Homomorphic encryption for secure information retrieval from the cloud

Cloud computing has established itself as a major way of controlling the technology infrastructure costs borne by the organizations. A cost-sensitive organization would most likely find a certain amount of delay to be acceptable while retrieving information from the cloud. The main focus of this paper is on cost-efficiency and privacy. Three secure search protocols, namely Ostrovsky protocol, COPS protocol and EIRQ protocol are discussed in this paper. Each of these protocols incrementally improves upon the basic keyword search. Ostrovsky protocol offers privacy. COPS protocol aggregates the search results and achieves cost efficiency. EIRQ allows the users to retrieve a certain percentage of files after the users assign ranks to the queries themselves. A comparison of these three protocols is followed by the future work that could be carried out in this area.