|
|
|
|
|
|
The M-190 is a cipher machine that is based on the Vernam
principle and belongs therefore to the mixer-class.
It mixes the signal from a clear-text paper tape with a
random number cipher tape.
In the German Army the machine
was often called LOMI after the Lorenz Mixer on which
the M-190 is based.
The picture on the right shows the machine with both the
clear-text tape and the cipher tape present in the machine.
|
|
|
|
|
|
Note the two large lamps (red and green) that are
prominently visible on the control panel. When the
red light was on, transmission was insecure, but when
the green light was on, the cipher system was enabled
and tranmission was safe.
The image on the left shows the entire M-190, aside a Siemens
T-100 (teletype) terminal. Both the clear-text tape and the
cipher tape are loaded into the machine and are clearly
visible. Click any of the images for a close-up.
|
At the exhibition Secret Messages
held in Museum Jan Corver in the Netherlands
between October 2008 and February 2009, we had the opportunity
to connect two M-190 machines together.
This picture shows Louis van Erck (rear) and Marc Simons (front)
each sitting behind a Siemens T-100 and transmitting messages
with an M-190.
|
|
|
|
Like most cipher machines of the mixer-class, the M-190 is not
(and never was) classified. It is the combination of the machine and
a NATO-issued cipher tape, that was classified as NATO SECRET.
Because of the fact that one-time pads (OTP) were used with the M-190,
it is impossible to use the machine to break old intercepts, as all
original OTP-tapes have been destroyed immediately after use.
Not many M-190 machines have survived as most of them were destroyed
in the early 2000s.
|
|
|
