Abstract: Ever increasing volume of back up data in cloud storage may be a vital challenge. There is a need of data management as back up windows are shrinking due to growth of information. So, to make data management scalable deduplication concept is used. It is a technique of keeping only one unique instance of data copy by detecting identical data copies and eliminating those so that it could improve storage utilization, system performance of storage system. There are different schemes introduced by people. This paper surveys these different deduplication approaches.

Keywords: deduplication, convergent encryption, cloud storage, cryptographic.