Skipjack for GNUPG

[Werner Koch]

Hi,

Panu Rissanen, Mark Tillotson and Paolo Barreto did a Skipjack
Implementation.  I made a gnupg extension out of their source code
and assigned cipher algorithm 101 for it. PGP-CFB is used.  

If you are interested in using a formerly secret NSA algorithm you
should get: 

 ftp://ftp.guug.de/pub/gcrypt/skipjack.c

See this file for instructions how to compile. Put the file into
/usr/local/lib/gnupg.

Usage (gnupg 0.3.0): 

  gpg --load-extension skipjack --cipher-algo skipjack -c <in >out

You can use it as any other cipher algorithm.

Skipjack has only a keysize of 80 bit and of course - the design
criteria are unknown.  I provide it just for your fun; it is
experimental and I may decide to use raw-CFB in the future.

I don't know about the legal status of the algorithm or the source
code.


Werner


p.s.  Anybody wants to do a GPLed Twofish implementation?