Pf - a Playfair cryptosystem implementation

Pf is a C program that implements the manual cryptosystem "Playfair" invented in 1854 by Charles Wheatstone.

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License (LICENSE in the source distribution) for more details.



Sample output

$ ./pf

pf version 1 Copyright (C) 2006 Timothy Jon Fraser 
pf comes with ABSOLUTELY NO WARRANTY.  This is free software, and you
are welcome to redistribute it under certain conditions.  See the
LICENSE.txt file in the source distribution for details.

Usage examples:

Encrypt text from stdin to stdout:
        pf -k MyKeyWord

Format output in 2-letter groups, 4 groups per line:
        pf -k MyKeyWord -l 2 -g 4

Decrypt text from stdin to stdout:
        pf -k MyKeyWord -d

Show key square for debugging purposes:
        pf -k MyKeyWord -s

Show letters used by keyword for debugging purposes:
        pf -k MyKeyWord -u

$ ./pf -k Apophenia -s

a p o h e 
n i b c d 
f g k l m 
q r s t u 
v w x y z
$ echo "An example message." | ./pf -k Apophenia
nfoz efhg duou qomp 

$ echo "An example message." | ./pf -k Apophenia | ./pf -k Apohenia -d
anex ampl emes sage 

Tim Fraser's homepage at the WPI alumni site

$Id: index.html,v 1.1 2006/09/22 18:43:24 tim Exp $