Cryptology ePrint Archive: Report 2016/461

NTRU Prime: reducing attack surface at low cost

Daniel J. Bernstein and Chitchanok Chuengsatiansup and Tanja Lange and Christine van Vredendaal

Abstract: Several ideal-lattice-based cryptosystems have been broken by recent attacks that exploit special structures of the rings used in those cryptosystems. The same structures are also used in the leading proposals for post-quantum lattice-based cryptography, including the classic NTRU cryptosystem and typical Ring-LWE-based cryptosystems.

This paper (1) proposes NTRU Prime, which tweaks NTRU to use rings without these structures; (2) proposes Streamlined NTRU Prime, a public-key cryptosystem optimized from an implementation perspective, subject to the standard design goal of IND-CCA2 security; (3) finds high-security post-quantum parameters for Streamlined NTRU Prime; and (4) optimizes a constant-time implementation of those parameters. The resulting sizes and speeds show that reducing the attack surface has very low cost.

Category / Keywords: post-quantum cryptography, public-key encryption, lattice-based cryptography, ideal lattices, NTRU, Ring-LWE, security, Soliloquy, Karatsuba, software implementation, vectorization, fast sorting

Original Publication (with major differences): SAC 2017, to appear

Date: received 11 May 2016, last revised 17 Aug 2017

Contact author: authorcontact-ntruprime at box cr yp to

Available format(s): PDF | BibTeX Citation

Version: 20170817:160919 (All versions of this report)

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