R-Dedup: Secure client-side deduplication for encrypted data without involving a third-party entity

Abstract Deduplication technology is used extensively in applications such as cloud computing services to optimize their storage performance (e.g., cloud service providers store only one copy of identical data). However, due to the use of encryption (to ensure the confidentiality of data stored in the cloud), it can be challenging for cloud service providers to perform deduplication (e.g., due to the use of different keys on the same content). In this paper, we propose a randomized, secure, cross-user deduplication scheme (R-Dedup). The scheme does not involve any third-party entity (e.g., an additional cloud server) or require assistance from other users. In R-Dedup, the randomness feature means that users with identical copies of a file share the same random value via ElGamal encryption. The security analysis and experimental results demonstrate that R-Dedup is lightweight, and achieves both data privacy and data integrity.