On trusting introductions from a reputable source: A utility-maximizing probabilistic approach

In many network environments, a node seeks to expand the number of connections to other nodes who can make valuable transactions possible. In the possible presence of misbehaving nodes, who make harmful transactions possible, each (behaving) node must use discretion on whether to accept a prospective connection. We study this problem when the mechanism for expansion is an introduction-based reputation protocol [1]: a prospective connection between two nodes is offered only by way of introduction via a third party already connected to both nodes, and each node´s accept/decline decision is driven by a privately-managed pool of reputations. Our probabilistic analysis exposes a delicate interplay between the policies for managing established and prospective connections as well as assumptions on adversary behavior and information decentralization. Our results are illustrated by examples.