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Secret Communications 4
2023: 23/24 September, 15 October, 11 November, 2/3 December, 17 December

Following the success of our previous exhibitions Secret Communications 1, 2 and 3the last of which was in 2019 — Crypto Museum and the Foundation for German Communication have once again teamed up and are pleased to announce Secret Communications 4 — to be held in Duivendrecht (Netherlands). Please note that for the first time, there are two weekends in which we will be open on two successive days. This might be particularly useful for foreign visitors. The exclusive exhibition Secret Communications 4 will be open to the general public on these days:

  Day Date  
23 September 2023
24 September 2023
  Sunday 15 October 2023  
  Saturday 11 November 2023  
2 December 2023
3 December 2023
  Sunday 17 December 2023  
On these days, we will be open from 10:00 to 17:00 and admission is free. Furthermore, coffee, tea and sandwiches will be available free of charge. We will be showing an exciting collection of cipher machines and espionage gear, some of which have never been on public display before. Check the overview below to see what we have selected for you. Large groups may apply for a visit outside the regular opening days and times. Contact Crypto Museum to make arrangements.

 What to expect

Main themes
The exhibition will cover the following main themes:

  1. Enigma & Friends
    Enigma is arguably the most famous and well-known cipher machine in the world. We have shown it previously in its many variations, with all kinds of peripherals, as it was used by the German Third Reich during World War II for their secret communication. This year, a new member has been added to the Enigma Family: the extremely rare Enigma G, also known as the Abwehr Enigma — ask for a demonstration.

  2. Operation Rubicon
    In February 2020 it was revealed that the largest civil manufacturer of cryptographic equipment — Crypto AG in Switzerland — was owned by the German intelligence service BND and the American CIA. In 1970 they had secretly purchased the company from its original owner Boris Hagelin, as part of Operation Rubicon. It was used it to spy on more than 130 countries and organisations. In this exhibition we will show many of the original devices that have been backdoored with help from the NSA and others.

  3. Optics
    Apart from radio waves, (invisible) light is an interesting medium for the transmission of speech over several kilometres. During the Cold War, the Stasi of the former DDR used infrared light beams for secret communication with its agents at the other side of the Berlin Wall. In this exhibition we will show and demonstrate a range of light communi­cation devices (German: Lichtsprechgeräte), the oldest of which is from World War II. In addition, a collection of espionage cameras and pinhole lenses from the Cold War era.

  4. Washington-Moscow Hotline
    In 1962, the so-called Cuban Missile Crisis almost led to the outbreak of a nuclear war between America and the former USSR. A year later, in 1963, it was decided to establish a direct line of communication between the two nuclear powers, which became known as the Washington-Moscow Hotline. Contrary to popular believe, this was a not a red telephone, but a teleprinter link with One-Time Tape cipher machines. In this exhibition we will demonstrate the original machines and their teleprinters.
Things to expect
Last updated 12 June 2023

Below is a non-exhaustive overview of the items we will be showing and demonstrating in this exhibition. Further information on each item is available by clicking the corresponding thumbnail image below. This list will be updated regularly so please visit this page again soon.

Enigma I
Naval Enigma M4 (used by the U-Boats or the German Kriegsmarine)
The main Commercial Enigma machine on which all later models were based
Special version of Enigma K for the Swiss Army
Zählwerk Enigma A28, the predecessor of the Enigma G
Smaller version of the Zählwerk ENigma (A28)
Schreibmax printer attachement
Enigma Uhr (also known as UhrBox)
Umkehrwalze D
Swiss NEMA (replacement for Enigma K)
Fialka M-125 cipher machines
Siemens T-52 Geheimschreiber
Operation RUBICON (THESAURUS) - the secret purchase of Crypto AG
M-209 (CX-38)
C-446-A and C-446(RT)
C-52 and accessories
30-character version of the C-52 with Arabic symbols
H-54 pin-wheel cipher machine (CX-52 clone)
CX-52 with removable wheels and irregular stepping
CD-57 pocket cipher machine
H-460, the first electronic Hagelin cipher machine based on shift-registers
HC-520 CRYPTOMATIC portable off-line cipher machine
HC-530 CRYPTOMATIC portable electronic cipher machine
HC-570 CRYPTOMATIC desktop electronic cipher machine
Hagelin CSE-280 voice encryption device
F/T voice scrambler for telephone and HF radio
Hagelin CVX-396 (SVZ-B) voice encryptor
CRM-008 CRYPTOCOM - Voice Crypto Unit
HC-3300 Secure Crypto Phone
HC-4220 Fax Encryptor
HC-2203 PSTN Phone Encryptor
Cryptovox SE-160 secure handheld VHF/UHF radio
Cryptovox SE-660 secure mobile VHF/UHF radio
Key entry device for the HC-3400 CRYPTOVOX embedded encryption unit
Various Hagelin-related items
Gretacoder 905, portable electronic cipher device
Washington-Moscow Hotline
ATCRRM mixer machine used on the Washington-Moscow hotline
Siemens M-190 OTT cipher machine, used on the Washington-Moscow hotline
Infrared transceiver (Lichtsprechgerät) JO-4 developed in the DDR
Infrared transceiver (Lichtsprechgerät) JO-4.02 developed in the DDR
Infrared transceiver (Lichtsprechgerät) JO-4.03 developed in the DDR
Modular infrared transceiver (Lichtsprechgerät) developed in the DDR
GSK with pinhole lens and 2.5x and 2x range extenders
Lens, range extenders and pinhole lens caps
Robot Star 50
ZOLA covert camera
Minox miniature and subminiature cameras
Tochka-58 and Tochka-58M subminiature clockwork cameras used by the KGB (Russian variant of the Minox-A)
Russian Photo Sniper (Foto Snaiper) with 300 mm telephoto lens used by the KGB
Russian Krasnogorsk F-21 spy camera used by the KGB for a variety of applications
Miniature electronic covert surveillance camera
High-volume covert surveillance camera
Commercial rollover camera, also used by the KGB
Click to see more

The exhibition is located at the premises of the Foundation for German Technology — the private museum of Dutch collector Arthur Bauer and his wife Karin — which is located in Duivendrecht, near Amsterdam (Netherlands). Click the map above for Google directions. The address is:

Kloosterstraat 25
1115 BJ Duivendrecht

 Find the museum on Google maps

 Arthur Bauer's museum
 Shadow server (in case the above link doesn't work)

House rules
  • Visitors are required to register upon arrival.
  • You are allowed to take photographs.
  • Please be aware that you may be photographed by others.
  • For your and our safety there will be CCTV cameras in operation. The recorded images will only be used in case of an incident and will otherwise be deleted after the event.
  • Please do not touch any of the exhibited objects unless specifically permitted by our staff.
  • All high-value items will be removed from the exhibition at the end of each day.
  1. Press announcement for websites and magazines (1.6 MB ZIP file)
    Announcement, text and photographs in English and Dutch.
Further information
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© Crypto Museum. Last changed: Wednesday, 13 September 2023 - 14:21 CET.
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