The invention presents a process for determining a video as being a spoof or a genuine recording of a live biometric characteristic, characterized in that it comprises the steps of: preprocessing (200) the video, determining a liveness score (300) of the video, said determination comprising, for each frame of a plurality of frames (j) of the video: computing a difference between a motion intensity of a current frame and that of each frame of a set of preceding frames to infer a differential motion intensity of the current frame, inferring (330), from the differential motion intensities of the plurality of frames, a motion intensity of the video, comparing (340) said motion intensity to a predetermined threshold, and assigning a liveness score to the video, and determining (400) whether the video is a genuine recording of a biometric characteristic or a spoof.