Evolution of network robustness under continuous topological changes

• The iterative attack/defense model on links is proposed.
• The performance of different attack/defense strategy is intensively evaluated.
• High-degree and high-centrality attacks are effective node attack strategies.
• The best edge attack is removing edges with the highest edge-betweenness.
• Connecting low centrality nodes can increase RR, but cannot enhance RlRl.

Many networks in reality face a dynamic iteration of attacking and defending, in which attackers and defenders take turns to destroy and replenish networks. The framework of iterative attacking and defending has been introduced, and Kim and Anderson gave an iterative model with much finer granularity and empirically studied three attack/defense strategies on nodes. However, in real-world networks, the failure can also occur on links. We therefore extend the iterative attack/defense strategies to links and apply the robustness measure RR and the link-robustness RlRl to evaluate the performance of each attack/defense strategy. Through intensive experiments on several well-known networks, the defense strategy of connecting nodes with low-centrality is effective enough to maintain network connectivity and increase the network robustness RR against targeted node attacks, but it cannot enhance the link-robustness RlRl against malicious link attacks during the iterative rounds. Significantly, on two real-world networks, this strategy is perfect for simultaneously enhancing the robustness RR and the link-robustness RlRl.