Research On Security Audits Supporting Ownership Changes In Cloud Data De-redundancy Scenarios

Cloud storage is an increasingly popular technology which can help data owners avoid investing a lot of time and efforts in maintaining and managing local hardware or software resources by storing data owners’ data in the remote cloud.However,in practical applications,a large amount of data stored in the cloud is duplicated,which means that cloud server needs to waste a lot of resources to store multiple equally identical data.In addition,since the data owner has lost direct control over the cloud data,even if the cloud server intentionally deletes the data or its breakdown makes its data corrupted or inadvertently deleted,it will not be known to the data owner.Thus,they have every reason to doubt that cloud server holds the data in good condition.In order to save the resources of cloud storage and improve its security,how to effectively deduplicate the cloud data and efficiently audit the integrity of cloud data has been a hot research topic in recent years,and the concept of secure auditing in deduplicated cloud data scenario also has emerged as the times required.In this thesis,we concentrate on studying the cloud data deduplication technology and cloud data auditing technology,and mainly make the following contributions:(1)In order to protect the data security of the data owner,we take the real user requirements that require data ownership modifications into account in a secure auditing in cloud storage deduplication scenario,and put forward the concept of secure auditing in the deduplicated cloud data scenario supporting ownership modification.The system model and system characteristics under this concept are designed and given.(2)We propose a concrete secure auditing scheme which supports ownership modification in the deduplicated cloud data scenario in this thesis.In this scheme,once the ownership of the data owner changes,the re-encryption algorithm will re-encrypt the data on the cloud server.Then the cloud server broadcasts the re-encryption keys to whole valid data owners via identity-based broadcast encryption.As a result,the user who has cancelled the data ownership cannot obtain the original ciphertext of the cloud data.In addition,this scheme effectively supports batch audits.(3)Considering guaranteeing the security of the proposed scheme,from many aspects,such as cryptographic analysis and simulation attack methods,we analyze the security of proposed scheme and give the detailed analysis process.Considering verifying the efficiency of the proposed scheme,we carry out the simulation experiments and give the related experimental results.We can draw a conclusion that our proposed scheme is efficient through the performance comparison with the related schemes.