Research On Data Integrity Auditing Methods Supporting Privacy Protection

In the cloud storage environment,users outsource their data to the cloud server,which greatly saves the storage cost,but data security cannot be guaranteed.Data integrity is still their core concern,so data integrity auditing is required.However,the computing burden of data integrity auditing for users is very heavy.At this time,users will commission a third-party auditor(TPA)to perform data integrity auditing,but the TPA may take the opportunity to steal users' data privacy during this process,resulting in privacy leakage.In addition,users sometimes need to dynamically update outsourced data.In view of the above issues,based on the existing methods,this paper conducts a thorough research on data integrity auditing and proposes two dynamic data integrity auditing methods supporting privacy protection.The main research work in this paper as follows:1.This paper studies and proposes the data integrity auditing method based on Hierarchical Multiple Branches Tree.First of all,build the Hierarchical Multiple Branches Tree(HMBT)data authentication structure in the initialization phase,which can implement data dynamic updating and batch dynamic updating of different granularities.Secondly,in the process of auditing,in order to prevent TPA from stealing users' data privacy when verifying evidence,cloud service provider(CSP)uses random mask technology to hide data information in the generation of evidence.Finally,the security analysis shows that this method can satisfy auditing correctness,support public auditing,protect data privacy,resist forgery attack and replay attack.2.In order to further reduce the computing cost of TPA,this paper improves the previous auditing method and proposes the data integrity auditing method based on Hash-based Message Authentication Code and Indistinguishability Obfuscation.First of all,also build the HMBT data authentication structure to support dynamic updating operations.Secondly,in the process of auditing,in order to protect users' data privacy while reducing the computing cost of TPA,this method generates a obfuscation auditing program based on Hash-based Message Authentication Code(HMAC)technology and Indistinguishability Obfuscation(IO)technology.CSP executes the obfuscation program to output HMAC tag,and TPA judges data integrity by verifying the HMAC tag.Finally,the security analysis shows that this method can also resist external attack.Experimental performance analysis shows that the data integrity auditing method based on Hierarchical Multiple Branches Tree reduces the time cost of data integrity auditing and dynamic updating compared with the existing method,thus improving the performance.The data integrity auditing method based on Hash-based Message Authentication Code and Indistinguishability Obfuscation has a higher efficiency when the TPA verifies the evidence,and the communication cost of data integrity auditing is also reduced.