March 12, 2002
Practical Aspects of Modern Cryptography
65
Clipper Weaknesses
nThe 80-bit session key was too small
nThe symmetric cipher (SKIPJACK) was classified; no public scrutiny
nLater, a “panel of outside experts” was allowed to look at it for a day
nEven later, after Clipper failed, SKIPJACK was declassified
n16-bit checksum could be defeated (Blaze ’94)
nChipID tagged every single communication