The KL-51 is an off-line keyboard

encryption In Cryptography law, cryptography, encryption (more specifically, Code, encoding) is the process of transforming information in a way that, ideally, only authorized parties can decode. This process converts the original representation of the inf ...

system that read and punched

paper tape Five- and eight-hole wide punched paper tape Paper tape reader on the Harwell computer with a small piece of five-hole tape connected in a circle – creating a physical program loop Punched tape or perforated paper tape is a form of data st ...

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 (telecommunications), point-to-point and point- ...

s. In

NATO The North Atlantic Treaty Organization (NATO ; , OTAN), also called the North Atlantic Alliance, is an intergovernmental organization, intergovernmental Transnationalism, transnational military alliance of 32 Member states of NATO, member s ...

it was called RACE (Rapid Automatic Cryptographic Equipment). It was developed in the 1970s by a Norwegian 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 an 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, collection, and proces ...

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