Research On Crowdsourcing Data Management Scheme Based On Blockchain And Differential Privacy Protection

In the context of the "Big Data" era,the importance of data is selfevident,so a number of crowdsourcing platforms with the main purpose of obtaining data have emerged.However,as people pay more and more attention to data privacy today,many crowdsourcing platforms that lack data protection methods urgently need to introduce security technologies to ensure data privacy.Blockchain technology,as a member of emerging data management technologies in recent years,has been introduced by many crowdsourcing platforms.However,simply using blockchain technology also faces a series of problems.Combined with the thinking of blockchain data management schemes,this paper conducts research on blockchain-regulated privacy protection schemes in the field of crowdsourcing in three main aspects:distributed storage,privacy protection,and supervision,also proposes two methods for different security scenarios.The main research content and innovation points of this paper are presented as follows:(1)In order to solve the problem of secure storage of crowdsourcing business data and the problem of identity transparency on the blockchain,we propose a crowdsourcing platform data efficient storage and privacy protection scheme.This solution uses IPFS(Interplanetary File System)to store encrypted raw data,avoiding the single point of failure problem caused by traditional single server storage.At the same time,the doublelayer blockchain technology is adopted,the alliance chain is adopted between the data supplier and the data collector,and the RAFT consensus algorithm is applied.Its security is guaranteed under the mechanism;between the data collectors,the PBFT(Practical Byzantine Fault Tolerance)consensus algorithm is adopted,which tolerates a certain number of malicious nodes in the blockchain network and has high security.It ensures the secure sharing of data between institutions.At the same time,the group signature technology is used in the alliance chain to hide the identities of data suppliers and ensure the data security of users in the chain.(2)Aiming at the reusability of the past data of the crowdsourcing platformthe power division of the supervisor,and the anti-statistical attack requirements of the statistical data,we propose an on-demand sharing scheme of the statistical data of the crowdsourcing platform.In this solution,aiming at higher data privacy protection requirements,combined with zero-knowledge proof,homomorphic encryption and differential privacy technology,only the data provider holds the original data in the whole process of data transfer,and the regulator and the data demander can only view the encrypted data or the statistical data after the differential privacy protection process.At the same time,this scheme divides the power of the supervisor,making it impossible for a single supervisor to obtain real user data.In addition,this solution also improves the data collection mechanism of the current crowdsourcing platform,which mainly uses task release,so that past task data can also be used on demand.