Internet censorship limits the access of nodes residing within a specific network environment to the public Internet, and vice versa. During the last decade, techniques for conducting Internet censorship have been developed further. Consequently, methodology for measuring Internet censorship had been improved as well. In this paper, we firstly provide a survey of network-level Internet censorship techniques. Secondly, we survey censorship measurement methodology. We further cover the censorship of circumvention tools and its measurement, as well as available datasets. In cases where it is beneficial, we bridge the terminology and taxonomy of Internet censorship with related domains, namely traffic obfuscation and information hiding. We further extend the technical perspective with recent trends and challenges, including human aspects of Internet censorship.

翻译：互联网审查限制了特定网络环境内节点对公共互联网的访问，反之亦然。在过去十年中，实施互联网审查的技术得到了进一步发展，相应的测量方法也随之改进。本文首先综述了网络层面的互联网审查技术，其次系统梳理了审查测量方法论。我们还涵盖了规避工具的审查及其测量方法，以及现有数据集。在适当情况下，我们将互联网审查的术语和分类体系与相关领域——即流量混淆和信息隐藏——进行了关联。此外，我们从技术视角延伸探讨了最新趋势与挑战，包括互联网审查中的人为因素。