© 2005 Ravi Sandhuwww.list.gmu.edu

Role Usage and Activation Hierarchies

(best viewed in slide show mode)

Ravi SandhuLaboratory for Information Security Technology

George Mason Universitywww.list.gmu.edusandhu@gmu.edu

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Reference• Ravi Sandhu, “Role Hierarchies and Constraints for Lattice-Based

Access Controls.” Proc. Fourth European Symposium on Research in Computer Security, Rome, Italy, September 25-27, 1996, pages 65-79. Published as Lecture Notes in Computer Science, Computer Security-ESORICS96 (Elisa Bertino et al, editors), Springer-Verlag, 1996.

• Ravi Sandhu, “Role Activation Hierarchies.” Proc. Third ACM Workshop on Role-Based Access Control, Fairfax, Virginia, October 22-23, 1998, pages 33-40.

• Sylvia Osborn, Ravi Sandhu and Qamar Munawer. “Configuring Role-Based Access Control to Enforce Mandatory and Discretionary Access Control Policies.” ACM Transactions on Information and System Security, Volume 3, Number 2, May 2000, pages 85-106.

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© 2005 Ravi Sandhuwww.list.gmu.edu

Role hierarchies

• Two aspects• Role usage: permission inheritance

• Role activation: activation hierarchy

• RBAC96 combines both aspects in a single hierarchy• ANSI/NIST standard model leaves this open

• Do one or both, just make it clear what you are doing

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Example Role Hierarchy

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LBAC to RBAC

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Simple security property

• some variations of LBAC use 2 labels for subjects• λr for read and λw for read • λr = λw for the single label case

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Variations of *-property

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LBAC to RBAC: independent read-write hierarchies

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LBAC to RBAC: intertwined read-write hierarchies

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Activation hierarchies and dynamic SOD

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Formal definition

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Activation hierarchy with non-maximal roles

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Read-write RBAC and LBAC

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LBAC with trusted strict *-property