Measuring the robustness of a network using minimal vertex covers

We define two quantities associated to each of the vertices of a simple graph, based on the collection of minimal vertex covers of the graph. They are called covering degree and covering index. We use them to describe new strategies for measuring the robustness of a network. We study the correlation between the defined quantities and other quantities used in the context of network attacks. Using the attack strategies associated to these quantities we study their effect on the connectedness of several network models. We also consider the complexity of the computation of the defined quantities and use a computational commutative algebra approach for their actual computation.