New spy gear: reflex biometric technology

To this end, the team has turned to one phenomenon that cannot be spoofed - a person's unique reflex responses. They point out that even if a person's pattern of reflex characteristics were revealed to a malicious third-party, they would not be able to replicate them adequately to impersonate the authorized individual. Reflexes by their very nature are beyond conscious control.

Nishigaki and Arai have turned to blind spot position and the so-called saccade response for their biometric. The blind spot, or scotoma, is a fixed region on the retina of the eye where the optic nerve bundle and blood vessels pass from the eyeball into the brain and so no image can be produced here. The position of the blind spot can be determined relative to the direction of gaze. Saccade response is the repeated, tiny, left-to-right movements made when our eyes track something moving right to left, and vice versa.

If physiological biometric information, such as blind spot, were used alone, Nishigaki adds, the possibility remains that an impostor could use surgery or an ingenious contact lens to change the shape of their own eyeball, and be successful in impersonating someone else. Blind spot alone would be no more sophisticated than iris recognition.

By using the blind spot position as a trigger to induce saccades, user authentication can be done by displaying a target within and outside the person's blind spot and using eye tracking technology to measure the reflex time taken until eye movements occur. Each pattern of responses will be unique to the individual.