Here are some links to free encryption software and related
goodies. If you want to let me know of other great sites that I
could add to this list, send me e-mail at mylastname@cs.ucdavis.edu.
Enigmail
Plugin for Mozilla Thunderbird and Communicator that uses GPG to encrypt and sign
e-mails. This is what I use (I'm sure there's a plugin for Eudora, too).
What's nice is that once installed, you can configure it to encrypt every message by default, if possible. http://enigmail.mozdev.org/
Pretty Good Privacy
Free (as in beer) encryption software. http://www.pgp.com/
PGP Pathfinder and Statistics
MySpace for geeks! (Note: The data this server depends on is outdated, as of
Nov 1st, 2006. To be sure, double-check links of trust directly with the keyservers. See also Henk's answer in the FAQ.) http://www.cs.uu.nl/people/henkp/henkp/pgp/
Encrypted Instant Messaging
The Psi instant messaging client
interfaces with GnuPG so that you can use encrypt and digitally sign
your chats (and file transfers, I think). There are other
clients that use encryption as well, but I haven't tried them.
TrueCrypt
Free software that encrypts entire volumes (hard drives, USB sticks, ...). This is
not the only tool doing this, and I haven't tried it yet. Available for Windows and GNU/Linux. http://www.truecrypt.org/