Thinking of using a wireless network? Then you should worry about their security more than the salesmen lead you to think.

Vendors of wireless network systems should take additional steps to alert users to possible security risks, according to security firm I-Sec.

"A warning system from vendors which highlights the obvious risks and necessity to turn on encryption systems would be a very good idea," said Geoff Davies, managing director of I-Sec.

All wireless networks have built-in encryption systems, but these are not turned on by default when the basic network hardware is set up. Instead they must be manually activated which is why, reckons I-Sec, more than two thirds of wireless network users fail to turn on network security.

"This function is simply for ease of use," said Davies. "If the encryption tool was turned on there would be certain actions, when setting up the system, that could not be performed."

But this ease-of-use leaves the system open to human error.

"Unfortunately vendors want to make things as simple as possible to cut down on the number of calls to their help centres," said Davies.

The company's own research has revealed that 67 percent of wireless networks were not using WEP (wireless equivalent privacy) encryption.

To highlight the deficiencies in Wireless LAN security, I-Sec staff drove around London last week with a homemade wireless network detection device.

Using a directional antenna comprising a Pringles crisp carton connected to a laptop, the company detected almost 60 wireless networks in the space of 30 minutes.

Allegedly, so-called 'war drivers' looking to take down corporate networks use similar systems every day.

"People look for unprotected high-speed bandwidth and then use it to download loads of files," said Davies.

Their convenient setup is making wireless networks increasingly popular and, protected properly, Davies thinks they are no less secure "than Windows 2000 straight from the box".

Basic steps such as moving wireless access points to the centre of a building, changing default names and switching off broadcast functions would significantly improve wireless security.

Computer manufacturers Hewlett Packard and IBM are developing security software, which will provide an added layer of protection for wireless users. Unfortunately both remain tight-lipped about the issue and were unavailable for comment.

For more information on wireless networks, our sister site Techworld has a comprehensive wireless network resource page.