MISTY1: Meaning (information, definition, explanation, facts)

In cryptography, MISTY1 (or MISTY-1) is a block cipher designed in 1995 by Mitsuru Matsui for Mitsubishi Electric. Two related designs are MISTY2 and KASUMI; the latter has recently been adopted as the standard encryption algorithm for European mobile phones. MISTY1 is one of the selected algorithms in the European NESSIE project, and has been recommended for Japanese government use by the CRYPTREC project.

MISTY1 is a Feistel network with a variable number of rounds (any multiple of 4), though 8 are recommended. The cipher operates on 64-bit blocks and has a key size of 128 bits. MISTY1 has an innovative recursive structure.

MISTY1 is provably secure against linear and differential cryptanalysis.

MISTY1 is covered by patents, although the algorithm is freely available for academic (non-profit) use. RFC2994.

References

• M. Matsui. Block encryption algorithm MISTY. In Fast Software Encryption, 4th International Workshop, FSE '97, LNCS 1267, pages 64–74. Springer, 1997.
• Mitsuru Matsui. "Block encryption algorithm MISTY." Technical report of IEICE ISEC96-11 (1996-07). (In Japanese).