The Bletchley Park Codebreakers
Page 53
Page 4 Poles had given GC&CS a reconstructed Enigma: on the Polish contribution to GC&CS’s Enigma work, see Appendix 30 to F. H. Hinsley et al., British Intelligence in the Second World War, (HMSO, London, 1984) 3(2).
Page 5 Birch and Turing on breaking Enigma: Alexander, ‘Cryptographic History of Work on the German Naval Enigma’, 19; ‘all German codes were unbreakable’: Birch, as quoted in A. P. Mahon, ‘History of Hut Eight’, 14 (PRO HW 25/2).
Page 6 Turing solved: ‘Mathematical theory of ENIGMA machine by A. M. Turing’, 136 (PRO HW 25/3). This version of ‘Prof’s Book’ is much more legible than the poor photostat copy, ‘Turing’s Treatise on the Enigma’ (NACP HCC Nr. 964), which lacks many figures; see also Alexander, ‘Cryptographic History’, 20.
Page 7 little headway: Alexander, ‘Cryptographic History’, 24.
Page 87 rotors, VI and VII were recovered: Hinsley et al., British Intelligence, 3(2): 957.
Page 9 Schiff 26 captures: Ralph Erskine, ‘The First Naval Enigma Decrypts of World War 11’, Cryptologia, 21(1) (1997), 42; Hugh Sebag-Montefiore, Enigma: The Battle for the Codes (Weidenfeld & Nicolson, London, 2000), p. 74. Schiff 26 is erroneously called VP 2623 in Hinsley et al., British Intelligence, 3(2): 959.
Page 10 Rotor VIII was captured: Hinsley et al., British Intelligence, 3(2): 957. For full details of the numerous captures of Enigma material, see Sebag-Montefiore, Enigma, but no one has discovered how rotor VIII was captured.
Page 11 ‘Foss’s day’ etc.: Alexander, ‘Cryptographic History’, 22.
Page 12 diagonal board: see p. 48.
Page 13 not getting ‘fair does’: Birch, 21 December 1940, as quoted in Mahon, ‘History of Hut Eight’, 29.
Page 14 Banburismus: see Alexander, ‘Cryptographic History’, chap, ix; Mahon, ‘History of Hut Eight’, 16. For an outstanding article on Banburismus, see Steven Hosgood ‘All You Ever Wanted to Know About Banburismus but were Afraid to Ask’ (http://tallyho.bc.nu/~steve/banburismus.html (accessed 5 November 2010). For a detailed contemporary account, see ‘Home Waters Enigma’ (NACP RG 38, Radio Intelligence Publications, Box 172, RIP 610).
Page 15 Enigma key-list for February: documents at NHB; on this and related captured documents, see Ralph Erskine, ‘Captured Kriegsmarine Enigma Documents at Bletchley Park’, Cryptologia, 32 (2008), 199.
Page 16 ‘Germet 3’: on this cipher, see ‘German Naval Meteorological Cypher’, Met 65 (NACP HCC Box 187 Nr. 874).
Page 17 broke the DAN meteorological cipher: G. C. McVittie, diary entry for 8 February 1941, with ‘Autobiographical Sketch’ prepared for Royal Society of Edinburgh (RLEW, CCAC).
Page 18 delay of fifty hours: Hinsley et al., British Intelligence, 2: 174.
Page 19 reconstructing … new bigram tables: Alexander, ‘Cryptographic History’, 31.
Page 20 a further two months: ibid.
Page 21 dummy signals … falsified: ibid., 30.
Page 22 unable to solve: ibid., 31.
Page 23 changed every two days: ibid., 5.
Page 24 only officers were permitted: Der Schlüssel M. Allgemeine Bestimmungen (M. Dv. Nr. 32/3), para. 130 (NHB).
Page 25 within thirty-six hours: Hinsley et al., British Intelligence (1979), 1: 338.
Page 26 Werftschlüssel, as well as Enigma: see e.g., identical Werft and Enigma signals in ‘German Reports of British Mining on 29/7/41’, ZG 45 of 31 July 1941 (PRO ADM 223/2). On the Werftschlüssel (M. Dv. Nr. 103) (NHB), see Michael van der Meulen, ‘Werftschlüssel: A German Navy Hand Cipher’, Cryptologia, 19(4) (1995), 349 and 20(1) (1996), 37.
