data,so as to enhance the credibility of the data.On the other hand,economic momentum is given to data by the proposed lattice-blockchain model,and data lacking in liquidity are tokenized into tokens with price in blockchain,so as to promote data sharing and the generated benefits will be skewed towards users.Finally,the proposed hybrid blockchain model and lattice-blockchain model are preliminarily applied in the field of medical health management.The main research results are as follows:(1)The self-sovereign identity management framework is constructed to realize the verification and management of digital identity based on blockchain technology.In the current identity management process,in response to the exposed problems such as increasing differentiation of digital identities,fragmentation and centralization of identity information,a self-sovereign identity management framework,using smart contracts based on Ethereum is thereby constructed,which enables the user to become the real dominant of his/her identity.The reliable digital identity provides an effective guarantee for the management of trusted data.(2)A hybrid blockchain model for data creditability is proposed,which not only takes into account the performance of the blockchain,but also improves the data credibility.In current data protection and sharing schemes,it is difficult to make a tradeoff among the consensus efficiency,security and cost.And,in the existing hybrid blockchain model,the performance of blockchian is limited by the traditional underlying blockchian structure.A hybrid blockchain model is proposed,consisting of a self-designed permissioned blockchain and permission-less blockchain.The permissioned blockchain protects the raw medical data,and periodically anchors the data snapshots of the permissioned blockchain to the permission-less blockchain,thereby forming a chained medical data protection mechanism from the permissioned blockchain to the permission-less blockchain.This further increases the credibility of the data in the permissioned blockchain and reduces the cost of anchoring the data in the permission-less blockchain.(3)A lattice-blockchain model for data tokenization is designed,and two consensus algorithms suitable for the public blockchain and the consortium blockchain are proposed respectively to help the nodes in the blockchain reach consensus effectively.The traditional blockchain suffers from poor performance with high latency and low throughput.Therefore,as an important part of the hybrid blockchain,we propose a blockchain model with a novel double-DAG architecture,which serves for data tokenization.The new proposed DPoS-BA-DAG consensus algorithm helps nodes to reach consensus in an open environment.And the proposed DPoS-Quorum consensus protocol helps nodes to reach consensus in a permissioned environment.(4)Based on the hybrid blockchain model,a trusted medical health data tokenization model is proposed and applied into the field of chronic disease management to realize the safe and effective management and sharing of medical health data.In the current medical data management,it is difficult to both share medical data and protect security of medical data.Therefore,we propose a model for trusted data tokenization based on hybrid blockchain,which consists of a permission-less blockchain and a medical permissioned blockchain.Safe and efficient circulations of medical health data are achieved,with the help of the method for trusted data tokenization,making the medical health data more valuable for their owner.The method for tokenization is also applied to chronic disease management,thus a blockchain-based closed-loop method for chronic disease management comes into being.Through relevant experiment,the consensus latency of the medical permissioned blockchain with 50 nodes is about 1.23s,and the average transaction troughput is about 1455TPS.