Privacy-preserving cross-user source-based data deduplication in cloud storage

Cloud storage services possibly store only a single copy of redundant data to save disk space and provide links to that copy rather storing other actual copies of data. This is called deduplication. If deduplication is performed across different accounts at each client side, this is classified into cross-user source-based deduplication. However, cross-user source-based deduplication can server as a side-channel of breaching user´s privacy. To protect user´s privacy, Harnik et al. proposed a randomized solution for cross-user source-based deduplication, user´s privacy is, however, still at risk with a high probability. In this paper, we propose a new cross-user source-based deduplication providing dramatically enhanced security.