The impact of ‘Tempest’ on Anglo-American communications security and intelligence, 1943–1970

ABSTRACT

This article examines the impact of the discovery by Britain and the United States in the late 1940s/early 1950s that cipher machines produced compromising emissions, a phenomenon which became known as Tempest. The British and Americans were forced to develop security measures to protect their encrypted communications but the Soviet Union was still able to exploit Tempest emissions from cipher machines in Western embassies in Moscow and read their diplomatic traffic. At the same time, Tempest became an important new way for the NSA and GCHQ to gather communications intelligence, particularly from developing world states and NATO allies.

Acknowledgements

The author is grateful to the generous assistance of Professor Michael Goodman, Alan Barnes and the Canadian Foreign Intelligence History Project

Disclosure statement

No potential conflict of interest was reported by the author.

Notes

1. Anderson, Security Engineering, 305–20; and Gehling, Ashley and Griffin, “Electronic Emissions Security,” 305–10.

2. van Eck, “Electromagnetic Radiation from Video Display Units,” 269–86.

3. Aldrich, GCHQ, 173, 215–8; Budiansky, Code Warriors, 199–201; and Sweetman, “TEMPEST and the Bank of England,” 1086–7.

4. National Security Agency, Declassified Documents (NSA), William F. Friedman Collection of Official Papers, https://www.nsa.gov/news-features/declassified-documents/friedman-documents/; NSA, History of the Army Security Agency, https://www.nsa.gov/news-features/declassified-documents/army-security-agency/.

5. Canadian Foreign Intelligence History Project database (CFIHP) https://carleton.ca/csids/canadian-foreign-intelligence-history-project/.

6. NSA, Friedman Collection, A70072, Memorandum Engstrom to Friedman, Attachment: ‘Office of Research and Development Task List’, 16 June 1952.

7. CFIHP, Kevin O’Neil and Ken Hughes, History of the CBNRC, 1987, Volume V, Chapter XXIV, 3; and NSA, Donahue, “Static Magic,” 1–2.

8. Bauer, Secret History, 343; Haslam, Near and Distant Neighbours, 241; and “The Tempest Surrounding Tempest,” Forbes, 10 August 2000, https://www.forbes.com/2000/08/10/mu9.html#3c0f3c5b1004.

9. NSA, Donahue, ‘Static Magic’, 1.

10. CIA Freedom of Information Act Electronic Reading Room (CIA FOIA), Briefing paper on ‘Hostile Exploitation of US Communications and Related Automated Systems’, Annex C Glossary, May 1984.

11. Ibid.

12. National Archives and Records Administration (NARA), ISCAP Releases, A History of U.S. Communications Security (The David. G. Boak Lectures), Tenth Lecture – TEMPEST, July 1973, https://www.archives.gov/files/declassification/iscap/pdf/2009-049-doc1.pdf (Accessed 9 October 2019).

13. Government Attic, www.governmentattic.org, The Achievements of the Signal Security Agency in World War II, Army Security Agency, 20 February 1946.

14. Kahn, The Codebreakers, 394–403.

15. Budiansky, Code Warriors, 199–200; and Sweetman, “TEMPEST and the Bank of England,” 1086–7.

16. Government Attic, The Achievements of the Signal Security Agency in World War II, Army Security Agency, 20 February 1946.

17. NARA, A History of U.S. Communications Security, Tenth Lecture – TEMPEST, July 1973.

18. Ibid.

19. Ibid.

20. Pröse, “Chiffriermaschinen,” 89–91; TICOM Archive, http://www.ticomarchive.com/, Report ‘OKW/Chi Cryptanalytic Research on Enigma, Hagelin and Cipher Teleprinter Machines’, TICOM I-45, 1 August 1945; NSA, Report “European Axis Signal Intelligence in World War II as revealed by “TICOM” Investigations and by other prisoner of war interrogations and captured material, principally German, Volume 2, Notes on German high level cryptography and cryptanalysis,” Army Security Agency, 1 May 1946.

