Paper 2023/968

SALSA VERDE: a machine learning attack on Learning with Errors with sparse small secrets

Cathy Yuanchen Li, FAIR, Meta
Emily Wenger, University of Chicago, FAIR, Meta
Zeyuan Allen-Zhu, FAIR, Meta
Francois Charton, FAIR, Meta
Kristin Lauter, FAIR, Meta
Abstract

Learning with Errors (LWE) is a hard math problem used in post-quantum cryptography. Homomorphic Encryption (HE) schemes rely on the hardness of the LWE problem for their security, and two LWE-based cryptosystems were recently standardized by NIST for digital signatures and key exchange (KEM). Thus, it is critical to continue assessing the security of LWE and specific parameter choices. For example, HE uses secrets with small entries, and the HE community has considered standardizing small sparse secrets to improve efficiency and functionality. However, prior work, SALSA and PICANTE, showed that ML attacks can recover sparse binary secrets. Building on these, we propose VERDE, an improved ML attack that can recover sparse binary, ternary, and narrow Gaussian secrets. Using improved preprocessing and secret recovery techniques, VERDE can attack LWE with larger dimensions ($n=512$) and smaller moduli ($\log_2 q=12$ for $n=256$), using less time and power. We propose novel architectures for scaling. Finally, we develop a theory that explains the success of ML LWE attacks.

Note: 18 pages

Metadata
Available format(s)
PDF
Category
Attacks and cryptanalysis
Publication info
Published elsewhere. Minor revision. NeurIPS 2023
Keywords
machine learninglearning with errors
Contact author(s)
cathyli @ meta com
ewenger @ meta com
zeyuanallenzhu @ meta com
fcharton @ meta com
klauter @ meta com
History
2023-10-27: revised
2023-06-20: received
See all versions
Short URL
https://ia.cr/2023/968
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2023/968,
      author = {Cathy Yuanchen Li and Emily Wenger and Zeyuan Allen-Zhu and Francois Charton and Kristin Lauter},
      title = {SALSA VERDE: a machine learning attack on Learning with Errors with sparse small secrets},
      howpublished = {Cryptology ePrint Archive, Paper 2023/968},
      year = {2023},
      note = {\url{https://eprint.iacr.org/2023/968}},
      url = {https://eprint.iacr.org/2023/968}
}
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