7. Security Considerations

7. Security Considerations

With CAs, logs, and servers performing the actions described here, TLS clients can use logs and signed timestamps to reduce the likelihood that they will accept misissued certificates. If a server presents a valid signed timestamp for a certificate, then the client knows that the certificate has been published in a log. From this, the client knows that the subject of the certificate has had some time to notice the misissue and take some action, such as asking a CA to revoke a misissued certificate. A signed timestamp is not a guarantee that the certificate is not misissued, since the subject of the certificate might not have checked the logs or the CA might have refused to revoke the certificate.

In addition, if TLS clients will not accept unlogged certificates, then site owners will have a greater incentive to submit certificates to logs, possibly with the assistance of their CA, increasing the overall transparency of the system.