US Patent 10111103 Spoof detection using proximity sensors

Computer-implemented methods and systems for liveness analysis using proximity sensors are described. Reflective strength readings from a proximity sensor, such as an infrared proximity sensor incorporated in a mobile device, are received. A liveness measure is determined based on the one or more readings and a reflection threshold, and, based on the liveness measure, a determination is made whether a target in range of the proximity sensor is likely to be a live human.