From: smb@research.att.com
Date: Mon, 14 Mar 94 07:37:07 PST
To: "Herb Lin" <hlin@nas.edu>
Subject: Re: Clipper and Traffic Analysis
Message-ID: <9403141537.AA24364@toad.com>
MIME-Version: 1.0
Content-Type: text/plain


	In the AOL debate between Barlow and Denning, Barlow asserted
	that Clipper increases the gov't capability to do traffic
	analysis.  Can someone please describe the technical basis for
	this claim?  (No rhetoric please, just the technical
	background...)

The LEAF can be decrypted with just the family key; from what's been
disclosed so far, local law enforcement agents will be able to do that
without contacting the escrow sites.  The LEAF contains the unit id of
the chip, independent of what phone number it's being used from, or
(in the case of cellular phones) where in the country it is.  The ordinary
signaling channels are (often) encrypted, and in general use a different
path than the call itself.