Formalizing Dependence of Web Infrastructure

Over the past decade, Internet centralization and its implications for privacy, resilience, and innovation have become a topic of active debate. While the networking community informally agrees on the definition of centralization, we lack a formal metric for quantifying it, which has limited in-depth analysis. In this work, we introduce a rigorous statistical metric for Internet centralization. In doing so, we also uncover how regionalization—geopolitical dependence on the Internet—fundamentally affects centralization. We argue that centralization and regionalization are intertwined forms of dependence that both affect the lived experiences of users and should be jointly studied. We develop a suite of statistical tools, which we use to better understand dependence across three layers of web infrastructure—hosting providers, DNS infrastructure, certificate authorities—in 150 countries. We hope that this statistical toolkit can serve as the foundation for future analysis of Internet behavior.