Separating: ID, Credential, and Attribute Management

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Session: Tuesday Session 4 Space I

Conference: IIW 10 May 17-19, 2009 this is the complete Complete Set of Notes

Convener: Jim Fenton, Cisco Systems 

Notes-taker(s): Jari Koivisto, Cisco Systems 

Tags:   Identity system, attribute, relying party, identity provider, authentication, assertion 

Notes:   Short presentation and discussion 



A basic identity system

  • e-commerce site
  • IdP
  • User

Elements of identity management

  • Authentication (establishing who the Subject is)
  • Credential managemen (prove to relying parties who the Subject is)
  • Attribute management (provide information about the subject)

User trust

  • User trust in their IdP is fundamental
  • An ecosystem of IdP is required


Authentication methods

  • Methods useful for user authentication are situation-specific
  • Problem: Many existing ID systems are bound tightly to IdP

Authentication Strength

  • Relying party knows how good the authentication should be

  Authentication endpoint  

Security opportunities

  • Users that authenticate frequently at a given service are more likely to detect anomalies
  • IdP providers can detect anomalous user behavior
  • Similar to detection of fraudulent credit card transactions 

Credential management

Credential management: functions

  • Act as a "key cabinet" for the user
  • Support directed ID
  • Enforce secure use of credentials

Directed identity 

Security and availability issues

  • Security
  • High value target
  • Availability
  • Failure of an ID manager may have severe impact on its Subjects 

Attribute management

Distributed attributes

  • Self-asserted attributes have limited utility
  • Authoritative sources for different attributes come from different places
  • ID system has a role in locating trustable sources of attributes
  • Attributes delivered as signed assertions

Attribute distribution: Example

  • Example of Alice buying wine online
  • Alice
  • Wine merchant
  • IdP
  • DMV or Healthcare provider

Attribute trust

  • Federation: Prearranged trust relationsships
  • Accreditation: indirect federation
  • Financial institutions, schools 

Identity provider trust

  • IdP has fiduciary responsibility
  • To the Subject:
  • Must use credentials only for the proper Subject
  • To RPs:
    • Must associate attribute request and responses reliably
    • IdP may coincidentally funtion as an attribute provider


  • Scaling is critical
  • etc.


  • RPs have different views what is identity
  • Identity vs. Identity information
  • Different IdPs give different sets of attributes
  • What is the question that RP needs to ask (over 18/21 vs. birth day)
  • Attributes of the Subject, e.g. Subjects attibute is: Subject is Cisco employee
  • User -> RP -> User -> IdP -> User -> RP
  • Yes User is >18
  • Discussion about: Is it IdP who user trusts to get the attributes, or should User be the one who makes the decision
  • Discussion about the assertions, e.g. State assertion does not mean that it is necessary better than self assertion. Address as an example.
  • Federated trust frameworks, level of assurance (1, 2, 3, 4)