Focus on Cipher Machines

This page focusses on some of the cipher machines that featured as
Image of the Month. The machines, already decribed in detail on other pages of this website, are omitted. Each photo is accompanied by a short description of the machine and web links direct the reader to further information about the machine. You can click the images to enlarge them.

All images are copyrighted and the owners of the images preserve all rights on their image. No use without explicit permission of the owner!

Siemens & Halske T-52 - December 2008
The German Siemens & Halske T-52 Geheimschreiber was an online teletype cipher machine for high-level strategic Luftwaffe (German Airforce) messages in the Second World War. It was one of the most secure German cipher machine. The early T-52a and T-52b versions were less secure. Their traffic was broken by Swedish cryptologists in 1940 and these messages were read throughout the war. The British codebreakers discovered the use of the T-52 in 1942 and codenamed its message traffic STURGEON. Although they succeeded in breaking a small part of STURGEON, they did not achieve the same success as they had with the Enigma and Lorenz machines. The T-52 enciphering was by far the most complex one. However, an important mistake by the Luftwaffe was that their messages were often sent through both T-52 and Enigma. With the Enigma broken on a regular basis, the T-52 traffic became less important and Bletchley Park gave priority to the Enigma traffic.

The T-52 was basically a combination of a Telex machine and a cipher machine. It used ten pinwheels of different sizes of which the output states were XORed with each other in a complex fashion. The output of these logic functions was mixed with the standard five-bit Telex signal of the machine through XORing and swapping of the bits. The early T-52a and T-52b had several security flaws and were less secure. The T-52c had a more complex logic mixing of the pinwheel output and the T-52d incorporated a highly irregular stepping of the wheels, controlled by cams. The T-52e was a combination of the improvements of the T-52c and T-52d, and was a highly secure machine.

Further Information:
Siemens T-52 on Crypto Museum
Technical details on the T-52 at John Savards crypto pages
T-52 software simulation at Frode Weierud's Crypto Cellar
STURGEON page on Jerry Proc's Crypto Machines
Bletchley's breaking of the T-52 traffic on Rutherford Journal

Image copyright Dirk Rijmenants 2009 All rights reserved
Photo taken by Dirk Rijmenants at the Secret Messages exhibition at the Jan Corver Museum, December 2008.

 Dirk Rijmenants

Siemens & Halske T-52 Dirk Rijmenants

SIGABA CCM - January 2009
The American SIGABA was probably the most secure rotor cipher machine during WW2. The SIGABA ECM Mark II (CSP 888/889) had three banks of five rotors each. One set of five rotors was used to encrypt the alphabet. The other two banks of rotors were used to scramble the signals that control the movement of the encryption rotors. The result is a very irregular and complex stepping of the encryption rotors. The SIGABA was a most secure machine and its message traffic has never been broken. It remained in service until the 1950s, when it was replaced by more modern systems such as the KL-7 and on-line ciphering machines.

During WW2 the US and Britain both developed a compatible cipher machine system, based on their own machines. On American side the special SIGABA CCM (Combined Cipher Machine), designated ASAM 5 by the Army and CSP-1700 by the Navy, was equipped with the CSP-1600 Typex compatible rotor cage. This machine was interoperable with the CCM version of the British Typex cipher machine. After the war, the CCM remained in service between The US, Britain and Canada, and later on within NATO.

The SIGABA was a wonderful machine that incorporated the newest developments in the field of cipher machines. Unfortunately all machines were systematically withdrawn and destructed for reasons of security. Only a hand-full most rare ECM Mark II's survived in museums and the special SIGABA CCM version is an even more endangered species. The story of the Famous German Enigma cipher machine is now widely known to the public, but regretfully the SIGABA with its far better cryptographic strength as the Enigma is only known within the world of cryptography.

More information is available on several good websites. On the Pampanito website you can read all about the history of the ECM Mk II. They also published the complete SIGABA manual. More technical details are found on John Savard's website. Jerry proc provides more military information on both the SIGABA ECM Mk II and the CCM version. Finally, you can also read the Cryptologia article on SIGABA.

Further information:
SIGABA op Crypto Museum
SIGABA on the USS Pampanito website
SIGABA operating instruction on Historic Naval Ships Association
Technical details on the SIGABA at John Savard's crypto pages
The SIGABA ECM Mk II on Jerry Proc's Cryto Machines
The SIGABA CCM on Jerry Proc's Crypto Machines
The ECM Mk II on Cryptologia

Image copyright Dirk Rijmenants 2009 All rights reserved
Photo taken by Dirk Rijmenants at the Secret Messages exhibition at the Jan Corver Museum, Januari 2009.

