Neptune (key network)

During the Second World War, Neptune was the German code name for a radio key network of the German Navy . The British code name was Barracuda ( German  " Barrakuda " ). It was intended for the secret communication of the High Command of the Navy (OKM) with the heavy German surface forces operating on the high seas , mainly in the North Atlantic , such as the battleships Gneisenau , Scharnhorst and Tirpitz and the heavy cruisers Prinz Eugen and Admiral Hipper .

history

Typical representation of the Roman sea god Neptune with his trident (sculpture near the castle of Copenhagen )

The " Greek cylinder" located behind the left cylinder window made the Enigma-M4 cryptographically stronger than the Enigma I used by the army .

In October 1941, with a letter from the OKM to the commander of the battleships, the Neptune key tablet was introduced as a new key . The namesake was the Roman sea ​​god Neptune  (picture) .

The key Neptun was only to be used together with the " key M form M4", ie the rotor cipher machine Enigma-M4 (with four rollers). In contrast to the Triton key network , which was introduced almost at the same time on October 5, 1941, the "Vierwalzen-Enigma" was used on the battleships a few months earlier than on the submarines , where it was not in service until February 1, 1942 was asked.

Unlike most other Enigma key networks, the Neptune key network was never broken .

See also

• Key network Medusa
• Key network Triton

literature

• Friedrich L. Bauer : Deciphered Secrets. Methods and maxims of cryptology. 3rd, revised and expanded edition. Springer, Berlin et al. 2000, ISBN 3-540-67931-6 .

Web links

• Scan of a (then) secret letter from the OKM dated October 15, 1941 to the commander of the battleships with an entry stamp dated October 23, 1941, accessed on January 29, 2019.
• Enigma M4 and Neptune in the Crypto Museum , accessed on January 29, 2019.

Individual evidence

1. ↑ Naval Enigma , accessed January 29, 2019.
2. ↑ Scan of a (then) secret letter from the OKM dated October 15, 1941 to the commander of the battleships with receipt stamp of October 23, 1941, accessed on January 29, 2019.
3. ^ Hugh Sebag-Montefiore: Enigma - The battle for the code . Cassell Military Paperbacks, London 2004, ISBN 0-304-36662-5 , p. 225.
4. ↑ Enigma M4 and Neptune in the Crypto Museum (English), accessed on January 29, 2019.