RFC 6962. Certificate Transparency is a way for interested parties, such as Certificate Authorities, to provide a publicly auditable record of certificate issuance, through submitting these certificates to a Certificate Transparency Log.
Discussions related to Chromium's Certificate Transparency support happen on the Certificate Transparency Policy group/mailing list.
In order to help protect the users of the Chromium Projects, CAs are expected to support Certificate Transparency. This allows users, the Chromium Authors, and the public to publicly audit that CAs are conforming to the policies set out in the Root Certificate Policy.
Currently, Chromium does not enforce that all Root CAs support Certificate Transparency for all certificates. However, it is required for some CAs, and it is required in order to have a certificate recognized as an EV certificate, that the certificate MUST be CT Qualified. For more details, including timelines and requirements, see the Certificate Transparency in Chrome Policy.
In order for a Log to be included within Chromium, it must meet the requirements of the Certificate Transparency Log Policy. The Log Policy also describes the steps for Log Operators to submit Logs for inclusion within Chromium.
The following table includes information about the Certificate Transparency Logs that are recognized by Chromium. It includes information about who operates the log, the name the log has been given, and the URL that can be used for logging certificates or inspecting the certificates that have been logged.
Note: The authoritative list is maintained in the Chromium source code. This is merely informational.
Once, but no longer, Qualified Logs