PQ/T Hybrid Key Exchange with ML-KEM in SSH
draft-ietf-sshm-mlkem-hybrid-kex-09

[Ballot comment]
Thank you for the work that has been put into this document. I do not see any transport-protocol related concerns.

In the abstract, I note:
"This document defines Post-Quantum Traditional (PQ/T) Hybrid key
  exchange methods based on the quantum-resistant the Module-Lattice-
  Based Key-Encapsulation Mechanism (ML-KEM) standard and traditional
  Elliptic-curve Diffie–Hellman (ECDH) key exchange schemes."
- which to me reads as containing an additional "the" (after resistant) or missing punctuation?

[Ballot discuss]
(revised ballot, I made a mistake in my earlier feedback)

Section 2.3.1.  This section appears to be normatively describing which algorithms are associated with the code point “mlkem768nistp256-sha256”.  Specifically:

  The HASH function used in the key exchange [RFC4253] is SHA-256
  [nist-sha2] [RFC6234].

As such, why is [RFC6234] or [nist-sha2] not normative referenced to cover SHA-256?  My thinking is that an implementer needs to read those algorithm descriptions to implement those code points.

Same thinking applies for 2.3.2 (mlkem1024nistp384-sha384) and 2.3.3 (mlkem768x25519-sha256).

[Ballot discuss]
Section 2.3.1.  This section appears to be normatively describing which algorithms are associated with the code point “mlkem768nistp256-sha256”.  As such, why are [nist-sp800-186], [FIPS203] and [RFC6234] or [nist-sha2] not normative references?  My thinking is that an implementer needs to read those algorithm descriptions to implement those code points.

Same thinking applies for 2.3.2 (mlkem1024nistp384-sha384) (but no new references beyond those in Section 2.3.1) and 2.3.3 (mlkem768x25519-sha256) which needs [RFC7748]

[Ballot comment]
Thank you for not referencing RFC 4086 :)

One minor comment:

        The following private namespace message numbers are defined in this document:

I was confused because I was thinking "IETF" namespace vs vendor namespace.  Since RFC 4250
calls these "Key exchange method numbers", perhaps write:

        This document defines the following Key exchange method numbers:

This also aligns up with how 2.3 talks about "key exchange method names".

[Ballot comment]
Hi Panos, Douglas, and Torben,

Thank you for the effort put into this well-written specification.

Thanks also to Thomas Graf for the OPSDIR review and the authors for engaging.

Please find below few comments:

# c2pq

I have one minor comment about this part:

  However, if sufficiently large quantum computers become available,
  these instances would no longer be computationally infeasible
  rendering the current key exchange and authentication methods in SSH
  insecure [I-D.hoffman-c2pq]. 

I-D.hoffman-c2pq was expired since 2020. More importantly, it is not clear to me which parts of that draft is important here.

If the intent is to have a reference for CRQC threats, maybe better to cite draft-ietf-pquip-pqc-engineers#Section 3.

# Packet Size

CURRENT:
  This document does not define behavior in cases where
  a PQ/T Hybrid key exchange message causes a packet to exceed the
  minimally supported packet length.

I understand that this is left unspecified. However, rfc4253#section-6.1 has the following provision:

  Implementations SHOULD
  support longer packets, where they might be needed.  For example, if
  an implementation wants to send a very large number of certificates,
  the larger packets MAY be sent if the identification string indicates
  that the other party is able to process them.  However,
  implementations SHOULD check that the packet length is reasonable in
  order for the implementation to avoid denial of service and/or buffer
  overflow attacks.

Are we also saying that part of 4253 should be skipped?

BTW, if the message is not sent because of a packet length issue, it would be helpful if that event is logged as this would help with troubleshooting.

Cheers,
Med

IESG/Authors/WG Chairs:

IANA has completed its review of draft-ietf-sshm-mlkem-hybrid-kex-07. If any part of this review is inaccurate, please let us know.

IANA understands that, upon approval of this document, there is a single action which we must complete.

In the Key Exchange Method Names registry in the Secure Shell (SSH) Protocol Parameters registry group located at:

https://www.iana.org/assignments/ssh-parameters/

three method names registered by an earlier version of this document will be updated as follows:

Method Name: mlkem768nistp256-sha256
Reference: [ RFC-to-be ]
Note:
OK to Implement: SHOULD

Method Name: mlkem1024nistp384-sha384
Reference: [ RFC-to-be ]
Note:
OK to Implement: SHOULD

Method Name: mlkem768x25519-sha256
Reference: [ RFC-to-be ]
Note:
OK to Implement: SHOULD

As this document requests registrations in an Expert Review or Specification Required (see RFC 8126) registry, we have completed the required Expert Review via a separate request.

