Semantically Secure and Verifiable Multi-keyword Search in Cloud Computing

Abstract

In cloud computing model, the data are usually encrypted before outsourced to the cloud server, which protects the data privacy, but also leaves keyword searches over ciphertext data a challenging problem. A keyword search scheme over encrypted data should achieve both index privacy and query privacy; moreover, verification of search results is desirable because the incorrectf results can be returned owing to system defects or the cloud server’s motivation to save computation recourses. Many multi-keyword search schemes have been proposed; however, few of these schemes are verifiable and adaptively index-hiding and adaptively query-hiding. In this paper, a semantically secure multi-keyword search scheme is constructed, which is adaptively index-hiding and adaptively query-hiding, also supports the correctness verification of search results. We provide a detailed performance comparison and give a thorough security proof by a sequence of games. The combined results demonstrate that our scheme is secure and practical.