Abstract: Provable data possession is an important research direction in the field of current cloud storage security.It allows user to verify whether his outsourced data stored in the cloud sever are complete without downloading all files efficiently and remotely.Currently,users tend to entrust TPA,a Third Party Auditor,to verify the integrity of their data instead of themselves.However,most of public auditing PDP schemes only consider whether malicious servers can forge data labels or proofs,rarely consider the case of whether malicious TPA may steal user’s data privacy.In recent years,some of PDP schemes that both ensure the data security in server and protect the data privacy for TPA have been proposed and applied in single-cloud server.Few of batch PDP protocols applied in multi-cloud server can effectively resist the malicious cloud server’s attack and achieve zero knowledge privacy for TPA.Therefore,based on the work proposed by Yu et al,this paper proposed a batch PDP scheme which can both guarantee the data security for malicious cloud servers and realize the perfect data privacy for TPA.Performance analysis and simulation experiments demonstrate the efficiency and feasibility of the proposed protocol.

Key words: Batch verification, Cloud storage security, Provable data possession(PDP), Zero knowledge privacy