Subspace Differential Uniformity

Sondre Rønjom; Arne Sandrib; Joakim Sunde

Paper 2026/1303 Original: eprint.iacr.org/2026/1303 ↗

Subspace Differential Uniformity

Sondre Rønjom

Arne Sandrib

Joakim Sunde

Abstract

The main contribution of this paper is to introduce Subspace Differential Uniformity (SDU) for S-boxes and block ciphers. The SDU is essentially a measure of how well any function spreads input differences clustered in affine subspaces away from affine clusters in output differences. We provide some lower bounds for the SDU and describe an efficient algorithm for computing the SDU. Moreover, we provide results for some popular classes of S-boxes up to $n=8$.

Metadata

Available format(s): PDF
Category: Secret-key cryptography
Publication info: Preprint.
History: 2026-06-22: last updated; 2026-06-22: published
Short URL: https://ia.cr/2026/1303
License: https://creativecommons.org/licenses/by/4.0/

BibTeX

@misc{cryptoeprint:2026/1303,
      author = {Sondre Rønjom and Arne Sandrib and Joakim Sunde},
      title = {Subspace Differential Uniformity},
      howpublished = {Cryptology {ePrint} Archive, Paper 2026/1303},
      year = {2026},
      url = {https://eprint.iacr.org/2026/1303}
}