R-Card

{{#eclipseproject:technology.higgins}}

Version

This page provides the Higgins definition of an R-Card ("relationship card") as used in Higgins 1.1.

• See wikipedia I-Card for an overview of I-Cards including ISIP-M-Cards and R-Cards.

Introduction

An R-Card is a kind of I-Card that holds a UDI that references an Entity in the Higgins Global Graph, in much the same way that a URL is a reference to an HTML document in the Web.

The Higgins Identity Attribute Service can be used to resolve an Entity UDI into an Entity.

For more background on R-Cards see: http://en.wikipedia.org/wiki/I-Card#Relationship_card_.28aka_R-Card.29

Schema of the R-Card's referenced Entity

• The R-Card inherits a linear list of supported claim URIs of the ISIP-M-Card fields. The semantics of these are unchanged from normal ISIP-M-Cards: the issuer defines the maximal set of supported claims; the actual set of claims encoded in a security token is some or all of this set of claims.
• The schema of the Entity to which the R-Card points also has a schema. IdAS can resolve the R-Card's UDI into an Entity, lookup it's Context and retrieve that Context's schema/ontology
• Unlike an ISIP-M-Card whose "supported claim" type URIs may only have zero or more simple, string-typed values, the URI's of an Entity may have complex attribute types (e.g. postal address) whose values contain structure

R-Card Functionality

An r-card is a superset of the functionality of an ISIP-M-card as defined by the MS ISIP specification. The differences are:

• Both r-cards and m-cards include a reference to the issuer's STS for obtaining a security token. However unlike m-cards, an R-Card includes a second reference: a Higgins UDI of an Entity in the HGG. This UDI is written/set by the R-Card issuer.
• An R-Card capable Selector receiving this R-Card can resolve the ContextId of the UDI (see that page for details) to discover the Context Provider configuration metadata necessary to access this context.
• R-Card data sharing relationships will work with any Context to which the Selector accepting the r-card can speak. For the greatest interoperability, R-Card issuers can use Contexts specifically designed for generalized cross-domain data sharing such as XDI.

XML Format

An R-Card requires an extension to the ISIP-M-Card XML Schema. It adds a single XML element, higgins:r.card.target whose content is a global UDI. Following are examples of such an element:

RelationURI:

<higgins:r.card.target>http://ldap.example.com/ldap.xrds#username</higgins:r.card.target>

RelationXRI (using XRI 2.0 syntax):

<higgins:r.card.target>xri://=example.name/($context)*($ldap)//username</higgins:r.card.target>