Subspace Differential Uniformity

Sondre Rønjom; Arne Sandrib; Joakim Sunde

Paper 2026/1303

Subspace Differential Uniformity

Sondre Rønjom, University of Bergen, Nasjonal sikkerhetsmyndighet

Arne Sandrib

, University of Bergen, Nasjonal sikkerhetsmyndighet

Joakim Sunde

, University of Bergen

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: Published elsewhere. Cryptography and Communications
DOI: 10.1007/s12095-026-00896-w
Keywords: differential cryptanalysis Truncated Differential differential uniformity S-boxes Boolean functions
Contact author(s): sondre ronjom @ uib no
arne sandrib @ student uib no
joakim sunde @ uib no
History: 2026-06-24: approved; 2026-06-22: received; See all versions
Short URL: https://ia.cr/2026/1303
License: CC BY

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},
      doi = {10.1007/s12095-026-00896-w},
      url = {https://eprint.iacr.org/2026/1303}
}