The History of Hut Eight

Seahorse passed only between Berlin and Tokio, different and unbroken keys (Seacow) were used for other Naval Attaches.

A few days were broken and various interesting facts established, notably that the Stecker lasted for 2 days, the wheel order for several days - in fact 10. No great interest was, however evinced by Naval Section and, as bombe time was valuable and throw-on menus not only extravagant but also very bad for the bombes, the key was abandoned. The credit for reviving Seahorse in 1944 goes entirely to OP-20-G who reaped their reward in the great interest shown in the key not only in America but also in Naval Section who came to regret their erstwhile disdainful attitude.

On January 10th 1945 Seahorse, like so many other keys, abandoned the throw-on system and would have been unbreakable on cribs - there were only some 10 messages a day. However, at the time Tokio had run out of keys and back keys were being used in a hatted order, so by breaking the appropriate back days it was possible to continue reading. The arrival of new keys in Japan made little difference as, the keys having passed at one stage through Japanese hands, the Germans were chary of using them and proceeded to combine them with either the Stecker or the wheel order of earlier keys. As a result of this Seahorse continued to be read until the end of the war.


Sunfish was another Far Eastern key carrying information about blockade-runners attempting to return home from Japan and to a lesser extent about outgoing ships. It has the distinction of having remained a 3 wheel key until the end and of having retained the throw-on indicators: the only problem involved in breaking it was a lack of traffic. Its most interesting characteristic was its method of discrimination by lists of pentagrams; the second and penultimate groups of the message were setting indicators, the first and last pentagrams from the Sunfish list.

Sunfish was broken extensively in October 1943 as it was expected to help Japanese book building. A Sunfish flap occurred at the time of the return of the Orsono and Alsterufer and we accomplished some current breaking, though most of the vital information was available in Limpet or Dolphin. Since then a considerable quantity of Sunfish has been broken by OP-20-G. Much of the traffic always consisted of personal (Kameradschaftsdienst) messages to crews of ships in Japan.

To OP-20-G goes the credit for discovering how the Starfish 3 keys worked. Starfish were groups of traffic externally similar to Sunfish but using different discriminants; they were distributed to individual blockade runners. Starfish 3 was built up from the Sunfish keys on a Stichwort principle; the first Starfish break was made in December 1943, and discovery of the Starfish 3 relationship came in March 1944.



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