International Association for Cryptologic Research

International Association
for Cryptologic Research

CryptoDB

LPN-based Attacks in the White-box Setting

Authors:
Alex Charlès , University of Luxembourg, Esch-sur-Alzette, Luxembourg
Aleksei Udovenko , University of Luxembourg, Esch-sur-Alzette, Luxembourg
Download:
DOI: 10.46586/tches.v2023.i4.318-343
URL: https://tches.iacr.org/index.php/TCHES/article/view/11168
Search ePrint
Search Google
Abstract: In white-box cryptography, early protection techniques have fallen to the automated Differential Computation Analysis attack (DCA), leading to new countermeasures and attacks. A standard side-channel countermeasure, Ishai-Sahai-Wagner’s masking scheme (ISW, CRYPTO 2003) prevents Differential Computation Analysis but was shown to be vulnerable in the white-box context to the Linear Decoding Analysis attack (LDA). However, recent quadratic and cubic masking schemes by Biryukov-Udovenko (ASIACRYPT 2018) and Seker-Eisenbarth-Liskiewicz (CHES 2021) prevent LDA and force to use its higher-degree generalizations with much higher complexity.In this work, we study the relationship between the security of these and related schemes to the Learning Parity with Noise (LPN) problem and propose a new automated attack by applying an LPN-solving algorithm to white-box implementations. The attack effectively exploits strong linear approximations of the masking scheme and thus can be seen as a combination of the DCA and LDA techniques. Different from previous attacks, the complexity of this algorithm depends on the approximation error, henceforth allowing new practical attacks on masking schemes which previously resisted automated analysis. We demonstrate it theoretically and experimentally, exposing multiple cases where the LPN-based method significantly outperforms LDA and DCA methods, including their higher-order variants.This work applies the LPN problem beyond its usual post-quantum cryptography boundary, strengthening its interest for the cryptographic community, while expanding the range of automated attacks by presenting a new direction for breaking masking schemes in the white-box model.
BibTeX
@article{tches-2023-33350,
  title={LPN-based Attacks in the White-box Setting},
  journal={IACR Transactions on Cryptographic Hardware and Embedded Systems},
  publisher={Ruhr-Universität Bochum},
  volume={2023, Issue 4},
  pages={318-343},
  url={https://tches.iacr.org/index.php/TCHES/article/view/11168},
  doi={10.46586/tches.v2023.i4.318-343},
  author={Alex Charlès and Aleksei Udovenko},
  year=2023
}