Basic Network Security

This page contains information about basic network security precautions.

There are a few simple steps you can take to make sure that your network communication is as secure as possible. Networking has three main stages -- the source (your computer), the link (cables or wireless signals that carry information), and the destination (another computer). Each of these stages should be protected individually.

Personal firewalls: Securing your source

Like antivirus software, a personal firewall is meant to secure your computer. Antivirus software can't stop network attacks that aren't based on a virus; a firewall helps keep non-virus attacks on the network from invading your computer. Most modern operating systems include built-in personal firewalls that are easy to enable and use.

More information is available from the Personal Firewall pages about enabling and using the Windows XP firewall (SP2 or later) or the Macintosh OS X firewall . (On Windows Vista, the firewall is enabled by default.)

Encryption: Using secure communication across any link

Encryption scrambles information so that only your computer and the computer you're communicating with can read it. If you're simply reading news online, it doesn't really matter whether your network use is protected from other network users with encryption. However, if you're entering passwords, financial information, or other sensitive information, encryption is essential. Fortunately, most modern web browsers offer the ability to encrypt communication with web sites, as explained in the scenarios referenced below.

The method of communication is also important to consider. Since wireless networking is inherently less secure than wired networking, encryption becomes more important over the wireless network. The VPN server allows UIUCnet students, staff, and faculty to establish a secure, encrypted link from your computer to the UIUCnet network from any wireless (or wired) network in the world.

For common, practical examples of how to keep your network communication safe in everyday situations, see CITES Security and the security scenarios, particularly:

What to trust: Secure vs. insecure destinations

Most people don't realize that email is not a secure method of communication. Since most email systems encrypt the user's password when logging in, they believe that email is safe. Unfortunately, email is not protected in any way as it travels across the network, just as a postcard isn't hidden from view as it's sent through the mail.

You should never send sensitive information such as a password or credit card number through email, because it could easily be intercepted in transit.

In addition, the fact that a web site offers a securely encrypted payment form doesn't mean it's a trustworthy web site. Scammers can set up fraudulent websites just as easily as legitimate businesses can. However, there are some strategies you can use to reduce your chance of becoming a victim of online theft.

For more information, see the following security scenarios: