Paper 2013/626

Improved Linear Attacks on the Chinese Block Cipher Standard

Mingjie Liu and Jiazhe Chen

Abstract

The block cipher used in the Chinese Wireless LAN Standard (WAPI), SMS4, was recently renamed as SM4, and became the block cipher standard issued by the Chinese government. This paper improves the previous linear cryptanalysis of SMS4 by giving the first 19-round one-dimensional approximations. The 19-round approximations hold with bias 2^{−62.27}; we use one of them to leverage a linear attack on 23-round SMS4. Our attack improves the previous 23-round attacks by reducing the time complexity. Furthermore, the data complexity of our attack is further improved by the multidimensional linear approach.

Note: Acknowledgments updated

Metadata
Available format(s)
PDF
Category
Secret-key cryptography
Publication info
Preprint. MINOR revision.
Keywords
Block CipherSMS4Linear CryptanalysisMultidimensional Linear Cryptanalysis
Contact author(s)
liumj9705 @ gmail com
History
2013-10-01: revised
2013-09-30: received
See all versions
Short URL
https://ia.cr/2013/626
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2013/626,
      author = {Mingjie Liu and Jiazhe Chen},
      title = {Improved Linear Attacks on the Chinese Block Cipher Standard},
      howpublished = {Cryptology ePrint Archive, Paper 2013/626},
      year = {2013},
      note = {\url{https://eprint.iacr.org/2013/626}},
      url = {https://eprint.iacr.org/2013/626}
}
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