A Survey and Taxonomy of Internet Censorship Methods

Despite the significance of the Internet in global information exchange, authorities in many jurisdictions apply censorship to online communications within their sphere of influence. Some people consider censorship a violation of human rights, such as the freedom of expression or the right to access information. Others view censorship methods as a means of social control, protecting national security or social harmony. Regardless of the motivation, researchers, policymakers, and technology practitioners should have a thorough understanding of the capabilities of Internet censors. We present a taxonomy of Internet censorship methods derived from a systematic review of the literature and analysis of the technology that has enabled the Internet’s progression. We describe the technical means that censors implement, contextualized by the legal and social circumstances in which they have occurred over the past three decades. We assert that the taxonomy has pedagogical value and serves as a research framework for further studies. Our study illuminates the dynamic challenges faced in interdisciplinary research on Internet censorship, offering direction for future work on Internet measurement, censorship circumvention, and protocol standards design.