Privacy Preserving synonym based fuzzy multi-keyword ranked search over encrypted cloud data

摘要

Cloud Storage is currently one of the most widely used applications of cloud. As usage of cloud is increasing, critical and personal data is also being outsourced making it important to maintain confidentiality and integrity of this data. A basic way of protecting data is encrypting it before outsourcing, but the retrieval of required files from the encrypted cloud becomes a problem which requires searching over the encrypted data. Various schemes have been proposed to deal with this issue of searching over encrypted cloud data, however none of the existent schemes provide optimum user search experience resembling plaintext search. In this paper we propose Privacy Preserving Synonym Based Fuzzy Multi-Keyword Ranked Search Over Encrypted Cloud Data, a scheme which enhances user search experience to a paramount by providing both fuzzy and synonym based multi-keyword ranked search, thereby taking encrypted search experience closer to free text search engines. The scheme additionally improves upon index generation time and search time in comparison to existing schemes by utilizing a binary tree based dynamic index. Experimental results portray the effectiveness of this proposed scheme as it reduces the search time, i.e. the time for finding the desired documents, by 90% along with minimizing overhead of updating index when new files need to be uploaded (index generation time) as compared to the existing efficient indexing schemes in literature for a similar dataset. Optimization of search time together with index generation time has not been achieved to this extent before.