Power unit for Cipher machine 'Fialka', with 10 rotors marked with Cyrillic (Russian) characters

A very secret Soviet Union cipher machine, 1958

The Fialka M-125 was a highly secure cipher machine, similar in operation to the German Enigma cipher but without Enigma’s weaknesses. It was developed by the Soviet Union after the Second World War but was not known in the West until after the Cold War.

This powerful machine used mechanical, electric and electronic circuits and moving rotors to encrypt messages.

Introduced in 1956, it was used by the Soviet Union and its allies, such as Cuba, throughout the Cold War.