We understand that this is the only action required to be completed upon approval of this document.

NOTE: The actions requested in this document will not be completed until the document has been approved for publication as an RFC. This message is meant only to confirm the list of actions that will be performed.

For definitions of IANA review states, please see:

https://datatracker.ietf.org/help/state/draft/iana-review

Thank you,

David Dong
IANA Services Sr. Specialist

The following Last Call announcement was sent out (ends 2026-01-01):

From: The IESG
To: IETF-Announce
CC: debcooley1@gmail.com, draft-ietf-sshm-mlkem-hybrid-kex@ietf.org, ssh@ietf.org, sshm-chairs@ietf.org, stephen.farrell@cs.tcd.ie
Reply-To: last-call@ietf.org
Sender:
Subject: Last Call:  (PQ/T Hybrid Key Exchange with ML-KEM in SSH) to Informational RFC


The IESG has received a request from the Secure Shell Maintenance WG (sshm)
to consider the following document: - 'PQ/T Hybrid Key Exchange with ML-KEM
in SSH'
  as Informational RFC

The IESG plans to make a decision in the next few weeks, and solicits final
comments on this action. Please send substantive comments to the
last-call@ietf.org mailing lists by 2026-01-01. Exceptionally, comments may
be sent to iesg@ietf.org instead. In either case, please retain the beginning
of the Subject line to allow automated sorting.

Abstract


  This document defines Post-Quantum Traditional (PQ/T) Hybrid key
  exchange methods based on the quantum-resistant the Module-Lattice-
  Based Key-Encapsulation Mechanism (ML-KEM) standard and traditional
  Elliptic-curve Diffie–Hellman (ECDH) key exchange schemes.  These
  methods are defined for use in the SSH Transport Layer Protocol.




The file can be obtained via
https://datatracker.ietf.org/doc/draft-ietf-sshm-mlkem-hybrid-kex/


The following IPR Declarations may be related to this I-D:

  https://datatracker.ietf.org/ipr/7097/

# Document Shepherd Write-Up for Group Documents

This document [1] defines hybrid KEMs that use the ML-KEM algorithm.  It has
been implemented and is starting to (or will soon) see widespread deployment.

    [1] https://datatracker.ietf.org/doc/draft-ietf-sshm-mlkem-hybrid-kex/

The main point of interest is how this is coupled with the earlier WG document [2]
on a very widely deployed hybrid that uses the sntru-prime PQ KEM, which is now
in the RFC editor queue. The WG had a very hard time reaching consensus on how
to position these two documents, and after much debate, and an appeal, decided
to treat both hybrid KEM drafts in the same way when it comes to the IANA
recommendation for implementers (that they SHOULD be implemented) and the type
of RFC desired (informational).

    [2] https://datatracker.ietf.org/doc/draft-ietf-sshm-ntruprime-ssh/

While informational is a somewhat odd choice for this document, that is firmly
what the WG wanted and the authors/proponents of this specification are fine
with that. Changing that would likely upset quite a few WG participants for
various good and less good reasons, so we'd ask the IESG to not propose making
any changes to these aspects as they review the document. (Sometimes, holding
your nose and letting imperfect things get resolved is the correct action:-)

There may be a later WG effort to revisit how the IANA recommendations are
handled for SSH. If the WG do have cycles to consider that, then it's likely
this situation could be regularised at that point in time. Now is not the
time for that however.

*This version is dated 4 July 2022.*

## Document History

1. Does the working group (WG) consensus represent the strong concurrence of a
  few individuals, with others being silent, or did it reach broad agreement?

The WG have broad consensus.

2. Was there controversy about particular points, or were there decisions where
  the consensus was particularly rough?

See above. Once the relative positioning of this and the sntru-prime draft
was agreed, things went smoothly.

3. 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. (It should be in a separate email because this
  questionnaire is publicly available.)

No.

4. For protocol documents, are there existing implementations of the contents of
  the document? Have a significant number of potential implementers indicated
  plans to implement? Are any existing implementations reported somewhere,
  either in the document itself (as [RFC 7942][3] recommends) or elsewhere
  (where)?

Yes, implementations exist and have been noted on the WG mailing
list.

