M-209 - Bibliography


M-209 homepage There are many books on Enigma. Several books talk about M-209 among others things, but only one is dedicated to it. It is the Barker's book "Cryptanalysis Of the Hagelin Cryptograph".

Battle of Wits, The Complete Story of Codebreaking in World in World War II – by Stephen Budiansky – 2000

In fact, this book talks only of the Allied codebreakers. About M-209, there are only few words: "… German POWs and captured documents would reveal periodically throughout the war that German Army field units were also breaking the American M-209 cipher machine, though this was a fairly insecure device used for enciphering tactical signals, made all the more insecure by the fact that it was so difficult to reset the rotors that operators tented to reuse settings day after day."
The author is not familiar with M-209. In fact, it was very easy to reset the rotors and then to have several messages in depth (this was the main flaw of the M-209). The operators didn't choose the Internal setting, it was imposed by SOI documents. Generally, there was a key by day.

Cipher Systems, The Protection of Communications – by Henry Beker & Fred Piper - 1982

This book talks about modern cryptography (Block Cipher, Public Key, …), but almost a chapter is dedicated to cryptanalysis of M-209 (plain text attack and crypto-alone attack).

Codes and Ciphers, Julius Caesar, the Enigma, and the internet – by Robert Churchhouse – 2002

This book talks about the cryptanalysis from very simple methods to modern cipher methods. The author uses a mathematical approach but very simple to understand. A chapter is dedicated to M-209.

The Code Book – by Simon Singh – 1999

This popular book does not say a single word on the M-209, amazing!

Codebreakers, Arne Beurling and the Swedish crypto program during World War II – by Bengt Beckman - 2002

This book talks principally about the A. Burling's success against the German cipher machine T-52 but few pages describe the invention of B-21, C-35/C-36 and M-206 by Boris Hagelin.

Codebreakers' victory, How the Allied Cryptographers Won World War II – by Hervie Haufler – 2003

Excerpt : "The Russians ...They also made some field use of hagelin's M-209 machines, which they received in lend-lease from the U.S. and copied." Personally, I have not seen this information anywhere, so I am very dubious.

The CodeBreakers, The Comprehensive History of Secret Communication from Ancient Times to the Internet – by David Kahn – 1967, 1996

This is the most famous book about the history of Cryptology. Obviously, several pages are dedicated to Hagelin's machines and particularly to M-209. Excerpt :
"The O.S.S. Employed a variety of other cryptographic systems for inter-communication among its branches in London, Chunking, Karachi, Burma, North Africa, and other places around the world. It had on-time pads, with random numbers generated by I.B.M. Machines, SIGABAS, which it called ''Berthas'', M-209s, and strips."

Cryptanalysis Of the Hagelin Cryptograph – by Wayne G. Barker – 1977

This book is my "bible" about M-209: At first, it describes in details the working of M-209. Then it gives the methods to break messages ciphered by machines with only one wheel, then two wheels until six wheels. It describes too a crypto-alone attack method on a message of only 800 characters … but ciphered with only four wheels! In the Barker's book there is a challenge with several messages of 1000 characters. They were broken only in 2015 by Georges Lasry.

Cryptology, Yesterday, Today, and Tomorrow – by C.A. Deavours & all - 1987

This book gathers several articles from Cryptologia review, among them some deal with M-209 :
  • Statistical Analysis of the Hagelin Cryptograph by Ronald L. Rivest, 1981.
  • The Hagelin Cipher Machine (M-209) : Reconstruction of the Internal Settings, by Robert Morris, 1978. This article is very famous in the history of M-209 cryptanalysis. It describes clearly how to find the Internal key when 75 letters of plain text are known.
  • Solving a Hagelin, Type CD-57, Cipher by Wayne G. Barker, 1978. In this article, Barker finds a CD-57 key thanks to two messages in depth. The position of superimposition is found using a probable word.

