Paper 2025/2144 Original: eprint.iacr.org/2025/2144 ↗

On Equivalence of the Butterfly Structure

Chin Hei Chan
Abstract

The butterfly structures were introduced by Perrin et al. as a generalization of the Dillon's APN permutation operated in 6 bits. It was proved by several authors independently that such butterflies are differentially 4-uniform and have best known nonlinearity among functions over $\mathbb{F}_{2^{2k}}$. In [LLHQ21, LHXZ22] authors provided sufficient coefficient conditions such that the closed butterfly is a permutation and they further prove that such functions have boomerang uniformity 4 and are linear equivalent to Gold functions. In this paper, we adopt techniques from [DZ23] and [GK] to classify closed butterfly structures satisfying more general conditions in terms of EA-equivalence and CCZ-equivalence.

Metadata
Available format(s)
PDF
Category
Attacks and cryptanalysis
Publication info
Preprint.
History
2026-01-30: last updated
2025-11-24: published
Short URL
https://ia.cr/2025/2144
License
https://creativecommons.org/licenses/by/4.0/

BibTeX

@misc{cryptoeprint:2025/2144,
      author = {Chin Hei Chan},
      title = {On Equivalence of the Butterfly Structure},
      howpublished = {Cryptology {ePrint} Archive, Paper 2025/2144},
      year = {2025},
      url = {https://eprint.iacr.org/2025/2144}
}
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