Secret decoder ring

A secret decoder ring (or secret decoder) is a device which allows one to decode a simple substitution cipher - or to encrypt a message by working in the opposite direction.

As inexpensive toys, they have been often used as promotional items by retailers, radio and television programs from the 1930s through to the current day. Decoders, whether badges or rings, are a fun way for children to tap into a common fascination with encryption, ciphers, and secret codes, and are used to send hidden messages back and forth to one another.

Secret decoders are generally circular scales, descendants of the cipher disk developed in the 15th century by Leon Battista Alberti. Rather than the complex polyalphabetic Alberti cipher method, the decoders for children invariably use simple Caesar cipher substitutions.

The most well-known example started in 1934 with the Ovaltine company's sponsored radio program Little Orphan Annie. The fan club's member's handbook included a simple substitution cipher with a resulting numeric cipher text. This was followed the next year with a membership badge or pin that included a cipher disk - enciphering the letters A-Z to numbers 1-26. Similar badges and pocket decoders continued with the Captain Midnight radio and television programs.

None of these early decoders were in the form of finger rings, but "secret compartment" rings were common radio program premiums and in the early 1960s secret decoder rings appeared - notably in conjunction with the Jonny Quest television program sponsored by PF Shoes. A later, less ornate, decoder ring was offered by Kix Cereals. and the men's magazine Oui offered a Captain Jet Decoder Ring- and in 2000 Ovaltine offered a Secret Decoder Ring to be worn on the finger which used their traditional A-Z to 1-26 scheme.

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