I’d like to share with you a closed federated system that we are currently promoting in the New Zealand Government context that is exactly what you’ve described.

Our notion is that government agencies hold a lot of personal information about people and organisations. If they act as authoritative sources of that data- what you call Claim Holders and we Attribute Providers- then other government agencies who need that information to make routine operational decisions (Claim Consumers or Service Providers) can get it at the person’s request and under his control (to protect privacy).

In between, there is an Integration and Coordination Layer- what you call the Claim Broker.

This is supplemented by an all-of-government logon system (Government Logon Service) and an identity service (Identity Verification Service).

We call the whole thing igovt and the federated claims part GOAAMS or Government Online Attribute Assertion System.

The main challenge for us is to get the Claims Holder to provide access for people to get their information. We find that Service Providers love the proposition of getting authoritative information in an online and real-time manner.

For more info, you can have a look at my posts http://yes2privacy.wordpress.com/2007/12/21/bc-nz-info-cards-liberty-specs/ and http://yes2privacy.wordpress.com/2007/10/15/identity-oracle-authoritative-data-sources/