Installing the Firefox Add-on

So we have a copy of GPG installed, and we have our key-pair. We can also let people know about our public key, that’s available on the key servers. Or we could just send them a copy (Using WinPT, you can right-click the key and copy it, for inclusion in an email, or even just mail it direct to them.)

So now we need to get Firefox talking the same language and using the same keys that are on the PC. Enter FireGPG - an add-on for Firefox that takes the pain out of signing, encrypting or decrypting emails - and the best thing is it integrates straight into the GMail client. Install the plugin and it works automagically - detecting GPG and using your secret key to decrypt or sign emails.

When you’ve installed it and restarted Firefox, there will now be new options in the context menu, allowing you to encrypt sections of text on a webpage with a public key, or decrypt them with your private key by right-clicking and selecting the relevant options. If you go to GMail, you will notice that not only is there the normal Send button while you’re composing an email, but a whole host of others, including the ability to sign an email (so anybody can still read the email, but also verify that the contents haven’t been changed - they would need a copy of your public key to do this) and the ability to encrypt the email and send it in one move - which will prompt a box with a list of your public keys, allowing you to select the recipient.

This is the key to the whole system. You now have the ability to take a plain-text message and encrypt the contents using the recipient’s public key. You also have the ability to encrypt files on your system, as GPG installs entries on the context menu in Window’s Explorer. Simply right-click any files, go down to the GPGee entry and choose your option. Either choose encrypt (PK) and be prompted for the recipients public key, or select Encrypt (Symmetrical) to use the traditional Private Key encryption method of a single key to encrypt, and the same key to decrypt. This option exists so you can encrypt something with a passphrase for your own use (to keep it private from other users perhaps).

To sum up

GPG is a great program that utilises an encryption method that is impossible to crack with today’s standards - even the US government don’t have enough CPU cycles to crack your GPG created key. Anything you encrypt with somebody else’s public key can only be decrypted with their private key. This is important to remember because even you, the person who encrypted the file won’t be able to read the contents. You can encrypt the file to more than one person, including yourself, which would allow you to decrypt the contents - however this is thought to be a less-secure method of keeping data private.

Combined with FireGPG, the two create a system that integrates into GMail to make it even easier to send encrypted emails. You also have the ability with the new system to encrypt files for your own use, using the traditional private key encryption system.

Any questions, post a comment or use the contact form. And if you like, send me something with your new-found encryption skills! A copy of my public key is available here. After clicking the link, FireGPG is clever enough to know it’s a GPG key and gives you the option to import it onto your keyring.