Research On Outsourced Data Integrity Verification Technology In Cloud Computing

With the rapid popularization of the Internet,cloud computing has become one of the important trends in information technology.More and more small and midsize businesses are interested in using cloud computing services than buying expensive hardware and software and hiring professionals to maintain their data.However,the development of cloud computing has also led to many new security issues.Because of the virtualization,reuse,and migration technologies used in computing and storage,data owners lose physical access to their data,while cloud service providers who are given permission to manage user data are not completely trusted.So how to ensure the security of user data stored in the cloud is a crucial issue.The traditional data integrity verification method is not suitable for the mass storage scale of user data in the cloud environment.In view of this,this paper focuses on the data integrity verification mechanism in outsourced storage environment.In order to solve the security problem in data outsourcing,in this paper,we propose a commitment-based outsourced data integrity verification scheme that supports dynamic update,public verification and forensics.Although part of the existing outsourced data integrity verification schemes have supported data dynamic update and public verification,in these schemes third-party auditors need to utilize the dynamic tag parameters unilaterally generated by the data owner,which leads to the lack of forensics ability of the verification result.In other words,the data owner cannot convince a neutral third party to believe the verification result in such a situation.The proposed scheme in this paper introduces a credible system generator to establish and publish the fixed parameters and makes those dynamic parameters be signed by both the data owners and service providers,which realizes the forensics ability of the verification results.Furthermore,we proposes a data outsourcing and sharing scheme by combining the above scheme with the proxy re-encryption under the publickey cryptosystem,which enables data owners to authorize a specific user to access certain data blocks.By using the characteristics of public verification and forensics,data users can achieve the data access and verify their integrity without the intervention of the data owner.Also,we formally prove the security of the above two schemes in the random oracle model and analyze their computational complexity in detail.Finally,based on the proposed data integrity verification scheme,we design and implement the prototype system of data integrity verification in the outsourced environment.We verify the correctness and feasibility of the proposed scheme according to this system and test the impact of the number and size of blocks on the performance of each entity.The security proofs,the complexity analysis and the test results prove the correctness,security and feasibility of our proposed scheme.It has good performance in real outsourcing environment with large-scale data.