Datasets for paper "Discovering Encrypted Client Hello Deployments by Active ECH Probing"

This data is supplement to https://doi.org/10.5281/zenodo.22012700 and contains the necessary data to recreate plots and tables of the following paper: Jonas Mücke, Konstantin Gasser, Thomas C. Schmidt, and Matthias Wählisch. 2026. Discovering Encrypted Client Hello Deployments by Active ECH Probing. In Proceedings of the 2026 ACM Internet Measurement Conference (IMC '26). Association for Computing Machinery, New York, NY, USA, 276–286. https://doi.org/10.1145/3777912.3839832

Paper abstract: We present a new measurement method to detect ECH deployments. This method leverages standard-compliant behavior of ECH servers. Prior measurements relied on DNS exposure and reported only one major ECH deployment (Cloudflare). Our measurements reveal yet undiscovered ECH deployments, including a large deployment at Meta. Meta servers support ECH, but ECH configuration is not exposed via the DNS. We also empirically study details such as the level of privacy improvement and latency impact of ECH.