Partial Sums Meet FFT: Improved Attack on 6-Round AES

Orr Dunkelman, Shibam Ghosh, Nathan Keller, Gaëtan Leurent, Avichai Marmor, Victor Mollimard

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

Abstract

The partial sums cryptanalytic technique was introduced in 2000 by Ferguson et al., who used it to break 6-round AES with time complexity of 252 S-box computations – a record that has not been beaten ever since. In 2014, Todo and Aoki showed that for 6-round AES, partial sums can be replaced by a technique based on the Fast Fourier Transform (FFT), leading to an attack with a comparable complexity. In this paper we show that the partial sums technique can be combined with an FFT-based technique, to get the best of the two worlds. Using our combined technique, we obtain an attack on 6-round AES with complexity of about 246.4 additions. We fully implemented the attack experimentally, along with the partial sums attack and the Todo-Aoki attack, and confirmed that our attack improves the best known attack on 6-round AES by a factor of more than 32. We expect that our technique can be used to significantly enhance numerous attacks that exploit the partial sums technique. To demonstrate this, we use our technique to improve the best known attack on 7-round Kuznyechik by a factor of more than 80.

Original languageEnglish
Title of host publicationAdvances in Cryptology – EUROCRYPT 2024 - 43rd Annual International Conference on the Theory and Applications of Cryptographic Techniques, 2024, Proceedings
EditorsMarc Joye, Gregor Leander
PublisherSpringer Science and Business Media Deutschland GmbH
Pages128-157
Number of pages30
ISBN (Print)9783031587153
DOIs
StatePublished - 2024
Event43rd Annual International Conference on the Theory and Applications of Cryptographic Techniques, EUROCRYPT 2024 - Zurich, Switzerland
Duration: 26 May 202430 May 2024

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Volume14651 LNCS
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349

Conference

Conference43rd Annual International Conference on the Theory and Applications of Cryptographic Techniques, EUROCRYPT 2024
Country/TerritorySwitzerland
CityZurich
Period26/05/2430/05/24

Bibliographical note

Publisher Copyright:
© International Association for Cryptologic Research 2024.

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