Subject: [TICTOC] AD Evaluation: draft-ietf-tictoc-security-requirements

From: Brian Haberman <[email-masked]>
Date: Fri, 27 Jun 2014 10:56:04 -0400

Hi All,
     I have completed my AD Evaluation of
draft-ietf-tictoc-security-requirements as a part of the publication
process.  I found this document well-written and easy to read.  I have a
few comments/questions that I would like to see resolved before moving
this document to IETF Last Call.  Please let me know if you have any
questions/comments/concerns about these points...

Introduction
------------

* It would be useful to explain what is meant by an "inherent security
protocol" with respect to RFC 5905.

* Please explain why PTP is included in these requirements even though
it is not an IETF standard.  This will eliminate a variety of questions
come IESG Evaluation.

Section 3.1.1
-------------

* I think it would be useful to clarify the relationship between the
internal attacks and Byzantine attacks in this context.

Section 3.2.7
-------------

* Provide a few informative references to these types of attacks.

Section 3.2.8
-------------

* There is a missing "." at the end of the section.

Section 3.3
-----------

* Can you explain in what situations a False Time would not also be an
Accuracy Degradation?

Section 5
---------

* I think it may be worth mentioning when a requirement can be met by an
existing protocol/practice/technique.  Given the dependency on time
information for most security protocols, existence proofs would be useful.

Section 5.6.2
-------------

* Does this requirement apply equally to clocks at different levels of
the hierarchy?  For example, the association between a Stratum 2 clock
and a Stratum 3 clock in NTP may have different characteristics than an
association between two clocks at the same stratum level.

Section 5.10.2
--------------

* The MAY seems too weak.  It makes the support of a solution completely
optional.  How will operators ever transition to a secure mode if
vendors ignore the MAY?

Regards,
Brian