Research On Integrity Verification Technology Of Outsourced Data In Cloud Environment

Cloud computing is a new type of computing model following peer-to-peer computing,grid computing,utility computing,and distributed computing.It turns people's long-cherished dream of “computing as a facility” into reality.Through the cloud computing model,cloud service providers can aggregate distributed computing nodes into a shared virtualized pool,and complete massive data analysis,processing,storage and other work within seconds.Finally,the computing and storage resources are provided to users in the form of service(e.g.,IaaS,PaaS and SaaS).Cloud storage is one of the concepts in the cloud computing system.Through the cloud storage system,people can outsource their data to the cloud server,so as to avoid the limitation of local storage space.In a cloud storage system,users purchase and use the storage services of cloud service providers in a pay-as-you-need manner,which improves users' data processing capabilities.However,compared with the traditional local storage technology,users do not physically possess these data.Once they store their data into the cloud,any failure(e.g.,hardware failures,external attacks and carelessness of humans)in the cloud may cause disclosure and loss of users' data.Therefore,the problem of secure storage with integrity verification of outsourced data in the cloud environment as the core technology has become a hot topic at home and abroad.This paper proposes three innovative schemes to the integrity verification process of outsourced data:(1)A lightweight cloud data audit scheme supporting identity privacy is proposed.This scheme reduces the burden of users by introducing the third party media to complete the complex computation instead of users.Meanwhile,a third party media management strategy is designed to avoid internal collusion and external attacks.The scheme introduces a blind data method to protect the privacy information of group members.In addition,the scheme can avoid the replace attack and replay attack of malicious cloud service providers.(2)A shared data auditing scheme supports efficient revocation of group members via multi-participation is proposed.Through the shamir secret sharing method,multiple group members participate in revoking the illegal group members,which solves the problem of too centralized user cancellation in the cloud data auditing scheme and ensures the equal rights between the group members.In addition,a new authentication label calculation method is designed to enable data owners to update their data stored in the cloud efficiently.This method enables homomorphic signature authentication and efficient auditing of cloud data.(3)A cloud data integrity verification scheme for associated tags is proposed.In the scheme,a novel grouping method of operation log vector and a novel tag association method are designed to solve the problem that the number of verified tags increases linearly with the number of updates.Introducing homomorphic hash function into the integrity verification of operation log can implement tag association verification efficiently,which reduces the cost of system tag calculation,improves operation update efficiency,and achieves better privacy guarantee.