An ElGamal Encryption with Fuzzy Keyword Search on Cloud Environment

With the continuous development of cloud computing, more and more sensitive data needs to be centrally stored in the cloud storage. For protecting the privacy of data, sensitive data must be encrypted before being outsourced to the server. The traditional PEKS (Public Encryption Keyword Search) enables users to search data by using keywords in the condition of encryption, however, it not only needs the security channel but also tolerates the huge pairing-computation. Although the pairing-free public key encryption with keyword search has been proposed, it can not support fuzzy keyword search and this drawback greatly reduces the usability of the system. In this paper, the proposed scheme features three good aspects: First, the keywords and data have been encrypted under the server’s public key and thus the secure channel of the keywords transmission has been eliminated in the sense that the outside attackers cannot obtain any information related to the keywords without the knowledge of the server’s private key. Second, our scheme not only supports accurate keyword search encryption but also supports the search when the keywords input have any spelling mistakes or format inconsistencies, which significantly improved the availability of the system. Finally, the proposed scheme is constructed on the El Gamal encryption instead of the bilinear-pairing encryption, which greatly improve the computational efficiency.