J. F. W. Nuboer and the Reintroduction of Machine Cryptography by the Royal Netherlands Navy, 1915–1940

Abstract

After experimenting with a rotor cipher machine in the first world war, the Dutch Navy resorted to the use of codebooks in combination with various types of cipher disks. During the next ten years, military exercises showed time and again that none of these devices functioned well. In 1931, a careful examination of radio practices of the belligerents by J. W. F. Nuboer led to a tightening of signaling procedures and a revision of the signal book for tactical use. Cipher machines were reintroduced for strategic communication.

Keywords:

• cipher disks
• Dutch Navy
• Dutch Navy Signal Corps
• Enigma G 31
• Hagelin B 21
• interbellum
• J. F. W. Nuboer
• Kryha machine
• signal books

Acknowledgments

I should like to thank David Kahn for his editorial advice and support, Hans van der Meer for giving me a valuable clue about symmetry of position and superimposition, Frode Weierud for pointing to relevant documents in Berlin and Washington, and to Leon Homburg and Paul Reuvers for providing me with Enigma serial numbers and sending me a few pictures.

Notes

¹Memorandum by the Chief of Staff for the Minister of the Navy, September 1922: Marinestaf, inv. nr. 306, pp. 5–6, from The Hague, Nationaal Archief.

²Agenda, 1918, January 30, 31, February 8: Marinestaf, inv.nr. 45, from The Hague, Nationaal Archief.

³Agenda, 1919: Marinestaf, inv. nr. 46, from The Hague, Nationaal Archief.

⁴Ibid.

⁵Agenda, 1920: Marinestaf, inv. nr. 47, from the Hague, Nationaal Archief.

⁶Memorandum by the Chief of Staff for the Minister of the Navy, September 1922: Marinestaf, inv. nr. 306, annex 2, from The Hague, Nationaal Archief.

⁷Agenda, 1921: Marinestaf, inv. nr. 48, from The Hague, Nationaal Archief.

⁸Memorandum by the Chief of Staff for the Minister of the Navy, September 1922: Marinestaf, inv. nr. 306, Annex 2: Considerations by captain-lieutenant Käyser, from The Hague, Nationaal Archief.

⁹Ibid., Annex 3: Considerations by Captain H. Koot, from The Hague, Nationaal Archief.

¹⁰Memorandum by the Chief-of-Staff for the Minister of the Navy, September 1922: Marinestaf, inv. nr. 306, p. 4, from The Hague, Nationaal Archief.

¹¹Agenda, 1923: Marinestaf, inv. nr. 50, from The Hague, Nationaal Archief.

¹²Memorandum by the Chief-of-Staff for the Minister of the Navy, September 1922: Marinestaf, inv. nr. 306, Annex 3: Considerations by Captain H. Koot, from The Hague, Nationaal Archief.

¹³Seinregister voor de Koninklijke Marine, vastgesteld bij ministeriële resolutie van 19 Februari 1926, 114 A geheim. ‘s Gravenhage, Algemeene Landsdrukkerij 1926, from The Hague, Nederlands Instituut voor Militaire Historie.

¹⁴Nuboer, J. F. W., “Het eerste begin van de Verbindingsdienst”: collectie Nuboer, inv. nr. 4.3, p. 13, from The Hague, Nederlands Instituut voor Militaire Historie.

¹⁵An., “De Marine Radio- en Verbindingsdienst van 1928 tot 1940”: collectie Nuboer, inv.nr. 4.3, p. 7, from The Hague, Nederlands Instituut voor Militaire Historie.

¹⁶Nuboer, J. F. W., “Het eerste begin van de Verbindingsdienst”: collectie Nuboer, inv. nr. 4.3, p. 1, 7, from The Hague, Nederlands Instituut voor Militaire Historie.

¹⁷Nuboer, J. F. W., “Lessen uit den Wereldoorlog. Collegediktaat voor de Hoogere Marine Krijgsschool, 1932–1933”: collectie Nuboer, inv. nr. 4.3, from The Hague, Nederlands Instituut voor Militaire Historie.

¹⁸Nuboer, J. F. W., “Het eerste begin van de Verbindingsdienst”: collectie Nuboer, inv. nr. 4.3, pp. 2–6, from The Hague, Nederlands Instituut voor Militaire Historie.

¹⁹Ibid., pp. 2–9, 12.

²⁰Ibid., pp. 2–9, 12, Annex 2: Studie ener Marine-Radio-Organisatie.

²¹Ibid., Annex 2: Studie ener Marine-Radio-Organisatie.

²²Ibid., Annex 3: Memorandum for vice-admiral Quant.

²³Ibid., p. 13.

