Volume 80, Number 5, December 2007
Article Number 58002
Number of page(s) 5
Section Interdisciplinary Physics and Related Areas of Science and Technology
Published online 31 October 2007
EPL, 80 (2007) 58002
DOI: 10.1209/0295-5075/80/58002

Scale-free networks resistant to intentional attacks

L. K. Gallos and P. Argyrakis

Department of Physics, University of Thessaloniki - 54124 Thessaloniki, Greece

received 30 July 2007; accepted in final form 9 October 2007; published December 2007
published online 31 October 2007

We study the detailed mechanism of the failure of scale-free networks under intentional attacks. Although it is generally accepted that such networks are very sensitive to targeted attacks, we show that for a particular type of structure such networks surprisingly remain very robust even under removal of a large fraction of their nodes, which in some cases can be up to 70%. The degree distribution P(k) of these structures is such that for small values of the degree k the distribution is constant with k, up to a critical value kc, and thereafter it decays with k with the usual power law. We describe in detail a model for such a scale-free network with this modified degree distribution, and we show both analytically and via simulations, that this model can adequately describe all the features and breakdown characteristics of these attacks. We have found several experimental networks with such features, such as for example the IMDB actors collaboration network or the citations network, whose resilience to attacks can be accurately described by our model.

89.75.Hc - Networks and genealogical trees.
89.75.Da - Systems obeying scaling laws.
87.23.Ge - Dynamics of social systems.

© Europhysics Letters Association 2007