The Effect of Topology on the Attachment Process in Trust Networks

The massive use of web based social networks endorse trustworthiness to establish reliable relationships. Trust is often used to rank entities hence during the attachment process in a trust network, newcomers aim at improving their rank. Moreover, since in real systems each new link implies some cost for the node, we also consider how many links (i.e. how much effort) a node must exert in order to achieve a given rank. In this work, the rank-effort relationship in networks with a high number of nodes and different topologies - random and scale-free - also in presence of communities is considered, in order to examine how the topology affects the attachment process. Results show that the behavior is similar with differences on the effort required to get the same rank in different topologies; in addition, a good rank can be achieved with a considerably less effort than the best rank, thus a satisfactory rank-effort tradeoff can be found for each topology.