Page 12–7 Wilson and Sinclair demand action: Andrew, Secret Service, pp. 383–6.
Page 13 Kamenev declared persona non grata: Johnson, Evolution, p. 48.
Page 14 Further press leaks and Krasin to Litvinov: ibid.
Page 15 Frunze complaint and change of ciphers: Christopher Andrew and Oleg Gordievsky, KGB: The Inside Story (Hodder & Stoughton, London, 1990), p. 55.
Page 16 Fetterlein success with new ciphers: Johnson, Evolution, pp. 48–9.
Page 17–8 Sources of telegrams: Denniston, ‘History of GC&CS’, pp. 10–15; ‘History of Military Sigint’, chap. 1 (PRO HW 3/90), 15–17; ‘Historical Notes on Formation of GC&CS’ (PRO HW 3/33), 1–3.
Page 18 Curzon embarrassment: W. F. Clarke, ‘Naval Section of GC&CS’ (PRO HW 3/1), 12.
Page 19 Sinclair appointment and move to Queen’s Gate: ‘Historical Notes on Formation of GC&CS’, 1–3.
Page 20 Curzon ultimatum: Andrew, Secret Service, pp. 417–19.
Page 21 Russian messages deciphered in India: Johnson, Evolution, p. 53.
Page 22 Tiltman career: ibid.; ‘History of Military Sigint’, chap. 1, 9–21; Ralph Erskine and Peter Freeman, ‘Brigadier John Tiltman: One of Britain’s Finest Cryptologists’, Cryptologia, 27 (2003), 289.
Page 23–9 Tiltman recollections of work in India: Tiltman, ‘Some Reminiscences’ (NACP HCC Nr. 4632).
Page 24 Details of Sigint operations in India: ‘History of Military Sigint’, chap. 1 (PRO HW 3/90), 9–21, 12–24; Johnson, Evolution, p. 53; GC&CS (Naval Section) 1919–1941’ (PRO HW 3/1), 5.
Page 25 Change of Soviet ciphers: John Ferris, ‘Whitehall’s Black Chamber: British Cryptology and the Government Code and Cypher School’, Intelligence and National Security, 2(1) (1987), 73–5.
Page 26 Cooper recruitment: J. E. S. Cooper, ‘Personal Notes on GC&CS 1925–39’ (PRO HW 3/83), 1.
Page 27 New sources of Soviet traffic: ibid.
Page 28 Move to Broadway: Denniston, ‘History of GC&CS’, 1.
Page 29 Co–opting of Metropolitan Police unit: H. C. Kenworthy, ‘A Brief History of Events Relating to the Growth of the “Y” Service’ (PRO HW 3/81), 1; C. L. Sinclair Williams, ‘H. C. Kenworthy’ (unpublished). The latter document makes clear that the unit remained in the attic at Scotland Yard until the mid-thirties. Denniston appears to suggest that the police unit was co-opted almost immediately following the SIS takeover of GC&CS (Denniston, ‘History of GC&CS’, 16). But Kenworthy specifically dates the first contact to the 1926 General Strike.
Page 30 £2 million Soviet subsidies to miners: [John Curry], The Security Service 1908–1945: p. 93.
Page 31 Daily Mail transmitter: Kenworthy, ‘A Brief History of Events Relating to the Growth of the “Y” Service’, chap. 1, 1–2.
Page 32–2 ARCOS as base for espionage against Britain: The Security Service 1908–1945, pp. 96–8; Nigel West and Oleg Tsarev, The Crown Jewels: The British Secrets at the Heart of the KGB Archives (HarperCollins, London, 1998), pp. 29–32; Andrew, Secret Service, pp. 463–71.
Page 33 Chamberlain’s acceptance of need to review relations: Chamberlain to Cunliffe-Lister, confidential letter, 19 January 1927, Chamberlain Papers (PRO FO 800/260).
Page 34 Doubts over Cabinet acceptance: Chamberlain to Balfour, private and personal letter, ibid.
Page 35 Tehran and Peking cables and breaking of complete additive tables: Cooper, ‘Personal notes on GC&CS 1925–1939’, 1.
Page 36 Knox beats Maynard Keynes: Penelope Fitzgerald, The Knox Brothers (London, Macmillan, 1977), pp. 187–9; work on Zimmermann Telegram: Johnson, Evolution, p. 38.