Page 27 Shark … introduced … 5 October: MND signal 27 September 1941 (NACP microfilm T1022/2325). Alexander, ‘Cryptographic History’, 34, suggests that the change occurred on 3 October, but the German signal is very specific.
Page 28 bigram tables … changed: Alexander, ‘Cryptographic History’, 35.
Page 29 tables … captured from Geier: documents at NHB. The tables, but not the Kenngruppenbuch, had also reached Bletchley Park from Donner on 30 December, when they were immediately borrowed by Turing.
Page 30 M4: see Ralph Erskine and Frode Weierud, ‘Naval Enigma: M4 and its Rotors’, Cryptologia, 11 (1987), 235.
Page 31 M4 lid … from U-570: documents at NHB. The lid was from machine M 3172.
Page 32 already solved the wiring: ‘Memorandum No. 3. “Schlüssel M (Form M 4)”’ (NACP RG 38, Radio Intelligence Publications, Box 169, RIP 403); cf. Alexander, ‘Cryptographic History’, 36.
Page 33 only three Shark keys: Alexander, ‘Cryptographic History’, 36.
Page 34–72 referred to the Y Board: DMI, minute, 19 March 1942, ‘Brief for C.I.G.S. on 20.3.42’ (PRO WO 208/5027).
Page 35 Soaring shipping losses: see table in Appendix O in S. W. Roskill, The War at Sea, Vol. II (HMSO, London, 1956).
Page 36 Wetterkurzschlüssel … seized: documents at NHB. For a description of the incident, see Sebag-Montefiore, Enigma, pp. 218–21.
Page 37 Hut 8 believed: McVittie, diary, 2 December 1942.
Page 38 Germet 3 additive tables … were repeated: ‘WW and other crib processes into U-Boat traffic’, nd, but between 12 December 1942 and 11 January 1943 (PRO HW 14/64).
Page 39 begin to be repeated on 8 December: memorandum of 15 December 1942 by RAF Section, ‘Report of Research and Exploitation’ (PRO HW 14/61).
Page 40 ‘hotted up’: McVittie, diary, 2 December 1942.
Page 41 sent a teleprint: ZTPGU 1 (PRO DEFE 3/705).
Page 42 eighty-eight out of the following ninety-nine days: Mahon, ‘History of Hut Eight’, 77.
Page 43 pessimistically advised: as quoted in Rear-Admiral J. H. Edelsten, minute of 9 March 1943 (PRO ADM 205/29).
Page 44 could not build: Alexander, ‘Cryptographic History’, 50.
Page 45 out of the 112: ibid., 49.
Page 46 stretched Allied HF-DF: on shore HF-DF, see Ralph Erskine, ‘Shore High-Frequency Direction-Finding in the Battle of the Atlantic: An Undervalued Intelligence Asset’, The Journal of Intelligence History, 4(2) (2004), 1.
Page 47 proved invaluable: Alexander, ‘Crytographic History’ 50.
Page 48 serious delays: see e.g. PRO ADM 223/OIC SI 641, 648 (weeks ending 19 and 26 July, when Shark had been partially read up to 19 June and 16 July, respectively); also OP-20-GM war diary (NACP RG 38, Crane Library, 5750/176), entries in July and August.
Page 49 British and US Navy … bombes: as to June, Hinsley et al., British Intelligence, 2: 751; as to August, ICY 51, 82 (NACP HCC Box 705, Nr. 1736). An early British four-rotor bombe had been available since April 1943, but for some reason (perhaps a lack of cribs) did not give any results against Shark until June: Alexander, ‘Cryptographic History’, 43.
Page 50 forty-five hours: OP-20-GY-A-1, memorandum, 3 November 1944 (NACP RG 38, Crane Library, 5750/205).
Page 51 Feynman adopted: Richard P. Feynman, Surely You’re Joking, Mr. Feynman (Unwin Hyman, London, 1985, pbk), p. 128.
Page 52 score over 100 tetras: Alexander, ‘Cryptographic History’, 108.
Page 53 Decibans played a vital part: they were also used in breaking Tunny, the Lorenz SZ 40/42 teleprinter cipher attachment.
Page 54 ‘to succeed where it would otherwise have failed’: Alexander, ‘Cryptographic History’, 108.
Page 55 Initially, Hut 8 consisted of: this section is based on ibid., 86–92.
Page 56 ‘… veil of considerable opacity’: ibid., 38.
