A Duquesne Cipher Follow-up

Many of you will remember the post I made last year concerning a photo of an encrypted message connected to the Duquesne espionage ring during WWII. There was quite a bit of discussion about the message and its bona-fides, and I expect that for many the question is unresolved.

Happily, thanks to a kind reader, I’m able to shed some additional, quite astonishingly detailed light on the matter.

Dan Fruchey just so happens to be an expert on the Duquesne matter, and had this to say in a comment left last week on the original post:

I just came across this thread and thought I would share what I know as I’ve been researching the Duquesne Spy Ring for almost a decade. This is a real message sent to Germany by the double agent William Sebold and his FBI handlers, a portion of a longer message that read:

“Dunn says four battleships and ten destroyers, Texas class, going to Caribbean to scout for English; 600 reserve officers and 600 enlisted men. The Todd Dry Dock have contract to put anti-bomb decks on U.S. destroyers, 20 new destroyers, 20 from World War; half with laminated decks; explosion takes place before bomb reaches lamination. Conservative papers call for union between England and U.S.A. Articles were written to be published when Roosevelt nominated. British Embassy, United States State Department, British Bureau of Information, drew up articles, and State Department O.K’d them to publishers. Greetings.?

This message was introduced as evidence in court (exhibit 14-K if you’re keeping track) and the sent date in the FBI record agrees with that in the photo (July 24, 1940). This was message #34 in a string of hundreds that were sent to Germany.

How accurate is the information? Duquesne produced some astonishingly accurate intelligence that had to be edited by the FBI to protect secrets before being sent overseas but he also wasn’t above inventing material to insure a payday. Just two days before this message was sent Duquesne had been paid $250 in cash by Sebold for his services. Sebold even talked Duquesne into providing a receipt for the funds which he signed “Jimmy Dunn? an alias referred to in this message.

The messages were usually broken into smaller sections for transmission, generally in logical blocks on a subject. The code was based upon a 1939 edition of Rachel Field’s novel entitled “All This And Heaven Too? (you need the UK edition to decipher the code, I picked up a copy from an online bookseller years ago).

Virtually every author who has ever tried to describe the code has cited a September 9, 1941 article from the New York Times which stated,

“The code system to which the novels were the keys was an ingeniously mystifying one, as it was outlined by the witness [Sebold].

The solution lay in the date a radio message was to be received by the agent. The day and the month were totaled up and to this sum was added twenty. This indicated the page of the book on which the message was contained. Then, starting with the first line on the given page, the agent worked up and down the page in a complicated series of squares until the message was decoded.?

Yes, they still really used these types of ciphers in those days. They recruited Sebold and many others in 1939 as they were reactivating elements of the German Military Intelligence apparatus and often called up old spies who hadn’t sharpened their skills since World War I. They taught what they knew and as it became apparent that someone had caught on they introduced new tricks. When caught, three of the spies in this case surrendered books used as the basis for their code. The technique was almost identical in each case and the same batch of spymasters trained many of the agents sent to South America.

I have copies of the original prosecution files which detail the encoding method used but the prosecuting attorney crossed out all of the pages, believing the cipher too confusing to present in court to a jury. I have a few samples from FBI and court files which I ran through the book and their explanation is accurate but the information was a real pain to encode and decode. Typically two FBI agents would work with Sebold to create the messages and even then mistakes were made. The day after this message was sent Sebold received an administrative message from Germany to try to help correct some of the mistakes that were occurring in preparing messages.

If I had to guess I would say that someone pulled out old documents used in preparing the court case and used a genuine artifact for the article. All the spies in this case had already been arrested in the summer of 1941 and the FBI probably felt comfortable flaunting the real thing as they trumpeted their success over the German secret service during prosecution later that year.

As some of you have noted the odd syntax and speculated that this was a staged message let me assure you it was real and add an explanation along those lines that might be helpful. Some of the FBI agents who helped encode and decode messages were Americans who had been taught German for business reasons or were second or third generation German-Americans who had a middling grasp of the language at best. Sometimes the spies who gave Sebold the messages didn’t even understand German and the info was copied verbatim from reports written in English without any attempt at harmonizing the content. Some of the spymasters who sent the messages from Germany were more American than German, speaking German with a notable American accent, after having spent a good portion of their adult years in the U.S. They returned to the Fatherland with promises of rewards or a better life and were sometimes more comfortable composing messages in English than German. In one instance an individual associated with the case, who was still living in Germany long after the war, wrote his memoirs in English and his manuscript had to be translated into German for publication.

So, there you go…

Published in: Geekiness, General, History, Security | on January 21st, 2009| Comments Off on A Duquesne Cipher Follow-up

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