U Boat lost ENIGMA

Your Enigma is obviously not a 4-wheel machine. The fourth wheel does not step. the 17576 key presses is irrelevant. What is significant is the 4-wheel M4 had 336 different wheel arrangements (wheel orders) compared with the 60 wheel orders of the 3-wheel Enigma. This made breaking much more difficult and Bombe runs incredibly slow, until the US navy 4 wheel Bombes were brought into service. In practice the basic wheel order was usually obtained from weather code breaks which use a 4-wheel machine set up to operate as a 3-wheel. Once this code was broken, it was only necessary to find the 4th wheel setting, the other settings being identical. M4 keying was also incredibly difficult to break, it used bigram tables,, this was done by Turing.

 

Not true. Rejewski recovered the first 3 wheels from a series of intercepts and a code book given to him by the French. The vital information from the code book was the Stecker settings; without this he would not be able to mathematically recover the entire machine wiring - which he did in as I mentioned previously. The two additional wheels were introduced before WW2. Rejewski quickly recovered these two wirings as the wheel changes were very infrequent. Actually he got one wheel with an error offset (of 1 or two positions) since he was not able to deduct the letter positions on the Ring. Bletchley used these wirings, with the offset error on their Bombes when the wiring was given to GC&CS in July 1939.

Yes, Convoy men were very brave.

geoff

 

Enigma Timeline:

http://www.********.co.uk/key/

 

Every ones wrong, we didn't recover the enigma from a U boat, it was the Americans, it must be true cos I saw it in a factual Hollywood film. Oh, and there never wrong.

 

A nice story but I'm not convinced. Do you have a source for this?
According the Kahn, a cupboard was forced with a gun and keys were found which opened a drawer containing the documents. It's unlikely that a signaller would have access to documents, it would be a captain or senior officer. The Enigma material would include 'Offizier' keys which only senior officers would have access to. And having to endure 288 depth charges in a little over 3 hours, i doubt that the signal man would be thinking of his poetry.

 

good day sadsac,may 15.2009.07:02am.re:u boat lost enigma.there seems to be differents of opinion as to who captured and decoded the secrets of this machine.it was in fact a u.k American effort.to the allies advantage.shorterning the war and saving many lives.the greatest thing that came out of code breaking was nothing,not even good news was made public,it was only told after the war. the code breakers were certainly the silent heroes, great thread,have a good one,bernard85

 

There is no clear thread on the wider aspects of 'Shark', so I will add this here. There are many threads which contain the word.

Bletchley Park Trust has published a podcast (1h 27m), their explanation:

Link: Bletchley Park / E144 - Shark Attack

 

Re #2 Colin Grazier is remembered on the War Memorial in Tamworth Staffs not far from which is the hotel/pub named after him.

Colin Grazier - Wikipedia