This server is running a web crawler that periodically scans entire zone files (such as .nl) and measures how many domain names use post-quantum cryptography (PQC) on their websites.
Why?
We are interested in measuring the uptake of PQC-enabled websites.
The measured data is published in a graph on stats.sidnlabs.nl. We only store aggragated results (number of domains with and without PQC support, number of domains per ASN) for later analysis.
What?
This crawler performs two functions: (1) resolve all domain names within a zone file, and (2) crawl the website for each domain and determine whether it supports PQC.
We currently support both the following algorithms: mlkem512,mlkem768,mlkem1024,SecP256r1MLKEM768,X25519MLKEM768,SecP384r1MLKEM1024.
We gladly refer to IANA's list of TLS algorithms for more information and references to these algorithms. As of 2026, we have removed support for the draft algorithms X25519Kyber768Draft00 and SecP256r1Kyber768Draft00.
We connect to webservers and only offer these algorithms using OpenSSL, without fallback to other algorithms. When we can succesfully connect and setup a secure connection, we know PQC is supported, otherwise not. We only collect the (binary) success/failure status for each queried domain name. At the end of the crawl, we store aggregated data for later analysis and plotting as graphs.
We currently run our crawls using the IP addresses 2001:67c:e6c:1700:be24:11ff:feda:f8d4 and 145.102.0.212.
Contact
If you have any questions, please contact us.