
Plymouth University's Steve Furnell said that cameras, touch screens and microphones could all be used in the future to protect the data stored on mobile phones and PDAs.
"If we want to go down the biometric route, maybe we could use things which already exist on mobile devices rather than have any additional expense," Professor Furnell said in his keynote address at the Infosec trade show in London.
"There is a camera on most phones now so why not try to leverage some of that for facial recognition?
"Potentially you could do something with signature recognition on a touch-sensitive screen or gesture recognition. You could also use voice verification in some contexts using a standard microphone."
Professor Furnell also suggested the use of behavioural recognition to establish a user's identity on a device.
This included keystroke dynamics, which is currently being researched at Plymouth University, looking at elements such as the way people type and send text messages.
"While keystroke dynamics did not work for everyone, it was effective for certain people," said Professor Furnell.
He added that biometrics options such as the fingerprint detector on the back of Compaq's iPaq had failed to catch on, with only one in eight models in the UK including the technology.