 Dirk Rijmenants

SIGABA CCM Dirk Rijmenants

US M-209 B Converter - March 2009
The photo shows a Converter M-209-B, manufactured by L.C. Smith-Corona Typewriters. In 1940, the US military selected the Hagelin C-38 as tactical ciphering device and designated it as M-209. The US Navy designated it CSP-1500. It was a lunchbox sized - highly portable - cipher machine with a simple and compact but ingenious design. By the end of the Second World War over 140,000 of these small M-209 machines were produced in the US. The M-209 is a typical pin-and-lug cipher machine with six relatively prime sized pin wheels, a drum with 27 sliding bars and a letter-dial/print-drum with reciprocal alphabet. Although the M-209 was not very secure, the easy to use and small machine was ideal for use in tactical circumstances where the content of the messages was no longer of importance after a few hours.

Further information:
The US M-209 B on Mark Blair's Crypto Pages, including a C++ M-209 simulation
Bob Lord's M-209 pages, including the manual and a training film
The M-209 on Crypto Museum
Description and Instruction manual of theCSP-1500 on the USS Pampanito website
The M-209 on Crypto Machines
M-209 Simulator for Windows

Image Copyright Mark J. Blair (NF6X) 2009 All rights reserved.
Photo taken by Mark J. Blair, February 18, 2009

 Mark J Blair

M-209 B - Mark J Blair

ETCRRM One-time Tape Mixer - April 2009
The ETCRRM (Electronic Teleprinter Cryptographic Regenerative Repeater Mixer) from the Norwegian company STK (Standard Telefon og Kabelfabrik A/S) applied one-time encryption on a standard commercial teleprinter. The ETCRRM mixed the five-bit Telex output signal with a one-time tape by XOR-ing both signals. An identical setup on the receiver's end, with an identical key tape stream, reversed the enciphering process. The one-time tapes or key tapes were truly random five-bit values. As long as there are only two copies of a one-time tape, these tapes are used only once and they are destroyed after use, the messages that are sent by this systems are mathematically unbreakable. The ETCRRM used tubes, relays and diodes to implement the logic XOR functions. A solenoid and ratchet system, the only mechanical parts in the machine, advanced the key tape.

The ETCRRM was used for high level military communications in several countries. ETCRRM's were also used on the Washington/Moscow Hot-line. Two were installed in Washington and two in Moscow. Although a system with absolute security, the unclassified standard teleprinters and ETCRRM's were sold by commercial firms and therefore did not disclose any secret crypto technology to the Soviets. Only the key tapes were considered secret crypto material. The Hotline was a full duplex teleprinter circuit, and not a so called 'Red Phone', as it was believed that spontaneous verbal communications could lead to miscommunications and misperceptions.

Further information:
ETCRRM on Jerry Proc's Crypto Machines
ETCRRM on Crypto Museum
The Washington - Moscow Hotline on Electrospaces
The Washington - Moscow Hotline on Crypto Machines

Image Copyright Jerry Proc 2009 All rights reserved
Photo by Jerry Proc, taken at the Communications and Electronics Museum in Kingston Ontario Canada

 Jerry Proc

ETCRRM - Jerry Proc

KWR-37 Fleet Broadcast Receiver - May 2009
The KWR-37 "JASON" was the receiver part of the KW-37 crypto system, developed by the NSA In the 1950s. The systems consisted of a KWT-37 transmitter and a KWR-37 receiver. It was used to secure fleet broadcasts of the US Navy. The shore station transmitted 24 hours a day a continuous stream of encrypted random data. If a message had to be sent to one of the ships, the encrypted message was inserted into the continuous stream. An enemy eavesdropper could not detect if or how many message were sent, when they started or ended, or how long they were. Therefore, the KW-37 system made traffic analysis by the adversary impossible. The output of the receiver was connected to a teletype machine that immediately printed the decrypted stream onto paper. Transmitter and receiver maintained synchronisation whole day. If synchronisation was lost, the receiving operator could re-established synchro by re-setting and running very fast through all past key stream until the KWR-37 could pick up the current stream again.

The KWR-37 was a marvel of miniaturisation in the 1950s. It contained approximately 500 miniature vacuum tubes for a large number of flip-flops and logic functions, required for the shift registers that generated the pseudo-random enciphering stream. The key of the KWR-37 was an IBM style punch card that was changed daily, just before the new synchro at midnight. The machine remained in service until the early 1990s.