21. Easter, “Protecting Secrets,” 159.

22. Ibid.

23. Ibid.

24. The National Archives (TNA), HW 9/27, CPB (48) 1, ‘Report by the Secretary for the year ended 31st July 1948ʹ, 19 February 1949; CFIHP, O’Neil and Hughes, History of CBNRC, Volume IV, Chapter XIV, 13, Aldrich, GCHQ, 57–8.

25. CFIHP, O’Neil and Hughes, History of CBNRC, Volume V, Chapter XXIV, 3.

26. NSA, Annual Report Army Security Agency, Fiscal Year 1949, Historical Section G-2, 1952; NSA, Friedman Collection, A67163, Memorandum for Director Communications-Electronics, by Earl Stone, Enclosure, 4 November 1950.

27. NSA, Friedman Collection, A43478, Minutes of Army Security Agency Technical Committee Meeting No. 6, Item 47, 2 December 1949.

28. See note 17 above, 1973.

29. Ibid.; CIA FOIA, History of the Office of Communications, Chapter II, Section 2, Organisation and Administration, not dated; Johnson, American Cryptology during the Cold War, 221.

30. Thompson and Harris, The Signal Corps, 610, footnote 15.

31. Ibid.

32. NSA, Summary Annual Report, Army Security Agency and Subordinate Units, Fiscal Year 1949, Historical Section G-2, 1952.

33. Blood, The Three Wars of Lt. Gen. George E. Stratemeyer, 80.

34. CIA FOIA, History of the Office of Communications, Chapter III, Section F, The Headquarters Signal Center, not dated.

35. See note 17 above, 1973.

36. Ibid.; NSA, Friedman Collection, A4045960, Circuit Discussion, not dated.

37. See note 17 above, 1973.

38. Ibid., Fourth Lecture, One-Time Tape Systems, July 1973.

39. Easter, “Protecting Secrets,” 159; CFIHP, O’Neil and Hughes, History of CBNRC, Volume V, Chapter XX, 21.

40. NSA, Friedman Collection, A523031, Memorandum for members of AFSAC by Statler, Enclosure B, 15 February 1954.

41. Johnson, American Cryptology during the Cold War, 215–7, 222.

42. See note 6 above, 1952.

43. Ibid.

44. Aldrich, “Whitehall wiring,” 182; and Easter, “Protecting Secrets,” 158.

45. TNA, CAB 21/4970, Memorandum S(PM)(59) 21, “The Threat from Eavesdropping Devices,” 25 February 1959.

46. TNA, T220/1406, Letter L/192A/0124, Cypher Policy Board to Treasury, 17 December 1952; Letter AB 18 LCESA to Wyatt, 26 October 1959.

47. NSA, Friedman Collection, A522530, U.S Communication Security Equipment and U.K. Cryptographic Equipment, 1953; A44757, Official Report National Security Agency Field Commanders Conference, 28 March to 1 April 1955; CFIHP, O’Neil and Hughes, History of CBNRC, Volume V, Chapter XX, 24.

48. See note 17 above, 1973.

49. NSA, History of the Army Security Agency and Subordinate Units, Fiscal Year 1956, Assistant Chief of Staff, G2, 1958.

50. NSA, History of the United States Army Security Agency and Subordinate Units, Fiscal Year 1957, Assistant Chief of Staff, G2, 1959.

51. See note 17 above, 1973.

52. NSA, “TEMPEST: A Signal Problem,” 28.

53. CFIHP, CSE Documents – Cipher Security Group, 56–07-12 to 57–07-29, Telegram Director NSA to GCHQ, 6 June 1957; CSE Documents – Cipher Security Group, 57–06-14 to 57–07-30, Letter LCSA to Secretary, Cypher Security Group, 17 July 1957.

54. CFIHP, CSE Documents – Cipher Security Group, 56–07-12 to 57–07-29, Telegram Director NSA to GCHQ, 6 June 1957.

55. Johnson, American Cryptology during the Cold War, 221.

56. See note 49 above, 1958.

57. TNA, T220/1406, Letter LCESA to Wyatt, 26 October 1959.

58. Johnson, American Cryptology during the Cold War, 222.

59. NARA, A History of U.S. Communications Security, Tenth Lecture – TEMPEST, July 1973; and Johnson, American Cryptology during the Cold War, 222.

