Optimizing polynomial convolution for NTRUEncrypt

Wei Dai; William Whyte; Zhenfei Zhang

Paper 2018/229

Optimizing polynomial convolution for NTRUEncrypt

Wei Dai, William Whyte, and Zhenfei Zhang

Abstract

NTRUEncrypt is one of the most promising candidates for quantum-safe cryptography. In this paper, we focus on the NTRU743 paramter set. We give a report on all known attacks against this parameter set and show that it delivers 256 bits of security against classical attackers and 128 bits of security against quantum attackers. We then present a parameter-dependent optimization using a tailored hierarchy of multipli- cation algorithms as well as the Intel AVX2 instructions, and show that this optimization is constant-time. Our implementation is two to three times faster than the reference implementation of NTRUEncrypt.

Metadata

Available format(s): PDF
Category: Implementation
Publication info: Published elsewhere. Major revision. IEEE Trans. on Computers: Special Section on Cryptographic Engineering in a Post-Quantum World
Keywords: Quantum-safe cryptography NTRUEncrypt security estimation constant-time implementation AVX2.
Contact author(s): zzhang @ onboardsecurity com
History: 2018-03-01: received
Short URL: https://ia.cr/2018/229
License: CC BY

BibTeX

@misc{cryptoeprint:2018/229,
      author = {Wei Dai and William Whyte and Zhenfei Zhang},
      title = {Optimizing polynomial convolution for {NTRUEncrypt}},
      howpublished = {Cryptology {ePrint} Archive, Paper 2018/229},
      year = {2018},
      url = {https://eprint.iacr.org/2018/229}
}