Abstract: Cloud computing as an emerging technology trend is expected to reshape the advances in information technology. In a cost-efficient cloud environment, a user can tolerate a certain degree of delay while retrieving information from the cloud to reduce costs. The most important aspect in the cloud environment is maintaining privacy and efficiency. In this paper an efficient information retrieval query (EIRQ) scheme to reduce the querying overhead in the cloud is presented. In EIRQ, queries are classified into multiple ranks, where a higher ranked query can retrieve a higher percentage of matched files. A user can retrieve files on demand by choosing queries of different ranks. The rank shows the percentage of files that will be returned to the user.

Keywords: Cloud computing, cost efficiency, differential query services, privacy.