Paper 2023/1340

Methods for Masking CRYSTALS-Kyber Against Side-Channel Attacks

Sıla ÖZEREN, Middle East Technical University
Oğuz YAYLA, Middle East Technical University
Abstract

In the context of post-quantum secure algorithms like CRYSTALS-Kyber, the importance of protecting sensitive polynomial coefficients from side-channel attacks is increasingly recognized. Our research introduces two alternative masking methods to enhance the security of the compression function in Kyber through masking. Prior to this, the topic had been addressed by only one other research study. The "Double and Check" method integrates arithmetic sharing and symmetry adjustments, introducing a layer of obfuscation by determining coefficient values based on modular overflows. In contrast, the Look-Up-Table (LUT) integration method employs arithmetic-to-Boolean conversions, augmented by a pre-computed table for efficient value verifications. Furthermore, by leveraging the alternative prime 7681, we propose a novel masked compression function. This prime, 7681, is also notable as the smallest prime suitable for fast NTT multiplication. While both algorithms prioritize data protection and streamlined processing, they also underscore the inherent challenges of balancing computational speed with the potential vulnerabilities to side-channel attacks.

Metadata
Available format(s)
PDF
Publication info
Preprint.
Keywords
MaskingCRYSTALS-KyberPost Quantum CryptographySide Channel Attacks
Contact author(s)
sila ozeren @ metu edu tr
oguz @ metu edu tr
History
2023-09-12: revised
2023-09-08: received
See all versions
Short URL
https://ia.cr/2023/1340
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2023/1340,
      author = {Sıla ÖZEREN and Oğuz YAYLA},
      title = {Methods for Masking {CRYSTALS}-Kyber Against Side-Channel Attacks},
      howpublished = {Cryptology {ePrint} Archive, Paper 2023/1340},
      year = {2023},
      url = {https://eprint.iacr.org/2023/1340}
}
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