Research On Data Provenance Scheme In Cloud Storage Based On Blockchain

With the continuous development of internet technology,the amount of information is expanding,and a new era of big data has arrived.Traditional storage technologies overload gradually,and then cloud storage as a new storage technology has come into being.Cloud storage is favored by more and more enterprises and individuals due to large storage capacity,remote service and support for multi-user data sharing.However,remote service makes cloud storage platform is difficult to control unauthorized access,and multi-user data sharing makes cloud storage platform is difficult to track malicious activities.Data provenance scheme can help to track malicious activities,thus realizing secure access control and multi-user data sharing.Therefore,in order to ensure the security of user's data,not only does data need to be encrypted,but also an data provenance scheme is needed.This thesis mainly focuses on the issue that malicious activities are difficult to track.Blockchain is applied to cloud storage platform to achieve cloud data provenance.As a key component of blockchain,consensus mechanism can ensure the continuous normal operation of blockchain in application scenarios.Therefore,an improved consensus mechanism is designed to solve the problems of centralization,reusage and information leakage of stake in the existing consensus mechanism,and a blockchain based cloud data provenance scheme is proposed to achieve cloud data provenance.The main work of this thesis is as follows:First,an improved consensus mechanism is designed to solve the issues of centralization,reusage and information leakage of stake in the existing consensus mechanism.In the improved consensus mechanism,the use of random number solves the problem of centralization of stake,and the use of the threshold encryption algorithm solves the problems of reusage and information leakage of stake.In addition,through the security analysis of the improved mechanism,the security of the improved mechanism is discussed.Finally,through simulating the improved mechanism by using Java programs and analyzing the simulation results,the feasibility of the improved mechanism is discussed.Second,aiming at solving the problem that malicious activities are difficult to track,a blockchain based cloud data provenance scheme is proposed.In the scheme,the introduction of blockchain ensures that provenance data cannot be tampered,and the accountability and forensics of cloud data are achieved.Therefore,the problem that malicious activities are difficult to track is solved,and the security of cloud storage platform is improved.In the scheme,the searchable encryption algorithm is used to ensure the confidentiality of cloud data and achieve flexible multi-user data sharing.In addition,through the security analysis of the scheme,the security of the scheme is discussed.Finally,through simulating the scheme by using Java programs and Tierion and analyzing the simulation results,the feasibility of the scheme is discussed.