Since receiving a letter turning me down for a credit card I hadn’t applied for, I have become obsessed with identity security. I’m particularly worried about wireless networks because they remain a vulnerable conduit for personal information.

If you thought unsecured wireless networks were a thing of the past, think again. I found several conveniently listed by XP when I switched on my new Centrino powered notebook. Click, click and I was in, with a totally new IP address, happily surfing the web using someone else’s account, capturing their browser sessions and, well, you can guess the rest.

OK, I didn’t actually go that far (too scared they’d come round and sort me out) but it wouldn’t be difficult. Even on networks where steps have been taken to keep hackers at bay.

Take, for example, those that limit access by MAC address filtering, a very popular strategy in technologically challenged small to medium-sized businesses because it’s easy to set up and needs very little management. Unfortunately, without additional precautions, it’s as effective as a chocolate teapot.

That’s because MAC addresses are routinely included in Ethernet transmissions. So, if I wanted to find out what addresses were being given access to nearby wireless networks, all I’d need is a wireless sniffer and a few minutes to collect both the IP and MAC address details of any access points and their clients.

Which is where encryption comes in. It won’t stop hackers finding MAC addresses, but it does put a major hurdle in their way and will also hide important personal information. However, you need to choose the right technology – Wired Equivalent Privacy (WEP), for example, is no longer a viable option.

Don’t believe me? Type “WEP cracks” into Google and be prepared to find step-by-step guides telling you how to pluck WEP keys out of the air.

So, what exactly am I trying to say here? Well, I guess it’s to make sure that no matter what else you do, employ the highest form of encryption available to protect your wireless networks. These days, that means Wi-Fi Protected Access (WPA) at the very least or WPA2, which has even stronger encryption. Of course, if your hardware is more than a few months old it may not have such options, but new hardware isn’t expensive and I’d definitely recommend replacement in such cases.

It may not stop the kind of identity theft I’ve been subject to (the information turned out to be publicly available – even my date of birth), but it will help you sleep more soundly.