Cipher Machines Timeline Deze pagina in het Nederlands


On this timeline you can follow the development of cipher machines. The machines are presented with a brief description, some history and a few links to more pictures or detailed information. This is not a complete list! There were many more cipher machines, but this timeline gives a good view of the development of these machines in the 20th century. I have omitted the on-line cipher equipment because these were mostly devices that encrypt signals rather than messages. On the
Focus page you can also view some cipher machines that were previously featured as Image of the Month. Any complementary information or links are most welcome by e-mail. If you have found one of these cipher machines, please contact me!



The M-94 (CSP-448) was a cryptographic device, used by the United States Army, consisting of 25 aluminium discs, arranged as a cylinder on an axle. Each letter disc had a scrambled alphabet. A message was encrypted by turning the discs until all plain text was arranged on one line. Another line of the disc was then read off and sent as cipher text. The order of the different discs was the actual secret key. Although the M-94 provided a low level of security it was good enough for tactical purposes. It remained in service until 1943. [1] [2] [3]



The Hebern machine, invented by Edward Hugh Hebern, was the first of a cipher machine class called rotor machines with one or more rotors, containing scrambled wiring. The scrambled wiring had the effect of a substitution cipher. The most important difference with the simple substitution was that the rotor turned on each depressing of a key. Although the machine never became a commercial success due to the limited cryptographic strength it did lay the foundations for many future rotor cipher machines. [1] [2] [3]



The German Kryha was a fully mechanical cipher machine with two alphabet discs of which the inner disc stepped a variable number of places. There was also a larger electrical version. The Kryha was used by the German Diplomatic Corps and Marconi England. [1] [2] [3] [4]



Arvid Damm developed the A-21, which was commercialised by A.B. Cryptograph (the successor of Hagelin Cryptos). It uses a revolving drum with 26 alphabet strips that can be attached in any order. The 26 alphabets together are a scrambled vigenére square with alphabets in reversed order. For each encrypted letter the drum stepped one alphabet strip further. A normal reference alphabet is mounted in front of the drum and a chain with low and high links controlled the position of the reference alphabet above one of the two visible scrambled alphabet strips on the drum.[1]



Enigma B
Already in 1918 the German engineer Arthur Scherbius applied for a patent on a machine he called Enigma. The machine used three stepping rotors, similar to the principle of the Hebern machine. In 1923 his company presented their first commercial models, the typewriter versions Enigma A and B. The invention of the reflector and using lamps instead of the heavy typewriter made it possible to develop the compact Enigma C. [1]



In 1925 Boris Hagelin developed the B-21, his first cipher machine. It used two rotors in a 5 by 5 grid system and pins on the rotors to control the stepping. The unique design of pinwheels would become popular in many of Hagelin's successors. [1] [2] [3] The B-21 was revised to B-211 in 1932 [4]
  The German Navy adopts the Enigma and named it Enigma Funkschlussel C.



Enigma D
The Enigma D replaced the Enigma C and was commercialized in different versions and sold all over the world. Switzerland bought the Enigma K, Italy and Spain used the Enigma D and Japan the Enigma T or Tirpiz Enigma. All of them were broken by several Intelligence Agencies. [1] [2]



Enigma G
The German Abwher (Secret Service) started using the Enigma G (Zahlwerk Enigma), a securer version with a gearbox to drive the rotors. The Wehrmacht adopted the Enigma D and revises it to Enigma I in 1932. This version is the first to use the plugboard which increases the key space enormously. It is this version that would become famous as the German wartime cipher machine, however in 1932 the Polish Cipher Bureau broke into the Enigma message traffic. Their knowledge was turned over to British and French cryptologists prior to the invasion of Poland. [1] [2] [3]



On request of the French Cipher Bureau Hagelin developed the portable C35. This was the first real pin-and-lug type ciphermachine. Five pinwheels, each with another number of pins, controlled sliding bars on a revolving drum. This drum is used as gearwheel with a variable number of teeth, driving a reciprocal alphabet. The machine output was printed on a paper ribbon. [1] [2]




The Siemens & HalskeT-52, codenamed STURGEON by British cryptologists, was the first important German high level teleprinter cipher machine. It had 10 pinwheels that stepped in a very complex way. Contacts that were controlled by the wheels were XORed with the teletype output. [1] [2] [3]


The M-325, codename SIGFOY, was designed by William Friedman. By 1944 it was extensively used by the US Foreign Services. [1] [2]

The Hagelin C36 was very similar to C-35 but had a protective casing and another distribution of the lugs on the drum. A later model had two movable lugs per drum bar. [1] [2] [3]



The British TYPEX was an adapted version of the Enigma with several important improvements. The increased security and complexity meant that the message traffic of this machine never was broken, unlike the German Enigma. An estimated 12,000 Typex machines were used in the UK, Canada and New Zealand until the 1970's. [1] [2]



