DES encryption with encrypt(3C)

[J.ALBERI]

Before you try to use encrypt/decrypt for general purpose encryption,
remember it is intended as a password encryption function.  If you read
the paper on Password security distributed with the UNIX documentation,
you will see that it was specially designed to BE SLOW!  This is great
for password checking, since it means that somebody down the other end
of the terminal line can't program his/her own desktop PC to repeatedly
try passwords until it finds a correct one.  But it makes encrypt/decrypt
pretty well useless for data encryption.