Patent US 4,245,213

A security system includes apparatus for producing a pair of identical keys in the form of photographs of a kaleidoscopic image. One photograph is retained in the system and upon introduction of another photograph back into the system, the images thereon are compared and employed to sound an alarm if the introduced photograph is not the same as the stored photograph or to open a door in response to a favorable comparison of the images. In either case, inasmuch as kleidoscopic images are substantially unique, the photographs become garbaged and are dumped into a bin.