The Hagelin C38, another version of the C-36, came on the market. [1] [2]

Another Hagelin C-38 variant was the BC-543 which incorporated a keyboard and both cipher and plaintext output [1]




PURPLE (97-shiki O-bun In-ji-ki) was a Japanese cipher machine, used by their Diplomatic Services. Both British and US cryptologists had already broken the PURPLE message traffic before the attack on Pearl Harbor. [1] [2]


The Polish Cipher Bureau developed the Lacida, also called LCD. It was a rotor cipher machine. Although similar to the German Enigma it had some major security flaws such as the lack of a plugboard, the reflector design and the wiring. [1]
  In 1939 the German Kriegsmarine took over the Wehrmacht Enigma model, designated it M3, and extended the set of rotors from five to eight.




The ECM Mark II, codename SIGABA, was the most important American rotor cipher machine for high level communications. The SIGABA had three banks of five rotors each. The first bank were the main rotors to encipher the alphabet. The second bank of rotors scrambled four signals into one to six signals. The third bank of rotors scrambled these signals and used them to advance the main encryption rotors in a very complex pseudorandom fashion. The SIGABA traffic is never been broken and the machine remained in use until the 1950's. [1] [2] [3] [4] [5]


The German Lorenz SZ-40, codenamed TUNNY by British cryptologists, had 12 pinwheels and was similar in design to the STURGEON. TUNNY was also used for high level German communications. It was broken by British cryptologists and they developed the first electronic digital computer ever, the top secret Colossus, to automate the breaking of the TUNNY messages. The Colossus was so secret that for many years the world believed that the American ENIAC was the first digital computer. [1] [2] [Colossus]


Hagelin succeeds in selling the C-38 to the United States Armed Forces. They produced a licensed version, designated M-209, in large quantities as low level tactical cipher machine. Approximately 140,000 M-209's were produced. [1] [2] [3] [4] [Simulator]



Schlusselgeraet 41 or SG-41 was the last cipher machine that was developed by Germany during WW2. Its encryption principles were clearly based on the pin-and-lug machines of Hagelin, with some changes to improve its security. German crypto experts wanted to replace the Enigma machine by the SG-41, but by then tens of thousands of Enigma's were already in service. By the end of the war only about 500 of these SG-41 were produced. [1]



Enigma M4
In 1942 the German Kriegsmarine introduced the notorious Enigma M4. The M4 had four instead of three rotors, but the fourth rotor could not step since the stepping mechanism was identical to the three-rotor version. After an initial ten months blackout the British codebreakers in Bletchley Park succeeded in breaking into the M4 message traffic, codename SHARK, thanks to cryptanalysis of the fourth rotor and the capturing of codebooks and weather codes that were used as cribs. [1] [2] [Simulator]
  JADE was the codename, given by the US, to a Japanese cipher machines that was used by the Imperial Japanese Navy from 1942 to 1944. It was used to encipher messages in katakana, using an alphabet of fifty characters. [1]



The SIGCUM or M-228 was developed by the US as attachment for a teleprinter. The system produced a pseudorandom sequence of five bits which were XORed with the teleprinter signal. To produce the sequence the SIGCUM used a bank of five rotors with 26 contacts each. Thirteen of the inputs passed through the rotors to be scrambled and result in a five-signal output. The rotors stepped just like an odometer, but which rotor was the fast one, and which the slower ones was controlled by switches. Once in service the machine showed some cryptographic flaws and was withdrawn immediately. After some revisions it was brought back into service until the 1960's. [1]



To enable communications between the Allied Forces in WW2 and later NATO, the US developed the CCM, Combined Cipher Machine. Adaptors were developed to make the CCM interoperable with both the US SIGABA and the British TYPEX. There are reports about security problems with the encryption system used and that some rotor combinations had dangerously short cycle periods. CCM proved to be a very expensive program. [1] [2]



In 1941, after the commercial Enigma was broken, Swiss mathematicians started working on a new and more secure design. In 1944 the first prototypes were ready and in 1947 the NEMA or Neue Machine (new machine) came into service. Although basically very similar to the Enigma, the NEMA had ten rotors, of which four were wired to scramble the signals and one was used as reflector. The other five rotors were used to control the stepping of these rotors. [1] [2] [3]



The BID/60 SINGLET is a British machine, used by the Intelligence services. The similarity in technical details suggests that this machine was related to the American KL-7 which went into service in 1952. [1]

The Portex BID/50/1 was mainly used by the British Secret Service [1]



