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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. TAM: Typed Access Matrix Model TAM adds types to HRU and preserves strong safety results of SPM/ESPM
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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
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
Binary and Unary MTAM • Unary MTAM • Useless • Binary MTAM • Single-parent creation or spontaneous double-child creation • Less expressive than multi-parent creation
SOTAM • SOTAM is equivalent in expressive power to TAM
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”