Two-party interactive secure deduplication with efficient data ownership management in cloud storage.

Deduplication, which stores only one copy of duplicate data, is used extensively in cloud storage to reduce the overhead associated with storage. Unfortunately, client-side encryption prevents cloud storage from performing deduplication due to the randomness of traditional encryption. Some existing schemes can balance encryption and deduplication, but their interaction with third-party servers or online users adds additional overhead to the system. Also, the ownership of outsourced data will change frequently due to users’ requests to upload/delete/modify the data. But many existing schemes that can achieve dynamic ownership management have security flaws or require users to manage multiple keys. By focusing on these troubles, we have developed a secure deduplication scheme that does not rely on any third-party entities and supports data ownership management. More specifically, we take advantage of elliptic curve cryptography to design a key-sharing method so that different owners of the same data can share a random key only by interacting with the cloud service provider. And the broadcast encryption is used to manage the ownership of data, and this allows the cloud service provider to control users’ access to outsourced data by updating the broadcast key. In addition, the security analysis shows that the proposed scheme can meet the required security and that it outperforms other related schemes. The detailed simulation comparisons with other related schemes demonstrate that the proposed scheme has good performance.