we’re responsible to Admiralty. We know the cribs and the odds on them and we believe in them and it's horrible to have no hold, no say, no nothing, on the use that is made of them or the way they are worked ......."
This letter has great value as a reflection of the relationship of Hut 8 with the outside world and of the cryptographic organization for breaking Enigma; the fact that the letter misinterprets the true position tends to show Mr. Birch at a disadvantage but it would be most unfair to look at it in this light as anyone must know who has read the early Naval Section Documents and has seen the efforts which Mr. Birch extended to further any work which might in any way assist Hut 8.
First of all the letter demonstrates clearly Turing's almost total inability to make himself understood. Nearly all Mr. Birch's suggestions, as is immediately obvious to anyone with actual experience of Hut 8 work, are impossible and are simply the result of not understanding the problem - his 100,000 answers (had the bombe been able to run the job, which it couldn't have done) would have taken 5 men about 8 months to test. Such problems as this and the disadvantages of the other suggestions should clearly have been explained but Turing was a lamentable explainer and, as Mr. Birch rightly says, not a good practical man: it was for these reasons that he left Hut 8 when the research work was done and the back of the problem broken. The lack of satisfactory liaison was a great disadvantage in early days but was fortunately most completely overcome later; in a letter to myself of May 16th, 1945, Mr. Birch speaks truly of "two independent entities so closely, continuously, and cordially united as our two Sections."
The second point of interest in the letter is the assumption that cribbing and all to do with it was the business of Naval Section and something quite separate from the mathematical work, classed as cryptography and belonging to Hut 8. This concept prevailed until 1941 when Hut 8 set up a Crib Room of its own. No one now would maintain that it would be feasible to separate cribbing from cryptography in this way: to be a good cribster it was essential to understand fully the working of the machine and the problems of Banburismus, bombe management, etc. On the other hand it remained highly valuable to us that Naval Section were always crib conscious and would send over suggestions for us to explore.
The view frequently expressed by Hut 8 was that a successful pinch of a month's keys with all appurtenances (such as bigram tables) offered the best chance of our being able to get into a position where regular breaking would be possible as in the course of that month crib records and modern statistics could