Secure Authorized Deduplication and Differential Query Services in Cost Efficient Cloud

The project first makes the attempt to formally address the problem of authorized data deduplication. Here apart from the traditional deduplication systems, the differential privileges of users are further considered in duplicate check besides the data itself. It shows the proposed authorized duplicate check scheme incurs minimal overhead compared to normal operations. The one of the advantage of cloud is that it is cost efficient, so cloud users can tolerate a certain amount of delay in order to reduce cost during information retrieval. The two issues which is addressed here in such an environment is privacy and efficiency. Here two efficient information retrieval for ranked query (EIRQ) schemes to reduce querying overhead is introduced. In EIRQ users can retrieve files on demand by choosing queries of different ranks. It is useful when a large number of matched files are there and the user only needs a subset of them.