Certificate Transparency

What is Certificate Transparency?

Certificate Transparency (CT) is a framework of public logs that record the issuance of SSL/TLS certificates. When a CA issues a certificate, it must log it to multiple CT logs. This allows domain owners and security researchers to monitor for unauthorized or misissued certificates. Security tools can query CT logs to discover subdomains, detect rogue certificates, and identify potential phishing infrastructure before it is used in attacks.