The (Hagelin) CD-57 was a portable, mechanical cipher machine manufactured by

Crypto AG Crypto AG was a Swiss company specialising in communications and information security founded by Boris Hagelin in 1952. The company was secretly purchased in 1970 by the US Central Intelligence Agency (CIA) and West German Federal Intelligence Se ...

, first produced in 1957. It was derived from the earlier CD-55, and was designed to be compatible with the larger C-52 machines. Compact, the CD-57 measured merely 5 1/8in × 3 1/8in × 1 1/2in (13 × 8 × 3.8 cm) and weighed 1.5 pounds (680 gr). The CD-57 used six wheels. A variant is the CD-57(RT), a similar device using a

one-time pad The one-time pad (OTP) is an encryption technique that cannot be Cryptanalysis, cracked in cryptography. It requires the use of a single-use pre-shared key that is larger than or equal to the size of the message being sent. In this technique, ...

system rather than rotating wheels. The STG-61 was a licensed copy of the CD-57 by Hell.
Sullivan (2002) shows how the CD-57 can be attacked using a

hill climbing numerical analysis, hill climbing is a mathematical optimization technique which belongs to the family of local search. It is an iterative algorithm that starts with an arbitrary solution to a problem, then attempts to find a better soluti ...

search technique.

Notes

References

* Wayne G. Baker, Solving a Hagelin, Type CD-57, Cipher, ''Cryptologia'', 2(1), January 1978, pp1–8. * Louis Kruh, Cipher Equipment: Hagelin Pocket Cryptographer, Type CD-57, ''Cryptologia'', Volume 1, 1977, pp255–260. * Geoff Sullivan, Cryptanalysis of Hagelin machine pin wheels, ''Cryptologia'', 26(4), pp257–273, October 2002.

External links

Photographs and a simulator (Windows)
* Photographs of the CD-57

* Jerry Proc's pages

Information about the STG-61
{{Cryptography navbox , machines Encryption devices

See also

Notes

References

External links