Blockchains, in general, and cryptocurrencies such as Bitcoin, in particular, are realized using distributed systems and hence critically rely on the performance and security of the interconnecting network. The requirements on these networks and their usage, however, can differ significantly from traditional communication networks, with implications on all layers of the protocol stack. This article is motivated by these differences and, in particular, by the observation that many fundamental design aspects of these networks are not well-understood today. To support the networking community to contribute to this emerging application domain, we present a structured overview of the field, from topology and neighbor discovery, over block and transaction propagation, to sharding and off-chain networks, also reviewing existing empirical results from different measurement studies. In particular, for each of these domains, we provide the context, highlighting differences and commonalities with traditional networks, review the state-of-the-art, and identify open research challenges. Our article can hence also be seen as a call-to-arms to improve the foundation on top of which blockchains are built.

中文翻译：

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区块链网络调查

一般来说，区块链，尤其是比特币等加密货币是使用分布式系统实现的，因此严重依赖于互连网络的性能和安全性。然而，对这些网络的要求及其使用可能与传统的通信网络有很大不同，这对协议栈的所有层都有影响。这篇文章的动机是这些差异，特别是观察到这些网络的许多基本设计方面今天还没有得到很好的理解。为了支持网络社区为这个新兴的应用领域做出贡献，我们提供了该领域的结构化概述，从拓扑和邻居发现，到块和交易传播，到分片和链下网络，还回顾了来自不同测量研究的现有经验结果。特别是，对于这些领域中的每一个，我们都提供了背景，突出了与传统网络的差异和共性，回顾了最新技术，并确定了开放的研究挑战。因此，我们的文章也可以被视为一个号召，以改善构建区块链的基础。