Building resilient low-diameter peer-to-peer topologies

As more applications rely on underlying peer-to-peer topologies, the need for efficient and resilient infrastructure has become more pressing. A number of important classes of topologies have emerged over the last several years, all with various strengths and weaknesses. For example, the popular structured peer-to-peer topologies based on distributed hash tables (DHTs) offer applications assured performance, but are not resilient to attacks and major disruptions that are likely in the overlay. In contrast, unstructured topologies where nodes create random connections among themselves on-the-fly, are resilient to attacks but can not offer performance assurances because they often create overlays with large diameters, making some nodes practically unreachable. We propose Phenix, a peer-to-peer algorithm for building resilient low-diameter peer-to-peer topologies that can resist different types of organized and targeted malicious behavior. Phenix leverages the strengths of these existing approaches without inheriting their weaknesses and is capable of building topologies of nodes that follow a power-law while being fully distributed requiring no central server, thus, eliminating the possibility of a single point of failure in the system. We present the design and evaluation of the algorithm and show through extensive analysis, simulation, and experimental results obtained from an implementation on the PlanetLab testbed that Phenix is robust to network dynamics such as bootstrapping mechanisms, joins/leaves, node failure and large-scale network attacks, while maintaining low overhead when implemented in an experimental network.