Further Information:
The KWR-37 JASON Broadcast Receiver on Jerry Proc's Crypto Machines
The KWT-37 Transmitter on Crypto Machines

Image copyright Jerry Proc 2009 All rights reserved
Photo by Jerry Proc, taken at the Communications and Electronics Museum in Kingston Ontario Canada

 Jerry Proc

KWR-37 JASON - Jerry Proc

FIALKA M-125 - June 2009
The Russian FIALKA M-125 is the most famous Soviet cipher machine of the Cold War era. In 1965, the Cyrillic version was introduced in the Soviet Army, and later on, versions with Czech, Polish and (East) German keyboard layout entered service in the Warsaw Pact. The FIALKA was operational until at least the 1990s and according to some sources even still in use today. Therefore, the FIALKA and its specifications were top secret until the late 1990s. The image shows the M-125-3MP2 version with Czech keyboard.

Although based on the WW2 German Enigma machine, Russian cryptologists were well aware of the security flaws of the Enigma and incorporated solutions to all of those flaws into this wonderful piece of mechanics. The small machine, only 10.8 by 12.5 inches and 8.3 inches high, is with its impressive mechanism the Swiss watch of the electro-mechanical cipher machines. The Fialka has 10 interchangeable, alternately counter-rotating rotors with 30 wirings each. Pins on each rotor mechanically control the irregular and most complex stepping of the rotors. The disassemblable internal wirings core of each rotor can be rotated, extracted and mirrored, or exchanged with other wirings. Several different types of rotor sets were produced. The plugboard, as used on the Enigma, is replaced by a punched card reader, and an electronic 3-point circuit in the reflector solves Enigma's flaw that a letter can never be encrypted into itself. The output is printed on a paper ribbon or punched on a five-bit paper tape, and the machine is also equipped with a paper tape reader.

Further Information:
FIALKA on Cryptomuseum with detailed information, a reference manual and FIALKA simulators.
Tom Perera's FIALKA page with many images of the machine and its interior.
FIALKA manual on the SASundChiffrierdienst website including keying and message procedures (German).

Image copyright Dirk Rijmenants 2009 All rights reserved.
Photo taken by Dirk Rijmenants at the Secret Messages exhibition at the Jan Corver Museum, Januari 2009.

 Dirk Rijmenants

FIALKA M-125 Dirk Rijmenants

TSEC/KL-7 - September 2009
The TSEC/KL-7, codenamed ADONIS or POLLUX, is an off-line rotor cipher machine that was developed in the late 1940s by the American National Security Agency (NSA) as a successor of the SIGABA. The machine entered service in 1952. ADONIS and POLLUX were two different encryption procedures for the KL-7. The American ADONIS procedure applied an encrypted message key to preset the initial startposition of the rotors, whereas the ‘export version’ POLLUX procedure used far less secure non-encrypted message keys. The KL-7 was compromised by John Walker who sold technical information and key lists to the Soviets. The KL-7 was used by the US and many of its Allies and retired in 1983.

Output of the KL-7 was printed on a paper ribbon and some versions had a paper puncher for 5-bit code output. The KL-7 has eight rotors (the fourth from the left was stationary) with 36 contacts each. During its service time, the rotors were recalled and re-wired regularly. The rotors are placed in a rotor basket, called KLK-7 which can be removed from the machine base KLB-7. Each rotor is placed in a plastic outer ring with cams. Microswitches, controlled by these cams, engage electro-magnets which in turn step the rotors. This resulted in a highly irregular stepping of the rotors. The 26 inputs and outputs of the rotor basket are used to encrypt the letters. The 10 remaining inputs and outputs are looped back through the rotors, resulting in a very complex signal path for the 26 letters. The machine was non-reciprocal. This was achieved by a sliding permutor board underneath the keyboard which swapped all input and output contacts of the rotor encryption. The exact rotor and stepping unit wiring remains classified. Today, all publicly availably machines, such as this machine from the Royal Dutch Signals Museum, are carefully sanitized and stripped of any wiring, related to the rotors and stepping unit.

Further Information:
TSEC/KL-7 Technical Detalis and History on this website
TSEC/KL-7 Simulator on this website
KL-7 page on Paul Reuvers' Crypto Museum with superb detailed photos and additional information.
KL-7 on Crypto Machines with historical and technical information and several images.
Hagelin's patent showing the loop-back of rotor wiring.

Image copyright Paul Reuvers 2009 All rights reserved.
Photo taken by Paul Reuvers at the Royal Dutch Signals Museum, 2009.

  Paul Reuvers - All rights reserved

TSEC/KL-7 Paul Reuvers