The Typed Access Matrix Model (TAM) and Augmented TAM (ATAM)

1. The Typed Access Matrix Model (TAM) and Augmented TAM (ATAM) Ravi Sandhu Laboratory for Information Security Technology George Mason University www.list.gmu.edu sandhu@gmu.edu

2. TAM: Typed Access Matrix Model TAM adds types to HRU and preserves strong safety results of SPM/ESPM SO-TAM: Single Object TAM SO-TAM manipulates one column of the access matrix at a time and is equivalent to TAM ATAM: Augmented TAM ATAM adds testing for absence of rights to TAM ATAM is equivalent to TAM in one sense but more expressive in another Outline

3. TAM adds types to HRU

4. TAM adds types to HRU

5. TAM commands

6. TAM primitive operations

7. TAM operations: enter and delete

8. TAM operations: create and destroy

9. TAM operations: create and destroy

10. ORCON in TAM

11. ORCON in TAM

12. ORCON in TAM

13. ORCON in TAM

14. MTAM: Monotonic TAM

15. MTAM Canonical Schemes

16. MTAM Canonical Schemes

17. ORCON as a MTAM Canonical Scheme

18. Acyclic TAM schemes

19. Acyclic TAM unfolded state

20. Acyclic MTAM unfolded state

21. Acyclic MTAM safety

22. Ternary MTAM

23. Ternary MTAM

24. Binary and Unary MTAM • Unary MTAM • Useless • Binary MTAM • Single-parent creation or spontaneous double-child creation • Less expressive than multi-parent creation

25. SOTAM: single object TAM

26. SOTAM • SOTAM is equivalent in expressive power to TAM

27. ATAM: Augmented TAM • Allow testing for absence of rights in the conditions of commands • ATAM is equivalent in expressive power to TAM in unbounded simulation but most likely not in bounded simulation • “Most likely not” has recently been shown to be “provably cannot”