Whether you stride purposefully or shuffle along, your unique mode of locomotion could soon be used to secure your cell phone against theft and unauthorised use.
Researchers at the VTT Technical Research Centre of Finland have developed a prototype of a cell phone that uses motion sensors to record a user’s walking pattern of movement, or gait. The device then periodically checks to see that it is still in the possession of its legitimate owner, by measuring the current stride and comparing it against that stored in its memory.
If the phone suspects it has fallen into the wrong hands, it will prompt the user for a password if they attempt to make calls or access its memory.
Heikki Ailisto at VTT says, because the monitoring is constant, the method is better than requiring a password or fingerprint each time the phone is used. “It records walking style in the first few hours and constructs what we call the ‘gait code’,” he told New Scientist.
The motion sensors used in the prototype measure just 3 millimetres x 2mm x 2mm. Similar components already feature in some cell phones, enabling users to play games by manoeuvring or shaking their handset.
Gait analysis is an established “biometric” method for identifying a person. It normally involves analysing video footage of a subject as they walk past a camera and is generally less reliable than fingerprint or iris analysis.
Ailisto says, using the simple motion sensing gait method, the prototype phone correctly identified when it was being carried by someone other than its owner 98% of the time. It also only triggered accidentally, when it was with its rightful owner, 4% of the time.
The team is currently looking for a company to help them develop a commercial product. Ailisto says this could be a cell phone firm, or a company that makes handheld computers.
As it stands, however, the system has its limitations. It worked best when attached the phone was attached to a user’s belt and proved much less reliable when carried in a bag or purse. Ailisto adds that wearing high heels, suffering an injury foot and, especially, having a few drinks, are activities likely to set the device off by accident. “You would need to either turn it off before you start drinking or make sure you remember your password,” he says.
By Will Knight