From CryptoDox, The Online Encyclopedia on Cryptography and Information Security
MISTY1 (or MISTY-1) is a block cipher designed in 1995 by Mitsuru Matsui and others 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.
RFC 2994 describes the MISTY1 algorithm.
MISTY1 is covered by patent PCT/JP96/02154 in several countries.