Research And Implementation Of Key Technologies For Secure And Controllable Data Sharing Based On Blockchai

As a new type of production factor,data has high commercial value and increases the possibility of illegal individuals stealing data for criminal purposes.Therefore,it is very important to achieve secure and controllable data sharing.Existing data sharing systems are mostly based on centralized cloud computing models,facing security issues such as central node failures and user privacy breaches.Blockchain technology has the characteristics of decentralization,tamper resistance,and traceability,providing new solutions to the aforementioned problems in centralized data sharing.However,in the blockchain environment,there is no third-party management,and users,especially individual users,still face problems such as low sharing willingness,difficulty in ensuring sharing benefits,easy privacy leakage,and uncontrollable data access due to privacy and economic benefits issues.The above issues need to be addressed through incentives and controllable data sharing.The main research content and contributions are as follows:1.In response to the problems of low user willingness to share,poor data quality,malicious evaluations,and inability to guarantee sharing benefits in personal data sharing,this article proposes a sharing incentive method based on reputation reward and punishment mechanism.Calculate the reputation values of both sharing parties based on user behavior,use non homogeneous tokens(NFTs)as data access credentials,and combine improved hash lock design to manage NFTs and deposit rent sharing incentive smart contracts to improve user data sharing quality,stimulate sharing willingness,restrain malicious behavior,and ensure sharing benefits.2.In response to the issues of user identity privacy leakage and uncontrollable data access after authorization in data sharing,this paper proposes a secure and controllable data sharing method based on time-varying identity watermarking.In order to strengthen the protection of user identity privacy,a timestamp based user time-varying identity(TDID)is proposed.The mapping relationship between TDID and DID identification is stored on the chain,and the user’s identity is determined while protecting privacy.At the same time,TDID is embedded as a watermark into the data file,and accurate accountability for illegal data abuse is achieved based on the accountability smart contract.3.Based on the above research content,a data security and controllable sharing system based on blockchain is designed,which realizes distributed digital identity,digital watermark,data sharing,information query on the chain and other functions.The experimental results show that the system has good performance and can meet the user’s usage needs.