Beware of nosy neighbours as you log on to your laptop
The greater use of wireless computer networking brings with it new security concerns
WALKING around festival Edinburgh on a sunny August afternoon, you are struck by the variety of sounds wafting towards you – a lone piper at the top of Waverley Bridge, a jazz band in front of Marks & Spencer, the chirpy sound of Andean pipes from the front of the National Gallery. Each becomes audible as you pass by and as you briefly become part of the audience.
If you were to take a laptop computer with a wireless networking card along George Street or through the Exchange district, you might find something similar happening.
Except in this case it will be computer networking traffic that wafts towards you as you move around. Instead of the sounds of music, it will be bursts of internet network connections – networks that are intended for the organisations inside the offices.
One of the very few high-tech success stories of the past year has been the fast growth of wireless networking systems. These use the unregulated 2.4GHz frequency band, so manufacturers have not had to go through complicated international approval processes to get their products on to the market quickly.
They are also relatively inexpensive – a base station costs about £400 and a card for a PC about £100. So networking a small batch of computers can be done for less than £1,000, and there is no need to run any special cables under floors or through walls.
2.4GHz is unregulated because at concentrated power levels it is the frequency that causes water molecules to heat up and so is used by microwave ovens to cook food. Because of all the microwave ovens in the world generating “noise” at 2.4GHz, it was thought for decades that this frequency could not be used for other purposes.
But new techniques, such as spread spectrum and frequency hopping, now allow these frequencies to be used reliably for local networking. One new standard, Bluetooth, has been developed for linking local personal devices, such as personal digital assistants and cordless earpieces, to mobile phones.
The technology for computer networking that uses this unregulated bandwidth runs under an industry standard called 802.11b. As this is hardly a catchy title, many manufacturers have labelled it “wi-fi” and some of them, such as Apple, have begun to build it into their computers as a standard feature.
Wi-fi networks are very easy to install – they just plug into your existing network and they work straight away. Lots of small or medium-sized enterprises find them ideal, particularly if staff tend to take their laptops round the office as they move between their desk, meeting rooms and other people’s work areas.
But although they are restricted by distance, they are not restricted by walls. If a wi-fi base station is installed without any special customisation, it will work with any wi-fi PC card, including, more than likely, any in the office next door.
If that eavesdropping computer in the next room is owned by somebody who has less than honest intentions, it would be relatively easy for them to use “sniffer” software to look at your e-mails, or your confidential files and records. They could be stealing your proprietary information.
The wi-fi standards include security facilities which allow you to limit access to your network to authorised users, but these have to be specially configured, and it seems that most people do not bother. A recent survey in the United States showed that an estimated 95% of wireless networks had not installed protection, not even the optional built-in wi-fi security.
And even if they do, a team of researchers at Berkeley University has pointed out that these security systems are not actually very secure, and can be broken. A student at AT&T recently announced that he had managed to break the standard security of a wi-fi signal in less than two hours.
And even if your IT department does install proper security, that might not be the end of the matter. Any member of staff could simply plug a wi-fi base station into the network connection under their desk, without you (or perhaps even them) knowing that your company’s internet is now wide open to anybody nearby with a laptop.
So watch out – it might not just be the sounds of the buskers that are being picked up on the streets. It could be your internet traffic.