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Engima encoding machine

Discover the secrets of this famous code maker.

This Enigma machine is of the type used by the German Navy on submarines to encode messages during World War II.

The machine is an electro-mechanical device that relies on a series of ‘rotors’ to scramble plaintext messages into incoherent ciphertext. Similar machines were first made in the early 20th century, and the first ‘Enigma’ was invented by German engineer Arthur Scherbius, who sought to sell it for commercial, rather than military, purposes. 

The Enigma was redesigned and improved several times in the following years, and this particular machine was made in 1944. It uses four code rotors and is housed in a wooden case. With it comes a rare survival, a smaller case containing five interchangeable spare rotors. 

This naval-type machine is the most advanced Enigma machine which was used in World War II, those used by the other military forces only had three rotors, and two spares.

British Intelligence officers working at Bletchley Park near London cracked the Enigma code, initially using methods developed by Polish mathematicians. The messages sent out each day used a different password, and discovering this password permitted the messages to be read. The machines used in the decoding work were called Bombes. They could only solve one problem, so were not really true computers. The pioneering Colossus computers at Bletchley Park were used to decode messages encoded by a different machine, but decades of secrecy delayed the recognition of this work.

The information received from deciphered material was codenamed ULTRA, as the fact that messages could be deciphered had to be closely guarded to prevent the encryption methods being changed. This ability to decipher German military communications is often thought to have helped bring the war to a swifter end.