The Bletchley Park Codebreakers (62 page)

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).

Page
1
Birch was able to write: A. P. Mahon, ‘History of Hut Eight’, 24 (PRO HW 25/2).

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 Story 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).

Page
22
‘a little uneasy’: Memorandum to Commander Denniston, 5 August 1941 (ibid.).

Page
23
cleared the matter up: Washington & E. Traffic, Notes on Correspondence, ‘Bombe Correspondence’; Memorandum for Director of Naval Communications, Subj: History of the Bombe Project, ‘Captain Wenger Memorandum’ (NACP HCC, Nr. 4419), 1–2.

Page
24
‘No results are being passed out’: CSS to Washington, CXG 105–109, 1 December 1941 (PRO HW 14/45).

Page
25
Denniston … at once sent a message: personal from Denniston for Washington, CXG 139, 23 December 1941 (PRO HW 3/33).

Page
26
all sixteen bombes that were available: ‘Squadron Leader Jones’ Section’ (PRO HW 3/164), 4.

Page
27
Tiltman cabled to London: Travis from Tiltman, [18 (?) April 1942],
‘Bombe Correspondence’ (NACP RG 38 Crane Library, CNSG 5750/441).

Page
28
Travis informed OP-20-G: for OP-20-G from GC&CS, 13 May 1942, ‘Bombe Correspondence’.

Page
29
were concealing the fact: J. N. Wenger, Memorandum for OP-20-GM, Subject: Recent information on ‘E’, 6 August 1942, ‘Bombe Correspondence’.

Page
30
to build 360 four-wheel bombes: Memorandum for OP-20, Subject: Cryptanalysis of the German (Enigma) Cipher Machine, 3 September 1942, ‘Bombe Correspondence’; Wenger to GC&CS for Eachus, 4 September 1942, ‘Bombe Correspondence’.

Page
31
tried to head off the American move: Memorandum for Director of Naval Communications, Subj: History of the Bombe Project, ‘Captain Wenger Memorandum’ (NACP HCC, Nr. 4419), 4.

Page
32
only had about thirty bombes: ‘Squadron Leader Jones’ Section’, 4.

Page
33
overloaded the available bombes: Hut 6 Report of July and August 1942 (PRO HW 14/51).

Page
34
‘most alarming’: Memorandum, 5 January 1943 (PRO HW 14/63).

Page
35
negotiated an agreement: Ralph Erskine, ‘The Holden Agreement on Naval Sigint: The First BRUSA?’,
Intelligence and National Security
, 14(2) (1999), 187.

Page
36
GC&CS memorandum in late 1942: memorandum, 21 December 1942 (PRO HW 14/62).

Page
37
Army was proposing to build its own machine: William Friedman, memorandum for Colonel Bullock
THRU
Colonel Minckler, Subject: Project in the Cryptanalysis of German Military Traffic in their High-Grade Cipher Machine, 14 September 1942, ‘Project 68003’ (NACP HCC, Nr. 3815).

Page
38
$530,000 contract: ‘Project X68003-Army Bombe’ (NACP HCC, Nr. 2723).

Page
39
Turing went to Dayton: visit to National Cash Register Corporation of Dayton, Ohio, ‘Bombe Correspondence’ (NACP RG 38 Crane Library, CNSG 5750/441), 3.

Page
40
Arlington Hall received permission: Frank W. Bullock, Memorandum for File, 4 January 1943, ‘Project 68003’ (NACP HCC, Nr. 3815).

Page
41
‘had better get together’: author’s interview with Dale Marston, September 1998.

Page
42
Turing was shown the actual prototype: Major C. G. Stevens, Report on Visit to Bell Laboratories, ‘Project 68003’ (NACP HCC, Nr. 3815).

Page
43
Tiltman tactfully responded: William F. Friedman, Memorandum for Colonel Corderman, 8 February 1943, ‘GCHQ/US Cooperation’ (NACP HCC, Nr. 2820), 2.

Page
44
OP-20-G was involved in solving Enigma keys by hand: ‘OP-20GM-6/GM-1-C-3/GM-1/GE-1/GY-A-1 Daily War Diary’ (NACP RG 38 Crane Library,
CNSG 5750/176).

Page
45
internal GC&CS memorandum: ‘Co-operation with US & Allocation of Tasks on “E” signals’, 8 January 1943 (PRO HW 14/63).

Page
46
followed up with additional pressure: Taylor to Clarke, 5 April 1943, ‘Army and Navy Comint Regs & Papers’.

Page
47
more acerbic internal memoranda: ‘Briefly stated the reasons why the British are averse to the Americans exploiting the intercepted German signals encyphered on their machine’, 4 May 1943 (PRO HW 14/75).

Page
48
Taylor advised: Taylor to Clarke, 5 April 1943, ‘Army and Navy Comint Regs & Papers’, 6–7.

Page
49
‘never on God’s green earth’: Scope of E Operation – other than Personnel, excerpt from Cable V4772, 13 May 1943, ‘Col. McCormack Trip to London, May–June 1943’ (NACP HCC, Nr. 3600).

Page
50
Gordon Welchman urged moderation: Welchman to Travis, ‘The Americans and “E”’ (PRO HW 14/68).

Page
51
BRUSA Agreement: memorandum for Assistant Chief of Staff, G-2, ‘Special cryptanalytic Project in SIS ETOUSA, Project Beechnut’ (NACP HCC, Nr. 3049); the full text of the BRUSA agreement has also been published in ‘The BRUSA Agreement of May 17, 1943’,
Cryptologia
, 21 (1997), 30.

Page
52
Telford Taylor to select decrypts: Benson,
US Communications Intelligence
, p. 111.

Page
53
summary of State Department cables: memorandum for Colonel Clarke, 15 June 1943, ‘Army and Navy Comint Regs & Papers’ (NACP HCC, Nr. 4632).

Page
54
British were equally suspicious: signal. To Corderman from Fried from Bicher, 1 November 1944, ‘Clark Files’ (NACP HCC, Nr. 4566); Report IB 32164, ‘Clark Files’ (NACP HCC, Nr. 4566), 15.

Page
55
behind a plywood partition: author’s interview with Cecil Phillips, November 1998; Stephen Budiansky, ‘A Tribute to Cecil Phillips – and Arlington Hall’s “Meritocracy”’,
Cryptologia
23 (1999), 97.

Page
56
on 24 March 1944 GC&CS cabled: memorandum for Director of Naval Communications, 30 May 1944, ‘History of the Bombe Project’ (NACP HCC, Nr. 4584), 10.

Page
57
‘dudbusting’: C. H. O’D. Alexander, Dud-busting, ‘Capt. Walter J. Fried Reports/SSA Liaison With GCCS’ (NACP HCC, Nr. 2612).

Page
58
nearly automatic system for decryption: Stephen Budiansky, ‘Codebreaking with IBM Machines in World War II,
Cryptologia
, 25 (2001), 241.