INFO5301 Information Security Management
nates (L2,C2)iff; L 1≥L2and C 2⊆C1.
Answer:
2.2What does a path between two nodes in the lattice mean?
Answer: A path in the lattice from one node (L1) to another (L2) says that L2 dominates
L1. That means “information is allowed to flow" from L1 to L2. That can happen in either of
two ways:
- a subject at level L2 can read a level L1 object, or
- a subject at level L1 can write a level L2 object.
(Discussion:7 mins)
Exercise 3
Duration: 15 mins
Now, assume that the above company has decided to expand the security model presented
in Table 1 categorising objects in each security class into categories according to "need-to-
know" principle. The considered tree categories are (i) Financial - [FIN], (ii) Operational -
[OPR], and (iii) Research - [RES].
3.1Draw a lattice for to show dominance relationship among difference combinations of
category labels in a given security level.
Answer:
3.2Assume that Bob is cleared into security level (SC, [FIN, OPR]), and the following three
objects (files in this case) are classified as below;
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