Friday, September 9, 2011

German success with Purple ?

The Japanese Foreign Ministry used the Purple machine cipher for communication between embassies and Japan from the late 30's to the end of the war.The US cryptanalysts led by Frank Rowlett  managed to solve it and completely reconstruct it.Thus they read the traffic between Tokyo and the Washington embassy  before the Pacific War.

In Europe Bletchley Park did not manage to solve it but they received a replica  from the Americans in January 1941(Source:The Sigint secrets p207).
The Soviet Union was successfull in the autumn of 1941 thanks to the efforts of NKVD cryptanalyst Sergei Tolstoy (Source: ''The Mitrokhin Archive'' p125)

So what about the Germans did they manage to solve this machine? They definitely had success with the predecessor of Purple the Red machine.

The ‘’European Axis Signal Intelligence in World War II ‘’ reports state categorically that the Germans had no success with the Japanese Purple cipher machine.

EASI vol1 mentions the Purple machine as not read by the Germans.Specifically it mentions that it was attacked by Pers Z.No mention of efforts by OKW/Chi and Forschungsamt though…

According to EASI vol2 ,p70  :
Although they were successful with the Japanese "Red" machine, they did not solve its successor, the "purple’’ machine.
It cannot be said that this failing was necessarily due to inability or ignorance. Perhaps, Japan being Germany's ally  Germany felt it was not worth while to expend the great energy  necessary to solve the difficult Japanese "purple ‘’machine.
So that’s it ? End of story ? Not  really.Let’s take a look at recent developments.
From Stalin's ocean-going fleet  by Jürgen Rohwer, Mikhail S. Monakov ,p143 : 
It may be of interest that this cipher(Purple) was not only broken by the Americans, as is known since the Pearl Harbor investigation of the US Congress in 1946, but also by cryptanalysts of the German Foreign Office and the OKW, who also broke many other Japanese ciphers, as one of the translators, Prof. Cort Rave wrote to J.Rohwer on 01.03.96.
Rave is mentioned in EASI vol3 p122 : Rave, Kurt ,Mr . OKW/Chi employee detached to the Foreign Office Cryptanalytic Section (Pers Z S)  for training

