A method for creating a nanostructure surface, comprises creating a nanostructure master having a surface being the negative of a shape that, when illuminated with a predefined illumination, provides a unique optical pattern; and creating nanostructure molds from the nanostructure master, wherein each nanostructure mold has a negative of the master surface which, when illuminated with the predefined illumination, provides the unique optical pattern, which may be a hologram. A nanotag may incorporate an image for identification and a unique pattern that can be identified for authentication.