I have reviewed this document as part of the security directorate's ongoing effort to review all IETF documents being processed by the IESG. These comments were written primarily for the benefit of the security area directors. Document editors and WG chairs should treat these comments just like any other last call comments. The summary of the review is ready. This document describes an online certificate enrollment protocol that automates the certificate issuance and verification process. The document currently focuses on the web server use case where the identifier is a domain name. The security considerations section is well-written and detailed. I don't see any issues with this document.