Status: 9 November 2020
TICOM/ D-83
Summary of Work Done by (the German)
OKH/In 7/VI
(In = Inspektion = Controlling Office)
(OKH = Oberkommando des Heeres; High Command of the German Army)
(OKW = Oberkommando der Wehrmacht; High Command of the German armed Forces (Army, GAF and Navy)
The Germans, long denied in Britain, captured 3 Typex machines (without their according rotors, but with some clue giving documents, during their Campaign against France and the B.E.F. in May - June 1940
Please be aware: that albeit that the Germans had captured three Typex machines during their operation in France 1940,
and considering our transcript, and the sound investigations maintained at OKH/In 7/VI,
that: only by pure coincidence, they discovered much later - that three Typex machines were in their hands, but at OKW/Chi! (Chi = Cipher department)
This report had been found in Austria in 1947.
There were two kind of approaches:
One commenced by personnel engaged at a dedicated "Horchstelle" (dedicated intercept station).
They weren't scientists and after several months surrendered their attempts.
However, now the OKH Inspektion 7/VI, came in.
This service possessed Hollerith punch-card machines; for extensive (also mathematical analysis work).
And with some success.
The work was broken off somewhere late 1941.
AOB: in my perception striking was, for example, the fact that: the Germans somewhere concluded that: apparently one of the rotors is moving the other way around.
Which wasn't actually the case; but their analysis, nevertheless, were correct.
They could not have known what actually had been the case, that:
the order in which, say, the alphabet appears on the drum "tyre" was in reverse to that of the adjacent wheel motion!
Crown Copyright
Typex machine
Actually, its principle was more or less basically equal to the Enigma-machine principle
The German Plug-board was now substituted within the functioning of the wheels VI and V; which therefore did not move during encryption!
This report reflects the technology status of early 1940.
We know that the Germans later might have captured (not unlikely), at their capture of Tobruk 2 Typex machines, on 201/21 June 1942 (by Rommel's DAK);
It isn't truly known whether, these machines had been destroyed in time, or not.
But, in a state of great panic it is not unlikely, that matters went not always according the regulations. British Secret Services bothered with this subject for some time after 1945.
In 2012 it was discovered - that even some relevant files have been blocked for public access, still!
We know, that also the British 8th Army possessed such early models, lacking a real plug-board.
The reading off the Typex rotor-settings through the small-windows equals the starting position, only.
Cryptomuseum.com contribution on the Typex machine subjects
https://www.cryptomuseum.com/crypto/uk/typex/index.htm
Paul Reuvers most kindly provided some photos of the Typex machines in their collection.
To what I understand from a label on it: that one at least once belonged to the Royal Air Force.
Please don't copy it! Cryptomuseum.com
The plug and connectors left and right, once belonged to an additional so-called plug-board provision
Please don't copy it! Cryptomuseum.com
Please consider the plate marked on top with Modified
And consider the slits, which facilitate the manual setting of the code-wheels;
but in contrast to the Enigma operation, the small-windows (holes) showing the setting of the wheels (rotors) which being considered only in case of the so-called
"Indicator" settings, thus before enciphering was started.
The plain text related paper-tapes runs out-off the left-hand side drum, and the encrypted text out-off the right-hand side drum-slit.
Please don't copy it! Cryptomuseum.com
Please notice the facility of small and capital letters; and the other symbols provided
What becomes clear, is, that these kind of messages had been conveyed by means of teletyping (Fernschreiber) machine,
as hardly W/T operators could have coped with the unusual Morse-code symbols (when a substitute would even have existed)
Found in the next TICOM/D-83 report
Amazing also is: that the small letters aren't related to the capital letters.
According to our TICOM document version, the space-bar-key generated always the letter X
as often was also maintained in conjunction to the German Enigma communications.
This aspect being dealt with in our next provided German investigations in: Ticom /D-83
TICOM /D-83 on the Typex coding machine
By Arthur O. Bauer