However as historians know one witness is no witness.
Thankfully there are other people who claim that Purple was read.
From ''War Secrets in the Ether'' ,p158
In Eastern Europe the picture was growing less pretty from day to day. To wait, you need time, and in Hitler's case time was getting short. He had to use this chance while the myth of the power of the German armed forces was not yet shaken. Today his credit was unlimited, but no one could tell how it would be in six months.
When it became clear that Japan did not intend under any circumstances to enter the war against the Soviet Union but was looking for a front in another direction, they intimated to Oshima that they were ready to give Japan the solved American and British ciphers and to collaborate in this field in case Japan's declaration of war against the two countries followed at once.
Oshima telegraphed to Tokyo. The telegrams were long and there were many of them. They were intercepted by the German intercept station, deciphered by OKW, and translated in the Foreign Office. What Oshima radioed was known. Also what he received by radio. The message indicators were:
KOSHI and GAIMUDAIJIN (Foreign Ministry)
Moreover, telegrams with the address RIKUGUN TOKYO were not to be despised. Hence it was known how and where to apply pressure. Day and night before Oshima's eyes dangled the bait of the solved ciphers as well as the possibilities of listening in on the radio conversations between Churchill and Roosevelt. "Now or never!", said the Germans, but Oshima said: "First the ciphers! Complete cooperation in the field of cryptanalysis! Declaration of war by Germany and Italy against the United States within a week after the beginning of hostilities in the Pacific!".
It was a hard deal. But it came about. On Germany's part, challenges now began. On 17 October the American destroyer "Kearny" was torpedoed in the Atlantic, shortly after the American destroyer "Greer" had been attacked. On 1 November Hitler's Headquarters issued a sharp official statement referring to a speech by Roosevelt. Goebbels let loose a wild press campaign against Roosevelt. The articles in German papers from 1 November on can only be evaluated correctly in connection with the intention to worsen a situation and to spur Japan to attack.
Further incidents followed. On 9 November Hitler delivered a flaming speech in which he violently attacked Roosevelt, Wilkie, and the United States. German submarines were ordered to display the utmost activity. Japan was to have a good impression. The British carrier "Ark Royal" and the battleship "Malaya" were torpedoed. Collaboration in the field of cryptanalysis got under way. The prerequisite exchange of "information" for the struggle was already established.
On 7 December followed the Japanese attack on Pearl Harbor.
But there is more :
From Leiberich,Otto: Vom diplomatischen Code zur Falltürfunktion. Hundert Jahre Kryptographie in Deutschland. In: Spektrum der Wissenschaft 4/2001, S. 14-16 :
Deutsche Erfolge
Es wäre ein Fehler, aus der Enigma-Katastrophe auf ein generelles Versagen der deutschen Kryptologen zu schließen. Vielmehr haben sie in Einzelfällen Höchstleistungen erbracht, die gleichrangig neben denen der Alliierten stehen, allerdings den Ausgang von Schlachten oder des Krieges nicht beeinflußt haben.
Zwei Erfolge verdienen eine besondere Würdigung: die Entzifferung des Purple-Verfahrens der Japaner und die Entzifferung der amerikanischen Chiffriermaschine M 209.
Während des Krieges hatten die Japaner eine Chiffriermaschine entwickelt und zum Einsatz gebracht, die der amerikanischen Aufklärung größte Probleme bereitete. Da gelang es einer amerikanischen Gruppe um den Kryptologen William Friedman, diese Maschine, die als purple machine bezeichnet wurde, zu rekonstruieren und zu entziffern.
Dies gilt seither in Amerika als der größte Erfolg in der Kryptologie-Geschichte. Angeregt durch eine kürzlich ausgestrahlte Fernsehsendung fragte ich bei einem ehemaligen Kollegen nach, der während des Krieges auf diesem Gebiet tätig gewesen war, und erhielt bestätigt, woran ich bis dahin nur eine ungefähre Erinnerung hatte: Auch die Deutschen hatten die Sendungen der verbündeten Japaner bearbeitet, insbesondere die Meldungen, die der japanische Botschafter Oshima aus Berlin nach Tokio sandte. Einer Gruppe von Kryptologen und Technikern der Chiffrierabteilung des Oberkommandos der Wehrmacht (OKW) unter der Leitung des Mathematikers Erich Hüttenhain war die Entzifferung ebenso gelungen wie den Amerikanern. Hin und wieder war ein Bericht schon entziffert und weitergeleitet, wenn Tokio wegen Übermittlungsfehlern um nochmalige Übersendung bitten mußte. Wenn also die Entzifferung der purple machine der größte Entzifferungserfolg während des Zweiten Weltkrieges gewesen wäre (er war es nicht!), so hätten ihn Hüttenhain und sein Team ebenfalls errungen. Leider existieren in Deutschland hierzu keine Unterlagen mehr.
According to google translate :
German success
It would be a mistake to conclude from the Enigma-disaster on a general failure of the German cryptographers. Rather, they have provided excellence in individual cases that are par with those of the Allies, however, have not influenced the outcome of battles or the war.
Two results deserve special recognition: the deciphering of the Purple process of deciphering the Japanese and American cipher 209th M
During the war the Japanese had developed a cipher machine used and brought that gave the American Enlightenment biggest problems.
Since it succeeded in an American group led by the cryptographer William Friedman, this machine was called the purple machine to reconstruct and decipher.
This has since been in America as the greatest achievement in the history of cryptology. Inspired by a recently aired television show I asked a former colleague who had been active during the war in this area, and received confirmed what I had until then only a vague recollection: The Germans had dealt with the broadcasts of the allied Japanese especially the messages sent by the Japanese Ambassador Oshima in Berlin to Tokyo. A group of cryptographers and technicians of the cipher of the High Command of the Wehrmacht (OKW), headed by the mathematician Erich Hüttenhain was just as successful as the deciphering of the Americans. Now and then a report was already deciphered and forwarded for transmission errors if Tokyo had to ask for repeated transmission. When would therefore have been the deciphering of the largest machine purple Crypto Program during World War II (he was not!), So it would have won Hüttenhain and his team also. Unfortunately there are no records for this purpose in Germany
Although the ’European Axis Signal Intelligence in World War II'' reports  say that the Germans had no success with Purple there is interesting information in vol7 p59:
Goering was of course fulsome in his praises or the FA and has been cited in considerable detail for its history, and accomplishments. He stated  that he did not control the work program of the cryptanalysts and therefore should not ,be expected to know too much technical detail although  he mentions the use of special cipher keys or a change of key when something important was happening. Specific examples recalled by Goering were the ‘’messages of the American minister in Berne’’ and the ‘’Japanese Ambassador in Berlin, reporting home’’.

Finally in TICOM I-25 ‘’Second interrogation of five members of the RLM/Forschungsamt’’ Paetzel ( deputy director of Hauptabteilung  IV ,Entzifferung ) stated that : ‘’ they had broken a Japanese system in ‘41-’42 which was thought to be a machine system though their solution was not mechanical but employed simply paper strips.’’
Taken together all this information points to German success with the Purple machine.The extent  of this  success however is a  mystery.
Did they solve only messages that were sent several times to ensure reception in Japan or could they read all the traffic? Did they only decode messages in the Berlin-Tokyo link or of other embassies too?
If they could read Oshima’s messages did they suspect that the Allies could also decode them?
Unfortunately all we can do right now is speculate.Maybe in the archives of NSA and GCHQ there is an old dusty file that can give us the answers...


In 2013 i managed to contact mr Otto Leiberich and we had a short telephone conversation. Since his article was written a long time ago he didn’t remember all the details but he was able to give me the following information:

1). He did not have any documentary evidence and his statements were based on discussions with his colleagues.

2). Rave said it was a cipher machine and he remembered specific messages.

3). Regarding the years of solution he said probably 1943-44.

4). He had asked Rave why he hadn’t mentioned this success to the American interrogators and he responded that he feared it would be dangerous for him to say too much

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