Paper 2010/062 Original: eprint.iacr.org/2010/062 ↗

Differential Cryptanalysis of SMS4 Block Cipher

Bozhan Su
Wenling Wu
Wentao Zhang
Abstract

SMS4 is a 128-bit block cipher used in the WAPI standard for wireless networks in China. In this paper, we analyze the security of SMS4 block cipher against differential cryptanalysis. Firstly, we prove three theorems and one corollary that reflect relationships of 5- and 6-round SMS4. Nextly, by these relationships, we clarify the minimum number of differentially active S-boxes in 6-, 7- and 12-round SMS4 respectively. Finally, based on the above results, we present a family of about $2^{14}$ differential characteristics for 19-round SMS4, which leads to an attack on 23-round SMS4 with $2^{115}$ chosen plaintexts and $2^{124.3}$ encryptions. Our attack is the best known attack on SMS4 so far.

Metadata
Available format(s)
PDF
Category
Secret-key cryptography
Publication info
Preprint.
History
2010-02-08: last updated
2010-02-08: published
Short URL
https://ia.cr/2010/062
License
https://creativecommons.org/licenses/by/4.0/

BibTeX

@misc{cryptoeprint:2010/062,
      author = {Bozhan Su and Wenling Wu and Wentao Zhang},
      title = {Differential Cryptanalysis of SMS4 Block Cipher},
      howpublished = {Cryptology {ePrint} Archive, Paper 2010/062},
      year = {2010},
      url = {https://eprint.iacr.org/2010/062}
}
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