New Impossible Differential Attacks of Reduced-Round Camellia-192 and Camellia-256

Jiazhe Chen; Keting Jia; Hongbo Yu; Xiaoyun Wang

Paper 2011/017

New Impossible Differential Attacks of Reduced-Round Camellia-192 and Camellia-256

Jiazhe Chen, Keting Jia, Hongbo Yu, and Xiaoyun Wang

Abstract

Camellia is a block cipher selected as a standard by ISO/IEC, which has been analyzed by a number of cryptanalysts. In this paper, we propose several 6-round impossible differential paths of Camellia with the $FL/FL^{-1}$ layer in the middle of them. With the impossible differential and a well-organized precomputational table, impossible differential attacks on 10-round Camellia-192 and 11-round Camellia-256 are given, and the time complexity are $2^{175}$ and $2^{206.8}$ respectively. An impossible differential attack on 15-round Camellia-256 without $FL/FL^{-1}$ layers and whitening is also be given, which needs about $2^{236.1}$ encryptions. To the best of our knowledge, these are the best cryptanalytic results of Camellia-192/-256 with $FL/FL^{-1}$ layers and Camellia-256 without $FL/FL^{-1}$ layers to date.

Note: A flaw was corrected.

Metadata

Available format(s): PDF
Publication info: Published elsewhere. Unknown where it was published
Keywords: Camellia Block Cipher Cryptanalysis Impossible Differential Path Impossible Differential Attack
Contact author(s): jiazhechen @ gmail com
History: 2011-01-19: revised; 2011-01-10: received; See all versions
Short URL: https://ia.cr/2011/017
License: CC BY

BibTeX

@misc{cryptoeprint:2011/017,
      author = {Jiazhe Chen and Keting Jia and Hongbo Yu and Xiaoyun Wang},
      title = {New Impossible Differential Attacks of Reduced-Round Camellia-192 and Camellia-256},
      howpublished = {Cryptology {ePrint} Archive, Paper 2011/017},
      year = {2011},
      url = {https://eprint.iacr.org/2011/017}
}