PC: Hey, your mobile's being stolen!

Researchers at the University of Leeds say they have figured out a way of measuring the distance between Bluetooth-enabled devices such as notebook computers, PDAs and mobile phones. They say the development could be used to track movement of devices; for instance, if a computer is moved, an alert could sound and a record of its unauthorised movement could be used in court.

Dr David Walsh, of Leeds University's department of electronic and electrical engineering, said: "The main application is for crime detection and prevention. By locating equipment to half a metre radius or less it will be a deterrent to crime. If something is stolen it will be possible to pinpoint the exact location it was stolen from."

Sadly, the technology on its own is unlikely to be able to pinpoint where the stolen equipment has been taken to. As a crime prevention measure the technology is also limited in that it can only help protect against physical loss. Leaving Bluetooth switched on can place devices at risk of Bluesnarfing -- a technique in which an attacker reads, modifies and copies a phone's address book and calendar without leaving any trace of the intrusion. But, although the tracking only works over a short range -- typically a few tens of metres -- it could still find a large range of applications, said Dr Walsh. "If it works well enough it could be used for locating firefighters in a burning building or to keep track of equipment on large industrial sites, instead of blueprints which have to be constantly revised."

The joint two-year £240,000 project with Imperial College is being carried out with the Home Office Police Scientific Development Branch and the Forensic Science Services.