Page 37 Knox celebration: Fitzgerald, The Knox Brothers, pp. 187–9.
Page 38 ARCOS raid: Andrew, Secret Service, pp. 469–71. Warning of impending raid: West and Tsarev, Crown Jewels, p. 29.
Page 39 Sequence of events on Government’s revelations of deciphered Soviet telegrams: The Times and the Daily Telegraph, 25–27 May 1927.
Page 40 Change to one-time pad system: Denniston, ‘History of GC&CS’, 6.
Page 41 Brief period during which the old ciphers continued to be used: Ferris, ‘Whitehall’s Black Chamber’, 73–5.
Page 42 Denniston on ‘HMG found it necessary’: Denniston, ‘History of GC&CS’, 6.
Page 43 Tiltman reads Russian OTP: Cooper, ‘Personal Notes on GC&CS 1925–1939’, paras 28, 29.
Page 44 Comintern role: The Security Service 1908–1945, pp. 90–108. See also Jan Valtin, Out of the Night (Fortress Books, London, 1988).
Page 45 First appearance of Comintern transmissions: Kenworthy, ‘A Brief History of Events Relating to the Growth of the “Y” Service’, 5–6.
Page 46 Denniston on ‘successful work on clandestine traffic’: Denniston, ‘History of GC&CS’, 6.
Page 47 Tiltman running of Mask and experience in Soviet wireless and cipher practice: Ralph Erskine and Peter Freeman, ‘Brigadier John Tiltman: One of Britain’s Finest Cryptologists’, Cryptologia, 27 (2003), 289.
Page 48 Denniston on the attack on the Comintern ciphers: Denniston, ‘History of GC&CS’, 6.
Page 49 Make-up of Section V: The Security Service 1908–1945, pp. 103–5.
Page 50–5 Curry on subjects dealt with in the messages: ibid.
Page 51 SIS use of deciphered messages to penetrate Comintern: ibid.
Page 52 Best source within the Comintern was Jonny X (Johann Heinrich de Graf): Michael Smith, Foley: The Spy Who Saved 10,000 Jews (Hodder & Stoughton, London, 1999), pp. 51–61; The Security Service 1908–1945, pp. 103–5.
Page 53 Curry on ‘close and fruitful collaboration’ and value of Jonny X: The Security Service 1908–1945, pp. 103–5.
Page 54 Move to Denmark Hill: Williams, ‘H. C. Kenworthy’. GC&CS accounts of the Metropolitan Police unit normally refer to it as being at Denmark Hill. Sinclair Williams makes clear that it was not until some time in the early 1930s that it moved from Scotland Yard.
Page 55 Direction-finding operation: Kenworthy, ‘A Brief History of Events Relating to the Growth of the “Y” Service’, 5–6.
Page 56 MI5 surveillance operation and names of those involved: The Security Service 1908–1945, pp. 103–5. Curry gives later dates for this operation. He says, for instance, that the station did not begin operating until January 1934. But it is clearly the same operation and the evidence of the GC&CS files on the Mask operation, in particular the index of decrypts in PRO HW 17/80 (Index to Communist Party of Great Britain COMINTERN messages) makes clear that the Wimbledon transmitter was already being intercepted in March 1930.
Page 57 Operation to find Wheeton: Kenworthy, ‘A Brief History of Events Relating to the Growth of the “Y” Service’, 5–6.
Page 58 Co-operation with French: Tiltman memo to Goodall on Col. Bertrand, 29 May 1974 (PRO HW 25/16), 1.
Page 59–8 Mask operation continues until mid-1937: Moscow to Basle message serials: 29–30. April 1937 (PRO HW 17/35).
Pages 60 Mask operation of great importance to GC&CS: Cooper, ‘Personal Notes on GC&CS 1925–1939’, para. 18.
Page 61 For Tiltman work in India, see J. H. Tiltman, ‘Some Reminiscences’, 3; for Simla and Sarafand work on Russian military traffic see Robert Louis Benson and Cecil Phillips, History of Venona (NSA, Fort Meade, 1995), 1:9.
Page 62 Work on OGPU: Naval Section Report for 1930 dated 24.3.31. Annex A, ‘Russian Black Sea Naval Ciphers’, Paper 29 (PRO HW 3/1). The Russian Secret Service went through a number of name changes during the twentieth century, of which OGPU was just one. For ease of understanding, the abbreviation KGB will be used throughout.
