Russian Cold War Era M-125 Fialka Cipher Machines


Very little information has previously been available about this interesting machine. I have produced a set of hundreds of detailed photographs and descriptions of my Fialkas and their disassembly as well as rotor wiring and rotation advance data for the two different Fialka rotor sets. They may all be viewed in the THE STORY OF THE ENIGMA CD. If you have a fast internet connection, you can see much of this information by selecting the LARGE scrollable picture-filled pages from the following Fialkia Menu. The size of each page is given for each selection. If you have a slow internet connection, you can read the following introduction and click on the pictures and read the descriptions that follow the introduction.



The Fialka is generally similar in design to the German Enigma cipher machine but it has 10 rotors with 30 Russian characters/contacts instead of the 3 or 4 rotors with 26 letters/numbers/contacts in the German WW-2 Enigmas. The first version of the Fialka, the M-100 was produced in the 1930s and it was followed by the M-105 and then the M-125 models described here. The M-125 models include the M-125-MN and the much more complicated M-125-3MN. (M-125-3MP3 and M-125-3MP2 models have also been reported. They appear nearly identical with the M-125-3MN but may have different keyboards.) The codename “FIALKA” is the Russian word for “VIOLET”.

Instead of illuminating light bulbs to display the output characters resulting from inputting characters into the keyboard, the Fialka prints the output characters on paper tape and simultaneously punches holes in the tape in 5 level characters resembling those of a Baudot teletype machine tape. The Fialka also includes a paper tape reader for use in rapidly inputting characters that have been punched into a paper tape.

The Fialka incorporates a card reader which allows punched paper cards to be used to set internal coding parameters. These cards replaced the clumsy, difficult-to-set, and therefore error-prone plugboards of the German Enigmas.

The Fialka rotates each of its 10 rotors in a direction that is opposite to that of each neighboring rotor. Most other cipher machines have rotors that all turn in the same direction. The pins that control the rotation of individual rotors are described and the locations of all pins for all rotors are given in tables in this rotor description link:

The reflector at the left of the rotor stack is different from the reflector in an Enigma and different in each Fialka model. Unlike an Enigma which has a completely self-contained reflector, the reflector in the M-125-MN Fialka has one bundle of wires extending down from it. The reflector in the M-125-3MN / -3MP3 has three bundles of wires coming out of it.

The M-125-3MN and M-125-3MP3 models differ from the M-125-MN models in that they incorporate multi-lingual keyboards and some unique and complex switches that allow the machine to function with several languages.

There are two different sets of 10 rotors that can be inserted into either machine. If present, the second set of rotors may be carried in a cylinder inside the cover of the machines. One set is non-adjustable with fixed ring settings and a fixed wiring maze. The other set is exceptionally cleverly designed in that it allows for both the normal Enigma-like changes in ring settings (the outer lettered ring may be rotated) coupled with the ability to actually remove the internal wiring maze module from each rotor. Once the wiring maze is removed, it may be reinserted into the rotor in any of the 30 possible positions and/or flipped upside down and inserted in any of the 30 positions to give a total of 60 unique wiring circuits. In addition, the wiring maze module itself may be removed from the rotor and inserted into a different rotor.

There are at least two series of rotors. Each series has unique wiring and rotation blocking pin locations. Each series is documented in the links that accompany this publication. One wiring and rotation option is found in the series of rotors with the numerical prefix ‘3K’. At lease some of these rotors are known to have come from Poland. A second wiring and rotation option is found in the series of rotors with the numerical prefix ‘6K’. At least some of these rotors are known to have come from the former Czechoslovakia. It is possible, therefore, that the different series were used in different countries and/or by different military entities. All rotor photographs and wiring data are given in this rotor description link:

The following photographs should help to clarify the comments and descriptions above: Hundreds of additional Fialka photographs, descriptions and wiring and rotation data tables are available in THE STORY OF THE ENIGMA CD and some may be viewed in the links listed in the Fialka Menu at the top of this section. Much higher resolution versions of all of these Fialka photographs are available on a separate Fialka CD.