Patent attributes
Methods, systems, and apparatus, including computer programs encoded on computer-readable storage media, are provided. In one aspect, a first image of an eye region of a subject is received, the first image captured under illumination by electromagnetic radiation having a wavelength in the 850 nm-1100 nm range. Based on the first image, a metric indicative of differential absorption of the electromagnetic radiation by an iris of the subject and a sclera of the subject is determined. It is identified, based on the metric, that the subject is a spoof representation of a human. Responsive to identifying that the subject is a spoof representation of a human, access to a secure system is prevented.