An organic light-emitting diode includes an organic light-emitting layer located between a transparent electrode and one other electrode on a substrate. A character box within the document is printed in thermosensitive ink which is rendered transparent upon the document’s heating by a heating element or device. The composition is comprised of various edible items, such as seeds and non-edible items such as pumice, volcanic ash, and calcareous sand. Either set-top box may decrypt the content instance key with the private key that corresponds with its public key so that the encrypted content from the removable storage media may be made available in the clear.