To: uri@bunyip.com
Subject: using digital signature of `original content' as name
From: Larry Masinter <masinter@parc.xerox.com>
Message-Id: <93Oct18.020207pdt.2794@golden.parc.xerox.com>
Date: Mon, 18 Oct 1993 02:01:52 PDT
Using digital signatures as part of the name means that you don't need
to rely on an authority to guarantee the name. For example:
urn:urn.xerox.com:ad43e6025b5a1e90492f6eafd7ca2d53
which consists of:
urn:<host>:<signature>
where <host> is an optional host name which is willing to map the URN
to a URL, and <signature> is the digital signature of the original
byte stream of the document contents. (use md5, NIST, or snefru as you
like).
The <host> is optional; to compare equality of urns, just compare the
signatures.
If a publisher goes out of business, hope that some collection of
sites pick up the complete index for that publisher, so that your
hints still can help you.
In this situation, no-one has to be responsible for guarantee of
identity, since that guarantee is contained in the name itself.
In this case, someone is responsible for the mapping between the URN
and its URL, but any number of sites could be responsible for that --
the responsibility can be distributed, replicated, cached.