Paper 2020/707 Original: eprint.iacr.org/2020/707 ↗

Faster Enumeration-based Lattice Reduction: Root Hermite Factor k^(1/(2k)) in Time k^(k/8 + o(k))

Martin R. Albrecht
Shi Bai
Pierre-Alain Fouque
Paul Kirchner
Damien Stehlé
Weiqiang Wen
Abstract

We give a lattice reduction algorithm that achieves root Hermite factor $k^{1/(2k)}$ in time $k^{k/8 + o(k)}$ and polynomial memory. This improves on the previously best known enumeration-based algorithms which achieve the same quality, but in time $k^{k/(2e) + o(k)}$. A cost of $k^{k/8 + o(k)}$ was previously mentioned as potentially achievable (Hanrot-Stehlé'10) or as a heuristic lower bound (Nguyen'10) for enumeration algorithms. We prove the complexity and quality of our algorithm under a heuristic assumption and provide empirical evidence from simulation and implementation experiments attesting to its performance for practical and cryptographic parameter sizes. Our work also suggests potential avenues for achieving costs below $k^{k/8 + o(k)}$ for the same root Hermite factor, based on the geometry of SDBKZ-reduced bases.

Metadata
Available format(s)
PDF
Category
Public-key cryptography
Publication info
Preprint.
History
2020-06-14: last updated
2020-06-14: published
Short URL
https://ia.cr/2020/707
License
https://creativecommons.org/licenses/by/4.0/

BibTeX

@misc{cryptoeprint:2020/707,
      author = {Martin R.  Albrecht and Shi Bai and Pierre-Alain Fouque and Paul Kirchner and Damien Stehlé and Weiqiang Wen},
      title = {Faster Enumeration-based Lattice Reduction: Root Hermite Factor k^(1/(2k)) in Time k^(k/8 + o(k))},
      howpublished = {Cryptology {ePrint} Archive, Paper 2020/707},
      year = {2020},
      url = {https://eprint.iacr.org/2020/707}
}
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