Research And Application Of Privacy Protection And Restricted Sharing Of Digital Credit Data Based On Blockchain

With the rapid development of technologies such as big data,cloud computing,blockchain and the Internet of Things,credit data sharing has been widely studied as a key issue in the financial field.However,the traditional credit platform has many problems,such as high cost,single point of failure,difficult to confirm the right of data and illegal use.Therefore,a credit solution that balances privacy protection and data sharing is needed.In response to the above problems,the paper first proposes an access control scheme that supports users to flexibly update permissions,and then proposes a credit model based on this scheme that integrates blockchain,full homomorphic security computing and elliptic curve encryption technology,and finally designs and implements a credit data privacy protection and restricted sharing system.The main contents of the paper are as follows:First,a credit data access control scheme supporting users to dynamically update permissions is proposed.In this scheme,the data owner implements fine-grained access control by formulating attribute-based access policies for the data demander.At the same time,the data owner can flexibly update the access rights,including attribute revocation,user revocation and attribute addition.Among them,most of the operations caused by permission revocation,including ciphertext re-encryption and key update,are completed by the cloud server.At the same time,with the help of proxy re-encryption,key blinding and inert revocation technologies,the control of data is also protected from being stolen by the cloud on the basis of improving performance.Finally,the function analysis and performance test of this scheme are carried out.Second,research the credit data privacy protection and restricted sharing model based on blockchain.First of all,put forward the credit system architecture and design the credit block structure.Then the model is introduced in detail from five aspects:blockchain layer,access control layer,security computing layer and storage layer.Finally,combined with the credit case,the actual data flow is clarified in three stages:initialization,access control and data analysis.The model is analyzed from two aspects of function and safety.Third,the design and implementation of credit data privacy protection and restricted sharing system based on blockchain.The bottom layer of the system uses Fabric architecture,and combines smart contract,docker,and front-end and back-end interaction technologies to realize the prototype system.The background is written in Java language,the front end uses Vue framework,and the smart contract is written in Go language.The system mainly realizes six functions:identity management,contract management,data query,data analysis,access control,and data release.The paper analyzes and displays the functions of the last four core modules.Finally,the function and performance of the credit data privacy protection and restricted sharing system based on the blockchain are tested.The test results show that the system has complete functions and good performance,which can better achieve the privacy protection and restricted sharing of credit data.