Two-Server Network Disconnection Problem

Abstract

Consider a set of users and servers connected by a network. Each server provides a unique service which is of certain benefit to each user. Now comes an attacker, who wishes to destroy a set of edges of the network in the fashion that maximizes his net gain, namely, the total disconnected benefit of users minus the total edge-destruction cost. We first discuss that the problem is polynomially solvable in the single-server case. In the multiple-server case, we will show, the problem is, however, NP-hard. In particular, when there are only two servers, the network disconnection problem becomes intractable. Then a -approximation algorithm is developed for the two-server case.