Years ago, a home network was a luxury. But today, with multiple computers sharing an Internet connection in a home, it's a necessity.

The most common — and easiest — method of networking is Wi-Fi (wireless fidelity). It uses radio waves to allow computers and accessory devices to communicate with each other and the Internet. But your Wi-Fi signal can easily extend beyond the walls of your home, making it possible for neighbors and strangers with Wi-Fi-enabled computers to pick up and use your Internet connection if it is not properly secured. Worse still, if your signal is left unprotected, hackers could use it to access your personal data.

Wi-Fi hardware includes security features to encrypt your data as it moves through the airwaves, but they're rarely turned on by default. That's because security features add to the hurdles that users must jump. Manufacturers want setup to be easy. But in Wi-Fi, "easy" translates to "dangerous."

So, figure on taking extra time to set up your network. Security is worth it. You'll need to follow three steps:

1. Use strong encryption. There are three types of Wi-Fi encryption: WEP (wired equivalent privacy), WPA (Wi-Fi protected access) and WPA2. The latter also is known as 802.11i.

WEP is old and useless. It can be broken in minutes. WPA is strong; WPA2 is stronger.

Check the manufacturer's Web site to see which encryption method your hardware supports. If it's WEP, it's time for an upgrade. Some manufacturers offer upgrades that can be downloaded.

If your hardware uses WEP and cannot be upgraded to something stronger, now's a good time to buy new equipment. Don't stick with WEP. Security is not the place to save money.

WPA2 offers stronger encryption than WPA. According to the Wi-Fi Alliance, a standards-setting organization, WPA is safe. But I would go with the strongest encryption available. Why take the chance?

2. Change the password. Each manufacturer has a default password for wireless routers. Unfortunately, crooks know these defaults, and they know that many people don't bother to change them.

So change yours. Use a password of at least 20 characters. Pick letters, numbers and symbols. Letters should be both uppercase and lowercase.

Finally, write down the password and keep it in a safe location. You probably won't have to use the password often, so it'll be easy to forget.

3. Add more security. Even with WPA2 encryption and a killer password, you can increase security. One way is by turning on the firewall in your router. A firewall monitors Internet traffic, checks for suspicious patterns and blocks unauthorized access to a computer or network. You should have firewalls on your computers, too, but the router's firewall adds extra protection.

Also, place the wireless router in a central location in your house. This allows the radio signal to reach into as many places as possible in your house. The signal also is less likely to extend past the walls of the house.

With solid encryption, there's really no need to worry about stray signals. But if you're extra-cautious, test the signal with NetStumbler (www.netstumbler.com). It will show where your signal is straying.

You'll probably pick up signals from a neighbor or two. So, be nice and show them this column.

Contact Kim Komando at gnstech@gns.gannett.com.