Public SSL & TLS Security Intelligence Hub
Reference guides on TLS misconfigurations and Certificate Transparency, built from public CT-log data and industry research — free to read, no signup required.
Intelligence Guides
In-depth references on the TLS issues that cause real outages — free to read and share.
The most common TLS/SSL configuration errors seen across the web — what causes each one, why it matters, and exactly how to fix it.
How public CT logs record every certificate issued globally, and how to use them to detect rogue issuance for your domains early.
Why We Publish These Guides
Transparency and information sharing make the web safer. Certificate security affects everyone — so the knowledge should be public.
Learn which TLS misconfigurations actually cause outages and breaches, and how prevalent each one is.
Run your own domain through our free checkers to see where your configuration stands.
Pair these guides with automated monitoring so certificate expiry never takes you by surprise.