²⁴Warnsinck to the Chief-of-Staff of the Navy, Amsterdam, 1930, 12 November, No. 1414 R.D., ing. 1930, November 13, Ag. No 24/2/3: Marinestaf, inv. nr. 306, from The Hague, Nationaal Archief.

²⁵Nuboer, J. F. W., “Het eerste begin van de Verbindingsdienst”: collectie Nuboer, inv. nr. 4.3, pp. 13–14, from The Hague, Nederlands Instituut voor Militaire Historie.

²⁶Ibid., Annex 6: Verslag van de bespreking op 2 Juni 1931 tusschen de heeren G. H. Poolman, H. Koot, G. W. Heringa en J. W. F. Nuboer over de cryptografische gebreken in het geheimschrift der Koninklijke Marine.

²⁷Ibid., p. 15.

²⁸Ibid., Annex 6: Verslag van de bespreking op 2 Juni 1931 tusschen de heeren G. H. Poolman, H. Koot, G. W. Heringa en J. W. F. Nuboer over de cryptografische gebreken in het geheimschrift der Koninklijke Marine.

²⁹Memorandum by Henri Koot about a cryptographic watch by D. Maillard, the Hague, 1921, July 29: Buitenlandse Zaken, Kabinet, inv. nr. 106, from The Hague, Nationaal Archief.

³⁰Memorandum by Henri Koot about a transposition method, devised by Mr. Oehme in Berlin, the Hague, 1922, September 22: Buitenlandse Zaken, Kabinet, inv. nr. 106, from The Hague, National Archief.

³¹Koopman to the Chief of Cabinet at the Ministry of Foreign Affairs, Amsterdam, 1924, February 4, exh. 1924, February 5, nr. 484: Buitenlandse Zaken, Kabinet, inv. nr. 106, from The Hague, Nationaal Archief.

³²Kryha to the Dutch ambassador in Berlin, Berlin Charlottenburg, 1929 October 29: Buitenlandse Zaken, Kabinet, inv. nr. 106, from The Hague, Nationaal Archief.

³³Koot to Türkel, 1931, April 25, the Hague (transcript): Code Coördinatie Bureau, box 50, BH 010505, from The Hague, Ministry of the Interior, AIVD.

³⁴Türkel to Koot, 1931, May 30, Vienna (transcript): Code Coördinatie Bureau, box 50, BH 010505, from The Hague, Ministry of the Interior, AIVD.

³⁵An., “Vergleich zwischen der Enigma-Chiffriemaschine und der mechanischen Chiffriermaschine Kryha”: Code Coördinatie Bureau, box 50, BH 010505, from The Hague, Ministry of the Interior, AIVD.

³⁶Chief-of-Staff of the Navy to the Chief-of-Staff of the Navy in Batavia, The Hague, 1932, January 14 (no. 81/1/3), copy: Marinestaf, inv. nr. 306, from The Hague, Nationaal Archief.

³⁷Nuboer, J. F. W., “Het eerste begin van de Verbindingsdienst”: collectie Nuboer, inv. nr. 4.3, p. 15, Annex 8: Enigma chiffreermachines, from The Hague, Nederlands Instituut voor Militaire Historie.

³⁸Nuboer, J. F. W., “Nota betreffende de chiffreermachines Kryha, Enigma en AB-Cryptograph type B 21”: Code Coördinatie Bureau, box 50, BH 010504, from The Hague, Ministry of the Interior, AIVD.

³⁹Ibid.

⁴⁰Voorschrift Geheime Berichtenwisseling 1927 No. 54, from The Hague, Nederlands Instituut voor Militaire Historie.

⁴¹Nuboer, J. F. W., “Nota betreffende de chiffreermachines Kryha, Enigma en AB-Cryptograph type B 21”: Code Coördinatie Bureau, box 50, BH 010504, from the Hague, Ministry of the Interior, AIVD.

⁴²Bestand Rückgabe TICOM, Politisches Archiv des Auswärtigen Amts Berlin, inv. nr. T 1717, from Berlin.

⁴³NARA, NSA Historical Collection, Record Group 457, Box 705, Nr. 1736, CBLH 17, from Washington.

Additional information

Notes on contributors

Karl de Leeuw

Karl de Leeuw has a degree in history from the University of Utrecht and a degree in computer science from the University of Amsterdam. He wrote his PhD thesis about the history of cryptology in the Netherlands and has published extensively about this subject in scholarly journals, such as The Historical Journal (1999), Diplomacy & Statecraft (1999), Intelligence & National Security (2015), and Cryptologia (1993, 1995, 2001, and 2003). In 2007, he acted as principal editor of The History of Information Security. A Comprehensive Handbook.