Speeding up R-LWE post-quantum key exchange

Shay Gueron, Fabian Schlieker

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review


Post-quantum cryptography has attracted increased attention in the last couple of years, due to the threat of quantum computers breaking current cryptosystems. In particular, the key size and performance of post-quantum algorithms became a significant target for optimization. In this spirit, Alkim et al. have recently proposed a significant optimization for a key exchange scheme that is based on the R-LWE problem. In this paper, we build on the implementation of Alkim et al., and focus on improving the algorithm for generating a uniformly random polynomial. We optimize three independent directions: efficient pseudorandom bytes generation, decreasing the rejection rate during sampling, and vectorizing the sampling step. When measured on the latest Intel processor Architecture Codename Skylake, our new optimizations improve over Alkim et al. by up to 1.59× on the server side, and by up to 1.54× on the client side.

Original languageEnglish
Title of host publicationSecure IT Systems - 21st Nordic Conference, NordSec 2016, Proceedings
EditorsJuha Roning, Billy Bob Brumley
PublisherSpringer Verlag
Number of pages12
ISBN (Print)9783319475592
StatePublished - 2016
Event21st Nordic Conference on Secure IT Systems, NordSec 2016 - Oulu, Finland
Duration: 2 Nov 20164 Nov 2016

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Volume10014 LNCS
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349


Conference21st Nordic Conference on Secure IT Systems, NordSec 2016

Bibliographical note

Publisher Copyright:
© Springer International Publishing AG 2016.


  • AES-NI
  • AVX2
  • AVX512
  • Post-quantum key exchange
  • Ring-LWE
  • Software optimization

ASJC Scopus subject areas

  • Theoretical Computer Science
  • General Computer Science


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