Modern economies rely heavily on their infrastructure networks. These networks face threats ranging from natural disasters to human attacks. As networks are pervasive, the investments needed to protect them are very large; this motivates the study of targeted defense. What are the 'key' nodes to...

Infrastructure networks -- in communication and transport -- are a key feature of an economy. The functionality of these networks depends on the connectivity and sizes of different components. However, these networks face a variety of threats ranging from natural disasters to intelligent attacks...

Individuals derive benefits from their connections, but these may, at the same time, transmit external threats. Individuals therefore invest in security to protect themselves. However, the incentives to invest in security depend on their network exposures. We study the problem of designing a...