Security

The Internet may feel like a place where you roam anonymously and privately, especially if you access it from your own home. However, with every foray onto the Internet, your computer and other computers actively exchange information. So just how private and secure are these communications? That depends primarily on the sites you visit and your Web browser's security features.

How often do you hand your credit card to a waiter in a restaurant or give out your account number over the telephone when ordering products? Such actions probably pose a greater security risk than charging items online at least from trusted Web sites.

Certificates
If you have doubts about providing your credit card number or other personal information on a company's Web site, check for the site's certificate. With Microsoft Internet Explorer 5.0, on the File menu, click Properties and then click Certificates. A Web site certificate is an online document that certifies the site's identity so you know your information is going where you intend it to go.

Weighing the risk
There is a chance that a thief could intercept your credit card number as it travels from your computer to the Web site's server, but it's a faint possibility. In fact, it's much more difficult to carry out such a scheme online than it is in the real world where your credit card number is printed on statements and receipts that are mailed, filed, or thrown away. Some sites may work with your browser to encrypt, or encode, your transaction information so that, if it's intercepted, it can't be read.

Two levels of encryption
Servers and Web browsers use 40-bit or 128-bit encryption. With 40-bit encryption, there are many billions of possible keys to unlock the code for each unique transmission, and only one of them works. With 128-bit encryption, there are 300 billion trillion times as many possible keys as with 40-bit encryption.