A Note on the use of the Double Boomerang Connectivity Table (DBCT) for Spotting Impossibilities

Xavier Bonnetain; Virginie Lallemand

Paper 2024/1218

A Note on the use of the Double Boomerang Connectivity Table (DBCT) for Spotting Impossibilities

Xavier Bonnetain, Université de Lorraine, CNRS, Inria, LORIA, Nancy, France

Virginie Lallemand, Université de Lorraine, CNRS, Inria, LORIA, Nancy, France

Abstract

In this short note we examine one of the impossible boomerang distinguishers of Skinny-128-384 provided by Zhang, Wang and Tang at ToSC 2024 Issue 2 and disprove it. The issue arises from the use of the Double Boomerang Connectivity Table (DBCT) as a tool to establish that a boomerang switch over 2 rounds has probability zero, whereas the DBCT only covers specific cases of difference propagation, missing a large set of events that might make the connection possible. We study in details the specific instance provided by Zhang et al. and display one example of a returning quartet that contradicts the impossibility.

Metadata

Available format(s): PDF
Category: Secret-key cryptography
Publication info: Preprint.
Keywords: Cryptanalysis Boomerang DBCT
Contact author(s): xavier bonnetain @ inria fr
virginie lallemand @ loria fr
History: 2024-07-31: approved; 2024-07-30: received; See all versions
Short URL: https://ia.cr/2024/1218
License: CC BY

BibTeX

@misc{cryptoeprint:2024/1218,
      author = {Xavier Bonnetain and Virginie Lallemand},
      title = {A Note on the use of the Double Boomerang Connectivity Table ({DBCT}) for Spotting Impossibilities},
      howpublished = {Cryptology ePrint Archive, Paper 2024/1218},
      year = {2024},
      note = {\url{https://eprint.iacr.org/2024/1218}},
      url = {https://eprint.iacr.org/2024/1218}
}