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← Crypto ← Mehano News →
Alphabet substitution cipher
Barbie 1 Typewriter, is a series of electronic typewriters,
developed around 1998 by Mehano in Slovenia
(ex-Yugoslavia) as a childeren's toy.
It was sold worldwide by Mattel (US).
The E-118 is the latest model in the product
line that started with the E-115.
The electronic typewriter was the successor to the
earlier purely mechanical Barbie typewriter models.
It is little known that most electronic variants
have a hidden built-in cryptographic capability
that allows secret writing. 2
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Although the E-118 is bascially identical to the earlier models, the
exterior has changed quite a bit over the years, probably to appeal more to
young girls.
Furthermore, the interior (especially the PCB) has been simplified
several times in order to cut on production cost. Wilst the earlier models
were all made at the Mehano factory in Slovenia, the latest one is
assembled in China.
The E-118 consists of a plastic body with a 49-button keyboard, a plastic
carriage that accepts common paper sheets, and a daisy wheel printer.
It is aimed at children of 5 years and older.
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Wilst the earlier models allowed the machine to be operated on internal
batteries or an external mains power supply unit (PSU), the battery
compartment was omitted from the later E-117 and E-118 models.
The first model was E-115 which was initially sold directly by
manufacturer Mehano.
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The image on the right shows the initial electronic Mehano typewriter
on which all later electronic Barbie typewriters are based. The original
version can be recognised by the typical grey colour of the case and the
blue-ish knobs.
Apart from a range of typesetting features, such as letter-spacing
and underline, this children's toy was capable of
encoding and decoding secret messages,
using one of 4 built-in cipher modes. These modes were
activated by entering a special key sequence on the keyboard,
and was explained only in the original documentation.
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When the E-115 was adopted by Mattel as an addition to the Barbie™
product line, it was aimed mainly at girls with a minimum age of 5 years.
For this reason the product was given a pink-and-purple case and the
Barbie logo and image were printed on the body. As it was probably thought that
secret writing would not appeal to girls, the coding/decoding facilities
were omitted from the manual. Nevertheless, these facilities can still
be accessed if you know how to activate them.
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Barbie is a registered trademark of Mattel (USA).
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Note that encryption is not available on the earlier mechanical typewriters.
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Below is an overview of all electronic Barbie Typewriter models that are
currently known. In all models, a
simple daisy wheel printer is used,
consisting of plastic parts, two solenoids and a motor.
The electronics are on a small PCB at the center of the unit.
In order save on production costs, the microcontroller was directly bonded
to the PCB in the later models.
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All electronic Barbie typewriters are based on the initial Mehano E-115 model
that was sold directly by Mehano in 1998. This early variant can be recognised
by its grey case
as shown above. The image on the right shows the Barbie-version
of this typewriter with its typical colours.
This version contains the first revision of the electronics (revision A),
which consists of a well designed PCB
with all components on one side, including a
24-pin microcontroller which logo of the Swiss company EM Microelectronic.
It is a customised part with a 4-bit microcontroller [5].
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Although we have seen at least one E115 that has the hidden encryption
capability, we have received reports from readers, that it might not be
available on all E115 models and language variants. It would be great if
owners of an E115 could confirm this feature.
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So far we have not seen the Barbie-variant of the E-116, so we are
showing the Mehano-variant instead. It is very similar to the E-115
and has the same case layout. The battery compartment of the
E-115 is still present, but can no longer be used as its contacts
are missing completely.
The image on the right shows the French version of the E-116,
on which the crypto features are not available. It is currently
unknown whether these features can be unlocked on this version.
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Although this version looks different from the one above, it is basically
the same machine in a different case. In order to cut costs, the
EM microcontroller is now
bonded directly to the solder side of the PCB.
It is visible as a black 'blob' which can not be replaced.
The PCB still shows the tracks that were used for a microcontroller
in SMD/QFP packaging,` that could be fitted instead of the direct bonded one.
