On February 23, 1918, Arthur Scherbius filed a patent application for a cipher machine based on rotating wired wheels, now known as a rotor machine.
Later, the machine became widely known to the public under the name "Enigma". Its iteration was actively used for conducting private correspondence in commercial activities.
Modified versions of the "Enigma" were later adopted by the German navy and army and played an important role in maintaining the dominance of Nazi Germany's military forces during World War II.
Despite the fact that in 1940 Alan Turing developed the "Turing Bomb" – a device for decrypting "Enigma" messages – both machines were constantly modified, and in the field of cryptography, as well as on the front, a fierce struggle was waged for years.