To conclude a trilogy of WiFi Security blogs this week, I’m going to touch on an accidental home encounter I had with wifi signal jammer. As we become ever more WiFi enabled, particularly in the UK, where there has been a bit of WiFi explosion of late, with whole areas of cities becoming WiFi enabled. There is little doubt in my mind that we will become more and more dependant on WiFi networks. Anyone who has read any formal IT Security book will know about the CIA Triad, Confidentially, Integrity and Availability, well security wise this post is going to be about Availability, i.e. jamming the WiFi signal. Now you might think WiFi jamming sounds a bit far fetched and that it would require a lot of expensive equipment and expertise, but as I accidently discovered recently, it does not have to be.

A couple of weeks ago I finally gave in and bought my kids a Nintendo Wii, well I figure it keeps them physically active while playing the video games, which sounds like a fair trade off to me. Anyway I placed the Wii under the main household TV and then tried to connect the Wii up to my home WiFi network, which would allow the Wii to receive software updates, weather forecasts and even browse the web through the Wii’s Opera web browser, however I soon discovered the Wii wouldn’t connect to the WiFi network.

So after an or so hour of troubleshooting, by temporary stripping down all my WiFi security, and then actually plugging the WiFi Router in downstairs as close as possible to the Wii’s location, I discovered the Wii could only pick up my WiFi network signal from a maximum distance of 10 centimetres! Even then the bandwidth (network speeds) appeared to be far too slow. Well I gave up with it for the day as the kids wanted to play Wii Sports. I just thought I had a dodgy WiFi card built into my Wii, but later that night I had an epiphany while watching Satellite TV upstairs in bed.

You see I have Satellite TV, which feeds into the main TV, however earlier this year I wanted the ability to watch all those lovely Satellite TV channels on the bedroom TV as well, so I bought a cheap "Technika" TV broadcasting solution from the local supermarket for £20 ($40), instead of paying over odds with the Satellite TV company for a second set top Sat Box. The equipment consisted of a broadcast unit which attached to the SCART OUT of the downstairs Satellite TV box, which sends TV pictures, Sound and even the remote control infra red signals to a receiver, which connects to a SCART IN on the bedroom TV. My epiphany was the theory that TV broadcast unit was somehow jamming the WiFi signal, especially considering the Wii and TV broadcast unit both resided under the main TV. So I switched off the TV broadcast unit and immediately the Wii connected to the internet.

The following day I did some experiments with my laptop, I noted with the TV broadcast unit switched on, in parts of the house it dropped the WiFi network signal strength by two thirds, while downstairs it wiped all connectivity to the WiFi network.

So after an or so hour of troubleshooting, by temporary stripping down all my WiFi security, and then actually plugging the WiFi Router in downstairs as close as possible to the Wii’s location, I discovered the Wii could only pick up my WiFi network signal from a maximum distance of 10 centimetres! Even then the bandwidth (network speeds) appeared to be far too slow. Well I gave up with it for the day as the kids wanted to play Wii Sports. I just thought I had a dodgy WiFi card built into my Wii, but later that night I had an epiphany while watching Satellite TV upstairs in bed.

You see I have Satellite TV, which feeds into the main TV, however earlier this year I wanted the ability to watch all those lovely Satellite TV channels on the bedroom TV as well, so I bought a cheap "Technika" TV broadcasting solution from the local supermarket for £20 ($40), instead of paying over odds with the Satellite TV company for a second set top Sat Box. The equipment consisted of a broadcast unit which attached to the SCART OUT of the downstairs Satellite TV box, which sends TV pictures, Sound and even the remote control infra red signals to a receiver, which connects to a SCART IN on the bedroom TV. My epiphany was the theory that TV broadcast unit was somehow jamming the WiFi signal, especially considering the Wii and TV broadcast unit both resided under the main TV. So I switched off the TV broadcast unit and immediately the Wii connected to the internet.

The following day I did some experiments with my laptop, I noted with the TV broadcast unit switched on, in parts of the house it dropped the WiFi network signal strength by two thirds, while downstairs it wiped all connectivity to the WiFi network.

So it is possible to have effective wifi disruptor jammer at a very cheap cost, I imagine with some customisation you could increase the range of the WiFi jamming and make it a mobile device.