Page 63 Clarke unhappy and setting up of naval section: W. F. Clarke, ‘Naval Section of GC&CS’ (PRO HW 3/1), 3–5.
Page 64 Use of Sarafand: ibid.
Page 65 1927 difficulties: Paper 22. Naval Section Report for 1927 dated 6.1.28 (PRO HW 3/1).
Page 66–9 Clarke tour: Naval Section Report for 1928 dated 25.2.29, Paper 27 (PRO HW 3/1).
Page 67 Improv
ement: Naval Section Report for 1929 dated 27.2.30, Paper 28 (PRO HW 3/1).
Page 68 Cooper survey, Titterton returns as Russian interpreter, and concerted effort: Naval Section Report for 1930 dated 24.3.31, Paper 29 (PRO HW 3/1).
Page 69 Cooper’s report of his Sarafand survey on Russian traffic: attached as Annex A to ibid.
Page 70 Titterton departure and lack of success: Denniston memo to Rear-Admiral G. C. Dickens DNI, 20 October 1932, Paper 31b (PRO HW 3/1); ‘W. Bodsworth’s Account of the Naval Section 1927–1939’, Paper 91 (PRO HW3/1), 6.
Page 71 Russian Navy dropped in 1935 because of insufficient staff: ‘Naval Section GC&CS Reorganisation Proposals’ dated 29.6.36. Paper 40 (PRO HW 3/1); ‘Will cryptography be of use in the next war?’ dated 1.9.38, Paper 47 (PRO HW 3/1).
Page 72 Tiltman Army Section: Johnson, Evolution, p. 53; Estonian material: Air Section GC and CS and the Approach to War 1935–1939. ‘Reminiscences of J. E. S. Cooper June 1949’ (PRO HW 3/83), 4–6.
Page 73 Recruitment of P. K. Fetterlein: ibid.
Page 74 Creation of Air Section under Cooper and lack of air messages in the Estonian material: ibid.
Page 75–76 Cooper quotes: ibid., 4–6.
Page 77 Titterton return: Naval Section Standing Orders, September 1937, Paper 43 (PRO HW 3/1).
Page 78 Home Fleet working on Russian naval traffic: papers placed between items 60 and 60a, detailing ciphers monitored by various RN stations and ships (ibid.).
Page 79 Recruitment of Vlasto and another specifically for their Russian skills: Air Section CC&CS and the Approach to War 1935–1939. ‘Reminiscences of J. E. S. Cooper, June 1949’, 11–12.
Page 80 Vlasto details: The Times, 12 September 2000.
Page 81 India break into super-enciphered code: Russian Section Report on Work for 1940 (PRO HW 14/11).
Page 82 Military Section takes over Russian material: Air Section GC&CS and the Approach to War 1935–1939. ‘Reminiscences of J. E. S. Cooper, June 1949’, 22–23.
Page 83 Origins of Station X: Michael Smith, Station X: The Codebreakers of Blettchley Park (Channel 4 Books, London, 1998), p. 20.
Page 84 Number of codebreakers: ‘Personnel at BP’ (PRO HW 3/82).
Page 85 Co-operation with French expanded: Expansion of Anglo–French Cooperation in Naval Work – German, Russian and Italian. Item 10 dated 6 April 1940 (PRO HW 14/4).
Page 86 Russian section at Wavendon: ‘Russian Naval Section at Wavendon (Combined Section)’, handwritten notes (PRO HW 3/151).
Page 87 Russian section at Sarafand: Denniston Minute, Item 35, dated 26 April 1940 (PRO HW 14/4).
Page 88 High-grade military cipher broken during Finnish–Russian War: Russian Section Report on Work for 1940 (PRO HW 14/11); Denniston Minute, Item 35, dated 26 April 1940 (PRO HW 14/4). These breaks were to be the last into any high-grade Russian armed forces traffic for at least another decade. See Benson and Phillips, History of Venona 1:29.
Page 89 Tiltman foresight in arranging deal with Finns: Denniston to Menzies dated 29 April 1940, Item 47 (PRO HW 14/4).
