Chapter 3. Hello, World!
Table of Contents
Now that you have your key created, let's try writing a signed piece of email.
Find a friendly face. Not all people have Enigmail installed. In fact, very few people use email cryptography at all. It's probably a good idea to send your first test email to a mailing list that has a lot of GnuPG folk around, and that offers support to newcomers who are just starting out.
One of the best options to start with is to send a signed or encrypted email to Adele, the "Friendly OpenPGP Email Robot". Adele accepts OpenPGP messages and replies in an explanatory way to any kind of OpenPGP messages. Don't forget to attach your own public key if you send your first email to Adele. You can use the menu OpenPGP -> Attach My Public Key for this.
In case you are stuck or need further help, two of the best options are PGP-Basics and Enigmail Users. Both places are friendly and welcoming. If you make a mistake, no one will scream at you or call you names.
Write a plain-text email. Enigmail does not work very well with HTML email. While it can be made to work, it's pretty far beyond the scope of this guide. If you normally compose your email in plain text, then you're just fine. If you normally use HTML, then hold down the shift key as you click on "Write" in the Thunderbird window.
While your email can say anything you like, really, it is probably a good idea to give a little bit of an introduction. Tell us about yourself, and ask for people who are willing to help you test Enigmail's encryption features.
Tell Enigmail to sign it. At the top of your Compose window you will see a button reading "OpenPGP". Click on this. Make sure that the "Sign" option, and only that, is checked.
Hit "Send". You will be asked for your passphrase. Once you enter it, Enigmail will sign your email and send it off to the list.
Congratulations! You've just sent your first signed email.
Before encrypting email to someone, please make sure that you can sign messages. The old adage of learning to crawl before learning to walk applies here.
You will need someone to help you with this. Learning how to get people's keys from a keyserver is an important skill to develop, and you won't do yourself any favors by just encrypting messages to yourself. You already have your public key, so you'll miss out on the entire process of finding keys.
Once you've found someone to help you, ask them for their key ID. This will be an eight-character sequence of letters and numbers. Write it down, and then open up the Enigmail Key Manager ("OpenPGP --> Key Management" from the main window).
From the Key Manager, click on "Keyserver --> Search for keys". Enter the person's key ID in the search box, prefixing it with "0x", if necessary. For instance, if someone were to tell you their key ID was "DECAFBAD", you'd enter it as "0xDECAFBAD". But if someone were to tell you their key ID was "0xDEADBEEF", you'd enter it exactly as-is, "0xDEADBEEF".
Make sure your internet connection is active and click "OK". Enigmail will begin searching through the keyserver looking for the key you want. If Enigmail finds it there, it will be added to your own local copy of keys.
Once you've obtained a copy of your correspondent's key, you're set to send encrypted email. Write an email to them just as you normally would, but before sending, click on the OpenPGP button and select "Encrypt". Once that's done, click "Send".
There are two options here. If the email address of your message matches an address on your keyring, there's nothing more to do; your message will be encrypted and sent on to your correspondent. If there's a problem with the matching, you will be asked to manually select a key from your keyring. If you see this menu, then simply select the proper keys and you're done.