A new security technology provides a hologram invisible to the naked eye. The tool requires viewing with a prism to discover the holographic image. The product also supplies a primary and complementary hologram for applications where visibility is required or desired. Both approaches offer robust authentication and are extremely difficult to counterfeit. The technology is suitable for high-volume production.Until the hologram is coupled to an optical modifier, the covert holographic image is invisible and not observable by a user. An article containing a security hologram can be authenticated by coupling a prism, for example, to the surface of the security hologram and illuminating it with a specific bandwidth of laser (collimated) light.