60. Johnson, American Cryptology during the Cold War, 222.

61. Klein, Securing Record Communications, 10–1.

62. TNA, DEFE 59/16, Report by the Defence Cryptographic Committee on “Standardisation of On-Line Cryptographic Equipment,” DSS 23/64 (Final), 26 May 1965.

63. NARA, A History of U.S. Communications Security, Tenth Lecture – TEMPEST, July 1973; NSA. Freidman Collection, A44645, Memorandum Frost to U.S. Communications Security Board, 6 December 1960.

64. See note 17 above, 1973.

65. CFIHP, O’Neil and Hughes, History of CBNRC, Volume V, Chapter XX, 25; NATO Archives Online, https://archives.nato.int/Memorandum SGM-645-56, Sampson to the Chairman, European Communications Security Agency, 14 September 1956; NSA, History of the United States Army Security Agency and Subordinate Units, Fiscal Year 1957, Assistant Chief of Staff, G2, 1959.

66. NSA, Friedman Collection A60669, Memorandum for the Record, Hagelin Negotiations by Friedman, 18 December 1957.

67. NSA, Friedman Collection, A4146578, “List of countries using Hagelin machines,” December 1953.

68. Mainwaring, “Division D,” 627–9.

69. NSA, Friedman Collection A60669, Memorandum for the Record, Hagelin Negotiations by Friedman, 18 December 1957.

70. Aldrich, GCHQ, 216–7.

71. Ibid., 217.

72. Ibid.

73. See note 25 above, 14.

74. Ibid.

75. Aldrich, GCHQ, 217.

76. Johnson, American Cryptology during the Cold War, 221; Emelyanov, Larin and Butyrsky, ‘Prevrashchenie Kriptologii”; Haseltine, The Spy in Moscow Station, 237. Haslam and Easter give the acronym as PEMNI but that is not supported by Emelyanov, Larin and Butyrsky or Haseltine. See Haslam, Near and Distant Neighbours, 241; and Easter, “Protecting Secrets,” 164.

77. Johnson, American Cryptology during the Cold War, 221.

78. TNA, CAB 21/3233, Letter Millar to Brook, 11 February 1959; Minute Brook to Macmillan, 18 February 1959.

79. Easter, “Soviet Bloc and Western Bugging,” 43–4.

80. Ibid., 34–6.

81. History of the Bureau of Diplomatic Security, 178.

82. Emelyanov, Larin and Butyrsky,” Prevrashchenie kriptologii”.

83. NARA, RG 59 State Department Central Decimal File, 1955–59, Box 493, File 116.11/1-59, Letter A-147 Dillon to Moscow, 13 February 1959; Central Foreign Policy File, 1963, Box 3140, File CR 12-3-US-USSR CR 12–3. Telegram 413 Moscow to State Department, 31 July 1963; and Emelyanov, Larin and Butyrsky, ”Prevrashchenie kriptologii”. Translation by author.

84. Haslam, Near and Distant Neighbours, 241.

85. NARA, RG 59 Central Decimal File, 1960–1963, Box 208, File 116.1/1-162, Telegram 678 State Department to Moscow, 28 September 1960.

86. Ibid., File 116.13/1-1460 Memorandum Haines to Dwinell, 3 October 1960; NARA, A History of U.S. Communications Security, Tenth Lecture – TEMPEST, July 1973; CIA FOIA, Memorandum by Executive Officer, 10 March 1961; CIA FOIA, Bell Telephone Laboratories, Final Test Report, Shielded Soundproof Booths, Contact SCC-28,160, 27 April 1961.

87. CIA FOIA, “MK II SECURE ROOM,” not dated.

88. Ibid.; NARA, A History of U.S. Communications Security, Tenth Lecture – TEMPEST, July 1973.

89. FO 366/3359, Brief for Secretary of State’s visit to Moscow, “British Embassy Building, Moscow,” 16 July 1964.

90. Easter, “Soviet Bloc and Western Bugging,” 44–45.

91. History of the Bureau of Diplomatic Security, 176; Foreign Relations of the United States, 1964–1964, Volume XIV, Soviet Union, Document 47, Report by State Department, “Estimate of Damage to U.S. Foreign Policy Interests,” 2 October 1964.

