Graph Analysis of Blockchain P2P Overlays and Their Security Implications.

In blockchain systems, similar to any distributed system, the underlying network plays a crucial role and provides the infrastructure for communication and coordination among the participating peers. As a result, the properties of the network define the level of security, availability, and fault tolerance within a blockchain system. This study aims to improve our understanding of the structural properties of peer-to-peer overlay networks that underpin blockchain applications. Our objective is to gain insights into the security and resilience of these systems. By analyzing seven distinct blockchain overlay networks and evaluating a comprehensive set of graph characteristics, we draw important conclusions about their overall robustness. Our findings reveal that major blockchain networks have vulnerabilities that make them susceptible to exploitation by malicious actors. Furthermore, despite relying on similar protocols for node discovery and network formation, we observe dissimilar characteristics among these blockchains.