Solved: In a company, the lattice model of information

Chapter 8, Problem 8.6.47

(choose chapter or problem)

In a company, the lattice model of information flow is used to control sensitive information with security classes represented by ordered pairs (A, C). Here A is an authority level, which may be nonproprietary (0), proprietary (1), restricted (2), or registered (3). A category C is a subset of the set of all projects {Cheetah, Impala, Puma}. (Names of animals are often used as code names for projects in companies.) a) Is information permitted to flow from (Proprietary, {Cheetah, Puma}) into (Restricted, {Puma})? b) Is information permitted to flow from (Restricted, {Cheetah}) into (Registered, {Cheetah, Impala})? c) Into which classes is information from (Proprietary, { Cheetah, Puma}) permitted to flow? d) From which classes is information permitted to flow into the security class (Restricted, {Impala, Puma})?