This package implements an algorithm that was developed by Eli Biham and Paul Kocher and that is described in this paper (Postscript, 80k).
The attack is a known plaintext attack, which means you have to know part of the encrypted data in order to break the cipher.
The original page on PkCrack, by Peter Conrad, can be found here. Please refer to the original page to get more information.
This package was written and is copyright by Peter Conrad <email@example.com>. Commercial use in any form is strictly forbidden! You may use parts of the code in your own programs for non-commercial use in case you clearly state where you got it. Do not release software using parts of the code without the author's explicit consent.