The Turing Guide

NOTES TO PAGES 74–92 | 491

29. Von Neumann (Note 13).


30. B. Randell, ‘The origins of computer programming’, IEEE Annals of the History of Computing, 16(4)
    (1994), 6–14.


31. Randell (Note 11).


32. Randell (1973).

CHAPTER 9 AT BlETCHlEy PARk (COPElAND)

1. For a detailed account of Turing’s work on Enigma, see my chapter ‘Enigma’ in The Essential Turing.


2. A. P. Mahon, ‘History of Hut 8 to December 1941’, in The Essential Turing, p. 275.


3. For additional information about Rejewski and the Polish work on Enigma, see ‘Enigma’ in The
   Essential Turing.


4. ‘Meeting held on 6th July 1950 to discuss “Bombes” ’, GCHQ, NA HW25/21, p. 1.


5. F. H. Hinsley et al., British Intelligence in the Second World War, Vol. 2, Her Majesty’s Stationery Office
   (1981), p. 29.


6. For a detailed account of Turing’s battle with U-boat Enigma, see Turing (Copeland 2012), Chapter 5.


7. W. L. S. Churchill, The Second World War, Vol. 2: Their Finest Hour, Cassell (1949), p. 529.


8. For information about Seelöwe, see F. H. Hinsley et al., British Intelligence in the Second World War,
   Vol. 1, Her Majesty’s Stationery Office (1979), pp. 186, 188, and Appendix 7, and N. de Grey, ‘1939–
   1940 Sitz and Blitz’ (no date), part of ‘De Grey’s history of Air Sigint’, NA HW3/95, pp. 58–9.


9. Hinsley et al. (Note 8), p. 183.


10. For more information about the early bombes and the attack on Luftwaffe Enigma, see Turing
    (Copeland 2012), pp. 62–9.


11. See Turing (Copeland 2012), pp. 78–80, and Hinsley et al. (Note 5), pp. 422–50.


12. Quoted in Hinsley et al. (Note 5), pp. 448–9.


13. Bletchley Park’s English translation of a crucial Tunny decrypt relating to the Battle of Kursk (a turn-
    ing point of the war in the east) is reproduced in Copeland et al. (2006), pp. 5–6.


14. Here I argue against numerous authors who claim that the work done at Bletchley Park shortened
    the war by at least 2 years; see, for example, F. H. Hinsley, ‘The counterfactual history of no Ultra’,
    Cryptologia, 20 (1996), 308–24.

CHAPTER 10 THE ENIGmA mACHINE (GREENBERG)

1. With thanks to Jack Copeland for his editorial contributions to this chapter.


2. See K. de Leeuw, ‘The Dutch invention of the rotor machine, 1915–1923’, Cryptologia, 28 (2004), 73–94.


3. D. Kahn, Seizing the Enigma, Barnes & Noble Books (1991); C. A. Deavours and L. Kruh, Machine
   Cryptography and Modern Cryptanalysis, Artech (1985).


4. D. Hamer, G. Sullivan, and F. Weierud, ‘Enigma variations: an extended family of machines’
   Cryptologia, 22 (1998), 211–29.


5. R. Erskine and F. Weierud, ‘Naval Enigma: M4 and its rotors’, Cryptologia, 11 (1987), 227–34 (p. 243).


6. Home waters and Mediterranean messages continued to be read in very large numbers during the
   first nine months of 1942, whereas the Atlantic U-boat traffic could not be read during that period.
   This presumably indicates that the replacement of M3 by M4 was limited to the Atlantic U-boat fleet.


7. Some accounts give the call sign simply as MMA.


8. A. P. Mahon, ‘History of Hut 8 to December 1941’, in The Essential Turing.


9. ‘The history of Hut 6’, Vol. 1, p. 87, NA HW43/70.


10. A. P. Mahon, ‘The history of Hut Eight, 1939–1945’ (1945), NA HW25/2, p. 99. A digital facsimile of
    Mahon’s 1945 typescript is available in The Turing Archive for the History of Computing (http://www.
    AlanTuring.net/mahon_hut_8).


11. C. H. O’D. Alexander, ‘Cryptographic history of work on the German naval Enigma’ (c.1945), NA
    HW25/1; a digital facsimile of Alexander’s typescript is available in The Turing Archive for the History
    of Computing (http://www.AlanTuring.net/alexander_naval_enigma).