From: baldwin@LAT.COM (Bob Baldwin)
Date: Thu, 30 Dec 93 09:30:44 PST
To: cypherpunks@toad.com
Subject: Trapdoor vs. Escrow
Message-ID: <9312301653.AA20061@LAT.COM>
MIME-Version: 1.0
Content-Type: text/plain


	I was shock when I read the material in John Gilmore's message
of 12/30/93 (Revised Clipper FOIA results from Asst Secretary of Defense).
It strongly suggests that the government has two options:
1. Key Escrow, and
2. Trapdoor chips.
	The comment about ATT being willing to make the chips suggests
that the clipper/Capstone project includes BOTH Key Escrow and Trap Door.
The chips would use a subliminal channel (like the bits that can be
hidden in a DSS signature) to reveal the chips key.  Presumably the
revealed key is encrypted to make sure that only the "good guys" can
recover the key.

	Notice that the NSA has plenty of motivation to have already
developed trapdoor chips long before the need to use them in public
cryptography.  The US exports its crypto hardware to "friendly nations"
and has a strong interest in being able to read our friend's traffic.
The old fashion way of doing this was to sell old crypto hardware to
these nations even though the NSA new how to break the systems.
I recall that an NSA employee went to jail for telling Sweden that
the NSA knew how to break the Hagelin cipher machine at the end of WWII
when the US gave Sweden and other nations a large number of these machines.
Given the length of the jail sentence (30 years), I suspect that he did
other crimes, but the government did not want to expose them.
	Perhaps the modern way of reading our friends traffic is
to sell them chips that reveal key bits via a subliminal channel.
		--Bob Baldwin