Secure your e-mail from prying eyesGnuPG is an absolutely free way to digitally sign and encrypt your e-mail.
Some say that if everyone in the world properly secured their e-mail, there would be no spam. Well that's one of many good reasons to do so. But isn't using PGP security really expensive and hard? Well it's actually free and after this Insider Secret, hopefully, it won't be so hard either. If you just send an e-mail on the Internet there's no way the recipient can be sure it really came from you, unless you digitally sign the e-mail. Also e-mail is unencrypted and anybody could intercept it and read it, unless you encrypt it. GnuPG is a free and open source package that gives you the capability to digitally sign and encrypt e-mail, among many other things. I'm going to demonstrate this on Mac OS X, but he process is similar for Windows users. First go to GnuPG.org. Windows users should click off from there to the Gpg4win project. For the Mac, I'm going to head to MacGPG find the proper file for my version of OS X and download it. After downloading, open the .DMG and first read the Read Me file! There you'll find instructions for what to do whether you've had GnuPG before, had another PGP program before, or never had it ever. I'm going to assume the latter. Then run the install program. PGP is something called public key encryption. Which means you have to create some keys you'll use to encrypt your data. For first-time users of PGP, the Read Me has a link to an excellent, illustrated guide. This next part may sound and look scary, but if you breathe deeply and follow closely, you should be able to come out with some encryption keys without too much trouble. If this is too scary, the Fink Project still uses the command line, but it only needs one command. But let's show you the more involved way so you see what's going on behind the scenes. Launch Terminal. The easiest is way is to press command and space at the same time and type terminal. Type "gpg --gen-key" and press enter. Choose option 1 for standard signing text and strong encryption. The longer number the better so I'm choosing 4096. Type "0" unless you want your key to expire. And "Y" to confirm. Choose your user ID carefully. It can't be changed later, though you can add additional users. Your key itself needs to be protected, so choose a passphrase that is impossible for someone to guess but that you won't lose! Now GnuPG will create your encryption keys! Move the cursor around or do some typing while it generates. That helps make the keys more random. It really does! Now these keys can be used for lots of things, but we're going to demonstrate e-mail. And as you can see there are plug-ins for most all e-mail clients. I'm going to use Thunderbird as an example. Go to "enigmail.mozdev.org" for complete instructions and to download the plug-in. Here are the basics. Launch Thunderbird. Go to Tools and Add-ons Press Install Browse to where you saved the download. Press the Install button. Then restart Thunderbird. Finally, you need a couple more keys. Hang with me, we're almost through. Go to the OpenPGP menu and choose Key Management. Select generate and new key pair. Make sure the proper e-mail address is selected. Choose a properly long and secure passphrase, but one which you won't forget. Forget it, and you're out of luck. Press the generate key and wait for the new keys to generate. Click yes to create a revocation certificate. This will be handy if you ever need to kill this key due to theft or a hard drive crash. And now, exhale, you're secured. When you create an e-mail, click on Open PGP, and choose whether you want to digitally sign, encrypt, or both. A digital signature will prove the e-mail came form you, no spoofing! And Encryption prevents interlopers from determining the contents of the e-mail if they intercept it. And that's it! Lots of steps, but no real difficult thinking and you have a much more secure environment for e-mail. And if you poke around on the GnuPG site you can find a million more uses for the PGP keys. That's it for this Insider Secret. I'm Tom Merritt, CNET.com.