Page 57 visitor from Hut 6 pointed out: ibid., 39.
Page 58 Süd: Kenngruppenverfahren Süd Januar 1944 (M. Dv. Nr. 608) (PRO ADM 223/331).
Page 59 Alan Turing had written: ‘Mathematical theory of ENIGMA machine by A. M. Turing’, 130.
Page 60 Sunfish … was broken: ‘German Supply Ship [‘Versorgungsschiff’] Traffic’, ZG 240, 19 August 1943 (ADM 223/4).
Page 61 broke Seahorse: ‘War diary of SCHIFF 28, Mar–June’, ZG 244 of 15 September 1943 (PRO ADM 223/4); on breaking Seahorse and the other throw-o
n ciphers, see Ralph Erskine and Philip Marks, ‘Naval Enigma: Seahorse and other Kriegsmarine cipher blunders’, Cryptologia, 28 (2004) 211.
Page 62 broken, ‘[a]fter a certain amount of trouble’: Alexander, ‘Cryptographic History’, 71.
Page 63 Kriegsmarine … fully informed: see Deckblätter Nr. 1-8 ‘Schlüsselanleitung zür Schlüsselmaschine Enigma vom 13.1.40’; cf. Der Schlüssel M Verfahren M Allgemein (M. Dv. Nr. 32/1 – August 1940 edition), para. 140, referring to single encipherment for Heer Enigma.
Page 64 about 460 intercepts each day …: Mahon, ‘History of Hut Eight’, 7.
Page 65 by about one year: Alexander, ‘Cryptographic History’, 9 (although not mentioning HF-DF).
Page 66 twenty-three … stations: ‘The Communication Intelligence Organizations of the British Empire’, 73–6 (NACP RG 38, Radio Intelligence Publications, Box 65, RIP 99).
Page 67 Tina: see ‘Tina, 1946’ (NACP HCC Box CBCB 43 Nr. 901), ‘Tina, 1941’ (ibid., Nr. 902), ‘Tina, 1942–1943’ (ibid., Nr. 903); ‘Rep/Tina Historical Documentation’ (ibid. Box CBKH 68 Nr. 1540); on RFP, see ‘Report on R.F.P. Identifications’, 15 November 1942 (PRO HW 14/58); ‘Sample Oscilligrams – RFP Groups, 1944’ (NACP HCC Box 585 Nr. 1451); ‘RFP Manuals’ (ibid., Box 806 Nr. 2330).
Page 68 seldom do more than distinguish: ‘Report on R.F.P.’, 19 November 1944 (PRO HW 18/89).
Page 69 Ultra: ‘Ultra’ was a short title for ‘special intelligence’: signal of 20 August 1944 (quoted in full in G. E. Colpoys, ‘Admiralty Use of Special Intelligence in Naval Operations’, 43 (PRO ADM 223/88)).
Page 70 all attempts … should be abandoned: minute of 19 November 1944, ‘Summary of R.F.P. Classification of Naval Units during the German War’ (PRO HW 18/89).
Page 71 US Navy RFP gave worse results: minute of 9 March 1944, ‘R.F.P. and Tina Effort on German U-boats’, 9 March 1944, para. 8 (PRO HW 18/89).
Page 72 Mrs Agnes Driscoll: ‘Naval Security Group History to World War II’, 400 (NACP RG 457, SRH 355).
Page 73 exasperated by GC&CS’s failure: Cdr. J.N. Wenger, Cdr. H. T. Engstrom, Lt-Cdr. R. I. Meader, memorandum of 30 May 1944, ‘History of the Bombe Project’, para. 5 (NACP HCC, Box 1414, Nr. 4584).
Page 74 an extensive bombe programme: J. N. Wenger, memorandum of 3 September 1942, endorsed as approved by Admiral Home, the Vice-Chief of Naval Operations (NACP RG 38, Crane Library, 5750/441).
Page 75 Desch … had completed: memo of present plans for an electromechanical bombe, 17 September 1942 (NACP RG 38, Crane Library, 5750/441). The report can be downloaded from http://cryptocellar.web.cern.ch/
cryptocellar/USBombe/desch.pdf.
Page 76 Holden Agreement: PRO HW 3/193, f. 69; on the Agreement, see Ralph Erskine, ‘The Holden Agreement on Naval Sigint: The First BRUSA?’, Intelligence and National Security, 14(2) (1999), 187.
