Secure Random Encryption for Deduplicated Storage

In Storage Services, Deduplication is used to reduce the data size by eliminating storage of duplicate data. Deduplication is an effective data reduction technique to minimize the storage cost as well as communication cost. However, Deduplication raises significant security issues. Malicious users and semi-trusted Storage Server tries to learn the data outsourced by other users. Encrypting the data at user side before uploading to Storage Server is essential for protecting outsourced data. However, conventional deterministic encryption techniques are vulnerable to brute-force attacks and dictionary attacks for predictable files. In this paper, we propose secure random key based encryption technique for Deduplicated Storage. In our approach, user encrypts the file with a randomly chosen key. Random key is encrypted by set of hash values generated from plaintext file. In this way, our approach provides protection against brute-force attack and dictionary attack. We analyze security of our approach with theoretical proof and experimental analysis.