Tap Code Cipher

How would you communicate with someone else who you couldn’t talk to, but was close enough to hear you if you banged or tapped on something, or see you flashing a light or waving an object?

The Tap Code Cipher device teaches the “tap code” that has been widely used by prisoners or POWs to communicate through walls, pipes or any material that carries sound vibrations.  The code is based on a 5×5 square grid, each of the 25 squares representing a letter in the English alphabet (the letters K & C are located on the same square to make the 26 letters fit in 25 squares.  This grid is usually referred to as the “Polybius square” after a Greek historian who lived around 150 BC and described a similar grid-based method to send or encode messages.

Letters are identified by tapping the number of the row the letter is located, pausing, then tapping the number of the column the letter is located.  The letter “C” would be communicated by 1 tap (first row) – pause – 3 taps (3^rd column)

The Tap Code Cipher comes with two “Polybius square” blocks that have the letters of the English Alphabet laser engraved into the 25 squares of the block, and brief instructions are also laser engraved on the backs.

Of course, in practice prisoners don’t have handy wood squares to refer to, but using the Tap Code Cipher helps visualize the tap pattern, and learn quickly that memorizing the first letter of each row, A-F-L-Q-V, and quickly correlating the first tapped number to that letter, then just reciting the alphabet from that letter to correlate to the second tapped number, they arrive at the letter being communicated.

This method works not only with tapping sounds, but visually also.  Flashes of light, or waving of objects can be substituted for tapping.

Each block is 3” x 3” x 1/4″ wood with deeply laser engraved text.  An encryption worksheet is also included to help learn the code.

Tap Code Cipher is a perfect complement to the Enigma Machine.