Thursday, July 11, 2024

Update 2024

Recently new information was published on the M-209 cipher machine and this information coupled with all the material that I have collected over the years led me to write a new essay on the M-209 cipher machine and its exploitation by the German and Japanese codebreakers.

The new essay is:

The American M-209 cipher machine - 2024

The American M-209 cipher machine

At the start of WWII, the US armed forces used various means for enciphering their confidential traffic. At the lowest level were hand ciphers. Above that were the M-94 and M-138 strip ciphers and at the top level a small number of highly advanced SIGABA cipher machines.

The Americans used the strip ciphers extensively however these were not only vulnerable to cryptanalysis but also difficult to use.  Obviously a more modern and efficient means of enciphering was needed.

At that time Swedish inventor Boris Hagelin was trying to sell his cipher machines to foreign governments. He had already sold versions of his C-36, C-38 and B-211 cipher machines to European countries. He had also visited the United States in 1937 and 1939 in order to promote his C-36 machine and the electric C-38 with a keyboard called BC-38 but he was not successful (1). The Hagelin C-36 had 5 pin-wheels and the lugs on the drum were fixed in place. Hagelin modified the device by adding another pin-wheel and making the lugs moveable. This new machine was called Hagelin C-38 and it was much more secure compared to its predecessor.

In 1940 he brought to the US two copies of the hand operated C-38 and the Americans ordered 50 machines for evaluation. Once the devices were delivered, they underwent testing by the cryptologists of the Army’s Signal Intelligence Service and after approval it was adopted by the US armed forces for their midlevel traffic. Overall, more than 140.000 M-209’s were built for the US forces by the L.C. Smith and Corona Typewriters Company. (2)


The American version of the Hagelin C-38 was called Converter M-209 by the Army and USAAF and CSP-1500 by the Navy. Compared to the original version it had a few modifications. The M-209 had 27 bars on the drum while the C-38 had 29. Another difference was that the letter slide was fixed. During operation the text was printed by setting the letter spindle on the left to the desired letter and then turning the hand crank on the right.

The M-209 was a medium-level crypto system used at Division level down to and including battalions (Division-Regiment-Battalion) (3) and even up to Corps for certain traffic. The USAAF used it for operational and administrative traffic and the Navy aboard ships. SIGABA was used for higher level messages (Army-Corps-Division) and hand systems like Slidex and the Division Field Code used for tactical messages (Battalion-Company-Platoon).

The Germans called it ‘AM 1’ (Amerikanische Maschine 1) and the Japanese ‘Z code‘.

Monday, June 1, 2020

End of the road

I’ve been posting here since 2011 and during that time I have covered a variety of subjects on military and intelligence history.

From the economics of war, to strength and loss statistics for the opposing sides of WWII, the performance of weapon systems and of course the use of codes and ciphers by the participants.

Especially in the field of cryptology I have presented new information using files that have been recently released to the archives of the US, UK, Germany and other countries. 

I’m happy to see that some of this information has found it’s way into new books and academic articles.

After covering all the cases that interested me I feel it’s time to stop updating this site. I am content with the essays I’ve written and I don’t think I have much to add to them.

Finally, I’d like to thank all the people who’ve helped me by giving me information and/or files. You know how much I appreciate it and how I’ve tried to repay you all by sharing my own material.

You can read my top essays here.

You can download files that I have copied from archives or received via the freedom of information program here.

Sunday, May 31, 2020

My experience with the US FOIA program

Since I no longer have any active cases I think it’s time to write a summary of my experience with the US freedom of information act program.

The good:

1). Everyone can request files using the FOIA program. This is really useful for those of us that are non-US citizens.

2). The agencies involved respond in a professional manner, assign case numbers, send letters detailing the progress of the case etc.

3). The FOIA departments that I had contact with responded quickly to emails.

Overall, from 2012 till 2018 I received 1 file from the CIA FOIA department, 1 file from the US national archives FOIA department and 20 files from the NSA FOIA department.

Total page count for this material was about ~1.300. So, I’m satisfied with the material I received.

The bad

1). The main problem was that my cases took too long to be processed. Files that had been previously declassified were sent to me quickly, however new cases that required review of the documents took years to complete.

Most of the files that I received from the NSA were requested in early 2012 and released in the second half of 2017.

2). For several of my cases the NSA FOIA department’s response was that the relevant files had been sent to the US national archives (NARA) and that I should request them from them instead. However, the document transfer numbers they gave me were in all cases incorrect.

In fact, it was the opinion of the NARA FOIA staff that the NSA was purposefully misleading me. I do not believe that to be true, instead I believe that they simply do not always know what kind of material they are sending to NARA.

The ugly

For whatever reason some of the people at the US national archives FOIA department were rude and/or passive aggressive. I did not let that interfere with my research till 2018 when I finally had enough and I cancelled my remaining two cases.

Conclusion

In conclusion I’d like to say that I am grateful for the existence of the FOIA program since I received many interesting files that contained valuable information.

Ideally, I would have liked to receive this material years in advance but c'est la vie…

Having said that, if I had to use the FOIA program again today I wouldn’t do it due to the great delay in the processing of the cases and the NSA FOIA department’s strategy of ‘reviewing’ a case for years and then informing me that the file has been sent to NARA and giving me incorrect transfer numbers.

If you are a US citizen it’s best to use the mandatory declassification review program. If you (like me) are not a US citizen, then there are simply no good choices…

Thursday, May 28, 2020

Cancellation of my FOIA cases

My two remaining FOIA cases were filed in 2015 and 2018. I decided to cancel both of them because so much time has passed that this material is no longer of use to me.

Friday, May 22, 2020

Histocrypt 2020 proceedings

The proceedings of the International Conference on Historical Cryptology 2020 are available here.

Thursday, May 14, 2020

Interesting Enigma article

Cryptologia: Enigma: the spoils of Gustave Bertrand, or “par où tout a commencé” by Jean-François Bouchaudy

Abstract

As early as 1931, Gustave Bertrand of the French intelligence services received from the traitor Hans Thilo Schmidt documents concerning the Enigma cipher machine. This machine was intended to equip all the German military forces. This is the beginning of an epic that has probably changed the History. The main documents collected by Bertrand have not been destroyed and are available in the archives of the French Army (SHD). This article describes and analyzes each of these documents, including the evolution of the Enigma and its procedures related in these documents. In conclusion, the article lists the findings that come from reading these originals and first and foremost the impact of having a cipher message with its plaintext on the British attempt to recover Enigma rotors wiring. Oddly enough, it seems that this message was not used by the Poles to break the Enigma.