Investigating the OpenPGP web of trust

Abstract

We present results of a thorough analysis of the OpenPGP Web of Trust. We conducted our analysis on a recent data set with a focus on determining properties like usefulness and robustness. To this end, we analyzed graph topology, identified the strongly connected components and derived properties like verifiability of keys, signature chain lengths and redundant signature paths for nodes. Contrary to earlier works, our analysis revealed the Web of Trust to be only similar to a scale-free network, with different properties regarding the hub structure and its influence on overall connectivity. We also analyzed the community structure of the Web of Trust and mapped it to social relationships. Finally, we present statistics which cryptographic algorithms are in use and give recommendations. © 2011 Springer-Verlag.