Many nice things in Seth's journal today, especially:
I've been having a debate with a friend about how to calculate the area of a moebius strip, where the moebius strip is constructed by taking a 1" by 10" area, twisting it, and joining the ends…
My observation was that if you did make the strip from paper, you would need 20 sq. in. of paint in order to paint the whole thing. If you used 10 sq. in. of paint, you would have 10 sq. in. of surface unpainted.
However, Jonathan argues that this is a misinterpretation if the Möbius strip is seen as having zero thickness, because then points on one "side" are actually identical with the corresponding points on the "other side". He suggests that, on a zero-thickness strip, you can go only 10" before you return to your starting point. (On a strip made of paper with non-zero thickness, you must go 20" before returning to your starting point.)
And don't miss:
Five people came from Microsoft to meet with us on Tuesday about Palladium. It was very interesting.
"Sealed storage" is a very technically clever idea. Some of the subtleties hit me only after the meeting. Basically, you have a hardware co-processor within a machine which contains some unique secret symmetric key (not known to anybody other than the co-processor). Call this s. Also assume that the co-processor is also to take a hash h of whatever kernel k is running on the ordinary CPU. (In Palladium this is actually something called a "nub" — in their marketing materials a "Trusted Operating Root" or "TOR" — but we can pretend it's the OS kernel instead.)
Seth is probably the most knowledgeable tech person to have been briefed on Palladium by MSFT without signing an NDA. Accordingly, Seth's notes on what Palladium does and doesn't do, as well as what it can be used for, are likely the very best on the Net right now. Palladium (and TCPA) are "security" initiatives that may well make workable copy-prevention practical, but the cost to civil liberties of doing so need to be carefully considered.