Skipjack (cipher): Difference between revisions

From Citizendium
Jump to navigation Jump to search
imported>Sandy Harris
(new article, moving text from block cipher)
imported>Sandy Harris
No edit summary
Line 23: Line 23:
</ref>
</ref>
followed.
followed.
==References==
{{reflist|2}}

Revision as of 03:16, 23 July 2009

Skipjack was a block cipher devised by the NSA, originally intended for use in the controversial Clipper chip. It was to be used only in tamperproof hardware, and the algorithm was originally classified. This added to the controversy, with many people citing Kerckhoffs' Principle and arguing that a cipher whose details were classified could not be trusted. Some felt that nothing from the NSA should be trusted in any case.

Eventually, the algorithm was de-classified. Skipjack is an unbalanced Feistel cipher with 64-bit blocks, an 80-bit key and 32 rounds. Once the algorithm was public, the first paper describing an attack on a reduced-round version [1] appeared in days and other papers on cryptanalysis of Skipjack [2] [3] followed.

References

  1. Eli Biham & Adi Shamir, Initial observations on Skipjack
  2. Eli Biham, Adi Shamir & Alex Biryukov (1999), "Cryptanalysis of Skipjack reduced to 31 rounds using impossible differentials.", EUROCRYPT: 12-23
  3. Lars Knudsen & David Wagner (1999), "Truncated differentials and Skipjack", CRYPTO