“How safe is your wireless home network?”

According to tech research firm Jupiter Research, roughly 21.6 million U.S. households have a wireless Internet network.

Studies and polls generally find that about half of wireless networks are unsecured. Jupiter Research also says:

• 11 percent of consumers have used an open network while traveling
• 5 percent have used a neighbor’s access without that person’s knowledge
• 2 percent freeload Wi-Fi as their only Internet connection

The main conclusion would seem to be that most of us doing online banking and stock trading with our laptop over breakfast are taking a huge risk.

Here’s a simple test.

Try searching for wireless networks within range of your laptop. What you’ll find may startle you.

Here are some of the connections I found one morning in my neighborhood.

Three out of these four connections are unsecured

What this means is any nefariously intentioned person driving around with a laptop and a homemade booster/interceptor (usually an aluminum-lined, cylindrical potato-chip container or ‘cantenna’) could access these internet connections as freely as the home owners.

Once an unauthorized person gains access to one of these networks, he can wreak havoc. Things like:

• Accessing files on the network (including accounts and passwords)
• Sending spam
• Launching attacks against other computers on the Internet which would appear to come from your house

What’s worse is whoever owns the wireless network could be held liable.

Steps you can take to secure your network:

• Check your computer’s operating system (like Windows XP) to see if its firewall is functioning. A firewall helps prevent someone who hops on your network from accessing the information on your machine. Products by McAfee, Symantec, and others also help with this.
• Change the name of your wireless system, often referred to as the Service Set Identifier (SSID). Plenty of personal wireless networks are named “Linksys,” the default SSID of routers built by Cisco. Using the default name for your network is analogous to never changing the home page on your Internet browser from the one that appeared the day you took your computer out of the box.
• Turn off the “broadcast” part of the SSID. This feature sends out to the surrounding area the name of your network and if it is secured or not. By not broadcasting the name, when someone scans for available wireless networks, they won’t be able to see and use yours unless they can guess what you named it.

Reading your router’s user manual (and getting on the phone with tech support if need be) is essential to securing your network.