Research On Secure Storage Of Cloud Data

Today's society is a digital society,and all data can be stored digitally,which has led to an explosive growth of data.Massive data has enabled cloud storage to develop widely,cloud storage does not occupy local storage and users can access cloud data anytime and anywhere,these are the key advantages of cloud storage development.Yet,the problem of secure storage of cloud data is the primary problem that restricts the development of cloud storage.Malicious hackers,software and hardware vulnerabilities,etc.will pose a threat to users' data stored in the cloud.To ensure that cloud storage serves the society better,cloud auditing solutions had emerged.Existing cloud storage auditing solutions place high requirements on the integrity and privacy of user outsourced data.However,the computing overhead of the user side has been neglected.Whether in the user initialization phase or the user verification auditor audit result phase,we want the user-side calculations to be efficient.To this end,we propose two solutions to further improve and optimize the cloud storage audit function.The specific work of the solution is divided into the following two parts:(1)For the problem of excessive computing overhead on the client side of the initialization phase,this article proposes a data integrity audit scheme for lightweight verification tags.In this article's scheme,the verification tags that the user needs to calculate to upload data correspond to the entire file,which means that the user does not need to calculate verification tags for each data block and consumes huge computing resources.At the same time,in order for the auditor to complete the verification operation smoothly,the user adds many padding values in the uploaded data file to mark the locations of the data blocks,and these positions are known to the auditor.Auditors only need to audit permutations and combinations between different data blocks.The scheme for this article achieves the purpose of complete auditing on the premise of reducing the computational cost of the client.To reduce the auditor's auditing costs,this article further expanded the program to support batch auditing occasions.In the final efficiency analysis,the scheme for this article reduces the cost of client computing by hundreds or even thousands of times.(2)For the problem of computing overhead when the user verifies the auditor's log,this article proposes a cloud audit scheme for efficiently verifying the auditor's audit results.We use blockchain and smart contracts to build the scheme for this article.In this article's scheme,the auditor needs to call a smart contract for re-inspection after verifying the certification message of the cloud server.If the verification is correct,the hash value of the audit result will be recorded in the blockchain.In the end,all verification results will be recorded in the blockchain in a logical chain,which is convenient for users to verify the audit results of the auditors.When the user verifies the audit result of the auditor,the user only needs to verify the latest audit data.For the previous audit results,user only needs to verify the blocks that contain the audit results in the blockchain.To reduce the gas cost of invoking smart contracts for the auditor's audit,this article further expands the scheme to support batch auditing.The final efficiency analysis shows that this article's scheme is friendly to the consumption of user computing resources.