Page 77 British official history errs: see Hinsley et al., British Intelligence, 2: 57.
Page 78 Adam … delivered: serial 003 of 27 May 1943 (NACP RG 38, Crane Library, 5830/116).
Page 79 Neither machine was running well: see e.g., serials 852 of 3 July 1943 (‘Adam out of operation’), 439 of 31 July 1943 (‘Eve still out’) (ibid.); cf. OP-20-GM war diary, 3 June 1943.
Page 80 production models began to be shipped: ibid., 31 August 1943.
Page 81 ‘semi-continuous operation’: ICY 51, 82 (NACP HCC Box 705, Nr. 1736).
Page 82 530 and other USN bombes: ‘Tentative Brief Description of Equipment for Enigma Problems’ (NACP HCC Box 1419, Nr. 4640).
Page 83 ninety-five Navy 530 bombes (and other production figures): ibid.
Page 84 forty-eight and sixty three-rotor runs: as to forty-eight, C. H. O’D. Alexander, minute of 4 November 1943 (PRO HW 14/91); as to sixty, ‘The Standard #530 Bombe’ in ‘Tentative Brief Description of Equipment for Enigma Problems’.
Page 85 down time was about 2.7 per cent, etc.: OP-20-GM-3 war diary, summary for 1–30 April 1944 (NACP RG 38, Crane Library, 5750/159).
Page 86 ‘still poor…’: Alexander to Church, 24 March 1944 (ibid., 5750/441).
Page 87 still attacking old wartime ciphers: OP-20-GE war diary, summary for 1–31 March 1946 (ibid., 5750/159).
Page 88 to tackle an East German version of Enigma: the bombes were indeed used against East German traffic police up to 1955 – Colin Burke ‘From the Archives: The Last Bombe Run, 1955’ (Cryptologia, 32 (2008) 277).
Page 89 about seventy-five bombes in service: OP-20-GM-7 war diary, summary for 1–15 July 1943 (ibid.).
Page 90 four cryptanalysts: Alexander, ‘Cryptographic History’, 73.
Page 91 only five Shark keys: OP-20-GM war diary. Figures for April and May are not available.
Page 92 very apprehensive: see e.g. E. E. Stone, memorandum of 16 September 1943 for director naval communications (NACP RG 38, Crane Library, 5750/225).
Page 93 it agreed to run Hut 6: Alexander, minute of 4 November 1943 (PRO HW 14/91).
Page 94 Travis was pressed: Travis, letter of 31 March 1944 to Colonel Carter Clarke (NACP RG 38, Inactive Stations, Box 55, 3200/2).
Page 95 chided Travis and Redman: Clarke, letter of 4 April 1944 to Travis, memorandum of 4 April to Redman (ibid., 3200/3).
Page 96 about 45 per cent: memorandum of 2 February 1945, ‘Summary of Attack on January Enigma Traffic’, para. 84 (NACP RG 38, Crane Library, 5750/205); 115 bombes: ‘History of OP-20-G-4E’ (NACP HCC Box 1419, Nr. 4640).
Page 97 three-rotor bombes in service: ‘Squadron-Leader Jones’ Section’, 9, 13 (PRO HW 3/164).
Page 98 fifty additional bombes, etc.: Travis, letter, 19 February 1944, as quoted in R R. Kinney, memorandum of 18 November 1944 (NACP RG 38, Crane Library, 5750/205).
Page 99 OP-20-GM recovered: memorandum of 15 July 1944, ‘Brief Resumé of OP-20-G and British Activities vis-à-vis German Machine Ciphers’ (ibid., 5750/205).
Page 100 Stichwort: on this procedure, see p. 333.
Page 101 until mid-November: the first Sonderschlüssel intercept was on 17 November, OP-20-GY-A-1 war diary, 19 November 1944 (NACP RG 38, Crane Library, 5750/176).
Page 102 5,300 bombe hours: ibid., 5 April 1945.
Page 103 three Sonderschlüssel were broken: on 19 and 20 January, and 5 April, 1945 – ibid, for those dates.
Page 104 virtually all operational intelligence: Hinsley et al., British Intelligence, 3(2): 853.
Page 105 ‘one of the most formidable changes’: Alexander, ‘Cryptographic History’, 83.
Page 106 broke about 1,120,000: NS 31 May 45 (PRO HW 14/142).
