1. A method of authenticating an object in situ, comprising: creating an authentication pattern signature for the object to be authenticated; associating a random distribution of at least three, three-dimensional elements with the object; aiming a portable, handheld, image capture device at the object to capture return light from the elements as a single image; verifying from the single image that the elements are three-dimensional; processing the single image to generate an image pattern of the elements; comparing the image pattern with the authentication pattern signature; and indicating that the object is authentic when the image pattern matches the authentication pattern signature.