PROJECT TITLE:

Server-Aided Public Key Encryption with Keyword Search - 2016

ABSTRACT:

Public key encryption with keyword search (PEKS) could be a well-known cryptographic primitive for secure searchable knowledge encryption in cloud storage. Unfortunately, it's inherently subject to the (inside) offline keyword guessing attack (KGA), that is against the data privacy of users. Existing countermeasures for managing this security issue mainly suffer from low potency and are impractical for real applications. In this paper, we tend to give a practical and applicable treatment on this security vulnerability by formalizing a replacement PEKS system named server-aided public key encryption with keyword search (SA-PEKS). In SA-PEKS, to generate the keyword ciphertext/trapdoor, the user desires to question a semitrusted third-party called keyword server (KS) by running an authentication protocol, and hence, security against the offline KGA will be obtained. We then introduce a universal transformation from any PEKS theme to a secure SA-PEKS scheme using the deterministic blind signature. To illustrate its feasibility, we gift the first instantiation of SA-PEKS theme by utilizing the Full Domain Hash RSA signature and therefore the PEKS scheme proposed by Boneh et al. in Eurocrypt 2004. Finally, we tend to describe the way to securely implement the client-KS protocol with a rate-limiting mechanism against on-line KGA and evaluate the performance of our solutions in experiments.