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. This document defines channel binding types for Transport Layer Security (TLS), in accordance with RFC 5056. The security considerations section seems adequate to me (especially the discussion about the consequences of sending channel binding data in the authentication mechanism). It would have been nice with an example of an authentication mechanism using one of the channel bindings in this document, perhaps in the form of an illustrative appendix. Nits: -Section 2 should reference RFC 5056, not RFC 5246. -There should be some spell checking, like "descritption" -- Magnus