Watch out for wi-fi

30 January 2009


A computer mouseIt's hard to deny that having wireless access to the internet is incredibly convenient for users at home and at work. But is WiFi putting our security at risk?

A group of scientists have this week published a paper in the journal PNAS which used computer models to predict the spread of infectious disease and show just how susceptible users of WiFi networks can be to the computer equivalent of virulent bugs, the malicious worms and viruses known collectively these days as malware.

Alessandro Vespignani from Indiana University in the US led a team of researchers who built models of WiFi networks based on actual geographic distribution of WiFi routers, the boxes that beam out WiFi signals, around several major US cities.

There's no doubt how populat WiFi is becoming. Around 8% of all households in the US and Europe already have a wireless router in them.

And now that WiFi networks are becoming so dense in urban areas, routers are often close enough to communicate with each other wirelessly and if security levels aren't high enough they can very quickly pass on malware.

The team found that the infection of just a small number of routers can lead to tens of thousands of routers being infected within a week, and most of those infections taking place within the first 24 hours.

The good news is that there are things you can do to help cut down the chances of picking up and passing on malware through wireless networks. Firstly, the authors recommend users change their default passwords and make sure they pick a password that isn't easy to guess.

Secondly, they worked out that if between 60 and 70% of routers used encryption software that would create enough "immunity" to prevent malware spreading through the system like wildfire. This is the same theory behind why only a certain proportion of a human population need to be immunised against a certain disease to prevent an epidemic from being unleashed. While the exact percentage of immunisation needed in different cities will vary, this study did show how important it is to increase the security in current WiFi networks.

So next time you turn on your lap top and tune into the nearest WiFi signal, you might want to think twice about the bugs it might be transmitting or picking up.


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