In cryptography , FIALKA (M-125) is the name of a
The machine's rotors are labelled with Cyrillic , requiring 30 points on the rotors; this is in contrast to many comparable Western machines with 26-contact rotors, corresponding to the Latin alphabet . The keyboard, at least in the examples of East German origin, had both Cyrillic and Latin markings. There are at least two versions known to exist, the M-125-MN and the M-125-3MN. The M-125-MN had a typewheel that could handle Latin and Cyrilic letters. The M-125-3MN had separate typewheels for Latin and Cyrilic. The M-125-3MN had three modes, single shift letters, double shift with letters and symbols, and digits only, for use with code books and to superencrypt numeric ciphers.
* 1 Encryption mechanism * 2 Keying material * 3 Comparison with other rotor machines * 4 See also * 5 References * 6 External links
There are two types of rotors:
* disassemblable (zerlegbar) rotors, used with M-125-3MN. Rotorset name is "PROTON." The disassemblable rotors consisted of an insert with electrical contacts and scramble wiring, and an outer ring with mechanical pins whose presence or absence controlled rotor stepping. As part of the key setup, the stepping control pins could be rotated relative to the outer ring. The inner, electrical ring could also be rotated relative to the outer ring and could be inserted in one of two ways, with side 1 or side 2 up. * unitary rotors, used with M-125-MN. These had both electrical contacts and mechanical pins. The only key adjustment was the order of the rotors on the axle and the initial rotor settings. There was one combination for the disassemblable rotors that was compatible with the unitary rotor. One East German manual that has become public contains typed-in and hand written addenda that suggest the East Germans, at least, later stopped using the added features of the disassemblable rotors and only used them in unitary compatibility mode.
Adjacent rotors step in opposite directions. A spare rotor assembly was kept in unit's top cover.
The keying material for the
The message key table contained the initial rotor settings to be used with each message. A message key was never to be used more than once. The keying material was distributed in a foil-covered package, with the daily key tables and punched cards fan-folded in a pouch with perforations between each item. The other tables were in a side pouch.
COMPARISON WITH OTHER ROTOR MACHINES
* M-125 Operation (Nutzung) manual, DV A 040/1/321, December 1978,
National People's Army,
German Democratic Republic