1. The Attribute and the ecosystem

2. Topics Basics Common Schema Complexity and Extensibility
LOA of attributes
Privacy
Naming
Complexity and Extensibility
Tagging
Complexity vs Metadata
IdP releasing vs SP asking
Query languages
Dealing with Aggregation

3. Killer Attributes (and the applications that love them)
Human readable identifiers
address, eppn, display name, etc
Opaque identifiers
ePTID
Affiliation
Citizenship
Over legal age

4. Community or collaboration asserted
Types of attributes
Institutional
Organizational
Reassertion of Official attributes
Temporal – geolocation, etc.
Community or collaboration asserted
Formal – Virtual organizations, groups
Informal – reputation systems, FoF
Self-asserted

5. Common Schema
NIEM – National Information Exchange Model –
eduPerson -
Accessability schema - and

6. Eve Maler’s Attribute Assurance Matrix

7. Naming
Oids vs URNs vs URLs vs URI’s vs
Registering name spaces

8. Which attributes are PII?
Privacy
Which attributes are PII?
ePTID – opaque, non-correlating, but 1-1
IP address
Which jurisdiction applies?
IdP? SP? Nationality of user?
Which require consent and for what purpose?

9. Authorization – Problem Statement
In a federated landscape, with scale in mind, groups more than identities control access
But attributes may express, in addition or instead, a user's relationship with the authenticating organization, membership in groups, or possession of roles or entitlements that signify permission to access application resources. In such cases, authorization may be delegated or distributed to the authenticating organization, or even across additional organizations. This is a relatively common pattern when the authorization policy is simple (typically all or nothing) and applies to large numbers of users at multiple organizations. It is less common as policies become more complex and fine-grained.

10. Groups Local Groups User Identification
Provisioning (and Deprovisioning)
Representation
isMemberOf
eduPersonEntitlement
Groups with Federated Members
Federated Groups
Privacy Implications
Visibility of members to other members
Sharing groups across services

11. Of Entitlements and Attributes
In entitlements, SP community passes business logic to IdP’s, who compute authorization and pass entitlement
To scale, must have common license terms
SP’s need to be willing to expose business logic
In attributes, IdP’s pass attributes to SP for authorization
Raises privacy issues
To scale, must have shared community attributes

12. Some key issues Which schema
Knowing which IdP to ask for which attributes, especially as we get into aggregation
How to ask, e.g. over 18
Making values extensible, so that they can be tagged, like validation, date, terms of use

13. Attribute Release SP Asking vs. IdP Releasing
Specifying requirements (queries, metadata, policy files, web pages, etc.)
Consent

14. Attribute aggregation
At the IdP
Already doing internal aggregation
Can arrange bulk feeds – e.g. IEEE member
At the SP
Already in the Shib code
At an intermediate point
Portals and gateways do this now
Can greatly simplify trust

15. Use cases are legion and confusing
“Over legal age”
Use cases are legion and confusing
Legal age of the web site country
Legal age of the IdP country
Legal age of the identity holder’s country
Authoritative sources and delegation
Query languages

16. Complexity and Extensibility
Tagging within attribute vs use of metadata vs context
Extensibility
The ability to add new controlled values
How much flat attribute proliferation can be managed through a structured data space?
DRM of metadata

17. Principles of the Tao 属性之道
Least privilege/minimal release
Using data “closest” to source of authority
Late and dynamic bindings where possible
Dynamic identity data increases in value the shorter the exposure.  If identity data is cached away from the source there is increased likelihood of staleness and over-exposure which can lead to privacy and data accuracy concerns.

18. Beyond the first horizon
LOA of attributes
Specifying semantic rules
Shifting from attribute values as text strings to rich signed data
Terms of use
Time limits
etc