Paper 2024/2033 Original: eprint.iacr.org/2024/2033 ↗

General Practical Cryptanalysis of the Sum of Round-Reduced Block Ciphers and ZIP-AES

Antonio Flórez-Gutiérrez
Lorenzo Grassi
Gregor Leander
Ferdinand Sibleyras
Yosuke Todo
Abstract

We introduce a new approach between classical security proofs of modes of operation and dedicated security analysis for known cryptanalysis families: General Practical Cryptanalysis. This allows us to analyze generically the security of the sum of two keyed permutations against known attacks. In many cases (of course, not all), we show that the security of the sum is strongly linked to that of the composition of the two permutations. This enables the construction of beyond-birthday bound secure low-latency PRFs by cutting a known-to-be-secure block cipher into two equal parts. As a side result, our general analysis shows an inevitable difficulty for the key recovery based on differential-type attacks against the sum, which leads to a correction of previously published attacks on the dedicated design Orthros.

Metadata
Available format(s)
PDF
Category
Secret-key cryptography
Publication info
Preprint.
History
2024-12-17: last updated
2024-12-17: published
Short URL
https://ia.cr/2024/2033
License
https://creativecommons.org/licenses/by/4.0/

BibTeX

@misc{cryptoeprint:2024/2033,
      author = {Antonio Flórez-Gutiérrez and Lorenzo Grassi and Gregor Leander and Ferdinand Sibleyras and Yosuke Todo},
      title = {General Practical Cryptanalysis of the Sum of Round-Reduced Block Ciphers and ZIP-AES},
      howpublished = {Cryptology {ePrint} Archive, Paper 2024/2033},
      year = {2024},
      url = {https://eprint.iacr.org/2024/2033}
}
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