Decrypted Secrets, Methods and Maxims of Cryptology – F.L. Bauer, Springer – 2002

This book is dedicated to classical Cryptography and Cryptanalysis. It covers manual methods and cipher machines. There are many pages about M-209, but it contains an error which comes from the C.A. Deavers and L. Kruh's book (Machine Crytpography and modern cryptanalysis): "Messages of over 1000 characters are in any case at risk, since automatic decryption techniques for the M-209, for example, work well with a message of about 800 characters or more …"

Delusions of Intelligence, Enigma, Ultra, and the End of Secure Ciphers – by R.A. Ratcliff – 2006

This book contains some pictures and some interresting information about M-209. Excerpts :

"...Heer cryptanalysts began attacking the American M-209, a hand-held cipher they called a ''machine'' cipher. The M-209 (code named AM-1 by the Germans) operated mechanically, not electrically. Far more portable than the Enigma, M-209 apparead in all the theaters where Americans fought, carrying tactical-grade information. Well before D-Day, the Heer cryptanalysts exploited two types of weakness in the M-209 : physical capture of key lists and messages in ''depth''.
The German quickly discovered the vulnerability of the M-209 to depths (more than one message being encrypted at the same or nearly the same setting). Two German cryptanalysts, Herbert Schwartz and Werner Graupe, described the cracking of M-209 signals to their captors in late 1944. They noted that in five days they could locate the set of similar messages and then establish the internal settings of the M-209 that sent them. Since decryption of these messages took about five days, ''the value of cracking this code ..lay...in the order of battle information, casualtry figures and personality data which it was valuable to learn even after five days's delay''. Consistently they read 10 percent of all M-209 trafic in the European theater."
Mr Ratcliff cites his sources :
NARA : RG 457 HCC Box 1367 NR 4263 - Reports on Enemy Successes Against U.S. Crypto Systems, 17 may 1945 ; pp. 4-5.
NARA : RG 457 HCC Box 769, NR 1995 – Reports on Iterrogation of Werner Graupe and Herbet Schartz, 9 December 1944, p 10.

"The U.S. Signal Security Service conducted a ''cryptographic security survey of other government departments'', including the State Department. They also had units to attack the security of all military systems. One unit, headed by Margaret Evans Lerche, took on the popular M-209 (a medium-grade nonelectric rotor cipher). The unit broke this widely used machine numerous times in several different ways. The first SIS attack on the M-209 in 1942 found several possible methodes of acquiring material sufficient for an inital break. When they studied ''live'' trafic from the battles in Europe, the team reconstructed keys and read serveral days' signals. They urged better security trainning for operators and noted that the forces using M-029s in North Africa had demonstrated improved security. With this proff of M-209's weaknesses, the Americans did not remove the system completely but rather limited its use to information of only short-term value to the enemy."
NARA : RG 457 HCC Box 1019 NR 3242 – Weekly Notes on Cryptanalytic Efforts Against U.S. Equipments, 1943-45.
NARA : RG 457 HCC Box 1124 R 3609 – Research and Development of Cryptogaphic Equipments 1918-45.

"The breaks into M-209, perphaps the most widely used and most insecure mechanical U.S. system, came almost exclusively from depths. These depths into the ''American Hagelin'' as the German called it, all stemmed from errors such as sloppily repeated mssages, reuse of identical indicators, and similar security violations. None of the Wehrmacht's cryptanalysts seems to have expanded these lucky breaks into a more systematic compomise of the system. In spite of having known the general weaknesses of Hagelin machines for years, even the OKW/Chi's experts considered ''common and regular solution impossible''.
Dr. Erich Hüttenhain in NARA : RG 457 HCC Box 1006 NR 3142 – Statements by POWs, p 5.

"In the case of the tactical cipher machine M-209, the Americans had postwar confirmation that the machine had been read. Yet, the U.S. military continued to include the M-209 in its cryptographic inventory through the Korean War. Only early in the Vietnam War, when a speech ciphony system known as the KY-8 became available, did the United States retire M-209. One reason for the long wait for M-209's replacement may very well have been the considerable costs involved..."
Reference : Mr Ratcliff is indebted to Robert J. Hanyok of NSA for this point.

