If you haven't been living under a rock for the past month or so, you're probably aware of the NSA's massive, ongoing internet surveillance program called PRISM. If you're a Mac user concerned about privacy, one of the best ways to protect it is to encrypt your email.
Normally, the process to add encryption to the Mail program built into OS X involves obtaining and installing a certificate (a small file stored in the OS X Keychain that verifies your identity), then clicking on two new buttons that appear in a new email window when sending email from your verified account (you need a unique certificate for each email account you wish to encrypt). This Macworld article by Chris Breen goes into copious detail on the process. PC World also has an excellent article called How To Protect Your PC From PRISM Surveillance.
If that seems daunting, there's an easier way. GPG Mail is a new, free application for adding PGP encryption to OS X Mail. GPG Mail allows you to encrypt, decrypt, sign, and verify files or messages and manage your GPG Keychain with a few simple clicks.
Once you install the application, it will prompt you to generate a key pair and send your key to a key server. From there, it's simply a matter of launching Mail and composing a new email. Inside the new email window, you'll see a green OpenPGP button in the upper-right corner of the compose window, and two new lock and checkmark buttons that look like this:
You'll need the public key of the recipient, which you can retrieve by searching in the GPG Keychain Access application (or by importing a key that they send to you.) After that, simply enter their mail address in the To: field, and you'll be able to click on the lock icon (to encrypt the message) and click on the sunburst icon to digitally sign the message. The email that the recipient receives will look like this:
And that's it, you're done. If you have any questions or issues, just follow the Quick Start tutorial. In addition to encrypting email, GPG Tools also allows you to encrypt files via the OS X Services menu. For more on that, watch this screencast.
GPG Mail from GPGTools protects your email and files from prying eyes — in theory, anyway. (That new $2 billion NSA skunkworks in Bluffdale, Utah, has some massive computing power at its disposal.)
Do you use email encryption?