BIOIMPEDANCE SPOOF DETECTION

摘要

Embodiments relate to bioimpedence-based spoof detection in an optical biometric reader. For example, embodiments operate in context of a biometric reader having a platen integrated with substantially transparent bioimpedance source and receiver electrodes covered by a substantially transparent protective layer. A multi-frequency input signal can be injected from the source electrode into a purported skin site (through the protective layer), so that a response signal is received by the receiver electrode. The response signal is interrogated to formulate a dispersive bioimpedance response of the purported skin site to the input signal over multiple frequencies. A biometric spoof determination can then be made according to the dispersive bioimpedance response. The spoof determination can be used for spoof detection, presence detection, and/or other functions.

主权项

1. A biometric sensor comprising:
a platen; a source electrode and a receiver electrode disposed on the platen; an imaging system that operates to form an image of a purported skin site through the platen using optical wavelengths; and a controller that operates to:
inject an input signal from the source electrode into a purported skin site that is coupled with the source electrode and the receiver electrode via the protective layer, thereby causing the receiver electrode to receive a response signal, the input signal comprising a plurality of frequencies;interrogate the response signal to formulate a dispersive bioimpedance response of the purported skin site to the input signal over the plurality of frequencies; anddetermine whether the purported skin site is a live finger according to the dispersive bioimpedance response.