be built up. Naval Section papers of the barren days of the autumn of 1940 discuss various plans for obtaining keys in this way.
On September 7th Mr. Birch distributed the following document to his sub sections, requesting their comments:
"When talking to Lt. Cdr. Fleming the other day, Mr. Knox put forward the
The Enigma Key for one day might be obtained by asking for it in a bogus signal.
Lt. Cdr. Fleming suggested that the possibilities should be examined and something got ready and kept ready for use in emergency.
Four groups of questions need answering:
1. In the light of our knowledge of German Codes and Cyphers, W/T routine and coding cyphering instructions, what signals could be made for the purpose,
(1) in what code,
(2) on what frequency,
(3) at what hour (s),
(4) from what geographical position accessible to us?
2. Of the various alternative possibilities, in what circumstances would which be most likely to fox the enemy?"
This scheme found little favour and was soon rejected as impracticable but a week later Mr. Birch produced his own plan in a letter to D.N.I. -
I suggest we obtain the loot by the following means
1. Obtain from Air Ministry an air-worthy German bomber (they have some).
2. Pick a tough crew of five, including a pilot, W/T operator and word perfect German speaker. Dress them in German Air Force uniform, add blood and bandages to suit.
3. Crash plane in Channel after making S.O.S. to rescue service in P/L.
4. Once aboard rescue boat, shoot German crew, dump over board, bring rescue boat to English port.
In order to increase the chances of capturing an R. or M. with its richer booty, the crash might be staged in mid-Channel. The German would presumably employ one of this type for the longer and more hazardous journey."
This somewhat ungentlemanly scheme was never put into practice although detailed plans for it were made and it is discussed several times in Naval Section papers.