Obtaining and solving systems of equations in key variables only for the small variants of AES

Stanislav Bulygin; Michael Brickenstein

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Paper 2008/435

Obtaining and solving systems of equations in key variables only for the small variants of AES

Stanislav Bulygin and Michael Brickenstein

Abstract

This work is devoted to attacking the small scale variants of the Advanced Encryption Standard (AES) via systems that contain only the initial key variables. To this end, we introduce a system of equations that naturally arises in the AES, and then eliminate all the intermediate variables via normal form reductions. The resulting system in key variables only is solved then. We also consider a possibility to apply our method in the meet-in-the-middle scenario especially with several plaintext/ciphertext pairs. We elaborate on the method further by looking for subsystems which contain fewer variables and are overdetermined, thus facilitating solving the large system.

Metadata

Available format(s): PDF PS
Category: Secret-key cryptography
Publication info: Published elsewhere. Unknown where it was published
Keywords: AES block ciphers boolean functions cryptanalysis implementation
Contact author(s): bulygin @ mathematik uni-kl de
History: 2008-10-20: received
Short URL: https://ia.cr/2008/435
License: CC BY

BibTeX

@misc{cryptoeprint:2008/435,
      author = {Stanislav Bulygin and Michael Brickenstein},
      title = {Obtaining and solving systems of equations in key variables only for the small variants of AES},
      howpublished = {Cryptology ePrint Archive, Paper 2008/435},
      year = {2008},
      note = {\url{https://eprint.iacr.org/2008/435}},
      url = {https://eprint.iacr.org/2008/435}
}