Here is a disturbing thought.  Now, we no longer live in the days of big filing cabinets. We live in the electronic age. I asked myself, how big could the escrow database get? How hard might it be to steal the whole thing, particularly were I an NSA official operating with the tacit permission of the escrow houses? (We can pretend that such will not happen, but thats naive.)  Well, lets see. Ten bytes of each escrow half. Lets asume ten bytes of serial number -- in fact, I believe the serial number is smaller, but this is an order of magnitude calculation. We assume 250*10^6 as the population, and that each person has a key. I get five gigabytes for each of the two escrow databases. Fits conveniently on a single very valuable Exabyte tape. This can only get easier with time, but who cares -- I can already hold all the clipper keys in the country in my pocket on two 8mm tapes.  Admittely, they will think of safeguards. They won't put the whole database on one disk, prehaps. Maybe they will throw stumbling blocks in the way. This changes nothing -- they keys will be needed every day by hundreds if not thousands of law enforcement types, so convenience will dictate that the system permit quick electronic retrieval. At some point, with or without collusion by the agencies, those exabyte tapes are going to get cut. Dorothy Denning and David Sternlight will doubtless claim this can't happen -- but we know that "can't" is a prayer, not a word that in this instance connotes realism.  With two exabyte tapes in your pocket, you would hold the keys for every person's conversations in the country in your hands. Yeah, you need the "master key" two -- but thats just ten bytes of information that have to be stored an awful lot of places.  Come to think of it, even if the NSA getting a copy of the database isn't a threat to you because unlike me you have no contraversial political views, consider foreign intelligence services. You know, the ones that David Sternlight wants to protect us from because of the evil industrial espionage that they do. The French apparently do have a big spying operation in friendly countries to get industrial secrets, so he isn't being completely irrational here (although why our companies couldn't use cryptosystems without back doors is left unexplained by those that point out this threat.)   Presumably, foreign intelligence services can get moles into the NSA and other agencies. We have proof by example of this: its happened many times. Presumably, someday they will get their hands on some fraction of the keys. You can't avoid that sort of thing.  Don't pretend that no one unauthorized will ever get their hands on the escrow databases.  We crypto types are all taught something very important at the beginning of intro to cryptography -- security must depend on the easily changed key that you pick to run your system, and not on a secret. The escrow databases aren't the sorts of secrets that our teachers told us about, but they are the sort of big secrets they would lump into this category. Imagine trying to replace 100 million Clipper chips.  I cannot believe that the NSA or whomever it is thats doing this doesn't realize all this already. They are too smart. There are too many of them who have made their bones in the real world. I suspect that they know precisely what they are doing -- and that what they are doing is giving us the appearance of safety so that they can continue to surveil in spite of the growth of strong cryptography. I suspect that they realize that they can't put things off forever, but they can try to delay things as long as possible.  Who knows. Maybe even some of the higher ups, the inevitable bureaucratic types that rise in any organization, really do believe that this scheme might give people some security, even as their subordinates in Fort Meade wring their hands over the foolishness of it all.  -- Perry Metzger		pmetzger@shearson.com