I admit, yesterday’s cipher, courtesy of the FBI and the Life Magazine photo archive, is neat, but not really all that exciting. That’s okay, because what I’ve got today is immensely awesome: An example of a pre-war German espionage code.

No, really…





The information for this picture says it was taken in 1941, and shows “An agent of the FBI decoding a message that was encrypted using the anagram encryption method”. Except… I’m fairly sure that’s wrong, and cool as the caption would be, were that true, reality, I believe you’ll find, is even better.

The date is July 24th, 1940. The place, the New York City Field Office of the FBI. The memo, from Director Hoover, is short and cryptic:

CLEARANCE AUTHORIZED FOR FOLLOWING MESSAGE: “DUNN SAYS FOUR BATTLESHIPS AND TEN DESTROYERS OF TEXAS CLASS GOING TO CARIBBEAN TO SCOUT FOR ENGLISH WITH SIX HUNDRED RESERVE OFFICERS AND SIX HUNDRED ENLISTED MEN.” HOOVER

Below that appears to be the same basic message… in German. Above, a number of five-character letter groups. What’s going on here? A lot more than meets the eye, that’s what.

Students of intelligence history may know that “Dunn” was the code-name given by the Germans to Fritz Duquesne, infamous linchpin of the Duquesne spy ring in the early part of WWII. Duquesne was “played” by an American double-agent named William Sebold, who was instrumental in crushing Duquesne’s – and Germany’s – espionage operations in this country.

What you see here is a photo that never should have been allowed to be taken, and one which provides an amazing, one-of-a-kind glimpse into the world of WWII espionage and counter-espionage. As far as I can tell, what is shown in this picture is an FBI agent in New York encrypting a message, passed from “DUNN” – Duquesne – through Sebold, prior to transmitting that message to Germany via shortwave radio. Unlike yesterday’s photo, which was clearly staged, this appears to be real cryptology at work. Even the message is most likely real: it refers to the Neutrality Patrol undertaken shortly before the outbreak of war.

What I think is really cool, though, is that the photo also shows the agent’s worksheet:

I know it’s a little difficult to read, and we’re only looking at a “message depth” of one, but I’m pretty confident that some clever reader out there can use this photo to re-create the code in question. Admittedly, doing so is pointless, except as an academic exercise, but consider: how many other opportunities are budding cryptologists going to get to examine and play with a pre-war German espionage code?