In the

history of cryptography Cryptography, the use of codes and ciphers, began thousands of years ago. Until recent decades, it has been the story of what might be called classical cryptography — that is, of methods of encryption that use pen and paper, or perhaps simple m ...

, the NEMA (NEue MAschine) ("new machine"), also designated the T-D (Tasten-Druecker-Maschine) ("key-stroke machine"), was a 10-wheel

rotor machine In cryptography, a rotor machine is an electro-mechanical stream cipher device used for encrypting and decrypting messages. Rotor machines were the cryptographic state-of-the-art for much of the 20th century; they were in widespread use from ...

Swiss Army The Swiss Armed Forces (; ; ; ; ) are the military and security force of Switzerland, consisting of land and air service branches. Under the country's militia system, regular soldiers constitute a small part of the military and the rest are ...

during

World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

as a replacement for their

Enigma machine The Enigma machine is a cipher device developed and used in the early- to mid-20th century to protect commercial, diplomatic, and military communication. It was employed extensively by Nazi Germany during World War II, in all branches of the W ...

History

The Swiss became aware that their current machine, a commercial Enigma (the Swiss K), had been broken by both Allied and German

cryptanalyst Cryptanalysis (from the Greek ''kryptós'', "hidden", and ''analýein'', "to analyze") refers to the process of analyzing information systems in order to understand hidden aspects of the systems. Cryptanalysis is used to breach cryptographic se ...

s. A new design was begun between 1941 and 1943 by Captain Arthur Alder, a professor of

mathematics Mathematics is a field of study that discovers and organizes methods, Mathematical theory, theories and theorems that are developed and Mathematical proof, proved for the needs of empirical sciences and mathematics itself. There are many ar ...

at the

University of Bern The University of Bern (, , ) is a public university, public research university in the Switzerland, Swiss capital of Bern. It was founded in 1834. It is regulated and financed by the canton of Bern. It is a comprehensive university offering a br ...

. The team which designed the machine also included Professors

Hugo Hadwiger Hugo Hadwiger (23 December 1908 in Karlsruhe, Germany – 29 October 1981 in Bern, Switzerland) was a Swiss people, Swiss mathematician, known for his work in geometry, combinatorics, and cryptography. Biography Although born in Karlsruhe, Ge ...

and

Heinrich Emil Weber Heinrich may refer to: People * Heinrich (given name), a given name (including a list of people with the name) * Heinrich (surname), a surname (including a list of people with the name) *Hetty (given name), a given name (including a list of peo ...

. :de:Heinrich Emil Weber In the spring of 1944, the first prototype had become available. After some modifications, the design was accepted in March 1945, and production of 640 machines began the following month by Zellweger AG. The first machine entered service in 1947. NEMA was declassified on 9 July 1992, and machines were offered for sale to the public on 4 May 1994. File:NEMA-IMG 0522.jpg, The NEMA machine was a

Swiss Swiss most commonly refers to: * the adjectival form of Switzerland * Swiss people Swiss may also refer to: Places * Swiss, Missouri * Swiss, North Carolina * Swiss, West Virginia * Swiss, Wisconsin Other uses * Swiss Café, an old café located ...

, designed to replace commercial

s. File:Cover-open-1000.jpg, NEMA uses 10 wheels, of which one is a reflector, four are normal rotors, and the remaining five are "Drive wheels", which control the stepping of the rotors and the reflector.

The machine

NEMA uses 10 wheels, of which four are normal electrical rotors with 26 contacts at each end that are scramble wired in a way unique to each rotor type; one is an electrical reflector (like the Enigma's ''Umkehrwalze'') with one set of 26 pairwise cross connected contacts; and the remaining five are "drive wheels", with mechanical

cam Cam or CAM may refer to: Science and technology * Cam (mechanism), a mechanical linkage which translates motion * Camshaft, a shaft with a cam * Camera or webcam, a device that records images or video In computing * Computer-aided manufacturin ...

s that control the stepping of the rotors and the reflector. The wheels are assembled on an

axle An axle or axletree is a central shaft for a rotation, rotating wheel and axle, wheel or gear. On wheeled vehicles, the axle may be fixed to the wheels, rotating with them, or fixed to the vehicle, with the wheels rotating around the axle. In ...

in pairs consisting of a drive wheel and an electrical rotor. File:NEMA-IMG 0516.jpg, The four rotor pairs and the reflector File:NEMA-IMG 0520.jpg, The rotor lodging with the cams and first rotor Image:F-rotor-top-1000.jpg, Top view of a NEMA rotor pair. Electrical rotor "F." Image:Rotor-bottom-1000.jpg, Bottom view of a NEMA rotor pair. Drive rotor "18." Note the three stepping-control cams. Image:Enigma-rotor-BP.jpg, An Enigma rotor. File:NEMA-IMG 0526.jpg, view of the right side of the machine with the port for the removable extra lamp panel The NEMA machine weighs about 10 kg and measures approximately 36×32×14 cm.

References

External links

Frode Weierud's page on the NEMA
– photographs and a simulator

– includes records of NEMA selling prices

– includes scanned manuals

{{DEFAULTSORT:Nema (Machine) Rotor machines Cryptographic hardware Military equipment of Switzerland

History

The machine

See also

References

Further reading

External links