Abstract: A device for verifying polarization-variant images has first and second illumination arrangements deployed in fixed spatial relation to a camera to illuminate the camera's field of view. A polarizing arrangement is deployed so as to selectively overlie the second illumination source without overlying the first illumination source, thereby allowing switching between differing conditions of polarized illumination without requiring moving optical elements. Also disclosed are various methods employing such a device for authentication and fraud prevention. Alternative implementations employ two cameras with a single illumination arrangement.