92. NARA, RG 59, Central Foreign Policy Files, 1964–66, Buildings and Grounds, Box 8, File BG Buildings & Grounds, Moscow 11/30/66, Telegram 1985 State Department to Paris, 19 June 1964; Telegram 1996 Paris to State Department, 27 June 1966.

93. Barron, KGB, 10–1.

94. Wright, Spycatcher, 241. Wright implies this was separate from the American Tempest attack on the French Washington embassy discussed below.

95. Fursenko and Naftali, “Soviet Intelligence and the Cuban missile crisis,” 70–1; and Andrew and Mitrokhin, The Mitrokhin Archive, 601.

96. Gale, U.S. Declassified Documents Online, https://www.gale.com/intl/c/us-declassified-documents-online/, Minute for President’s Foreign Intelligence Advisory Board, ‘Secure Room Installations’, 7 January 1966.

97. TNA, FCO 19/86, Minute by Askew, 25 June 1969.

98. CFIHP, O’Neil and Hughes, History of CBNRC, Volume V, Chapter XXII, 4.

99. Ibid.; Easter, “Protecting Secrets,” 160.

100. NARA, RG 84, Classified Central Subject Files, CR 7 Telecommunications, Services 1965, Airgram CA-5269 State Department to various posts, 6 January 1965, https://catalog.archives.gov/id/75583397 (Accessed 10 October 2019); Kahn, The Codebreakers, 714; CFIHP, O’Neil and Hughes, History of CBNRC, Volume V, Chapter XX, 34.

101. Lyndon Johnson Presidential Library, National Security Action Memorandums, NSF, Box 5, NSAM 315: Communications Security Survey, 10/29/1964, Survey of Technical and Physical Security Protection for the Presidency, 30 April 1965.

102. Stafford, Spies Beneath Berlin, 18–32.

103. Aldrich, GCHQ, 172–173; Vogel, Betrayal in Berlin, 210–1; Stockton, Flawed Patriot, 93.

104. Vogel, Betrayal in Berlin, 125–7, 252–3, 277–83.

105. Martin, Wilderness of Mirrors, 72–6, 84–5, 100–1.

106. Stafford, Spies Beneath Berlin, 33–7; and Bayard, Flawed Patriot, 94–5.

107. Murphy, Kondrashev and Bailey, Battleground Berlin, 206–7; and Stafford, Spies Beneath Berlin, 37.

108. NSA, Cryptologic Almanac 50th Anniversary Series, ‘The Berlin Tunnel Part 2: The Rivals’, March-April 2002.

109. Ibid.

110. Ibid.

111. Ibid.

112. Cryptome website, e-mail Dave Emery to John Young, 15 January 2000, https://cryptome.org/tempest-old.htm (Accessed 10 December 2019).

113. Wright, Spycatcher, 81–5.

114. Ibid., 84, 109.

115. Ibid., 113.

116. Ibid., 109–12.

117. Ibid., 114.

118. Ibid.

119. Ibid., 145–8, 241.

120. Ibid., 146, 241; Agee, Inside the Company, 474–8.

121. Agee, Inside the Company, 475.

122. Ibid., 474, 478, 480.

123. Aid, The Secret Sentry, 134.

124. NARA, A History of U.S. Communications Security, Fourth Lecture, One-Time Tape Systems, July 1973.

125. Wright, Spycatcher, 113–4.

126. Bamford, Body of Secrets, 110.

127. Agee, Inside the Company, 350–1, 528.

128. Ibid., 528.

129. Sheymov, Tower of Secrets, 76, 86, 141, 146.

130. Aldrich, GCHQ, 98–99.

131. Budiansky, Code Warriors, 184–188.

132. TNA, CAB 21/4003, Memorandum COMSECA (56) 5, LCSA, 30 July 1956.

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David Easter

Dr David Easter is a Lecturer in the Department of War Studies at Kings College London. His research interests are intelligence, communications security and the Cold War. He is currently writing a book on GCHQ and Britain’s withdrawal from empire.