quiz10_sol - such that for any a, b L there is a least...

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CIS 4360 Introduction to Computer Security QUIZ 10, Fall 2011 (5 minutes only) – with answers This quiz concerns access control. 1. Complete the sentences. (a) What is an Access Control matrix? Answer. A matrix whose rows are indexed by the subjects s and columns by the objects o , for which the entry in the ( s, o ) cell contains a list of operations that s can perform on o . (b) If the access rights are kept with the subjects then every subject is given a : capability . (c) If the access rights are kept with the objects then every object has an : Access Control List . (d) Defne a lattice ( L, ). Answer: L is a non-empty set with a partial ordering “
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Unformatted text preview: such that for any a, b L there is a least upper bound (lub) for a, b in L and a greatest lower bound (glb). (e) Let H = { , 1 , 2 , 3 } , with the natural order . Let C be the set oF subsets oF C = { a, b, c } . Consider the set oF L oF all pairs ( h, X ) where X is a subset oF C . i. How many elements does L have? Answer: 2 3 4 = 32 ii. Defne an ordering on L which makes it into a lattice. ( h, X ) ( h , X ) iF: Answer: and only if h h and X X . Mike Burmester...
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This document was uploaded on 12/04/2011.

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