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XML-DSIG Workshop input to XML Canonicalization

From: Joseph M. Reagle Jr. <reagle@mit.edu>
Date: Wed, 14 Apr 1999 14:13:05 -0400
Message-Id: <>
To: "Signed-XML Workshop" <w3c-xml-sig-ws@w3.org>
How many of you are savvy to Unicode canonicalization and
internationalization (I18N) character composition issues?

Forwarded Text ----
 From: "James Tauber" <jtauber@jtauber.com>
 To: "Joseph M. Reagle Jr." <reagle@MIT.EDU>
 Subject: XML-DSIG Workshop input to XML Canonicalization
 Date: Thu, 15 Apr 1999 01:27:11 +0800
 I have two items that I'd like to request you raise at the XML-DSIG
 Workshop, the response to which will be very valuable for the XML Syntax
 WG's Canonicalization work.
 They are:
 (1) could you ask the participants in the workshop to look at the current
 requirements definition for XML canonicalization
 (http://www.w3.org/TR/NOTE-xml-canonical-req) and make sure there is nothing
 they would like to see added or removed. There is another draft in progress
 but the public one should do in order to gain input
 (2) could you raise with the participants the question of whether Unicode
 characters should be canonicalized into only one of composed or decomposed
 forms. In Unicode one gets the situation where, say, an e with an acute can
 be represented as a single character "e with acute" or as two characters "e"
 + "combining acute". If you want to treat two documents that differ only in
 this respect as equivalent (say for DSIG checking), you need to pick one
 form as the canonical and map the other to it.
 The I18N WG has asked that the XML Syntax group follow their character model
 in our canonicalization work but this would significantly increase the work
 a canonicalizer would have to do because it would need to do all this
 mapping. So the question that we need to ask of those people that are
 interested in XML-DSIGs is: for the purpose of DSIGs should "e with acute"
 (composed form) be treated as *different* from "e" + "combing acute"
 (decomposed form) or the *same*. Hopefully there are some workshop
 participants who have I18N experience and/or requirements.
 I would greatly appreciate if you could gather some input from the workshop
 participants on these items.
 James Tauber
 (editor of Canonical XML, on behalf of XML Syntax WG)
End Forwarded Text ----
Regards,          http://web.mit.edu/reagle/www/
Joseph Reagle     E0 D5 B2 05 B6 12 DA 65  BE 4D E3 C1 6A 66 25 4E
independent research account
Received on Wednesday, 14 April 1999 14:13:16 UTC

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