MISTY1

"MISTY" redirects here. For other uses, see Misty.
MISTY1
General
Designers
  • Mitsuru Matsui,
  • Tetsuya Ichikawa,
  • Toru Sorimachi,
  • Toshio Tokita,
  • Atsuhiro Yamagishi
First published1995
SuccessorsCamellia, KASUMI
CertificationCRYPTREC (Candidate), NESSIE
Cipher detail
Key sizes128 bits
Block sizes64 bits
StructureNested Feistel network
Rounds4×n (8 recommended)
Best public cryptanalysis
Integral cryptanalysis leading to full key recovery with 263.9999 chosen ciphertexts and 279 time, or 264 chosen ciphertexts and 269.5 time.[1]

In cryptography, MISTY1 (or MISTY-1) is a block cipher designed in 1995 by Mitsuru Matsui and others for Mitsubishi Electric.[2][3]

MISTY1 is one of the selected algorithms in the European NESSIE project, and has been among the cryptographic techniques recommended for Japanese government use by CRYPTREC in 2003; however, it was dropped to "candidate" by CRYPTREC revision in 2013. However, it was successfully broken in 2015 by Yosuke Todo using integral cryptanalysis; this attack was improved in the same year by Achiya Bar-On.[1]

"MISTY" can stand for "Mitsubishi Improved Security Technology"; it is also the initials of the researchers involved in its development: Matsui Mitsuru, Ichikawa Tetsuya, Sorimachi Toru, Tokita Toshio, and Yamagishi Atsuhiro.[4]

MISTY1 is covered by patents, although the algorithm is freely available for academic (non-profit) use in RFC 2994, and there's a GPLed implementation by Hironobu Suzuki (used by, e.g. Scramdisk).

  1. ^ a b Achiya Bar-On (30 July 2015). "A 270 Attack on the Full MISTY1" (PDF).
  2. ^ Mitsuru Matsui (1997). Block encryption algorithm MISTY. Fast Software Encryption, 4th International Workshop, FSE '97, LNCS 1267. pp. 64–74. ISBN 9783540632474.
  3. ^ Mitsuru Matsui (July 1996). "Block encryption algorithm MISTY". Technical report of IEICE ISEC96-11 (PDF). Archived from the original (PDF) on August 23, 2000.
  4. ^ "Episodes in the development of MISTY". Archived from the original on 2005-03-22.