The M-125, codename Fialka (Russian: ФИАЛКА), was an electromechanical wheel-based cipher machine, developed in the USSR shortly after WWII. It was first introduced in 1956 and soon became one of the favorite machines of the Warsaw Pact and some allied nations, such as Cuba. The machine is similar to the American Sigaba, the KL-7 and — to a lesser extent — the Enigma. For this reason the machine is sometimes called: the Russian Enigma. The original M-125 was succeeded by the M-125-3 in the mid-1960s and remained in use until the early 1990s.
The fall of the Berlin wall in 1989, marked the decline and finally the collapse of the Soviet Union. With the retreat of the Russians from the countries behind the Iron Curtain, the remaining Fialka machines were taken back and have subsequently been dismantled or destroyed.
Each country of the Warsaw Pact had its own customized Fialka version, adapted for the local language. This means that each country had its own keyboard and print head. Furthermore, the wiring of the coding wheels is different for each country. The rest of the machine is identical.
Each country of the Warsaw Pact had its own customized Fialka version, adapted for the local language. This means that each country had its own keyboard and print head. Furthermore, the wiring of the coding wheels is different for each country. The rest of the machine is identical. Fialka M-125-3 with open lid
Most machines were capable of communicating either in Latin or Cyrillic (Russian) writing. Although the Latin alphabet was specific for each country, the Cyrillic alphabet had no punctuation marks and was identical on all machines, making them interoperable when a mutual set of wheels was used. A standard – Russian-only – version also existed.
Ukrainian programmer Vyacheslav Chernov (Чернов) has written a beautiful graphical simulator for Windows TM, that emulates all known Fialka models and countries. It supports the old wheels as well as the later adjustable wheels, and supports different wheel-wirings for the various countries. Furthermore, the wiring cores can be installed, flipped and rotated in any of the other wheels.
For more detailed information on the M-125 visit the Crypto Museum.