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Re: SWP Vocabulary Diagram

From: Chris Bizer <bizer@gmx.de>
Date: Thu, 15 Apr 2004 15:49:11 +0200 (MEST)
To: Patrick Stickler <patrick.stickler@nokia.com>, www-archive@w3.org <www-archive@w3.org>, ext Chris Bizer <chris@bizer.de>, Jeremy Carroll <jjc@hplb.hpl.hp.com>, phayes@ihmc.us
Message-ID: <9356.1082036951@www47.gmx.net>

Hi Patrick,

> >
> > Is the diagram all right?
>
> Looks correct insofar as the RDF schemas are concerned (noting that
> it is more constrained than the schemas since certain cardinalities
> are not specified in the schemas -- Jeremy, if you could indicate
> how to do that property, since I seem to have gotten it wrong
> earlier, feel free to do so).

Yes, defining these cardinalities sounds like a job for our OWL fraction.

>
> 1. Do we wish to require swp:signatureMethod if swp:signature is
> defined?

Yes.
It is impossible to express this constraint in the ER diagram.
Is it possible with OWL?

> 2. Do we wish to limit a warrant to a single signature?

Yes. The cardinallity in the diagram is already "?". Would be nice to have
the same in the schema.

>
>
> BTW, the updated RDF schema for SWP reflecting the same vocabulary as
> Chris' diagram is attached.
>
> I'm hoping that this is now the final vocabulary. Yes?
>

Nearly :-)

I think we should move to OWL in order to be able to express the cardinality
restrictions, or include them at least into the RDFS comments.
Other comments see below:

<?xml version="1.0"?>

<!DOCTYPE RDF [
   <!ENTITY rdf  "http://www.w3.org/1999/02/22-rdf-syntax-ns">
   <!ENTITY rdfs "http://www.w3.org/2000/01/rdf-schema">
   <!ENTITY xsd  "http://www.w3.org/2001/XMLSchema">
   <!ENTITY rdfg "http://www.w3.org/2004/03/trix/rdfg-1">
   <!ENTITY swp  "http://www.w3.org/2004/03/trix/swp-1">
]>

<rdf:RDF
   xmlns:rdf="&rdf;#"
   xmlns:rdfs="&rdfs;#"
   xmlns:xsd="&xsd;#"
   xmlns:rdfg="&rdfg;/"
   xmlns:swp="&swp;/">

   <rdfs:Class rdf:about="&swp;/Authority">
      <rdfs:label>Authority</rdfs:label>
      <rdfs:comment>
An authority, or origin, of a graph; such as a person or company.
      </rdfs:comment>
   </rdfs:Class>

   <rdfs:Class rdf:about="&swp;/Warrant">
      <rdfs:label>Warrant</rdfs:label>
      <rdfs:comment>
A relationship between an authority and

++++++++++++++++++++
a graph => one or more graphs
++++++++++++++++++++

, in which the authority is in
some way an origin of
+++++++++++++++++++
that graph. => the graphs
+++++++++++++++++++
 Warrants may include a digital signature of
the graph by the authority.
      </rdfs:comment>
   </rdfs:Class>

   <rdfs:Class rdf:about="&swp;/SignatureMethod">
      <rdfs:label>Signature Method</rdfs:label>
      <rdfs:comment>
A method used to construct a signature used to authenticate a graph.
      </rdfs:comment>
   </rdfs:Class>

   <rdf:Property rdf:about="&swp;/assertedBy">
      <rdfs:label>asserted by</rdfs:label>
      <rdfs:comment>
The subject graph
++++++++++++++++++++++
originates from and  => delete, because asserting says nothing about who
defined the original graph. It is possible that a graph originates from
Patrick and I assert it adittionally.
++++++++++++++++++++++
is asserted by the authority specified
for the object warrant. The statements expressed in the graph are taken to
be
claims made by that authority.
      </rdfs:comment>
      <rdfs:domain rdf:resource="&rdfg;/Graph"/>
      <rdfs:range rdf:resource="&swp;/Warrant"/>
   </rdf:Property>

   <rdf:Property rdf:about="&swp;/quotedBy">
      <rdfs:label>quoted by</rdfs:label>
      <rdfs:comment>
++++++++++++
The subject graph originates from the authority specified for the object
warrant.
Same comment as above.
++++++++++++
The statements expressed in the graph are not taken to be claims made by
that
authority, insofar as any statement using this property is concerned.
      </rdfs:comment>
      <rdfs:domain rdf:resource="&rdfg;/Graph"/>
      <rdfs:range rdf:resource="&swp;/Warrant"/>
   </rdf:Property>

   <rdf:Property rdf:about="&swp;/authority">
      <rdfs:label>authority</rdfs:label>
      <rdfs:comment>
The object authority is the origin of the graph with which the subject
warrant
is associated.
      </rdfs:comment>
      <rdfs:domain rdf:resource="&swp;/Warrant"/>
      <rdfs:range rdf:resource="&swp;/Authority"/>
   </rdf:Property>

   <rdf:Property rdf:about="&swp;/signature">
      <rdfs:label>signature</rdfs:label>
      <rdfs:comment>
The object is the signature to be used to authenticate
++++++++++++
the graph => the graphs
++++++++++++
with which the
subject warrant is associated.
      </rdfs:comment>
      <rdfs:domain rdf:resource="&swp;/Warrant"/>
      <rdfs:range rdf:resource="&xsd;#base64Binary"/>
   </rdf:Property>

   <rdf:Property rdf:about="&swp;/signatureMethod">
      <rdfs:label>signature method</rdfs:label>
      <rdfs:comment>
The object is the signature method by which  the signature specified for the
warrant subject was constructed.
      </rdfs:comment>
      <rdfs:domain rdf:resource="&swp;/Warrant"/>
      <rdfs:range rdf:resource="&swp;/SignatureMethod"/>
   </rdf:Property>

   <rdf:Property rdf:about="&swp;/certificate">
      <rdfs:label>certificate</rdfs:label>
      <rdfs:comment>
The object is a certificate by which the authority specified for the warrant
can be authenticated.
      </rdfs:comment>
+++++++++++++++++
      <rdfs:domain rdf:resource="&swp;/Warrant"/>
Certificates should be linked to authorities (or optionally authority and/or
warrant)
+++++++++++++++++
      <rdfs:range rdf:resource="&xsd;#base64Binary"/>
   </rdf:Property>

++++++++++++++++
   <swp:SignatureMethod rdf:about="&swp;/X509">
      <rdfs:label>X509</rdfs:label>
      <rdfs:comment>X509 Signature Method</rdfs:comment>
   </swp:SignatureMethod>

   <swp:SignatureMethod rdf:about="&swp;/PGP">
      <rdfs:label>PGP</rdfs:label>
      <rdfs:comment>The PGP Signature Method</rdfs:comment>
   </swp:SignatureMethod>

I think we should wait with instance definitions untill we have defined the
additional vocabulary that allows you to specifiy a method as a combination
of cantonalization method, hash algo and signature algo. PGP and X509 both
allow different hash and sig algo combinations. Thus it is a little
unprecise just to say X509.
+++++++++++++++++
</rdf:RDF>

Chris

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Received on Thursday, 15 April 2004 09:51:38 GMT

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