This tutorial will show you how to set up GPG for use with Firefox and Gmail on Win32 and Linux systems.

What you need:
Firefox
GPG

GPG allows to encrypt and sign your data and communication, features a versatile key management system as well as access modules for all kind of public key directories.

Win32: gnupg-w32cli-1.4.9.exe is the latest at this time.
Linux: gpg should be installed by default on most distros, if not, you’ll need to get the tar.gz and do the compile dance:
tar xvzf gnupg-?.?.?.tar.gz
./configure
make
(sudo) make install

FireGPG

FireGPG is able to detect PGP blocks in any page (for example a public key), and lets you easily manage these different blocks.

A movie or some other large file. It seemed to speed up generating my 4096-bit keys considerably.

Once you’ve installed the binary and Firefox plugin, you need to generate a new key.
Win32:
Start > Run > cmd
cd \
cd "Program Files\GNU\GnuPG"
gpg --gen-key

Linux:
Open a terminal and type:
gpg --gen-key

Tips:
Use a random password generator to generate a strong password.
Answer the questions, defaults are ok. When it starts to generate a key, start watching your movie.

Now, open up Firefox and verify that FireGPG has automatically found your new key:
Tools > FireGPG > Key Manager
You should see your new key in the list.

Now you can test it in Gmail by sending yourself a message with “Clear sign and send” option:

FireGPG has a bunch of other features that you’ll become familiar with as you browse the web from day to day. Gmail is really popular, so I figured this would be the best example of its usage. Leave a comment if you have found other unique tips that you want to share.