Paper 2024/1791

Discrete gaussian sampling for BKZ-reduced basis

Amaury Pouly, French National Centre for Scientific Research
Yixin Shen, Univ Rennes, Inria, CNRS, IRISA, Rennes, France
Abstract

Discrete Gaussian sampling on lattices is a fundamental problem in lattice-based cryptography. In this paper, we revisit the Markov chain Monte Carlo (MCMC)-based Metropolis-Hastings-Klein (MHK) algorithm proposed by Wang and Ling and study its complexity under the Geometric Series Assuption (GSA) when the given basis is BKZ-reduced. We give experimental evidence that the GSA is accurate in this context, and we give a very simple approximate formula for the complexity of the sampler that is accurate over a large range of parameters and easily computable. We apply our results to the dual attack on LWE of [Pouly and Shen 2024] and significantly improve the complexity estimates of the attack. Finally, we provide some results of independent interest on the Gaussian mass of a random $q$-ary lattices.

Note: The code to produce the figures is available upon request and will be made public at a later stage.

Metadata
Available format(s)
PDF
Category
Public-key cryptography
Publication info
Preprint.
Keywords
LatticesDiscrete Gaussian SamplingGeometric Series Assumption
Contact author(s)
amaury pouly @ cnrs fr
yixin shen @ inria fr
History
2024-11-04: approved
2024-11-02: received
See all versions
Short URL
https://ia.cr/2024/1791
License
Creative Commons Attribution-ShareAlike
CC BY-SA

BibTeX

@misc{cryptoeprint:2024/1791,
      author = {Amaury Pouly and Yixin Shen},
      title = {Discrete gaussian sampling for {BKZ}-reduced basis},
      howpublished = {Cryptology {ePrint} Archive, Paper 2024/1791},
      year = {2024},
      url = {https://eprint.iacr.org/2024/1791}
}
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