Checksums in Links

Stavros Macrakis (macrakis@osf.org)
Tue, 25 Jul 95 20:21:03 -0400


Date: Tue, 25 Jul 95 20:21:03 -0400
Message-Id: <9507260021.AA04415@imre.osf.org>
To: bsittler@prism.nmt.edu
Cc: www-html@www10.w3.org
In-Reply-To: <199507242010.OAA13977@white.nmt.edu> (bsittler@prism.nmt.edu)
Subject: Checksums in Links
From: Stavros Macrakis <macrakis@osf.org>

In <199507242010.OAA13977@white.nmt.edu>, bsittler@prism.nmt.edu
(Benjamin C. W. Sittler) says:

   ...should LINKs have an MD (checksum) attribute? That way one could
   verify that [an object]... hasn't been replaced without the user
   knowing....

The HTML 3.0 draft has this wherever a reference is possible.  See

  http://www.w3.org/hypertext/WWW/MarkUp/html3/Contents.html

But I would have thought it would make more sense to include an
(optional) checksum in the UR* itself, rather than requiring every use
of a UR* (within HTML or elsewhere) to have a parallel MD when an MD
is wanted.  The URN requirements document explicitly excludes
checksums as part of the URN.  The URC effort appears to be, um,
stalled.

I would appreciate any pointers to a discussion of this trade-off.

	-s