Ghosts of the ETO: American Tactical Deception Units in the European Theater 1944-1945, by Jonathan Gawne, Casemate Publishers (2007)

This book tells the deception operations done by the men of th US 23rd Special Troops against the German Army during WWII.

Excerpts:
Operation ELSENBORN (dec. 1944)
... Going out over the name of William C. Westomerelad, chief of staff of the 9th Infantry Division (and later commander of U.S. forces in VietNam), was the order for a radio operation test:

1. Commencing at 1400 on ____ October 1944 the following messages (encipherred by means of the M-209 Converter) will be transmitted on your ___net. The net control station will divide the traffic as equally as possible among the subordinate stations.

2. All stations will turn in their logs and files covering these transmissions to the Division Signal Officer.

What followed was a list of sixteen messages ranging from (message #1) "Patrols third Bn have taken seven enemy prisoners," to (message # 16) "Activity slight. Baker and Charlie reported nothing and Able reported only slight patrol action. Dog Company had some trouble in their sector by OK now".

What this did was set the stage for the Germans to see that American divisions in a rest area might be called upon to test their equipment and operators' competency wiht transmissions and cipher machines. When the 9th moved out, the Germans would not suspect anything when 4th Division radios began sending the same type of test messages. It was even possible that a German agent might hear some grumbling from signalmen who had to give up some of their free time to takje part in some ridiculous radio test....

Hitler's Codebreakers, German Signals Intelligence in World War 2 – by John Jackson – 2012

This book describes the German successes during WW2, among them, their attacks on M-209. Unfortunately it lacks TICOM documents references that are the basis of this book.

Inside Enigma, The secrets of the Enigma and other Historic Cipher Machines – by Professor Tom Perera - 2010

This book is dedicated to Enigma but it contains several pages about M-209 with many pictures. It contains too the TM 11-380 manual of 1944.

Machine Cryptogaphy and Modern Cryptanalysis – Cipher A. Deavours and Louis Kruh – 1985

This book describes the principal cipher machines and the methods to attack them. About M-209, this book gives an example of ciphering and an example of Morris's method attack with know plain text. Unhappily, it states wrongly (in 1985) that only a message of 800 letters long is enough to find the key : "Analysis of Hagelin lug and pin machines using only ciphertext is also possible under certain circontstances ...The best publicly known techniques using these types of methods require a cryptogram of at lesat 800 (M-209) characters to have a chance at solution."
Remark: The crypto-only attack method known in 1985 needed several thousand of letters to hope to be successful. A method which needs only 800 characters was published only in 2015.

Manual of Cryptography – General L. Sacco – 1941

This book describes the cipher methods and how to break them. About Hagelin serie C cipher machines, it describes the Kerckhoffs's superimposition method. The example given uses three messages ciphered by the same key.

Military Cryptanalytics, Part II – Volume 2 – By Lambros D. Callimahos and William F. Friedman - 1985

The ciphering of a message by M-209 is described in details.

Selections from CRYPTOLOGIA, History, People, and Technology – C.A. Deavours & all – 1998

This book contains several articles from Cryptologia review related with M-209 and more generally with Hagelin serie C machines:
  • The Story of Hagelin Cryptos – Boris C. W. Hagelin, edited by David Kahn – 1994 :
    Among other things, this article describes the invention of B-21, C-35/C-36, C-38 and the negotiations with the Americans that led to the production of the M-209.
  • The Cryptogaphic services of the Royal (British) and Italian navies A comparative analysis of their activies during analysis World War II – Rear Admiral Luigi Domini, tranlated by Augusto Buonafalce. - 1990. This article describes the using of cipher machine C38m by Italians. It describes too the indicator procedure and the attack by probable word when the Internal key was known.