Cryptanalysis of Block Ciphers Using Almost-Impossible Differentials

Hamid Mala; Mohammad Dakhilalian; Mohsen Shakiba

Paper 2010/485 Original: eprint.iacr.org/2010/485 ↗

Cryptanalysis of Block Ciphers Using Almost-Impossible Differentials

Hamid Mala

Mohammad Dakhilalian

Mohsen Shakiba

Abstract

In this paper, inspired from the notion of impossible differentials, we present a model to use differentials that are less probable than a random permutation. We introduce such a distinguisher for 2 rounds of Crypton, and present an attack on 6 rounds of this predecessor AES candidate. As a special case of this idea, we embed parts of the additional rounds around the impossible differential into the distinguisher to make a probabilistic distinguisher with more rounds. We show that with this change, the data complexity is increased but the time complexity may be reduced or increased. Then we discuss that this change in the impossible differential cryptanalysis is commodious and rational when the data complexity is low and time complexity is marginal.

Metadata

Available format(s): PDF
Category: Secret-key cryptography
Publication info: Preprint.
History: 2010-09-15: last updated; 2010-09-15: published
Short URL: https://ia.cr/2010/485
License: https://creativecommons.org/licenses/by/4.0/

BibTeX

@misc{cryptoeprint:2010/485,
      author = {Hamid Mala and Mohammad Dakhilalian and Mohsen Shakiba},
      title = {Cryptanalysis of Block Ciphers Using Almost-Impossible Differentials},
      howpublished = {Cryptology {ePrint} Archive, Paper 2010/485},
      year = {2010},
      url = {https://eprint.iacr.org/2010/485}
}