Domain Security Census: Aggregate Dataset

The Domain Security Census grades the registered-domain population on the public signals that decide whether a domain's email can be forged and whether its website is safe to visit: SPF, DMARC, DKIM, MX, reverse DNS, DNSSEC, CAA, name servers, SOA, HTTPS, TLS, certificates, IPv6 and the main HTTP security headers. Each domain receives a grade from A+ to F under a published methodology. A census, not a sample. Each edition scans every registered domain name listed in ICANN CZDS zone files, OpenINTEL and CommonCrawl, and grades every one that exists. Every figure is a full count over the scanned population, so the figures carry no sampling error, and the per-TLD breakdowns come from the same scan. Scope. The count covers every name the three sources list. Registered names that none of them lists are outside the census. In version 2026-11, 29,372,893 names that exist were scanned and reported as indeterminate (15,616,388) or unreachable (13,756,505); they are counted separately from the graded base. The README of each version gives that edition's coverage: names sourced, scanned, existing and graded, and the TLDs scanned and broken out. This record holds the census's monthly aggregate files. Every file is a count or a share of counts, overall and for each top-level domain broken out. No file names a domain, and no row describes a single domain. Each monthly edition is deposited as a new version of this record. The README.md deposited with each version gives that edition's basis, from names sourced to domains graded, every denominator the files use, a section per file with worked examples, the edition's highlights and its method notes. Read it before quoting a figure. Cite this dataset by its concept DOI, which resolves to the newest edition: Defaults Exposed FZ-LLC. (2026). Domain Security Census: Aggregate Dataset (Version 2026-11) [Data set]. Zenodo. https://doi.org/10.5281/zenodo.22690388 Also published as CSV tables on Kaggle (https://www.kaggle.com/datasets/defaultsexposed/domain-security-census) and Hugging Face (https://huggingface.co/datasets/defaultsexposed/domain-security-census). Current figures: https://defaults.exposed/data