Complementing Feistel Ciphers

Alex Biryukov; Ivica Nikolic

Paper 2015/426

Complementing Feistel Ciphers

Alex Biryukov and Ivica Nikolic

Abstract

In this paper, we propose related-key differential distinguishers based on the complementation property of Feistel ciphers. We show that with relaxed requirements on the complementation, i.e. the property does not have to hold for all keys and the complementation does not have to be on all bits, one can obtain a variety of distinguishers. We formulate criteria sufficient for attacks based on the complementation property. To stress the importance of our findings we provide analysis of the \textit{full-round} primitives: * For the hash mode of \camo without $FL,FL^{-1}$ layers, differential multicollisions with $2^{112}$ time * For GOST, practical recovery of the full key with 31 related keys and $2^{38}$ time/data

Metadata

Available format(s): PDF
Category: Secret-key cryptography
Publication info: A minor revision of an IACR publication in FSE 2013
Keywords: Complementation Feistel Camellia GOST related-key differential
Contact author(s): inikolic @ ntu edu sg
History: 2015-05-05: received
Short URL: https://ia.cr/2015/426
License: CC BY

BibTeX

@misc{cryptoeprint:2015/426,
      author = {Alex Biryukov and Ivica Nikolic},
      title = {Complementing Feistel Ciphers},
      howpublished = {Cryptology {ePrint} Archive, Paper 2015/426},
      year = {2015},
      url = {https://eprint.iacr.org/2015/426}
}