This was probably used in an earlier model (E-116?) or was provided to
allow regular chips to be used in case of shortages of bare ones.
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This is the latest model that is still being sold today (2015).
The design is largely unchanged from the previous one, although
the case has been given a more modern shape.
In order to reduce costs even further, the units are now built
in China and the PCB has received another makeover,
probably in order to use cheaper components.
The quality of the PCB is visibly
lower than with the earlier models. The PCB is now only suitable
for a directly bonded microcontroller and several
language variants
are known.
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Although there are many different models and country variants of the Barbie
typewriters, and the internal PCB was redesigned a number of times,
the encryption/decryption facilities seem to be present on all
electronic models. The crypto facilities can be accessed by pressing
SHIFT and LOCK in combination with one of the highlighted keys
in the diagram below.
As the keyboard layout can be different for each country, please use the
black numbers as a reference.
The encryption facilities of the Barbie Typewriter consist of a
mono alphabet substitution cipher, also known as MASC,
with 4 different keys
(i.e. 4 different transposed alphabets) which we will call KEY 1 thru 4.
When coding a message, the desired KEY is selected with the first 4
buttons on the top row of the keyboard.
Note that the black numbers are shown here for clarity only.
They are not printed on the keyboard.
To start coding, three keys have to be pressed simultaneously:
Once the KEY has been selected, the plaintext message can be entered
on the keyboard and the ciphertext message will appear on the paper.
The paper may now be sent to the recipient by means of regular mail
other otherwise. The recipient should now select the appropriate KEY
for decoding by using the corresponding key combination shown below:
Once the KEY for decoding has been selected, the recipient should
enter the ciphertext message on the keyboard and, if all goes well,
the original plaintext message will appear on the paper.
In order to return to normal use of the typewriter,
use the following key combination:
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For different countries in the worlds, different variants of the typewriters
were made. In some cases, this only affected the layout of the keyboard and
the printing wheel. In any case, Barbie/Mehano typewriters were made with
English, German and French keyboard layouts.
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On the foreign version of the E-118, not only the layout of the keyboard was
different, but also the firmware. This means that the instructions for
coding and decoding (see above), might not be correct for every language variant.
German collector karsten Hansky [4] has found a French version of the
E-118, which is shown in the image on the right. Although the crypto features
were not present on the French variant of the earlier E-116, they are
available on this one. Note however that to turn on the first encryption mode,
the user needs to press Shift + Lock + 1, and not the leftmost key as suggested.
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Furthermore, Karsten confirms that text written on the French variant, can not
be decoded on, say, a British variant. The machines are therefore not compatible.
A copy of the French operating instructions is available below. In this manual,
the cryptographic capabilities are not discussed.
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The tables below show the alphabet subsitution tables for each of the four
encryption modes of the British version of the E117B, which
has a QWERTY keyboard layout. Many thanks to Karsten Hansky for supplying the
tables below and the photograph
of the British keyboard layout
[4].
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The microcontroller inside the E-118 typewriter, is made by
EM Microelectronic-Marin SA, also known as
EM Microelectronic or EMM —
a developer and manufacturer of semiconductor components
based in Marin near Neuchâtel (Switzerland).
The company is specialized in the
design and production of ultra low-power and low-voltage integrated circuits
for battery-operated and field-powered applications in the consumer, automotive
and industrial market. EM Microelectronic-Marin SA has subsidaries in the
US (EM Microelectronic-US Inc.) and also in the Czech Republic (ASICentrum),
and is itself a subsidary of The Swatch Group [6].
➤ Wikipedia
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© Crypto Museum. Created: Thursday 09 July 2015. Last changed: Wednesday, 07 August 2024 - 06:40 CET.
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![The original Mehano E-115 typewriter. Photograph copyright Georg Sommeregger [2].](../img/mehano_e115.jpg)
![Photograph by Karsten Hansky [4]](../img/mehano_e116.jpg)
![EM Microelectronic logo. Obtained via Wikipedia [6].](img/EMM_logo.png){kind=logo}
