MISTY1
| General | |
|---|---|
| Designers |
|
| First published | 1995 |
| Successors | Camellia, KASUMI |
| Certification | CRYPTREC (Candidate), NESSIE |
| Cipher detail | |
| Key sizes | 128 bits |
| Block sizes | 64 bits |
| Structure | Nested Feistel network |
| Rounds | 4×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. | |
In cryptography, MISTY1 (or MISTY-1) is a block cipher designed in 1995 by Mitsuru Matsui and others for Mitsubishi Electric.
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.
"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.
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).