Why Twofish implementation only with 256 bit ?

Malte Gell malte_gell@t-online.de
Sat May 3 14:45:04 2003


one of the common capabilities of all AES candidates was to offer 
different key length, e.g. 128,192,256 bit. So one can edit his key in 
order to make use of AES256 instead of "standard" 128 bit AES.

Why is this not the case with Twofish ? If I look at cipher.h it seems 
128 bit Twofish is deprecated and only experimental and the cipher 
option "Twofish" always refers to 256 bit Twofish, so why is there no 
Twofish/Twofish192/Twofish256 just as it is the case with Rijndael ?

Are there any special implementation issues regarding Twofish one should 
be aware of ? I can't imagine that 128 bit Twofish is dropped due to 
security reasons...