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.