About
Project Team
- Jonas Mücke, TU Dresden
- Konstantin Gasser, TU Dresden
- Thomas C. Schmidt, HAW Hamburg
- Matthias Wählisch, TU Dresden
Contact
For questions about the measurement or this site, contact jonas.muecke@tu-dresden.de.
Partners
Discovering Encrypted Client Hello Deployments by Active ECH Probing
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.
If you use data or tools, please cite our 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). ACM, New York, NY, USA, 276–286. https://doi.org/10.1145/3777912.3839832
@inproceedings{10.1145/3777912.3839832,
author = {M{\"u}cke, Jonas and Gasser, Konstantin and Schmidt, Thomas C. and W{\"a}hlisch, Matthias},
title = {Discovering Encrypted Client Hello Deployments by Active ECH Probing},
year = {2026},
isbn = {9798400723278},
publisher = {ACM},
address = {New York, NY, USA},
url = {https://doi.org/10.1145/3777912.3839832},
doi = {10.1145/3777912.3839832},
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.},
booktitle = {Proceedings of the 2026 ACM Internet Measurement Conference},
pages = {276–286},
numpages = {11},
keywords = {ECH, TLS, HTTPS, DNS, privacy, hypergiant deployment},
location = {Karlsruhe, Germany},
series = {IMC '26}
}