Given the large adoption and economical impact of permissionless blockchains,
the complexity of the underlying systems and the adversarial environment in
which they operate, it is fundamental to properly study and understand the
emergent behavior and properties of these systems. We describe our experience
on a detailed, one-month study of the Ethereum network from several
geographically dispersed observation points. We leverage multiple geographic
vantage points to assess the key pillars of Ethereum, namely geographical
dispersion, network efficiency, blockchain efficiency and security, and the
impact of mining pools. Among other new findings, we identify previously
undocumented forms of selfish behavior and show that the prevalence of powerful
mining pools exacerbates the geographical impact on block propagation delays.
Furthermore, we provide a set of open measurement and processing tools, as well
as the data set of the collected measurements, in order to promote further
research on understanding permissionless blockchains.Comment: To appear in 50th IEEE/IFIP International Conference on Dependable
Systems and Networks (DSN), 202