Encrypting Elements and Transclusion

I was speaking to Henry Thompson about some of the XML Encryption issues, 
and he pointed out a similarity of element encryption (encrypting an element 
and replacing it with a new "stub" element with the encrypted element as its 
content) to transclusion (a linked resources is automatically fetch and 
embedded in place of the link). In my nascent understanding of the problem I 
hope encryption could borrow both the data model (Infoset, XPath, DOM, etc) 
and the processing model (XSLT, DOM, XLink transclude) from elsewhere...

Consequently, I've been reading up on transclusion and thought I'd forward 
on my references. If other folks have given any thought to this, or can shed 
some light on the affects/requirements of  XLink on XML parsers and schema 
validity, please do!

[1] Problems with Dynamically Assembled Document Portions, and Some
Solutions. Steven J. DeRose and Christopher R. Maden.

[2.1] XML XLink Requirements. Steven J. DeRose. W3C Note 24-Feb-1999
transclusion: A specific kind of linking in which access of
one end automatically causes another end(s) to be retrieved and embedded,
appearing much as if their data had occurred at the same place as the
initial end that triggered its inclusion. The original definition also
requires that systems provide direct access to the originating document as
a whole, in its original document context (including, for example, its
copyright notice).
[2.2] XML Link. Steve DeRose, Eve Maler, David Orchard, Ben Trafford. W3C 
Candidate REC.
"embed": An application traversing to the ending resource should
load it in place of the starting resource.

[3]  "Prototyping an Updating Transclusion Tool based on XLink." By Richard 
Tobin (University of Edinburgh), presented at XTech '99.  "We have 
implemented prototype support for transclusion of changing material via 
XLink. Our tool, which makes use of the XML and XSL support in Internet 
Explorer Beta 2, will style and display XML documents which contain XLinks 
with actuate='auto' and show='embed' as if the linked-to material was 
actually contained within the linking element. Furthermore, we have written 
an update server, so that if any of the URLs contained in the XLinks so 
processed change, the page will be redisplayed. This update facility is 
restricted to URLs which are being served from an HTTP server which is also 
running our update server, but does NOT require polling from the 
client.   Aside from providing a modest level of support for exploring the 
benefits of XLink, standoff markup and just-in-time document composition, we 
think the major contribution of this effort is in illustrating a relatively 
novel distribution of effort for handling irregularly changing information 
over the Web."

[4] auto/embed is not node transclusion. Paul Prescod.
(Interesting list of some of the questions regarding transclusion)

Joseph Reagle Jr.
W3C Policy Analyst                mailto:reagle@w3.org
IETF/W3C XML-Signature Co-Chair   http://www.w3.org/People/Reagle/

Received on Thursday, 12 October 2000 11:59:45 UTC