Decryptable Public Key Encryption with Keyword Search Schemes

Abstract

A public key encryption with keyword search (PEKS) scheme does not allow the user to decrypt the encrypted keyword or decrypt the encrypted massage. This no-decryption property also limits the applicability of a PEKS scheme. Fuhr and Paillier also left an open problem on how to come up with a decryptable PEKS which security does not rely on random oracles. In this paper, we first enhance the security model of searchable encryption with decryption scheme (PEKSD) by allowing the test query, and present an efficient PEKSD scheme in the enhanced model without random oracle. And then, we extend our scheme to obtain PEKSD with independent decryption key and trapdoor derivation key. Finally, we also modify our scheme to achieve a PKE/PEKS scheme in which it allows to retrieve both the PEKS keyword and the message. To the best of our knowledge, this is the first PEKS scheme that allows to retrieve both the PEKS keyword and the message.