OMI cryptograph
The OMI cryptograph was a rotor cipher machine produced and marketed by Italian firm Ottica Meccanica Italiana (OMI) in Rome. The machine had seven rotors, including a reflecting rotor. Each rotor could be assembled from two sections with different wiring: one section consisted a "frame" containing ratchet notches, as well as some wiring, while the other section consisted of a "slug" with a separate wiring. The slug section fitted into the frame section, and different slugs and frames could be interchanged with each other to alow a large number of permutations for the key. The stepping of the machine was, however, regular.
The machine was offered for sale during the 1960s[1].
References
- Cipher A. Deavours and Louis Kruh, "Machine Cryptography and Modern Cryptanalysis", Artech House, 1985, pp. 146–147