The KL-51 is an off-line keyboard

encryption In cryptography, encryption is the process of encoding information. This process converts the original representation of the information, known as plaintext, into an alternative form known as ciphertext. Ideally, only authorized parties can de ...

system that read and punched paper tape for use with

teleprinter A teleprinter (teletypewriter, teletype or TTY) is an electromechanical device that can be used to send and receive typed messages through various communications channels, in both point-to-point and point-to-multipoint configurations. Init ...

s. In

NATO The North Atlantic Treaty Organization (NATO, ; french: Organisation du traité de l'Atlantique nord, ), also called the North Atlantic Alliance, is an intergovernmental military alliance between 30 member states – 28 European and two No ...

it was called RACE (Rapid Automatic Cryptographic Equipment). It was developed in the 1970s by a

Norwegian Norwegian, Norwayan, or Norsk may refer to: *Something of, from, or related to Norway, a country in northwestern Europe * Norwegians, both a nation and an ethnic group native to Norway * Demographics of Norway *The Norwegian language, including ...

company, Standard Telefon og Kabelfabrik (STK). It used digital electronics for encryption instead of rotors, and it may have been the first machine to use software based crypto algorithms. KL-51 is a very robust machine made to military specifications. U.S.

National Security Agency The National Security Agency (NSA) is a national-level intelligence agency of the United States Department of Defense, under the authority of the Director of National Intelligence (DNI). The NSA is responsible for global monitoring, collect ...

bought it in the 1980s to replace the earlier

KL-7 The TSEC/KL-7, also known as Adonis was an off-line non-reciprocal rotor encryption machine.

. As of 2006, the U.S. Navy was developing plans to replace KL-51 units still in use with a unit based on a more modern Universal Crypto Device.

References

Sources

*NSA museum caption shown in photo.
Crypto Machines - KL-51/RACE
*http://www.knobstick.ca/pdf_files/race1.pdf National Security Agency encryption devices {{crypto-stub