CHAPTER 12 HUT 8 FROM THE INSIDE
Page 1 Birch was able to write: A. P. Mahon, ‘History of Hut Eight’, 24 (PRO HW 25/2).
CHAPTER 13 BLETCHLEY PARK AND THE BIRTH OF THE VERY SPECIAL RELATIONSHIP
Page 1 series of increasingly exasperated despatches: Geoffrey Stevens, letter, 31 July 1942 (PRO HW 14/47); Stevens, letter, 17 August 1942 (PRO HW 14/49); Stevens, letter, 28 September 1942 (PRO HW 14/53).
Page 2 swagger stick: author’s interview with Cecil Phillips, November 1998.
Page 3 ‘we are entitled to recall’: Alastair Denniston to the Director (personal), 15 November 1940 (PRO HW 14/8).
Page 4 ‘I find myself unable to devise’: Stewart Menzies to Prime Minister, 24 June 1941 (PRO HW 1/6).
Page 5 Safford rejected any exchange: ‘Chronology of Cooperation’ (NACP HCC, Nr. 2738), 2–3.
Page 6 letter to President Roosevelt: Louis Kruh, ‘British–American Cryptanalytic Cooperation and an Unprecedented Admission by Winston Churchill’, Cryptologia, 13 (1989), 126.
Page 7 ‘lots of fun’: Memorandum for Colonel Clarke, 15 June 1943, ‘Army and Navy Comint Regs & Papers’ (NACP HCC, Nr. 4632). The British also broke American naval codes in the interwar years, a fact that did not come out until many decades later; see DENN 1/4, A. G. Denniston Papers, CCAC.
Page 8 had begun in the 1930s: DENN 1/4, 12 (CCAC); F. H. Hinsley and Alan Stripp (eds), Codebreakers: The Inside S
tory of Bletchley Park (OUP, Oxford, 1993), p. 257.
Page 9 supply the needed translators: Report of Technical Mission to England, A. Sinkov and Leo Rosen, 11 April 1941, ‘Army and Navy Comint Regs & Papers’ (NACP HCC, Nr. 4632).
Page 10 Red machine … Purple machine: ‘Chronology of Cooperation’ (NACP HCC, Nr. 2738), 5; ‘Naval Security Group History to World War D’ (NACP RG 457, SRH-355), 8; Report of Technical Mission to England, A. Sinkov and Leo Rosen, 11 April 1941, ‘Army and Navy Comint Regs & Papers’ (NACP HCC, Nr. 4632).
Page 11 British staff officials were astonished: Robert Louis Benson, A History of US Communications Intelligence during World War II (NSA, Fort Meade), p. 17.
Page 12 Army was essentially devoid of knowledge: Monitoring Activities, S. B. Akin to Signal Officer, Eighth Corps Area, 17 October 1939, ‘Intercept/Crypto Correspondence 1927–1941’ (NACP HCC, Nr. 2123).
Page 13 proposed giving to the British: J. O. Mauborgne, memorandum to Assistant Chief of Staff, G-2, 25 October 1940, ‘Chronology of Cooperation’ (NACP HCC, Nr. 2738).
Page 14 ‘Should this expert make a favourable impression’: letter, C/5392, 22 November 1940 (PRO HW 14/45).
Page 15 ‘As proposed’: Stewart Menzies to Prime Minister, C/5906, 26 February 1941 (PRO HW 1/2).
Page 16 handwritten agreement: R. H. Weeks to Commander Denniston, 3 March 1941 (PRO HW 14/45).
Page 17 sent each other recovered code groups: ‘History of GYP-l’ (NACP RG 38 Crane Library, CNSG 5750/202), 21; Benson, US Communications Intelligence, p. 20.
Page 18 At the time of Pearl Harbor: ‘OP-20-GY’ (NACP RG 38 Crane Library, CNSG 5750/198).
Page 19 not permitted to take notes: Briefs for Field Marshal by Colonel Tiltman, ref: General Marshall’s letter to Field Marshal of 23 December 1942, ‘Copies of Letters Between the Field Marshal and General Marshall, etc.’ (PRO HW 14/60).
Page 20 ‘still being copied’: Washington & E. Traffic, Notes on Correspondence, ‘Bombe Correspondence’ (NACP RG 38 Crane Library, CNSG 5750/441).
Page 21 memorandum to ‘C’: Denniston to the Director (personal), 5 August 1941 (PRO HW 14/45).