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.

翻译：鉴于无许可区块链的广泛采用及其经济影响，以及底层系统的复杂性和其运行的对抗性环境，深入研究和理解这些系统的涌现行为及特性至关重要。本文详述了我们从多个地理分散的观测点对以太坊网络进行为期一个月的细致研究经验。通过利用多个地理视角，我们评估了以太坊的关键支柱，即地理分布、网络效率、区块链效率与安全性，以及矿池的影响。除其他新发现外，我们识别了此前未记载的自私行为形式，并表明强大矿池的盛行加剧了地理因素对区块传播延迟的影响。此外，为促进对无许可区块链的进一步研究，我们提供了一套开源的测量与处理工具，以及所收集测量数据的数据集。