We study the development of conjunctive keyword searchable scheme which enables one to search encrypted documents by using more than one keyword. The notion of conjunctive keyword searching was presented by Golle et al. in 2004. However, their security model was constructed in a symmetric-key setting which is not applicable for the overall applications in the reality. So Park et al. extended Golle et al.'s security model into a public-key setting which calls the Public Key Encryption with Conjunctive Field Keyword Search (PECKS) scheme. In this paper, we examine six security models by concluding the secret-key setting and public-key setting, and sum up six security requirements that must satisfy to construct a secure conjunctive keyword searchable scheme. Then we compare and analyze the security and the performance of the security models. Finally, we list some issues that need to further discuss in the future.
International Journal of Network Security, 15(5):321-330.