[H-GEN] clipper chip algorithm (SkipJack)

[Paul Gearon]

>From TBTF today:
  NSA declassifies the algorithms behind the Clipper chip, and
  cryptographers worldwide are all over it

    On June 23 the Department of Defense announced that the NSA had de-
    classified the algorithms used in the Fortezza PC card and in the
    earlier, abandoned, Clipper chip. The Skipjack and Kea (Key Ex-
    change) algorithms were posted to the National Institute of Stand-
    ards and Technology site [12] in PDF format. Cryptography research-
    ers quickly rendered the information into HTML form [13] (this link
    loads 350K) and set about implementing the algorithms. Within 24
    hours of the announcement three separate implementations had been
    posted to the Cryptography list (examples at [14] and [15]). Within
    28 hours tuned implementations had appeared and people were running
    timing tests. At 48 hours an Israeli group, Biham et al., published
    an initial analysis [16] along with their own reference implemen-
    tation.

    [12] http://csrc.nist.gov/encryption/skipjack-kea.htm
    [13] http://jya.com/skipjack-spec.htm
    [14] http://www.cl.cam.ac.uk/~mgk25/download/skipjack.tar.gz
    [15] http://www.systemics.com/~iang/SKIPJACK.java
    [16] http://www.cs.technion.ac.il/~biham/Reports/SkipJack/


Paul Gearon
gearon at computer.org

Microsoft - Where every morning is the dawn of a new error.