Paper 2023/375

Accelerating exp-log based finite field multiplication

Nicolas Belleville, Univ. Grenoble Alpes, CEA, List, F-38000 Grenoble, France
Abstract

Finite field multiplication is widely used for masking countermeasures against side-channel attacks. The execution time of finite field multiplication implementation is critical as it greatly impacts the overhead of the countermeasure. In this context, the use of exp-log tables is popular for the implementation of finite field multiplication. Yet, its performance is affected by the need for particular code to handle the case where one of the operands equals zero, as log is undefined for zero. As noticed by two recent papers, the zero case can be managed without any extra code by extending the exp table and setting $log[0]$ to a large-enough value. The multiplication of $a$ and $b$ then becomes as simple as: $exp[log[a]+log[b]]$. In this paper, we compare this approach with other implementations of finite field multiplication and show that it provides a good trade-off between memory use and execution time.

Metadata
Available format(s)
PDF
Category
Implementation
Publication info
Preprint.
Keywords
finite field multiplicationlogmasking
Contact author(s)
nicolas belleville @ cea fr
History
2023-03-16: approved
2023-03-15: received
See all versions
Short URL
https://ia.cr/2023/375
License
Creative Commons Attribution-NonCommercial-NoDerivs
CC BY-NC-ND

BibTeX

@misc{cryptoeprint:2023/375,
      author = {Nicolas Belleville},
      title = {Accelerating exp-log based finite field multiplication},
      howpublished = {Cryptology {ePrint} Archive, Paper 2023/375},
      year = {2023},
      url = {https://eprint.iacr.org/2023/375}
}
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