Biblio

Cloud storage is an exclusive resource in cloud computing, which helps to store and share the data on cloud storage server. Clients upload the data and its hash information n server together on cloud storage. The file owner always concern about data security like privacy and unauthorized access to third party. The owner also wants to ensure the integrity data during communication process. To ensure integrity, we propose a framework based on third party auditor which checks the integrity and correctness of data during audit process. Our aim is to design custom hash for the file which is not only justifies the integrity but also version information about file.

In cloud storage systems, users can upload their data along with associated tags (authentication information) to cloud storage servers. To ensure the availability and integrity of the outsourced data, provable data possession (PDP) schemes convince verifiers (users or third parties) that the outsourced data stored in the cloud storage server is correct and unchanged. Recently, several PDP schemes with designated verifier (DV-PDP) were proposed to provide the flexibility of arbitrary designated verifier. A designated verifier (private verifier) is trustable and designated by a user to check the integrity of the outsourced data. However, these DV-PDP schemes are either inefficient or insecure under some circumstances. In this paper, we propose the first non-repudiable PDP scheme with designated verifier (DV-NRPDP) to address the non-repudiation issue and resolve possible disputations between users and cloud storage servers. We define the system model, framework and adversary model of DV-NRPDP schemes. Afterward, a concrete DV-NRPDP scheme is presented. Based on the computing discrete logarithm assumption, we formally prove that the proposed DV-NRPDP scheme is secure against several forgery attacks in the random oracle model. Comparisons with the previously proposed schemes are given to demonstrate the advantages of our scheme.