Send Secure E-mail

It's possible that someone uses your e-mail ID to send unsavory mail. This can be a big problem as the deceived recipient has no way of knowing that it was not you who sent it. Mail encryption and digitally signing your mail can save you from such disasters. Digital signatures make sure that a message sent by someone reaches the recipient securely. Encrypting them makes sure that no one in between can tamper with it. This article is a step-by-step guide to encrypting and digitally signing your mail using Thunderbird. We'll also show you how a recipient can decrypt a mail. 

We have given all the tools required for it on this month's PCQEssential CD. Copy Install.php and Windows privacy tool on your desktop. Then, install Thunderbird on your PC by double clicking on the Thunderbird installer. Then install the GPG encryption package on your PC in the same way. Then launch Thunderbird (Start>Programs> Thunderbird), and select Tool>Extension from the menu. This will open up a small window. Click on the Install button and you will get a Select dialog box. Here, select 'Install.php' (Enigmail plug-in for Thunderbird) file that you have copied from the PCQEssential CD. Then, click on the 'Install Now' to install the plug-in in to your Thunderbird mail client. Then configure your e-mail accounts in Thunderbird, from Tools>Accounts Settings in the menu.

Before you can start sending encrypted and signed e-mail, you have to generate a key. This process will create a pair of keys. One is a private key and other a public key. The public key is sent to the recipients to decrypt your encrypted mail. You can distribute the public key to legitimate recipients by sending them e-mail. To generate the key pair, select the 'Windows Privacy Tray' from the system tray and right click on it. From the context menu, select 'Key Manager'. You will get a Key Management window. Here from the menu, select Key>Generate. This will open a small window where you have to fill up your name, e-mail address and provide a 'pass phrase'. A pass phrase is similar to a password, which the recipients will type in while installing pubic keys at their end. Click on the Generate button to generate the key pair. This will create two files on your desktop: 'secring.gpg' (private key) and 'pubring.gpg' (public key). To send the public key, right click on 'Windows Privacy Tray' from the system tray and open 'Key Manager'. From its menu, select Key>Export. It will open a 'Save As' box. Give a name with an '.asc' extension (say, johndoe.asc) and send it as an attachment. Also send the recipient the pass phrase of your public key, if any. The recipient has to install the packages in the same way as we just discussed. He must also go to the system tray and open Key Manager. Here, the recipient selects Key>Import. Then select the '.asc' file received and click on the Import button. If the key has a pass phrase then the recipient will be asked for it during the import process. Before using Thunderbird, you must configure it's compose settings at both the ends (sender and recipient). Open Thunderbird and select Tools>Options from the menu. From the left panel select the compose icon and on the corresponding right side, click on the 'Send Option' button. You will get an options screen. Here, change 'Text Format' option to 'Convert the messages to the plain text' and click on OK. Compose your message. Click on 'Open PGP' from the window's toolbar. It will pop up a small window, select both 'Sign Messages' and 'Encrypt Message' check boxes and click on OK. Then click on Send. You will see your message get converted into some weird characters. It's your encrypted mail content. When the recipient receives this mail, he will need to click on the Decrypt button to read the content. 

Sanjay Majumder