Shield your home’s wireless network

Q: I have recently set up a Wi-Fi wireless network at home, and now I’m hearing talk about security problems. Should I be concerned?

A: Wireless networks have become more popular as prices for access points drop, and more hotels, restaurants and even parks set up networks for public use.

These networks, commonly known as Wi-Fi, are easy to use, though they carry risks.

If your network is insecure, neighbors and passers-by can steal sensitive data and even use your machine to spread junk e-mail, viruses and other mischief. People with the right software can also read e-mail and see what Web sites you visit as data are transmitted over the air.

Fortunately, there are easy ways to minimize the threats, said Neel Mehta, research engineer at Internet Security Systems Inc. in Atlanta.

These tips should apply to all three main flavors of Wi-Fi, known as 802.11a, b and g, security experts say. Your Wi-Fi equipment should have come with specific instructions.

For starters, change the default settings on your Wi-Fi access point, which is the device your computer connects with wirelessly to reach the Internet.

Each access device has a name known as SSID, or service set identifier, and your laptop needs to know it to connect.

Al Potter, manager of technical services with ICSA Labs in Mechanicsburg, Pa., recommends using a name that won’t give away your identity or location. So don’t name it after yourself, company, street or building number. Make it something generic, like "giraffe."

While you’re at it, change the access point’s default administrative password, which outsiders could use to give themselves access permission or redirect traffic elsewhere, Potter said.

Next, you should enable your access point’s built-in encryption. All devices ship with at least wired equivalent privacy, or WEP, an encryption standard for scrambling data transmissions between your computer and access point.

Gerry Cockram, Sprint Corp.’s senior architect for Wi-Fi in Kansas City, Mo., suggests creating a WEP password that avoids dictionary words and includes a punctuation mark or two and combination of upper and lower cases. And change the password every 30 days or so, says Cockram.

Newer devices come with Wi-Fi protected access, or WPA, a more robust encryption system. If you have it, use it.

Finally, Potter said, you should simply turn off your access point or disable your laptop’s wireless card when not in use.

A few additional precautions