According to notes published on this list, the NSA has already admitted that the LEAF is not itself encrypted with Clipper; we don't know what it is encrypted with, but I wonder: If you're referring to the meeting at AT&T Bell Laboratories, that is *not* what we were told. Rather, we were told that a unique mode of operation was used. The motivation for using a unique mode for the LEAF itself isn't completely clear; it may be related to the lack of space to send a random IV. The traffic key has to be encrypted a bit oddly, though; 80 bits doesn't mesh well with standard modes of operation of a 64-bit cipher if you want to minimize the number of encryption operations. Obviously, games can be played with the modes of oepration to weaken the cryptosystem. But that's the sort of thing that would stick out like a sore thumb to the review panel -- much more so than any flaws in Skipjack itself. But the question is worth asking of the review panel members. I'll pass it on to Steve Kent. --Steve Bellovin