A WELL-ORGANIZED PREVENTIVE SCHEME FOR KGA USING HASH CODES

We introduce two games, namely semantic-security against selected keyword attack and indistinguishability against keyword guessing attack1 to capture the safety of PEKS ciphers text and trapdoor, correspondingly. Searchable file encryption is of growing interest for safeguarding the information privacy in secure searchable cloud storage. When it comes to trapdoor generation, as all of the existing schemes don't involve pairing computation, the computation price is reduced compared to PEKS generation. It's important to note the trapdoor generation within our plan is slightly greater than individuals of existing schemes because of the additional exponentiation computations. Within this paper, we investigate security of the well-known cryptographic primitive, namely, public key file encryption with keyword search (PEKS) that is very helpful in lots of applying cloud storage. Regrettably, it's been proven the traditional PEKS framework is affected with a natural insecurity known as inside keyword guessing attack (KGA) launched through the malicious server. To deal with this security vulnerability, we advise a brand new PEKS framework named dual-server PEKS (DS-PEKS). Then we show a normal construction of secure DS-PEKS from LH-SPHF. As one example of the practicality in our new framework, we offer a competent instantiation from the general framework from the Decision Diffie-Hellman-based LH-SPHF and show that it may attain the strong security against within the KGA. As the second primary contribution, we define a brand new variant from the smooth projective hash functions (SPHFs) known as straight line and homomorphic SPHF (LH-SPHF).