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Shepherd writeup

This is the publication request and document shepherd write up for:

Network Time Security for the Network Time Protocol

Prepared by: Karen O’Donoghue, 7 November 2019

(1) What type of RFC is being requested (BCP, Proposed Standard, Internet
Standard, Informational, Experimental, or Historic)? Why is this the proper
type of RFC? Is this type of RFC indicated in the title page header?

Proposed Standard

This is a new badly needed security mechanism for client/server modes of
service for NTP. It is based on TLS. As such, it should be Standards Track, and
it has been proposed as such.

(2) The IESG approval announcement includes a Document Announcement Write-Up.
Please provide such a Document Announcement Write-Up. Recent examples can be
found in the "Action" announcements for approved documents. The approval
announcement contains the following sections:

Technical Summary:

This memo specifies Network Time Security (NTS), a mechanism for    using
Transport Layer Security (TLS) and Authenticated Encryption with Associated
Data (AEAD) to provide cryptographic security for the client-server mode of the
Network Time Protocol (NTP).

NTS is structured as a suite of two loosely coupled sub-protocols. The first
(NTS-KE) handles initial authentication and key establishment over TLS.  The
second handles encryption and authentication during NTP time synchronization
via extension fields in the NTP packets, and holds all required state only on
the client via opaque cookies.

Working Group Summary:

The document has clear working group consensus for publication, and has been
reviewed by several WG participants since its initial adoption as a working
group item.

Document Quality:

This document has been reviewed and revised several times during its
development. There were no specific external expert reviews conducted; however,
security area review was specifically solicited.


Karen O'Donoghue is acting as the Document Shepherd.  Suresh Krishnan is the
Responsible Area Director.

(3) Briefly describe the review of this document that was performed by the
Document Shepherd. If this version of the document is not ready for
publication, please explain why the document is being forwarded to the IESG.

The document shepherd has followed the working group process and reviewed the
final document and feels this document is more than ready for IESG review.

(4) Does the document Shepherd have any concerns about the depth or breadth of
the reviews that have been performed?

The document shepherd does not have any concerns about the reviews that were

(5) Do portions of the document need review from a particular or from broader
perspective, e.g., security, operational complexity, AAA, DNS, DHCP, XML, or
internationalization? If so, describe the review that took place.

This document does not require any special reviews beyond those planned during
the IESG review process.

(6) Describe any specific concerns or issues that the Document Shepherd has
with this document that the Responsible Area Director and/or the IESG should be
aware of? For example, perhaps he or she is uncomfortable with certain parts of
the document, or has concerns whether there really is a need for it. In any
event, if the WG has discussed those issues and has indicated that it still
wishes to advance the document, detail those concerns here.

The Document Shepherd is comfortable with this document.

(7) Has each author confirmed that any and all appropriate IPR disclosures
required for full conformance with the provisions of BCP 78 and BCP 79 have
already been filed. If not, explain why?

There are no IPR filings on this document. The document shepherd has requested
confirmation from all the authors that they are in full conformance with the
provisions of BCP78 and BCP79 with respect to IPR disclosures.

(8) Has an IPR disclosure been filed that references this document? If so,
summarize any WG discussion and conclusion regarding the IPR disclosures.

There is no IPR disclosures for this document.

(9) How solid is the WG consensus behind this document? Does it represent the
strong concurrence of a few individuals, with others being silent, or does the
WG as a whole understand and agree with it?

The document represents strong WG consensus. It has been evolving in the
working group for a number of years. There is one working group member who has
not agreed with the working group consensus. This is based on the fact that the
solution only provides for the client/server modes of NTP operation. However,
the remaining working members have agreed that the vast majority of NTP usage
is actually client/server mode, and there is a strong need to get this solution
out there. Additionally there are multiple independent implementations and two
public servers supporting NTS at this point in time.

(10) Has anyone threatened an appeal or otherwise indicated extreme discontent?
If so, please summarize the areas of conflict in separate email messages to the
Responsible Area Director.

There have been no threats of anyone appealing the documents.

(11) Identify any ID nits the Document Shepherd has found in this document.
(See and the Internet-Drafts Checklist).
Boilerplate checks are not enough; this check needs to be thorough.

The document shepherd ran ID nits and found a few minor issues that can be
fixed on the next iteration.

1 Error:
One normative reference to an informational RFC: RFC 5297
This was intentional and will remain as specified given that the referenced
document is for SIV, a block cipher mode of operation.

1 Warning:
One FQDN warning… (will be spelled out)

Two uses of square brackets in equations that trigger the “looks like a
reference but probably isn’t” comment An information reference that needs to be
updated RFC 5077RFC 8446 Date on document is old (delay in shepherd writeup)

(12) Describe how the document meets any required formal review criteria, such
as the MIB Doctor, media type, and URI type reviews.

There are no formal review criteria for this document.

(13) Have all references within this document been identified as either
normative or informative?

All references are tagged as normative or informative.

(14) Are there normative references to documents that are not ready for
advancement or are otherwise in an unclear state? If such normative references
exist, what is the plan for their completion?

All normative references are completed.

(15) Are there downward normative references (see RFC 3967)? If so, list these
downward references to support the Area Director in the Last Call procedure.

There is one downref flagged (RFC 5297), but this was intentional and will
remain as specified given that the referenced document is for SIV, a block
cipher mode of operation. This is IETF standard practice for crypto documents.

(16) Will publication of this document change the status of any existing RFCs?
Are those RFCs listed on the title page header, listed in the abstract, and
discussed in the introduction? If the RFCs are not listed in the Abstract and
Introduction, explain why, and point to the part of the document where the
relationship of this document to the other RFCs is discussed. If this
information is not in the document, explain why the WG considers it unnecessary.

This document does not change the status of any existing RFCs.

(17) Describe the Document Shepherd's review of the IANA considerations
section, especially with regard to its consistency with the body of the
document. Confirm that all protocol extensions that the document makes are
associated with the appropriate reservations in IANA registries. Confirm that
any referenced IANA registries have been clearly identified. Confirm that newly
created IANA registries include a detailed specification of the initial
contents for the registry, that allocations procedures for future registrations
are defined, and a reasonable name for the new registry has been suggested (see
RFC 5226).

This document requests allocations from five existing registries along with the
creation of four new registries. All the actions specified are consistent with
the document and reasonably specified.

(18) List any new IANA registries that require Expert Review for future
allocations. Provide any public guidance that the IESG would find useful in
selecting the IANA Experts for these new registries.

The new registries all require either IETF review or specification required.

(19) Describe reviews and automated checks performed by the Document Shepherd
to validate sections of the document written in a formal language, such as XML
code, BNF rules, MIB definitions, etc.

There were no automated checks on formal language.