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<div class=Section1>
<p class=MsoNormal><font size=3 color=navy face="Times New Roman"><span
style='font-size:12.0pt;color:navy'>>> </span></font><span
class=gmailquote>On 12/27/06, <b><span style='font-weight:bold'>Drummond Reed</span></b>
<<a href="mailto:drummond.reed@cordance.net">drummond.reed@cordance.net</a>>
wrote:</span><o:p></o:p></p>
<div>
<p class=MsoNormal style='margin-bottom:12.0pt'><font size=3 color=navy
face="Times New Roman"><span style='font-size:12.0pt;color:navy'>></span></font>>
XRI infrastructure solves this problem by explicitly supporting <br>
<font color=navy><span style='color:navy'>></span></font>> reassignable
identifiers (i-names) and persistent identifiers<br>
<font color=navy><span style='color:navy'>></span></font>> (i-numbers)
and permitting the resolution of any reassignable<br>
<font color=navy><span style='color:navy'>></span></font>> i-name to be
mapped immedidately to a synonymous<br>
<font color=navy><span style='color:navy'>></span></font>>
never-reassigned i-number which can be safely stored by an <br>
<font color=navy><span style='color:navy'>></span></font>> OpenID Relying
Party without exposing the identity owner to the<br>
<font color=navy><span style='color:navy'>></span></font>> risk of having
their i-name "taken over".<br>
<font color=navy><span style='color:navy'>><o:p></o:p></span></font></p>
<p class=MsoNormal style='margin-bottom:12.0pt'><font size=3 color=navy
face="Times New Roman"><span style='font-size:12.0pt;color:navy'>></span></font><font
size=2 color=navy face=Arial><span style='font-size:10.0pt;font-family:Arial;
color:navy'>Bob Wyman wrote:<o:p></o:p></span></font></p>
<p class=MsoNormal style='margin-bottom:12.0pt'><font size=3 color=navy
face="Times New Roman"><span style='font-size:12.0pt;color:navy'>></span></font><br>
<font color=navy><span style='color:navy'>></span></font>The XRI Syntax
specification says that a Persistent Identifier is "An identifier that is
permanently assigned to a <font color=navy><span style='color:navy'>></span></font>resource
and <b><span style='font-weight:bold'>intended</span></b> never to be
reassigned to another resource." While it may well be the
"intention" that <font color=navy><span style='color:navy'>></span></font>such
persistent identifiers are never to be reassigned, one must accept that an
"identity owner" is, in fact, <font color=navy><span
style='color:navy'>></span></font>exposed to some "risk of having their
i-name 'taken over'" in the case of unintended events. There is nothing <font
color=navy><span style='color:navy'>></span></font>technical which prevents
the taking over of XRI persistent identifiers. The only thing that reduces risk
here is <font color=navy><span style='color:navy'>></span></font>people's
and organization's willingness and ability to follow the rules. Such trust may
well be reasonably held, but <font color=navy><span style='color:navy'>></span></font>there
remains an ineradicable risk of entities' failure to perform as intended...
(Note: The previous comments <font color=navy><span style='color:navy'>></span></font>should
not be taken as a criticism of XRI. This 'risk' is an inevitable
characteristic of this class of system and of <font color=navy><span
style='color:navy'>></span></font>this type of "solution".) <font
size=2 color=navy face=Arial><span style='font-size:10.0pt;font-family:Arial;
color:navy'><o:p></o:p></span></font></p>
</div>
<p class=MsoNormal style='margin-bottom:12.0pt'><font size=2 color=navy
face=Arial><span style='font-size:10.0pt;font-family:Arial;color:navy'>The
point Bob makes is so important that I want to reinforce it further. He’s
absolutely right that there is nothing inherent in the technical aspects of XRI
architecture -- nor was there in the URN (Uniform Resource Name) architecture
that came before it – to prevent the reassignment of an identifier
intended to be persistent (which both XRI i-numbers and URNs are). Such
protection is afforded *<b><span style='font-weight:bold'>entirely</span></b>*
by the operational policies of the authority assigning the identifier, i.e.,
the registry. <o:p></o:p></span></font></p>
<p class=MsoNormal style='margin-bottom:12.0pt'><font size=2 color=navy
face=Arial><span style='font-size:10.0pt;font-family:Arial;color:navy'>Part of
the reason URNs did not catch on (besides the fact they are typically very un-human-friendly
identifiers) is that the operational requirements of a URN registry are so dramatically
different than a DNS registry. A URN is assigned once and never reassigned,
where as a domain name is registered for a specified period and then either
renewed or the registration expires and it is returned to the pool of names
available for registration.<o:p></o:p></span></font></p>
<p class=MsoNormal style='margin-bottom:12.0pt'><font size=2 color=navy
face=Arial><span style='font-size:10.0pt;font-family:Arial;color:navy'>As I
explained in the previous thread, one of the primary motivations for the
development of XRI architecture was to bring both reassignable and persistent identifiers
together under one unified registration and resolution architecture that could
not only solve the usability issues of persistent identifiers (by permitting
them to be discovered via human-friendly synonyms), but to enable a new type of
registry that supports policies for *<b><span style='font-weight:bold'>both</span></b>*
reassignable and persistent identifiers.<o:p></o:p></span></font></p>
<p class=MsoNormal style='margin-bottom:12.0pt'><font size=2 color=navy
face=Arial><span style='font-size:10.0pt;font-family:Arial;color:navy'>XDI.org is
(to my knowledge) the first global identifier registry infrastructure developed
using this model. Although the details are probably far too esoteric for most
members of this list, if you find yourself interested in the policies of a
global registry infrastructure that supports the registration of both reassignable
and persistent identifiers, by all means visit the XDI.org Global Services
Specifications site (<a href="http://gss.xdi.org/">http://gss.xdi.org</a>) and
review the main GSS document at <a
href="http://gss.xdi.org/moin.cgi/FrontPage?action=AttachFile&do=get&target=gss-v1.0.pdf">http://gss.xdi.org/moin.cgi/FrontPage?action=AttachFile&do=get&target=gss-v1.0.pdf</a>,
in particular the section on I-Numbers.<o:p></o:p></span></font></p>
<p class=MsoNormal style='margin-bottom:12.0pt'><font size=2 color=navy
face=Arial><span style='font-size:10.0pt;font-family:Arial;color:navy'>Net net:
as OpenID spreads, so will recognition of the value of having a persistent identifier
at the root of an OpenID identity – and so will appreciation of an
identifier infrastructure designed from top to bottom to support the policies
necessary to make reliance on these persistent identifiers a reasonable risk.<o:p></o:p></span></font></p>
<p class=MsoNormal style='margin-bottom:12.0pt'><font size=2 color=navy
face=Arial><span style='font-size:10.0pt;font-family:Arial;color:navy'>Note: This
issue is important enough that I blogged it at <a
href="http://www.equalsdrummond.name/?p=89">http://www.equalsdrummond.name/?p=89</a>.
<o:p></o:p></span></font></p>
<p class=MsoNormal style='margin-bottom:12.0pt'><font size=2 color=navy
face=Arial><span style='font-size:10.0pt;font-family:Arial;color:navy'>=Drummond<o:p></o:p></span></font></p>
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