Paper 2025/2144

On Equivalence of the Butterfly Structure

Chin Hei Chan, Hong Kong University of Science and Technology, Hetao Institute of Mathematics and Interdisciplinary Sciences
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.
Keywords
Butterfly structurebiprojective functionslinear equivalenceEA-equivalenceCCZ-equivalence
Contact author(s)
chenzhanxi @ himis-sz cn
History
2026-01-30: revised
2025-11-24: received
See all versions
Short URL
https://ia.cr/2025/2144
License
Creative Commons Attribution
CC BY

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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