Page 90 Tiltman’s role in breaking Japanese super-enciphered codes and JN-25 in particular: see Michael Smith, The Emperor’s Codes: Bletchley Park and the Breaking of Japan’s Secret Ciphers (Dialogue, London, 2010), pp. 54–60.
Page 91 Details of exchange deal and subsequent difficulties: Tiltman résumé of information obtained during recent tour of Finland, 10 April 1940, Item CC/27 (PRO HW 14/4).
Page 92 Finns provided an increased flow of Russian military and KGB traffic and two Russian Army codebooks: ‘Narrative of Liaison between British and Finnish General Staffs on the subject of cryptography and Wireless Interception’, 16 April 1940, Item 27 (PRO HW 14/4); Denniston to Menzies, 29 April 1940, Item 47 (PRO HW 14/4); Denniston to Menzies 7 July 1940, Item 12 (PRO HW 14/6); Tiltman to CSS 30 May 1941, Item 82 (PRO HW 14/15).
Page 93 Finns’ supply of codebooks: Godfrey to Tiltman, 2 September 1940. Report on the letterwriter’s liaison visit to the Finns, Item 4 (PRO HW 14/7); Russian Section Report on Work for 1940 (PRO HW 14/11). Since Godfrey appears to indicate these were full codebooks, they must have been ‘pinches’, i.e. captured codebooks. Finns’ supply of military and KGB (NKVD) traffic: Benson and Phillips, History of Venona,1:29.
Page 94 Stockholm receivers: ‘Russian Naval Pre-War, 1924–1939’ (PRO HW 3/151), 2.
Page 95 Flowerdown and Scarborough: second page of handwritten notes on ‘Russian Naval’ (ibid.).
Page 96 Vlasto sent to Sarafand: two trained cryptographers for Middle East, 28 May 1940, Item 31 (PRO HW 14/5).
Page 97 India, Sarafand and RAF experiment on Caucasus traffic: Wavell Report on Item 2 of the Agenda for the India Middle East Intelligence Conference held at Cairo, 3–8 April 1940, dated 9 April 1940, Item 38/5/1 (PRO HW 14/4).
Page 98 RAF in Cairo, minute 18 April 1940, Item 8a (PRO HW 14/5).
Page 99 Dingli and Ismailia: extract from CinC Mediterranean Most Secret Letter, 27 April 1940, Item 39 (PRO HW 14/4).
Page 100 Alexandria: Naval Y Service Proposed Expansion, Item 65 (PRO HW 14/6).
Page 101 FECB watch on Vladivostok and Kiel: second page of handwritten notes on ‘Russian Naval’, entry marked ‘GCCS papers’, 10 March 1940.
Page 102 Australian and New Zealand codebreakers: Papers on Visit of Captain F. J. Wylie to Australia and New Zealand (National Australian Archives (Melbourne)) MP1185 2021/5/529, 82–4.
Page 103 French codebreakers: ‘Russian Naval Pre-War, 1924–1939’, 4.
Page 104 Polish operators and codebreakers: Denniston to Menzies. Ref. No. 2572, 5 October 1940, Item 12 (PRO HW 14/7). It is interesting to note, given the minor degree of controversy surrounding the decision that the Poles should concentrate on Russian material, that both these references appear to indicate that it was they who first suggested it.
Page 105 Interception of traffic in Ukraine: Capt. A. C. Stuart Smith to Tiltman, 7 January 1941, Item 17 (PRO HW 14/10).
Page 106 Denniston on importance of Finnish liaison: Denniston to Menzies, 14 January 1941, Item 46 (PRO HW 14/10).
Page 107 Concern over increasing collaboration between the Finnish General Staff and the Germans: letter to General Tadeusz Klimecki re W/T Operators for Soviet military and air interception. Dated 6 June 1941, Item 18 (PRO HW 14/16).
Page 108 Poles asked to reinforce their operation: ibid.
Page 109 Tiltman query: Tiltman to Helsinki MI6 Head of Station, 16 June 1941, item 58 (PRO HW 14/16).
Page 110 According to popular mythology: F. H. Hinsley et al., British Intelligence in the Second World War (HMSO, London, 1979), 1:199. The discretion of the official historian of British wartime intelligence was again in evidence when he stated inaccurately but perhaps at the request of GCHQ that ‘All work on Russian codes and ciphers was stopped from 22 June 1941, the day on which Germany attacked Russia.’
