Reducing Network Vulnerability to Malicious Attacks

The underlying networks of many physical systems, including critical infrastructures, exhibit properties of complex networks such as scale-free properties. It is well-known that scale-free networks can tolerate random failures but show high vulnerabilities to targeted attacks, particularly compared to random networks of the same scale. In recent years many efforts have been made to reduce the vulnerability of such networks to targeted attacks by adding and/or rewiring links. However, to the best of our knowledge, the existing methods do not take attack patterns into consideration when determining how to improve or evaluate the resilience of a network. In this paper, we define an attack-dependent measure of vulnerability for networks and show that the problem of minimizing network vulnerability by adding a limited number of links while considering a potential attacks is NP-hard. Since the problem is intractable, we suggest a heuristic algorithm to reduces the vulnerability of a network with respect to specific attacks in polynomial time. By experimental results, we show that our approach outperforms the existing methods of network resiliency enhancement.