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.
An R-Card is a kind of I-Card that holds an Entity UDI as described by the Context Data Model. This Entity UDI references an Entity object, analogously to how a URL references an HTML document in the Web.
For more background on R-Cards see: http://en.wikipedia.org/wiki/I-Card#Relationship_card_.28aka_R-Card.29
An R-Card offers a superset of the functionality of an ISIP-M-card as defined by the Identity-Selector-Interop-Profile-v1.5.pdf specification that can be downloaded from here. As with an ISIP-M-card, the token service referred to by the card is responsible for generating the security token, and is thus the agent that sets the values of these claims. This token service generates the claim values in the token based on some underlying attribute values. R-Cards, in addition to holding the token service endpoint reference, also hold an Entity UDI reference that "points" to a data object that holds one or more of these underlying attribute values. The agent holding an R-Card may be able to edit the values of these underlying attributes. The ability to edit these attributes is subject to the access control policy of the data service holding and managing the underlying Entity and its attributes.
- An R-Card inherits from its ISIP-M-Card basis a linear set, S1, of supported claim URIs. The semantics of these claims 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 maximal set of claims.
- The Entity to which the R-Card points also has a schema also consisting of a linear set, S2, of claim/attribute type URIs.
- For those claims common to S1 and S2, the data type of the claim must be limited to what is supported in ISIP-M-Cards. For these common claims, the R-Card's Entity UDI (see below) can be used to resolve the data underlying these claims an in some cases (as controlled by the issuer) edit these values
- Claims that exist in S2 but not S1 are never represented in security tokens generated by the issuer.
- The data type of claims that exist only in S2 are not limited to those defined by ISIP-M-Cards. These S2-only claim values may be complex, structured objects.
- The S2 schema may be retrieved dynamically by dereferencing the Entity UDI (e.g. using IdAS) and querying the resulting Entity as to its schema.
An R-Card is an extention of the ISIP-M-Card XML Schema. It adds a single XML element, r.card.target whose content is an Entity UDI. The r.card.target element must occur within the <ic:InformationCard> scope where ic is defined as XXXX.
This Entity UDI is written/set once by the R-Card issuer and never changes.
Following are examples of this element:
XRI form (using XRI 2.0 syntax):
- Is the value of a claim in S1 the same as the value of the corresponding attribute/claim in S2?
- Tentative answer: Sameness is not guaranteed
- Is there a need to define how the UDI (perhaps as signed by the STS, etc.) is passed within the RST message.
- Need to explore the advantages of SAML 2.0's ability to individually sign attributes --e.g. allow the STS to indicate on a per attribute level what they are authoritative for