Encrypting documents

mcrypt

pgp

gpg

openssl enc -aes128 < in > out
openssl enc -aes128 -d -out
Credit-report-from-TrueCredit-2006-02-05.ps.gz.undone -in
Credit-report-from-TrueCredit-2006-02-05.ps.gz.openssl-enc-aes128


Presentation about gpg:
http://uuasc.org/p0411.html

Setting up gpg:

gpg --gen-key
...and follow the prompts

changing a key

gpg --edit-key emailaddr

gpg likes to have this in its ~/.gnupg/options file, so it can
automatically retrieve other folks' keys from the public keyservers:

# Use "host -l pgp.net | grep www" to figure out a keyserver.
#keyserver wwwkeys.eu.pgp.net
#keyserver certserver.pgp.com
keyserver wwwkeys.pgp.net
keyserver-options auto-key-retrieve