In
cryptography, the
IDEA NXT algorithm (previously known as
FOX) is a
block cipher designed by Pascal Junod and
Serge Vaudenay of
EPFL (
Lausanne,
Switzerland). It was conceived between 2001 and 2003, the project was originally named FOX and was published in 2003. In May 2005 it was announced by MediaCrypt under the name
IDEA NXT. IDEA NXT is the successor to the
International Data Encryption Algorithm (IDEA) and also uses the
Lai-Massey scheme. MediaCrypt AG holds patents on elements of IDEA and IDEA NXT. The cipher is specified in two configurations: NXT64 (with block of 64 bits, key of 128 bits, 16 rounds) and NXT128 (with block of 128 bits, key of 256 bits, 16 rounds).