New versions of this package (crypt_blowfish):

	http://www.openwall.com/crypt/

A paper on the algorithm that explains its design decisions:

	http://www.usenix.org/events/usenix99/provos.html

Unix Seventh Edition Manual, Volume 2: the password scheme (1978):

	http://plan9.bell-labs.com/7thEdMan/vol2/password

John the Ripper password cracker:

	http://www.openwall.com/john/
