Paper 2017/1215

Lattice-Based Public Key Encryption with Keyword Search

Rouzbeh Behnia and Muslum Ozgur Ozmen and Attila A. Yavuz

Abstract

Public key Encryption with Keyword Search (PEKS) aims in mitigating the impacts of data privacy versus utilization dilemma by allowing any user in the system to send encrypted files to the server to be searched by a receiver. The receiver can retrieve the encrypted files containing specific keywords by providing the corresponding trapdoors of these keywords to the server. Despite their merits, the existing PEKS schemes introduce a high end-to-end delay that may hinder their adoption in practice. Moreover, they do not scale well for large security parameters and provide no post-quantum security promise. In this paper, we propose novel lattice-based PEKS schemes that offer a high computational efficiency along with better security assurances than that of existing alternatives. Specifically, our NTRU-PEKS scheme achieves 18 times lower end-to-end delay than the most efficient pairing-based alternatives. Our LWE-PEKS offers provable security in the standard model with a reduction to the worst-case lattice problems. We fully implemented our NTRU-PEKS on embedded devices with a deployment on real cloud infrastructures to demonstrate its effectiveness.