Paper 2013/022 Original: eprint.iacr.org/2013/022 ↗

Nonlinear cryptanalysis of reduced-round Serpent and metaheuristic search for S-box approximations.

James McLaughlin
John A. Clark
Abstract

We utilise a simulated annealing algorithm to find several nonlinear approximations to various S-boxes which can be used to replace the linear approximations in the outer rounds of existing attacks. We propose three variants of a new nonlinear cryptanalytic algorithm which overcomes the main issues that prevented the use of nonlinear approximations in previous research, and we present the statistical frameworks for calculating the complexity of each version. We present new attacks on 11-round Serpent with better data complexity than any other known-plaintext or chosen-plaintext attack, and with the best overall time complexity for a 256-bit key.

Metadata
Available format(s)
PDF
Category
Secret-key cryptography
Publication info
Preprint.
History
2013-01-18: last updated
2013-01-18: published
Short URL
https://ia.cr/2013/022
License
https://creativecommons.org/licenses/by/4.0/

BibTeX

@misc{cryptoeprint:2013/022,
      author = {James McLaughlin and John A.  Clark},
      title = {Nonlinear cryptanalysis of reduced-round Serpent and metaheuristic search for S-box approximations.},
      howpublished = {Cryptology {ePrint} Archive, Paper 2013/022},
      year = {2013},
      url = {https://eprint.iacr.org/2013/022}
}
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