   >	The algorithm is classified because a military contract (or similar
   >government equivalent to military) has been let for this "proprietary"
   >design that the Feds say that NSA developed.  Is there a patent?  Is that
   >patent publicly available?  My betting is that that too is classified.

   Unless there has been a _major_ change in the law, there's no such beast
   as a "classified patent."  Patents exist to encourage communications and
   develop the state of the art. 

While there aren't classified patents, there are "patent secrecy orders".

Suppose you invent a voice scrambler for CB radio, and apply for a patent.
The Patent Office decides the NSA might be interested, gives them a copy
of your application, and you get a nice note back saying your patent
application has now been classified for national security reasons and
you're no longer allowed to make and sell it.  
I'm picking this example because it happened in the late 1970s.
It was probably some analog scrambler, and would have probably
violated FCC rules anyway, but it did get classified.

Or suppose you publish a paper on your Really Spiffy Algorithm and
then file a patent application.  Since it's been published,
they can't gain anything by classifying it, though you can't get
patents in most countries other than the US, where patent laws are different.

Obviously a system of classified patents would be highly bogus
"You can't sell that widget, because there's a classified patent on it.
You're not allowed to see the patent, or know who owns the design,
so just give us all your money and work in progress and maybe we won't throw
you in jail for espionage."  Some countries might have that kind of
system :-(, but we don't have that here.  Quite.  Yet.