1. Policy Based Management for Internet Communities Kevin Feeney, Dave Lewis, Vinny Wade, Knowledge and Data Engineering Group Trinity College Dublin Policy June 2004

2. © KF.VW,DLwww.cs.tcd.ie 2 Rationale for Applying Policy Solutions Internet Communities can be very large and complex Electronic Resources administered in decentralised way Communities bound together by a web of informal contracts

3. © KF.VW,DLwww.cs.tcd.ie 3 Problems of Applying Policy Solutions Structure of communities not centrally planned. Fluidity and complexity of structure makes requirements capture impractical. No single source of authority over resources. Heterogeneous internal organisations Internal organisation of some groups may be private. These features are also increasingly common in traditional organisations.

4. © KF.VW,DLwww.cs.tcd.ie 4 Community Grouping Abstraction Community which can divide itself into sub- communities is the basic abstraction Permissions and Obligations can be delegated to sub-communities Sub communities can own their own resources Process of sub-division and delegation creates community structure dynamically.

5. © KF.VW,DLwww.cs.tcd.ie 5 Community Specification Each community is specified as having –A set of membership rules –A set of sub-communities –A set of policy rules having the community as their subject –A set of resources - resources can be owned or delegated from a parent community.

6. © KF.VW,DLwww.cs.tcd.ie 6 Community Structure POLICY STORE Community Structure Rules - Membership Rules and Community Agency Rules (e.g. Any, All, Any Two, Majority) Policy Authoring Rules (who can change policy) Authorisation Policy Rules (e.g. Auth(Any, Read Doc1)) Obligation Policy Rules (Resource Configuration etc..) MembersResources

7. © KF.VW,DLwww.cs.tcd.ie 7 Sub-Communities & Delegation POLICY STORE Community Structure Rules - Membership Rules and Community Agency Rules (e.g. Any, All, Any Two, Majority) Policy Authoring Rules (who can change policy) Authorisation Policy Rules (e.g. Auth(Any, Read Doc1)) Obligation Policy Rules (Resource Configuration etc..) MembersResources Rules for owned resources Other rules refining mandate Members Resources Membership rule Authorisation & obligation rules for delegated resources Any other rules that parent wants to specify Mandate Policy Store subset

8. © KF.VW,DLwww.cs.tcd.ie 8 Rule for Delegation Resources are organised in hierarchical trees. Each node on the resource tree has an Authorisation Tree associated with it. The Authorisation tree is based on the implies relationship between authorisations. For a community to delegate authorisation A with target Resource X –The community must own resource X, or a resource higher in the resource tree or have been delegated it by its parent. –The community must itself have authorisation rule A, or an authorisation higher in the authorisation tree Simple Authorisation Tree (resource is file)

9. © KF.VW,DLwww.cs.tcd.ie 9 Community B Community A Hierarchical application of policy rules Resource X (delegated) Resource X (owned) Community C Mandated communities Resource X (delegated) 1. Members of community C author new policy rule P with Target resource X. Agency rules for resource X validated. 2. Agent of C passes P to Community B 3. B Checks that X has been delegated to C. Detects conflicts between P and policies applied to X by B. 4. Agent of B passes P to Community A 5. A Checks that X has been delegated to B. Detects conflicts between P and policies applied to X by A. 6. P is deployed to target Resource.

10. © KF.VW,DLwww.cs.tcd.ie 10 Indymedia Case Study

11. © KF.VW,DLwww.cs.tcd.ie 11 Architecture

12. © KF.VW,DLwww.cs.tcd.ie 12 Conclusions & Future Directions Community structure features: –Policy conflict resolution and refinement paths –Decentralised organisations and decision making –Dynamic structure minimises deployment costs. Currently performing full experiment in large, self- managed, online community Exploring use of Ontology languages (DAML/OWL) to describe resources (authorisation trees etc) Exploring extensibility of concept to traditional organisations. Performing experiments with simulated scenarios of organisational change in traditional organisations (e.g. Virtual Organisations)