The OMI cryptograph was a
rotor cipher machine
In cryptography, a rotor machine is an electro-mechanical stream cipher device used for encrypting and decrypting messages. Rotor machines were the cryptographic state-of-the-art for much of the 20th century; they were in widespread use in the 19 ...
produced and sold by
Italian
Italian(s) may refer to:
* Anything of, from, or related to the people of Italy over the centuries
** Italians, an ethnic group or simply a citizen of the Italian Republic or Italian Kingdom
** Italian language, a Romance language
*** Regional Ita ...
firm
Ottico Meccanica Italiana
Ottica Meccanica Italiana (OMI) was an Italian company producing photogrammetric instruments. It was founded in Rome
, established_title = Founded
, established_date = 753 BC
, founder = King Romulus (legendary)
, image ...
(OMI) in
Rome
, established_title = Founded
, established_date = 753 BC
, founder = King Romulus (legendary)
, image_map = Map of comune of Rome (metropolitan city of Capital Rome, region Lazio, Italy).svg
, map_caption ...
.
The machine had seven rotors, including a reflecting rotor. The rotors stepped regularly. Each rotor could be assembled from two sections with different wiring: one section consisted of 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. As a consequence, there were many permutations for the rotor selection.
The machine was offered for sale during the 1960s.
References
* Cipher A. Deavours and Louis Kruh, "Machine Cryptography and Modern Cryptanalysis", Artech House, 1985, pp. 146–147
*
F. L. Bauer, ''Decrypted Secrets'', 2nd edition, Springer-Verlag, 2000, , pp. 112,136.
{{Cryptography navbox , machines
Cryptographic hardware
Rotor machines