Brian D Williams <talon57@well.sf.ca.us> writes: I remember awhile back someone posted some clipper documents that were released under FOIA as I recall. The thing that struck me was that the NSA was refering internally to clipper as "The Trapdoor chip." Why refer to it as such if there is no back door?

Those letters made it clear the "trapdoor" was the escrow, and the internal debate was over whether the existence of the escrow would be made public. So far it's been NSA's consistent public position that the escrow is the only way in... and from the FOIA, that's evidently what they're telling the President also. Most days I'm pretty sure I believe that there aren't any known gotchas in the Skipjack algorithm. If they can really get the escrow, it's ever so much cheaper than doing real cryptanalysis. As Carl Ellison and others point out, that's really one of the big dangers -- if LE doesn't have to break Skipjack to read the traffic, neither do the attackers... and breaking the escrow is probably much cheaper than breaking the algorithm. My position is that Clipper is iniquitous whether or not there's a[nother] trap door. Jim Gillogly Mersday, 6 Astron S.R. 1994, 21:58