Lesson plan

CD-57

The (Hagelin) CD-57 was a portable, mechanical cipher machine manufactured by Crypto AG, 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 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 search technique.

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Article summary

The (Hagelin) CD-57 was a portable, mechanical cipher machine manufactured by Crypto AG, 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 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 search technique.

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Discussion questions

  1. Summarise the article in your own words. Which single claim would you verify first, and why?
  2. Which claim in this article is most likely to be revised as the sources update? How would you check its current status?
  3. If two sources disagreed about one of these facts, what would you need in order to trust one over the other?

Bibliography

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Key claims and bibliography are generated from the same tracked claims and sources as the article page.