Provable ownership of file in de-duplication cloud storage

The rapid adoption of cloud services has propelled network data sharing and storage. Client-side deduplication is proposed to minimize bandwidth and space needed to upload and store duplicated data. The existing solutions, however, were recently found to be vulnerable to attacks that enable the attackers to get full access to the entire file stored on the server after learning just a small piece of information about the file, namely its hash value. In this paper, to solve the problem mentioned above, we propose a cryptographically secure and efficient scheme for a client to prove to the server based on actual possession of the entire file instead of only partial information about it. Our scheme utilizes the technique of spot checking in which the client only needs to access small portions of the original file, dynamic coefficients and randomly chosen indices of the original files. Our extensive security analysis shows that the proposed scheme can generate provable ownership of the file (POF) and maintain a high detection probability of the client misbehavior. Both performance analysis and simulation results demonstrate that our proposed scheme is much more efficient than the existing schemes, especially in reducing the burden of the client.