On the construction of Perfect Keyword Secure PEKS scheme

With the growing popularity of cloud computing, searchable encryption has become centre of attraction to enhance privacy and usability of the shared data. First searchable encryption scheme under the public key setting was proposed by Bonah et al. which is known as PEKS. In the PEKS scheme, one can easily link between ciphertext and the trapdoor. In Information Sciences 2017 paper, Huang et al. proposed a public key SE scheme. In this scheme, encryption of a document or keyword requires the secret key of the data sender. The data sender generates ciphertexts, and upload them onto the cloud server. The data receiver generates trapdoors depending upon the public key of the sender and its own secretkey. Thus, the PEKS scheme of Huang et al. circumvents the above attack by linking the ciphertext and the trapdoor to the key of the sender. However no work is available in the literature to stop attacks against linking user key and cipher text and server key and ciphertext. In this paper we address these issues. We formalize the two new security notions, namely UKI-security and SKI-security. We have shown that our scheme is secure under these newly introduced security notions.