Error and attack tolerance of complex networks
Réka Albert, Hawoong Jeong, Albert-Ĺaszló Barabási · Princeton University Press eBooks · 2011
Many complex systems display a surprising degree of tolerance against errors.For example, relatively simple organisms grow, persist and reproduce despite drastic pharmaceutical or environmental interventions, an error tolerance attributed to the robustness of the underlying metabolic network [1].Complex communication networks [2] display a surprising degree of robustness: while key components regularly malfunction, local failures rarely lead to the loss of the global information-carrying ability of the network.The stability of these and other complex systems is often attributed to the redundant wiring of the functional web defined by the systems' components.In this paper we demonstrate that error tolerance is not shared by all redundant systems, but it is displayed only by a class of inhomogeneously wired networks, called scale-free networks.We find that scale-free networks, describing a number of systems, such as the World Wide Web (www) [3][4][5], Internet [6], social networks [7] or a cell [8], display an unexpected degree of robustness, the ability of their nodes to communicate being unaffected by even unrealistically high failure rates.However, error tolerance comes at a high price: these networks are extremely vulnerable to attacks, i.e. to the selection and removal of a few nodes that play the most important role in assuring the network's connectivity.Such error tolerance and attack vulnerability are generic properties of communication networks, such as the Internet or the www, with complex implications on assuring information readiness.