Research On Data Transaction And Sharing Scheme Based On Blockchain Technology

With the rapid development of informationization and Internet technology,data communication has changed from paper communication to paperless digital communication,which leads to the explosive growth of digital content,makes the data have a faster communication speed,and helps to realize data transaction and sharing.Data trading is the value exchange of data with currency as the medium,and data sharing refers to that users can obtain data and carry out various operations or analysis operations using the Internet anywhere in the world.Data transaction and sharing broke people's data demand dilemma,prevented the emergence of data islands,expanded the use dimension of data,gave full play to its energy and value,and made great contributions to improving the level of information development.Today,when the state energetically supports the development of Internet technology,data transaction and sharing have also dual development opportunities of market and policy.But in this case,it still faces many difficulties.There are two key problems to be solved,first,it is impossible to ensure data privacy,security and fairness of transactions without a third party,second,it is impossible to protect digital rights and complete the value transfer and the change of rights involved.Blockchain links data blocks with a particular chain-type structure according to time sequence,and uses cryptography to ensure data traceability and tampering,which has the characteristics of decentralization,security,credibility,collective maintenance,timing data and support programming.The above characteristics can ensure the fairness and sharing security of data transactions.At the same time,it can also complete the ownership change involved in value transfer and realize value circulation.Therefore,this thesis first integrates blockchain technology and conducts further research on the questions of data privacy protection and transaction fairness in data transaction and sharing;then,with this technology,we try to protect digital rights and realize value transfer in data transaction and sharing.The particular work of this thesis is as below:1.Considering the problems of data privacy protection and trading fairness in data transaction and sharing,this thesis proposes a data transaction and sharing project sustaining multi keyword ciphertext sorting and retrieval based on blockchain technology by taking advantage of the characteristics of blockchain,which is decentralized,tamper proof and supports smart contract.It realizes the verification of the search results,the fair payment among the three parties of the transaction and the multi keyword ranking search of the ciphertext.In this thesis,using searchable encryption technology,the cloud server realizes ciphertext data retrieval to protect the privacy of the data.Ethereum smart contract realizes the verification process of the results,ensures the integrity and validity of the query results,and completes the transfer of funds to guarantee the equitableness of the transaction.In addition,in order to settle the trouble of too limited function in keyword retrieval,the scheme also adopts the balanced binary tree as the index.On the basis of ensuring the retrieval efficiency,it realizes the dynamic update of multi keyword retrieval and the sorting of retrieval results,which promotes the flexibility and user friendliness of the scheme.Security analysis shows that the scheme has security and feasibility in blockchain.Performance analysis and experimental results display that the project has practical value.The function contrast outcome display that compared with some now available searchable encryption schemes based on blockchain,the scheme in this thesis has more comprehensive consideration in function.The performance comparison outcome display that compared with other schemes with verification function,the computational overhead of this scheme in the verification stage is the lowest.2.Considering the problems of digital rights protection and value transfer in data transaction and sharing,this thesis proposes a data transaction and sharing project sustaining digital rights protection based on blockchain technology by using the distinguishing features of blockchain,for instance,security,credibility and information openness and transparency.The smart contract realizes rights transfer and license distribution in the trading according to the preset conditions,and blockchain tracks and saves the corresponding transaction and license information to ensure the openness,transparency,practicality and reliability of the data.In addition,this project adopts Shamir threshold secret sharing project to store and distribute the key to the key server,which not only realizes the defense of the key,but also ensures the security of data transaction.Security analysis displays that the project has feasibility and security in the blockchain.Simulation outcome display that the project can complete rights protection and value transfer with acceptable overhead.3.Considering the data transaction and sharing project sustaining digital rights protection based on blockchain technology proposed in this thesis,we have implemented a data transaction and sharing system supporting digital rights protection based on blockchain technology,the system consists of four independent subsystems: blockchain,online web,key server and offline encryption and decryption,the blockchain subsystem is responsible for the confirmation of copyright,the uplink of authorization and the query of information after the uplink;the web subsystem provides easy-to-use human-computer interaction pages and various operations and management of accounts;the key server subsystem is responsible for storing the encryption key and realizing the information interaction with blockchain;the offline encryption and decryption subsystem is responsible for encrypting the copyright to be released and decrypting the copyright to be purchased.The system realizes the digital rights protection in data transaction and sharing,and has certain practical value.