Securing Email Messages and Files Using PGP

Unfortunately, using public key encryption isn’t as simple as just downloading an application and hitting a magical ‘encrypt’ button. To truly secure email messages or files exchanged between yourself and another person, you’ll need a better understanding of how public key cryptography works. Given that you may be using your laptop from a variety of different locations via private or public networks, the need to secure important business communications from prying eyes has never been greater. If you need data security and privacy, don’t fall into the trap of assuming that your communications will be secure – PGP makes securing files and messages simple, but you will need to know how it works in order to ensure this security.

Before we get to the basics of using public key cryptography (and specifically PGP), it’s worth taking a quick look at why this product is useful for all users, and especially laptop users. First and foremost, PGP is primarily used to encrypt and digitally sign email messages, which is of benefit to laptop and desktop users alike. However, PGP is especially useful to laptop users since it allows files stored on your portable system to be encrypted for your eyes only, others to be securely deleted from disk, and more. These features are especially useful if you regularly travel with your laptop and connect to different networks (such as wireless hotpots) where other users may be trying to access your files. If your laptop is ever stolen, trust us when we say that you’ll be glad that you encrypted all of your sensitive files – losing the laptop itself may be upsetting, but losing unsecured and sensitive business files can be devastating.

Without getting into all of the torrid details of cryptographic algorithms, there are a few critical concepts that you’ll need to be familiar with to use PGP. Of these, the most important is the concept of a key pair.

Public key cryptography relies on all users having a pair of keys: a public key and a private key. Your private key is known only to you and is stored (encrypted) on your PC. Your public key is the one that you’re free to distribute in the world, or anyone with whom you wish to communicate securely. Each of these keys has an important and distinct role.

Author: Dan DiNicolo

Dan DiNicolo is a freelance author, consultant, trainer, and the managing editor of He is the author of the CCNA Study Guide found on this site, as well as many books including the PC Magazine titles Windows XP Security Solutions and Windows Vista Security Solutions. Click here to contact Dan.