Research On Verification Method Of Dynamic Multiple-replica Provable Data Possession Based On Homomorphic Encryption

In the cloud storage environment,how to efficiently and dynamically complete the integrity of multi-replica data auditing is a very challenging issue.In order to save storage costs,data owners store data over the cloud service through remote services.As cloud service providers(CSPs)are not fully trusted,the security of outsourced data will be seriously threatened.On the other hand,CSPs may be maliciously deleted and tampered with copies of data or data that are not frequently used in order to save storage costs,so data owners(DO)or third party audits(TPAs)need to be periodically validated by service level agreements(SLAs)Requires the integrity of multiple copies of data stored.The research work mentioned in paper is summarized here:1.This paper studies and proposes a dynamic multi-replicasPDPverification method based on ElGamal encryption.First,BLS(Boneh-Lynn-Shacham)signature and bilinear mapping are used to realize the batch audit of multiple copies,which avoids the interaction between CSP and TPA,thus reducing the communication overhead in the audit process.it generated differentiable replicas by using ElGamal en-crypt the concatenation of the serial numbers of replicas and the file.Differentiable replicas could prevent the colluding attack among servers,and added the information of file identification and block position into the block tagsto ensure its safety And supports the efficient dynamic operation.Finally,the security of the verification method is analyzed theoretically and experimentally.The results show that the performance of this method is superior to the existing methods in terms of security,communication and computing overhead,which improves the efficiency of file storage and verification and reduces the computational cost.2.Multi-Replica File Version Control Method(MRFVCM)is an extension of the dynamic multi-replicas PDP verification method,which supports basic file version management.The data owner encrypts the data,creates multiple copies and stores it in the cloud.When updating the data,the data file is not updated directly,but is incrementally updated.When using MRFVCM,the data owner can still use the dynamic multi-replicas PDP verification method to verify the integrity of multiple copies and incremental.Through the theoretical analysis and experimental verification,this method can accurately verify the integrity of multi-replicas of data,while supporting data dynamic updates.