From TNPC issue #4.25...

PGP (Pretty Good Privacy) - Protecting Your Files

by Dan Butler
December 13, 2001

Pretty Good Privacy (PGP) has proven to be a versatile tool in any privacy toolkit. Past articles of this series taught you how to hide your passwords in plain sight, send messages encrypted, and send encrypted files to someone who doesn't have PGP. A handy toolkit for privacy, when you'll use it.

I wanted to mention a couple of helpful tips sent in by fellow security-conscious readers of The Naked PC. First, instead of saving a copy of what you are encrypting to a text file, several of you reminded me it's just as easy to add your PGP key to the list of recipients. Now both you and your friend will have encrypted copies of the message. Easy and handy. In fact, PGP has an option to "Always encrypt to default key". With this option checked you'll always be able to decrypt anything you've encrypted to someone else, just supply your private key.

This go-round you'll learn how to keep files on your system encrypted until you need them. Any of the following techniques work for leaving files on your system or sending them to someone else.

Let's say you have a file you want to keep away from prying eyes. Open Explorer and file your file. Right-click on the file choose PGP / Encrypt & Sign. The PGPshell Key Selection Dialog will pop- up. Look in the bottom right corner. I usually check the "Wipe Original" option which removes the original from your hard drive after creating the encrypted file.

----- Note -----
This is a wipe of the file and not a delete. You won't be recovering the file from your Recycle Bin or with an Undelete tool.
----------------

The other options you have are "Text Output" and "Conventional Encryption". Text Output creates an encrypted file like what you see in an encrypted email. Conventional Encryption lets you supply a passphrase just for this file. Share the passphrase with your friend and they can open the file. Check the "Self Decrypting Archive" box if it is available and your friend won't even need PGP to open the file.

When you Encrypt a text file you'll have the "Secure Viewer" option. When the file is opened it will be displayed in PGP's "Secure Viewer" with an option to use a Tempest attack prevention font. What? From the help file: "Tempest: An appropriately instrumented van can park near your office and remotely pick up all of your keystrokes and messages displayed on your computer video screen." As I said before, if you have to worry about this you've got bigger problems on your hands than this article will solve. Still, you may wish to use the Secure Viewer if you are sharing information you don't want others to leave around on their hard drive or if you have to worry about temporary files being created by other software programs.

Work through the above techniques. Choose what works best for you. You'll feel better just knowing you can encrypt things when you need to, and get to them later.

If you missed earlier segments of this series, point your browser here:
http://www.TheNakedPC.com/t/425/tr.cgi?dan1

You can reach Dan Butler at:
mailto:danbutler@TheNakedPC.com

Return to Top

---

TNPC Hot Tips:

• Email out of control? Spam filling your inbox? People trying to steal your identity? Same here - until I applied these tips. You can too in a new multimedia e-book. Tame Your Email.

• DO YOU MAKE THESE MONEY MISTAKES? Do you know that trying to pay off your high interest rate debts first and/or paying extra on more than one debt is the SLOWEST way to get out of debt? Don't make these same mistakes. Learn more at by clicking here...