On the Construction of Covert Networks

Centrality measures are widely used to identify leaders of covert networks. We study how a group of such leaders can avoid being detected. In more detail, we study the hardness of modifying the network in order to decrease the leaders' ranking positions according to three fundamental centrality measures, namely degree, closeness, and betweenness. We then study how the leaders can construct a network from scratch, designed specifically to keep them hidden. We identify a network structure that not only guarantees to hide the leaders to a certain extent, but also allows them to spread their influence across the network.