Paper 2021/820 Original: eprint.iacr.org/2021/820 ↗

Further Improving Differential-Linear Attacks: Applications to Chaskey and Serpent

Marek Broll
Federico Canale
Nicolas David
Antonio Florez-Gutierrez
Gregor Leander
María Naya-Plasencia
Yosuke Todo
Abstract

Differential-linear attacks are a cryptanalysis family that has recently benefited from various technical improvements, mainly in the context of ARX constructions. In this paper we push further this refinement, proposing several new improvements. In particular, we develop a better understanding of the related correlations, improve upon the statistics by using the LLR, and finally use ideas from conditional differentials for finding many right pairs. We illustrate the usefulness of these ideas by presenting the first 7.5-round attack on Chaskey. Finally, we present a new competitive attack on 12 rounds of Serpent, and as such the first cryptanalytic progress on Serpent in 10 years.

Metadata
Available format(s)
PDF
Category
Secret-key cryptography
Publication info
Preprint.
History
2021-06-16: last updated
2021-06-16: published
Short URL
https://ia.cr/2021/820
License
https://creativecommons.org/licenses/by/4.0/

BibTeX

@misc{cryptoeprint:2021/820,
      author = {Marek Broll and Federico Canale and Nicolas David and Antonio Florez-Gutierrez and Gregor Leander and María Naya-Plasencia and Yosuke Todo},
      title = {Further Improving Differential-Linear Attacks: Applications to Chaskey and Serpent},
      howpublished = {Cryptology {ePrint} Archive, Paper 2021/820},
      year = {2021},
      url = {https://eprint.iacr.org/2021/820}
}
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