An effective and efficient technique for supporting privacy-preserving keyword-based search over encrypted data in clouds

Nowadays, cloud providers offer to their clients the possibility of storage of emails and files on the cloud server. To avoid privacy concerns, encryption should be applied to data. Unlike searching plaintext documents by keywords, encrypted documents cannot be retrieved in the same manner. As keyword searches on encrypted data are in demand, this paper describes an effective and efficient technique to support privacy-preserving keyword-based search over encrypted outsourced data. With this technique, encrypted data are first searched with the keyword, support for dynamic operations is then checked, and all relevant data documents are finally sorted based on the number of keywords matching the user query. To evaluate the technique, precision and recall are measured. The results reveal the effectiveness and efficiency of the technique in supporting privacy-preserving keyword-based search over encrypted outsourced data.