No one really knows who invented this cipher or even why it is called the Pig Pen Cipher. Samples of it have been found in 18th-century writings. In 1863, a message sent in Pig Pen Cipher caused great confusion when it was intercepted by the Union army in the United States.

After intercepting an envelope addressed to a rebel agent, Postmaster Abram Wakemen of New York turned the letter over to the Secretary of War. The letter, as you might have guessed, was entirely enciphered in “…a complicated mixture of symbol ciphers”. Unable to decrypt the intended message, the War Department handed the responsibility to the “Sacred Three.”

David Homer Bates, Albert B. Chandler and Charles A. Tinker, the accomplished cryptographers referred to as the “Sacred Three,” first noticed the five different kinds of signs used in the text (representing the five different types of grids used). They also had some luck in that commas separated each word from another, as would spaces in plaintext. Whoever encrypted the message was even courteous enough to leave some plaintext in the letter. But most importantly, in a flash of insight, Bates recognized the use of a pigpen cipher, “which had been used as a price marker in the Pittsburgh store in which he had worked as a boy”.

By focusing on the heading, which included the standard date and address from which the letter was sent, the three deciphered the message within four hours “with the President hovering about anxiously”. Despite the presidential motivation, this argues against the security of the cipher. As it turns out, the message included details regarding the manufacture of Confederate plates for printing money, all of which were promptly seized shortly after decryption.

The Pig Pen Cipher lets you turn letters into symbols based on where they appear in the grids below:

A symbol with a dot in it tells you whether the letter comes from the first or second version of the grid. Good luck trying your hand at decoding Darlene’s message. 3 winners will be chosen from the correct submissions for a mystery prize. Submissions must be emailed to marketing@imperialsprinkler.com by Monday, June 22 to qualify. Good Luck! Download the key and message below!

 

Pigpen Cipher 

Cipher Key