Research And Practice Of Cloud Storage Data Security Scheme Based On Blockchain

With the rapid development of information technology,the demand of data storage is also growing rapidly.Although the emergence of cloud storage technology has solved the problem of rapid growth in data storage demand,at the same time,the physical separation of cloud storage technology between users and data has also brought many data security issues.In terms of data storage security,hardware failures of cloud storage servers,system software issues,and improper human operations threaten data integrity security.In terms of data usage security,after users upload data,they lose their physical access control rights and the control rights are transferred to cloud storage service providers.There are problems of illegal copy and illegal dissemination of data during use.In response to the above security issues,the research and practice on cloud storage data security issues have been conducted in this dissertation based on blockchain technology.The main work is as follows:1.Aiming at the problem of data storage security,a blockchain-based cloud storage data integrity verification scheme is proposed.The scheme uses a challengeresponse approach to verify the integrity of the user's data and its copies in cloud storage.Scheme introduces a third-party arbitration institution that uses the nontampering feature of the integrity certification stored in the blockchain to provide users and cloud storage service providers with data integrity arbitration services,and gives data integrity quantitative evaluation.The smart contract in the blockchain verifies the response of the cloud storage provider.Not only it uses the decentralized characteristics of the blockchain to get rid of the dependence on third-party institutions,and establishes a decentralized integrity verification framework.But also it uses the antitampering feature of the blockchain to construct an accountable integrity proof.Through safety analysis and experiments,the program is proved to be safe and feasible.2.Aiming at the problem of data usage security,a blockchain-based cloud storage data access control and anti-copy scheme is proposed.The scheme introduces CP-ABE encryption technology to return data access control rights from the cloud storage providers back to users,and at the same time introduces digital watermark technology to solve the problem of illegal copying of data.In order to combine the two technologies,a watermark embedding and CP-ABE encryption model based on the orthogonal operation domain is proposed,and specific watermark embedding and CPABE encryption methods based on the orthogonal operation domain are given for image type data.The solution stores the request-confirmation record in the blockchain to further strengthen the user's access control rights.At the same time,it also establishes the association between the requester and the watermark in the data to prevent the requester from denying the fact that it is illegally copied.Through safety analysis and experiments,the program is proved to be safe and feasible.3.The above two schemes are integrated to form a blockchain-based cloud storage data security scheme.Based on this scheme,a prototype system was designed and implemented.Finally,the system function test verified system function and the feasibility of scheme.