Last Call Review of draft-ietf-tcpinc-tcpeno-10
review-ietf-tcpinc-tcpeno-10-secdir-lc-ladd-2017-10-19-00

Dear all,

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 that the writing and most of the
structure is fine, but I am a bit confused by some of the security
properties and how they are stated. It is not clear to me why the
unpredictability of generated session IDs is required. It is also not
clear to me that the requirement that a TEP produce different keys for
different transcripts is strong enough: we need to ensure that every
TEP produces different keys (with high probability) (and session
identifiers) for different transcripts to prevent cross-protocol
attacks.

Sincerely,
Watson Ladd