Public Auditing for Ensuring Cloud Data Storage Security With Zero Knowledge Privacy

In cloud storage service, clients upload their data together with authentication information to cloud storage server. To ensure the availability and integrity of clients' stored data, cloud server(CS) must prove to a verifier that he is actually storing all of the client's data unchanged. And, enabling public auditability for cloud storage is of critical importance to users with constrained computing resources, who can resort to a third party auditor (TPA) to check the integrity of outsourced data. However, most of the existing proofs of retrievability schemes or proof of data possession schemes do not consider data privacy problem. Zero knowledge privacy requires TPA or the adversary can not deduce any information of the file data from auditing system. In this paper, after giving a new construction of a recently proposed cryptographic primitive named aggregatable signature based broadcast (ASBB) encryption scheme, we present an efficient public auditing scheme with zero knowledge privacy. The new scheme is as efficient as the scheme presented by Shacham and Waters without considering privacy and is secure in the random oracle model.