Page 111 Debate over when to stop Russian work: War Diary No. 5 Intelligence School, entry for 28 June 1941 (PRO WO 169/2578); CinC Med to Admiralty, 10 September 1941, Item 42 (PRO HW 14/19); CinC India to War Office, 9 September 1941, Item 46 (PRO HW 14/19); Denniston memo, 30 September 1941, Item 153 (PRO HW 14/19); minute dated 2 October 1941 (PRO HW 14/20); CinC India to WO, 9 September 1941, Item 46 (PRO HW 14/19); War Diary No. 5 Intelligence School, entry for 28 August 1941 (PRO WO 169/2578).
Page 112 Poles asked to continue covering Russian material and watch kept by British sites on known frequencies: Denniston memo, 30 September 1941 (PRO HW 14/19).
Page 113 Resurgence of Soviet illicit traffic: Benson and Phillips, History of Venona 1:30; Jefferson, Petrie-Menzies meeting, and ‘Bundles of Russian traffic’: The Security Service 1908–1945, pp. 358–9.
Page 114 Russian coverage refined: Benson and Phillips, History of Venona 1:30–1.
Page 115 GC&CS secret Russian section: John Croft, ‘Reminiscences of GCHQ and GCB, 1942–45’, Intelligence and National Security, 13(4) (1998), 138–9.
CHAPTER 4
BREAKING AIR FORCE AND ARMY ENIGMA
Ralph Erskine would like to thank Philip Marks, Geoff Sullivan, the late Derek Taunt and Frode Weierud for their comments on Chapter 4.
Page 1 Hut 6’s successes: for a comprehensive account of Hut 6’s work, see ‘The History of Hut 6, Volumes I to III’ (PRO HW 43/70–2).
Page 2 ‘was won, in a very large measure…’: ‘The History of WO “Y” Group’, 109 (PRO HW 41/119).
Page 3 Navy adopted two simple versions: minute, 15 September 1926 (PRO HW 25/6).
Page 4 ‘Practical knowledge of [Wehrmacht] enigma nil’: [D. Knox?], minute, 13 January 1939 (PRO HW 25/12).
Page 5 Figure 4.1: based on a figure in A. Ray Miller, The Cryptographic Mathematics of Enigma (NSA, Fort Meade).
Page 6 ‘a stony silence’, etc.: A. G. Denniston [nd], ‘How News was brought from Warsaw at the end of July 1939’ (PRO HW 25/12); Ralph Erskine, ‘The Poles Reveal their Secrets: Alastair Denniston’s Account of the July 1939 Meeting at Pyry’, Cryptologia, 30 (2006), 294.
Page 7 ‘Mrs B.B.’… ‘had seriously contemplated’: Knox to Denniston, letter [nd, but c. late July 1939, or early August, on Hotel Bristol, Warsaw, note-paper] (PRO HW 25/12).
Page 8 actual punching: A. D. Knox, and others, memorandum, 1 November 1939 (PRO HW 14/2).
Page 9 one third of the time predicted: ibid.
Page 10 contravene Denniston’s orders: Knox, memorandum, 3 December 1939 (PRO HW 25/12).
Page 11 could not solve any Enigma: F. H. Hinsley et al., British Intelligence in the Second World War: Its Influence on Strategy and Operations (HMSO, London, 1988), 3(2):952.
Page 12 rotors IV and V had been incorrect: ‘De Grey’s History of Air Sigint’, 95 (PRO HW 3/95).
Page 13 Denniston asked Menzies: Denniston, letter, 9 January 1940 (PRO HW 14/3).
Page 14 Menzies duly wrote: Menzies, letter, 10 January 1940 (ibid.).
Page 15 on 28 December 1939: Note from X to Y, 28 December 1939 (PRO HW 25/12).
Page 16 Jeffreys sheets: ‘Mathematical theory of ENIGMA machine by A. M. Turing’, 95 (PRO HW 25/3). Gordon Welchman, The Hut Six Story: Breaking the Enigma Codes (Allen Lane, London, 1982), pp. 71–2, errs in describing these sheets as being the same as the Zygalski perforated sheets. However, John Jeffreys was also working on a British version of the Zygalski sheets.
The Bletchley Park Codebreakers Page 50