title: Stability and topology of scale-free networks under attack and defense strategies.
abstract: We study tolerance and topology of random scale-free networks under attack and defense strategies that depend on the degree k of the nodes. This situation occurs, for example, when the robustness of a node depends on its degree or in an intentional attack with insufficient knowledge of the network. We determine, for all strategies, the critical fraction p(c) of nodes that must be removed for disintegrating the network. We find that, for an intentional attack, little knowledge of the well-connected sites is sufficient to strongly reduce p(c). At criticality, the topology of the network depends on the removal strategy, implying that different strategies may lead to different kinds of percolation transitions.
authors.affiliation: Department of Physics, University of Thessaloniki, 54124 Thessaloniki, Greece.
authors.forename: Lazaros K
authors.initials: LK
authors.lastname: Gallos
authors.forename: Reuven
authors.initials: R
authors.lastname: Cohen
authors.forename: Panos
authors.initials: P
authors.lastname: Argyrakis
authors.forename: Armin
authors.initials: A
authors.lastname: Bunde
authors.forename: Shlomo
authors.initials: S
authors.lastname: Havlin
mesh_terms: D000818:Animals; D002468:Cell Physiological Phenomena; D003195:Computer Communication Networks; D016494:Computer Security; D003198:Computer Simulation; D006801:Humans; D007113:Immunity, Innate / Q000276:immunology*; D008954:Models, Biological; D009415:Nerve Net / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology*