Disclosed is an input device, comprising a touch sensor and a processing system. The touch sensor includes a touch sensing region and a plurality of pixels in the touch sensing region. The processing system is coupled to the touch sensor and comprises circuitry configured to: determine that a touch has occurred on a touch sensor; for each pixel included in the touch, receive touch information from the touch sensor; for each pixel included in the touch, determine a pixel response value for the pixel; and, compute a touch-based metric based on one or more pixel response values, wherein a model is used to perform behavioral authentication based on the touch-based metric.