Public SSL & TLS Security Intelligence Hub
Reference guides on TLS misconfigurations and Certificate Transparency — what each issue is, why it matters and how to fix it. 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 the certificates publicly trusted CAs issue, and how to use them to spot issuance for your domains that you did not request.
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 what each one takes to fix.
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.