Efficient Information Retrieval for Ranked Queries in Cost-Effective Cloud Environments
Cloud computing as an emerging technology trend is expected to reshape the advances in information technology. In this paper, the authors address two fundamental issues in a cloud environment: privacy and efficiency. They first review a private keyword-based file retrieval scheme proposed by Ostrovsky et. al. then, based on an Aggregation and Distribution Layer (ADL), they present a scheme, termed Efficient Information Retrieval for ranked Query (EIRQ), to further reduce querying costs incurred in the cloud. Queries are classified into multiple ranks, where a higher ranked query can retrieve a higher percentage of matched files. Extensive evaluations have been conducted on an analytical model to examine the effectiveness of their scheme.