Robustness of Complex Networks Considering Attack Cost

Robustness of complex networks has attracted much attention in diverse disciplines. Most of previous studies did not consider the attack cost. In this paper, the network robustness is studied with the consideration of attack cost, with different complex network models and different robustness indices. It is found that with different cost function and attack budget, the best attack strategy changes. When the budget is low and attacking hubs costs much more than attacking an unimportant node, then the high-degree attack (HDA) strategy performs worse than the low-degree attack (LDA) strategy. On the contrary, HDA is always a better strategy when the budget is high. Therefore, there is an intersection before and after that different attack strategies perform better. The position of this intersection is affected by the network structure, robustness index, cost function and the budget.