by David Hakala
Encryption is the scrambling of digital data in such a way that it can be read only by its creator and intended recipients. It may be advisable to encrypt the data on your hard drives; your email during transmission; the information you send or receive via a Web browser; or any other digital information that you don’t want just anyone to read.
It’s easy to make a case for encrypting the passwords you use to log in to your bank account. If you just leave that password lying in plain sight, anyone who reads it can mail himself a check for your entire balance. But is there any reason to encrypt your Christmas email to Grandma? It depends on your overall feelings about privacy. Would you mail Grandma a postcard, or put the family’s news in a sealed envelope?
Online shopping is another clear application for encryption. Typically, you pay with a credit card including the CCV code on its back, providing all the information anyone needs to use your credit card. That data can be intercepted by bad guys on its way to the Web site, so it should be encrypted. All Web browsers support the Hypertext Secure Socket Layer (SSL) Protocol, a form of encryption that is fairly strong. Responsible Web stores use SSL to protect their customers. You can tell if your connection to a Web site is using SSL by just looking at the URL in the address bar of your browser. If it starts with “https” instead of just “http” then the connection is encrypted by SSL.
Encrypting email takes a bit of doing. Both parties to an email exchange must be using the same encryption software. PGP (Pretty Good Privacy) is a free program that can be used to encrypt email as well as other data. There are two “keys” to a PGP message. The public key is a string of letters and number published on a Web site or even in the signature area at the bottom of every email. If you want to send encrypted mail to someone whose public key you have, you just plug that key into PGP and it encrypts the message before it is sent. The recipient also has a private key that is used to decrypt the message.
Entire hard drives, or selected folders and files, can be encrypted and decrypted on the fly using TrueCrypt, another free encryption program. You have to enter a password to access encrypted files, but once you do everything operates normally.
David Hakala has perpetrated technology tutorials since 1988 in addition to committing tech journalism, documentation, Web sites, marketing collateral, and profitable prose in general. His complete rap sheet can be seen at http://www.linkedin.com/in/dhakala