1. A method for determining user liveness comprising: calculating, by a data capture device, eye openness measures for a frame included in captured authentication data and storing the eye openness measures in a buffer of the device, the buffer being configured to store eye openness measures calculated for frames included in the captured authentication data; calculating confidence scores from the eye openness measures stored in the buffer; determining, from the confidence scores, a maximum confidence score; and detecting an eye blink when the maximum confidence score is greater than a threshold score.