Reference no: EM133394291

Assignment:

(a) Consider a network where it is only known that the average path length differs substantially from the median path length. Formulate and justify hypotheses that can be formulated about other graph characteristics such as degree distribution and eccentricity? Give a reasoned answer.

(b) An attacker has obtained inside information about a targeted network, but is limited to knowing only the betweenness centrality of every switch/router in the targeted network.

(i) Give a definition (a formal definition is desirable) for betweenness centrality of vertices in a graph.

(ii) Describe a possible attack strategy to maximise disruption that the attacker can pursue based on the above information for the particular case where the attacker can launch multiple attacks in sequence. Give a rationale for why this attack strategy will be an improvement over randomly targeting switches/routers.

(c) Different models can be used to study large-scale networks and their characteristics.

(i) Briefly describe the Erdos-R ? enyi (ER) graph model.

(ii) Give a brief argument for why the ER model is poorly suited to model infrastructure networks such as power networks or the Internet based on what is known about the characteristics of the actual infrastructure.