A Survey on Secure and Authorized Data Deduplication

Data deduplication looks for redundancy of sequences of bytes across very large comparison windows. Sequences of data (over 8 KB long) are compared to the history of other such sequences and it is ideal for highly redundant operations like backup which requires repeatedly copying and storing the same data set multiple times for recovery purpose. To protect the confidentiality of sensitive data while supporting deduplication, convergent encryption technique has been designed to encrypt the data. Convergent encryption enables duplicate files to coalesced into the space of a single file, even the files are encrypted with different users keys. To overcome attacks, the notion of proofs-of-ownership (PoWs) has been introduced, which lets a client proficiently prove to a server that the client holds a file.