A New Public Key Encryption with Conjunctive Field Keyword Search Scheme

The scheme that searching over the encrypted data, which is also named conjunctive keyword searchable scheme, enables one to search the encrypted data by using conjunctive keywords. The concept was first presented by Golle et al., and then Park et al. extended their scheme into a public key system. According to the existing conjunctive keyword searchable schemes and the assumption that Golle et al. proposed, there are two types: the fixed keyword field scheme and the variable keyword field scheme. However, there are still rooms for both kinds of the schemes to improve both the performance and the security. In this paper, we propose an efficient secure channel free public key encryption with conjunctive field keyword search scheme that can stand against the off-line keyword-guessing attacks, which is more suitable for the weak devices used by users.