From: Matt Blaze <mab@research.att.com>
Date: Wed, 12 Jun 1996 15:20:59 +0800
To: coderpunks@toad.com
Subject: Oblivious key escrow
Message-ID: <199606111854.OAA02575@nsa.tempo.att.com>
MIME-Version: 1.0
Content-Type: text/plain


I've revised and expanded the paper on decentralized key escrow that I
presented at the Cambridge Information Hiding workshop and mentioned
here a few weeks ago.  The paper is now called "Oblivious Key Escrow",
and is available from:
	ftp://research.att.com/dist/mab/netescrow.ps    (postscript)
	ftp://research.att.com/dist/mab/netescrow.tex   (latex source)
-matt

\begin{abstract}
We propose a simple scheme, based on secret-sharing over large-scale
networks, for assuring recoverability of sensitive archived data ({\em
e.g.,} cryptographic keys).  In our model anyone can request a copy of
the archived data but it is very difficult to keep the existence of a
request secret or to subvert the access policy of the data ``owner.''
We sketch an architecture for a distributed key escrow system that
might be suitable for deployment over very large-scale networks such
as the Internet.  We also introduce a new cryptographic primitive,
{\em oblivious multicast,} that can serve as the basis for such a
system.
\end{abstract}