In this paper we introduce a deduplication system with improved reliability. As we all know the cloud computing performs a number of operations on data. All commercial cloud service providers know that the users demand for huge amount of storage space because number of online operations. Deduplication is good thing to implement but it will not work on encrypted data because of conflict in encryption. As we know convergent encryption, where key is derived from the hash of data which is recovered by the same encryption key.to overcome from all such interrupts we need a secure system which will perform the deduplication. The system checks at block level as well as file level with assignment of tags. Digital libraries contains huge amounts of data. Most of the times while data storage the number of copies of the same data are stored, again and again, so to remove such duplicate data copies we need a Deduplication technique. The deduplication removes unnecessary data, but at the same time, it is beneficial if it retrieves it with more reliability. In this paper, we have studied various approaches to improve the reliability of data after removing duplicate copies in data storage. The use of such deduplication schemes also reduces the data transfer rate to upload and download data .The time consumption should be less which will effect on its accessibility.

Cloud storage Deduplication Integrity Secret Sharing Scheme Message locked encryption.