Finger vibrations could unlock secure access revolution

Engineers have created a remarkably low-cost security access system that can verify users from finger vibrations alone.

This means any solid surface could be used to gain access to anything from your home or car to appliances.

The VibWrite smart access system created by Rutgers University engineers uses a sensor on the surface to detect vibrations.

It can be used to enter a gesture or passcode, with numbers simply painted on the surface, meaning any solid surface from a cupboard or a door can be turned into an authentication surface. The potential applications for technology could therefore be vast.

“Everyone's finger bone structure is unique, and their fingers apply different pressures on surfaces, so sensors that detect subtle physiological and behavioural differences can identify and authenticate a person,” said Yingying Chen, an electrical engineer at Rutgers University-New Brunswick, and senior author on the research.

Current security access devices typically use techniques such as fingerprints, cards, cameras or intercoms, all of which require costly equipment, hardware installation and diverse maintenance needs.

VibWrite, on the other hand, simply uses an inexpensive vibration motor and receiver, with simple installation and maintenance. Chen said the cost savings are likely to be 10-fold when deployed widely, and the system’s simplicity means VibWrite "probably could be commercialised in a couple of years”.

The system allows for three types of verification: a PIN number, lock pattern or gesture. The input ‘pad’ can be little more than numbers or a pattern printed on any solid surface.

The level of security of the system is obviously critical, and the paper claims VibWrite is resilient to “side-channel attacks,” which is when someone secretly places a hidden additional vibration receiver on the surface or uses a nearby microphone to capture vibration signals.

The authors also claim the device can resist several other types of attacks, such as when an attacker learns passcodes after observing a user multiple times. In two trials, VibWrite verified legitimate users with more than 95% accuracy, with a false positive rate of less than three per cent. The authors admit the device’s performance will need to be improved for rigorous security applications.

Richard Guest, a biometric systems engineer at the University of Kent who works in developing biometrics standards, also warned of the need for further testing. “We must be cautious about assessing performance with a small group of test subjects in a controlled environment,” he told PE.

However, he was optimistic about the device's potential, adding that it was  “a very interesting novel technology that potentially has a range of applications including supporting existing biometric modalities”.

The system does need improvements, though, as users are sometimes required to login several times to pass the device’s security. The Rutgers-led team is also working to improve other aspects of the system, such as using multiple sensor pairs to improve accuracy, refining the hardware and upgrading the authentication algorithms. Outdoor tests are also planned to account for changes in conditions such as temperature, wind and rain.

Aside from being low-cost, the VibWrite system also uses minimal power, which could make it ideal for easy-to-install battery-operated solutions.