Schreibende Enigma →
Enigma A →
Printing Enigma machine · 1923
Die Handelsmaschine (the commercial machine, or trade machine) was
a printing cipher machine,
developed in 1923 by Scherbius & Ritter oHG
in Berlin-Wannsee (Germany), and manufactured at
Gewerkschaft Securitas (later: Chiffriermaschinen AG) in Berlin.
It was the first cipher machine to be sold under the Enigma brand.
As far as we currently know, there are no surviving examples of this model.
The machine was succeeded in 1926 by
Die schreibende Enigma (printing Enigma).
The heavy and bulky Handelsmaschine printed its output
directly onto paper, which is why it belongs to the class of the
schreibende Enigma (printing Enigma).
The description below was taken from an
article in a technical magazine of November 1923
by inventor Arthur Scherbius .
The machine had four cipher wheels with 28 electrical contacts
at either side,
and a cog-wheel driven stepping mechanism. Each cog-wheel had a different
number of teeth (using prime numbers and numbers without a common factor)
in order to guarantee a long cipher period and irregular (i.e.
less predictable) stepping .
The four cipher wheels were fitted permanently inside the machine.
Their starting position could be set with four knobs at the right.
By pulling out a knob, the position of the driving (notched)
cog-wheel could also be altered.
A fifth knob at the top was fitted to the main transport axle.
By inserting a crank into this knob (as shown in the image on the right),
the entire cipher mechanism could be moved forward and backward,
allowing for simple typing errors to be corrected easily.
Above the cipher wheels was a 5-digit counter (German: Zählwerk)
that counted the number of characters entered on the keyboard.
The counter was reset with a handle sticking out at the left.
As the cipher operation was not reciprocal (i.e. reversible),
a handle was present at the front of the machine to select
between ciphering, deciphering and plain text.
When switching between ciphering and deciphering, the electric current through
the cipher wheels is reversed, which also reverses the algorithm.
When set to plain text,
the machine can be used as a common typewriter.
At the top of the machine, towards the rear, is the actual printer
which resembles the printing part of a standard electrical typewriter
of the era. It consists of a paper carriage and a wheel printer.
When creating cipher text, the characters were printed in groups
of 5 letters each, after which a space was inserted automatically.
Ten such groups fitted on a single line
(50 characters), and the user had to return the carriage manually
before each new line. When deciphering, spaces would be inserted automatically where appropriate,
so that the text was directly legible again.
The keyboard features letters, numbers and puctuation marks,
and has a spacebar.
A plain text message may consist of a mixture of these elements,
whilst two Shift-keys are used to toggle between letters and figures.
The output, i.e. the cipher text, only consisted of letters however,
as the cipher wheels have just 28 contacts each.
As an added advantage, letters are typically shorter in
morse code than numbers,
which resulted in shorter messages and cheaper telegrams .
The machine featured a complex cog-wheel driven wheel turnover
mechanism with irregular stepping.
Each cipher wheel had a large cog-wheel attached to its right side,
driven by a set of smaller cog-wheels (each with a different
diameter) from which a number of teeth were missing.
According to Scherbius, it had a cipher period of approx. 1 million,
which means that the cipher pattern repeats only after 1 million
characters. About 20,000 of such periods were present.
Part of the wheel turnover mechanism is described
in German patent DE429122
of 26 March 1924 .
So far, we have not found any better images of this Enigma variant.
The pictures shown here were taken from a detailed technical
description of the machine — by Arthur Scherbius himself —
in Elektrotechnische Zeitschrift (Electro-technical Magazine)
of 29 November 1923 .
In 2008 we found this magazine at an antiques shop in Germany.
The full article can be downloaded below.
Die Handelsmaschine – i.e. the first Enigma cipher machine –
was developed and introduced in 1923.
Due to reliability problems with the print wheel mechanism,
development of a new model was started in 1924. The new model
had type-bars (German: Typenhebel) – just like a regular
typewriter – but due to mechanical and manufacturing problems,
its introduction was delayed until 1926. The new machine became known as
Die schreibende Enigma (the printing Enigma).
Due to recurring mechanical problems with
Die schreibende Enigma,
it was decided to develop yet another model that had push-bars
— also known as shift-bars — instead of type-bars. It
was introduced in 1929 and became known as
Enigma Model H29, or simply
(internal designator Ch.14).
In the German Reichswehr (later: Wehrmacht) it was known as
A year after the introduction of Die Handelsmaschine,
the company also released the first portable Glühlampen-maschine (glowlamp machine),
the Enigma A,
which was much smaller, far less heavy
and above all much cheaper. Although the lamp-based machine was technically
far less advanced than the printing variants, it was far more successful
and eventually evolved into the Enigma I
that became the mainstream cipher machine of the German Army during
Over the years, the general understanding of the model names and
designators of the various Enigma machines, has changed several
times. For a long time, it was assumed that the machine described
on this page — i.e. Die Handelsmaschine
— was known as the
Enigma A, but from archived documents it has meanwhile become clear
that Enigma A was the first lamp-based Enigma machine (Glühlampenmaschine) 
It seems likely that the first two printing Enigma machines did not
have a single-letter model name.
Document courtesy Anders Wik .
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© Crypto Museum. Created: Sunday 23 August 2009. Last changed: Sunday, 14 June 2020 - 21:03 CET.