Adversarial analysis of similarity-based sign prediction

Adversarial social network analysis explores how social links can be altered or otherwise manipulated to hinder unwanted information collection. To date, however, problems of this kind have not been studied in the context of signed networks in which links have positive and negative labels. Such formalism is often used to model social networks with positive links indicating friendship or support and negative links indicating antagonism or opposition. In this work, we present a computational analysis of the problem of attacking sign prediction in signed networks, whereby the aim of the attacker (a network member) is to hide from the defender (an analyst) the signs of a target set of links by removing the signs of some other, non-target, links. While the problem turns out to be NP-hard if either local or global similarity measures are used for sign prediction, we provide a number of positive computational results, including an FPT-algorithm for eliminating common signed neighborhood and heuristic algorithms for evading local similarity-based link prediction in signed networks.