In 1952 the American National Security Agency introduced the KL-7 ADONIS, also known as POLLUX, as replacement for the SIGABA. The machine was developed in the late 1940's. 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 had eight rotors of which the fourth rotor from the left didn't move. The other rotors moved in a very complex way. The rotors were placed in an outer ring with cams. The stepping of the rotors was electrically directed by microswitches that were controlled by the cams on the rings. Rotor and stepping unit wiring remain classified. The KL-7 was used by many Allies and retired in 1983. [1] [2] [3] [KL-7 Simulator]

After the low level encryption C-38 and M-209 Hagelin decided to develop a system that would be usable for high level military and diplomatic encryption. In 1952 the Hagelin C-52 came on the market. Several improvements were introduced in the 52 model. The rotation of the pin-wheels became irregular and depended on the pin positions of the previous wheels and for the 6 wheel model there was now the choice between 12 pin-wheels. Also the number of slide-bars was increased to 32. A slightly different machine was the CX-52. A separate keyboard attachment was available under the name B-52. The combination of machine and keyboard was designated BC-52. Some versions had a punched tape reader or had only number keys. This very popular machine was sold all over the world and was widely used until the 1990's. [1] [2] [3] [4] [Simulator]



On demand of the French Gendarmerie Hagelin developed a small pocket device with the name CD-55. Two years later, the CD-57 was manufactured. Input and output consisted of a ring with an alphabet and a rotatable disc inside. The alphabet was displaced by pressing a levergrip with the thumb. The displacement depended on the setup of 6 small pin-wheels, similar to those used in the C Type machines. About 12,000 of these pocket models were sold to different countries. [1] [2] [3]



The OMI (Ottico Meccanica Italiano) was an Italian rotor cipher machine with seven rotors. Each rotor could be assembled from different wirings and rings with notches. [1]



The only electromechanical rotor machine, produced by Hagelin was the advanced HX-63. The HX-63 had 9 rotors with 41 circuits of which the surplus wires were looped back on the outside (somewhat similar to the KL-7 ADONIS). All circuits could be rearranged and the rotors performed irregular movements similar to the pinwheels on the C-52 series. All this provided an incredible key space of 10600. Production of the HX-63 was abandoned due to the development of fully electronic cipher machines. Only 12 of these machine are known to have been manufactured. [1] [2]



A true Cold War machine was the Russian Fialka M-125. Developed in the 1950's, the machine came into service in the Soviet Forces in 1965. Although based on the Enigma, Russian cryptologists were well aware of the security flaws of that machine, and incorporated solutions to all of those flaws into this wonderful piece of mechanics. The Fialka had ten rotors with 30 wirings each and these rotors stepped in opposite directions. Each rotor could be composed from different wiring cores and rings that controlled their stepping. The plugboard was replaced by a punched card reader and a 'magic' circuit in the reflector coutered the Enigma's flaw that a letter could never be encrypted into itself. The Fialka was top secret until the 1990's. [1] [2] [3] [4] [5]

1970's ...



The rise of electronics in the 1970's lead to smaller and cheaper electronic machines and the electromechanical versions could not compete with them. Although the electromechanical machines still remained in use for many years they would gradually be replaced by newer and sophisticated electronics and cryptographic software on computers. Hagelin's H-4605 was one of the first new generation machines with fully electronic generated key. [1] [2]

Another nice example of electronic cipher machines is the Gretacoder 805 from Edgar Gretener. This machine is mounted in a standard briefcase and incorporates a little printer. [1]

The Hagelin HC-520 was a pocket size cipher machine with LCD display. It can be seen as an electronic CD-57, but with a more complex encryption. There were several different version of which one was mounted together with a printer in a Samsonite briefcase. The HC-520 was in production until 1979. [1]

NSA developed the KL-51 in the 1980's. The KL-51 is a fully electronic rugedized cipher machine. Key entering was done by reading in a punched paper tape and it had a 20 letter display for message editing. The KL-51 was designated codename RACE by Canada and NATO. [1] [2]

At the end of the 1980's, the Soviet Union developed the ELEKTRONIKA MK-85, its most advanced commercial calculator ever to be in production (the MK- 9x series are prototypes or limited production). The MK-85 was a programmable CMOS BASIC microcomputer, apparently based on the western BASIC machines. The top secret military MK-85C cryptographic device with codename AZIMUT was based on the commercial MK-85. It is mainly used by the Soviet Forces. The text for ciphering is entered from the alphanumeric keyboard and can be edited on its matrix display. The MK-85C has 10100 key variations and can encrypt in both numeric and alphanumeric mode. [1]

This generation of handheld crypto devices can be seen as the last real stand-alone cipher machines. In the computer era, all firms that developed and manufactured cipher machines shifted their focus to on-line and real-time data encryption and software solutions on computer. Nonetheless, pocket-size electronic encryption devices are still developed and produced for special purposes. Most of the old cipher machines are now hot collector items.

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