An apparatus includes a digital signature verification data embedding unit and a signing unit. The light guide device includes a light guide block that is a light-transmitting block having a refractive index greater than one. A metal layer is put on said molded structure, the metal layer being in the holes, covering at least a portion of the second major surface, covering the sidewalls and portions of the first major surface to interconnect the sidewalls with other sidewalls via the metal layer on the second major surface and in the holes.