With the My Secret Key
Facebook app you can send unbreakable secret messages to your friends on FaceBook! (Or blogs, chat or email.) Only you and the people that know your Secret Key will be able to decipher it.
My Secret Key encrypts your message with a unique key (like a word or phrase) that is created by you. To encrypt your message, simply type or paste your text information into the Message box, enter a word or phrase into the My Secret Key box and click on the Encode Button. If you choose to, you can send your secret message directly to your friend's Facebook page!
You can also use My Secret Key to hide secret information on your computer or email from prying eyes at home or at work. Anyone who does not know your secret key will be unable to decrypt it! Make entire blocks of text incomprehensible to anyone but you and your friends. Encrypt your entire collection of Nancy Drew novels for posterity!