Vulnerability of weighted networks

Abstract

In real networks complex topological features are often associated with a diversity ofinteractions as measured by the weights of the links. Moreover, spatial constraints may alsoplay an important role, resulting in a complex interplay between topology, weight, andgeography. In order to study the vulnerability of such networks to intentional attacks, theseattributes must therefore be considered along with the topological quantities. In order totackle this issue, we consider the case of the worldwide airport network, which is a weightedheterogeneous network whose evolution and structure are influenced by traffic andgeographical constraints. We first characterize relevant topological and weighted centralitymeasures and then use these quantities as selection criteria for the removal ofvertices. We consider different attack strategies and different measures of thedamage achieved in the network. The analysis of weighted properties shows thatcentrality driven attacks are capable of shattering the network’s communication ortransport properties even at a very low level of damage in the connectivity pattern.The inclusion of weight and traffic therefore provides evidence for the extremevulnerability of complex networks to any targeted strategy and the need for them to beconsidered as key features in the finding and development of defensive strategies.