Click for homepage
De Beveiliging van Overheidsberichten

1945 - 1970

Author: M.R. (Maarten) Oberman
ISBN: 978-9-4644-8870-8
Released: 2022
Language: Dutch
Layout: 260 pages, full colour, hard cover

This book describes the development of cipher machines in The Netherlands in the post-WWII era, between 1945 and 1970. These machines were developed the author's father, Professor R.M.M. (Roelof) Oberman, at the time one of the leading scientists at the Dr. Neher Laboratory of the Dutch state-owned telecom provider PTT.

During WWII, the Duch Government in exile (in London) became increasingly aware of the need to protect top secret communication. After the war, Oberman was selected to develop a secure cipher machine for the Ministry of Defense and the Foreign Office. The first machine was Colex, a relay-based One-Time Tape cipher machine or mixer, soon followed by a much faster electronic equivalent, Ecolex, that was built with thermionic valves (vacuum tubes). The Ecolex was eventually succeeded by the fully transistorised Ecolex II.

The book describes not only the events that led to the development of the Colex, Ecolex and related equipment, but also the politics behind it. It shows how the national telecom giant PTT gradually lost interest in the crypto market, and how Philips Usfa picked up the pieces and developed new machines in its place. How Oberman left the PTT and became a Professor at the Technical University of Delft (TU Delft), and how many of his former colleagues soon followed.

Staatsgeheim, De Beveiliging van Overheidsberichten (State Secret, Government Communications Security) is unique in that it is the first book to describe the era after the mechanical rotor-based cipher machines and before software-based solutions. The era of the unbreakable One-Time Pad (OTP) and of cipher machines that were based on non-linear feedback shift registers (NLFSR). The book is based on Oberman's personal archive, complemented by documents found in the Dutch National Archives and in the archives of the Dutch General Intelligence Service AIVD, most of which were still classified and have never been seen by the public before.

 Order the book directly from the author

TRIVIA — In 2015, the author – Maarten Oberman – donated the circuit diagrams of the first Dutch OTT cipher machine — Colex — to Crypto Museum, after which we asked him to write a brief biography of his father, Professor R.M.M. (Roelof) Oberman, for our website. But when going through Oberman's personal archive, there appeared to be so many interesting new facts, that a brief biography wouldn't do justice to the man's interesting and secret past. This book is the highly recommended result. — Crypto Museum, 2023
Related subjects on this website
PTT Colex (predecessor of Ecolex)
EROLET, developed by PTT, manufactured by Philips Usfa
Ecolex I, developed by PTT, manufactured by Philips Usfa
Ecolex I Mark 2, developed by PTT, never produced in quantity
Ecolex II, developed by PTT, manufactured by Philips Usfa
Ecolex III (or Ecolex IIB), the synchronised variant of the Ecolex II
Professor Dr. Ir. RMM (Roelof) Oberman
Dutch Post Office (PTT, later: KPN)
Further information
Any links shown in red are currently unavailable. If you like the information on this website, why not make a donation?
Crypto Museum. Created: Friday 17 February 2023. Last changed: Wednesday, 03 April 2024 - 14:25 CET.
Click for homepage