## Additional Reviews

5. Do the contents of this document closely interact with technologies in other
  IETF working groups or external organizations, and would it therefore benefit
  from their review? Have those reviews occurred? If yes, describe which
  reviews took place.

Not needed here.

6. Describe how the document meets any required formal expert review criteria,
  such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.

N/A.

7. If the document contains a YANG module, has the final version of the module
  been checked with any of the [recommended validation tools][4] for syntax and
  formatting validation? If there are any resulting errors or warnings, what is
  the justification for not fixing them at this time? Does the YANG module
  comply with the Network Management Datastore Architecture (NMDA) as specified
  in [RFC 8342][5]?

N/A.

8. Describe reviews and automated checks performed to validate sections of the
  final version of the document written in a formal language, such as XML code,
  BNF rules, MIB definitions, CBOR's CDDL, etc.

N/A.

## Document Shepherd Checks

9. Based on the shepherd's review of the document, is it their opinion that this
  document is needed, clearly written, complete, correctly designed, and ready
  to be handed off to the responsible Area Director?

Yes.

10. Several IETF Areas have assembled [lists of common issues that their
    reviewers encounter][6]. For which areas have such issues been identified
    and addressed? For which does this still need to happen in subsequent
    reviews?

N/A.

11. What type of RFC publication is being requested on the IETF stream ([Best
    Current Practice][12], [Proposed Standard, Internet Standard][13],
    [Informational, Experimental or Historic][14])? Why is this the proper type
    of RFC? Do all Datatracker state attributes correctly reflect this intent?

Informational. See the discussion at the top.

12. Have reasonable efforts been made to remind all authors of the intellectual
    property rights (IPR) disclosure obligations described in [BCP 79][7]? To
    the best of your knowledge, have all required disclosures been filed? If
    not, explain why. If yes, summarize any relevant discussion, including links
    to publicly-available messages when applicable.

Yes. Mail was sent to the authors/list on 2025-11-25. Responses from all
authors indicate no issues. The thread on the WG are at [3].

    [3] https://mailarchive.ietf.org/arch/msg/ssh/TuY_noyQlsa9l7o_1MltmjSQzJY/

13. Has each author, editor, and contributor shown their willingness to be
    listed as such? If the total number of authors and editors on the front page
    is greater than five, please provide a justification.

That's fine.

14. Document any remaining I-D nits in this document. Simply running the [idnits
    tool][8] is not enough; please review the ["Content Guidelines" on
    authors.ietf.org][15]. (Also note that the current idnits tool generates
    some incorrect warnings; a rewrite is underway.)

The remaining I-D nits warnings are erroneous.

15. Should any informative references be normative or vice-versa? See the [IESG
    Statement on Normative and Informative References][16].

Those are fine.

16. List any normative references that are not freely available to anyone. Did
    the community have sufficient access to review any such normative
    references?

N/A.

17. Are there any normative downward references (see [RFC 3967][9] and [BCP
    97][10]) that are not already listed in the [DOWNREF registry][17]? If so,
    list them.

N/A.

18. Are there normative references to documents that are not ready to be
    submitted to the IESG for publication or are otherwise in an unclear state?
    If so, what is the plan for their completion?

N/A.

19. Will publication of this document change the status of any existing RFCs? If
    so, does the Datatracker metadata correctly reflect this and are those RFCs
    listed on the title page, in the abstract, and discussed in the
    introduction? If not, explain why and point to the part of the document
    where the relationship of this document to these other RFCs is discussed.

N/A.

20. 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 aspects of the document requiring IANA assignments are
    associated with the appropriate reservations in IANA registries. Confirm
    that any referenced IANA registries have been clearly identified. Confirm
    that each newly created IANA registry specifies its initial contents,
    allocations procedures, and a reasonable name (see [RFC 8126][11]).

The IANA code-points are already allocated. See the discussion
at the top wrt the recommendation for implementers.

21. List any new IANA registries that require Designated Expert Review for
    future allocations. Are the instructions to the Designated Expert clear?
    Please include suggestions of designated experts, if appropriate.

N/A.

# Document Shepherd Write-Up for Group Documents

This document [1] defines hybrid KEMs that use the ML-KEM algorithm.  It has
been implemented and is starting to (or will soon) see widespread deployment.

    [1] https://datatracker.ietf.org/doc/draft-ietf-sshm-mlkem-hybrid-kex/

The main point of interest is how this is coupled with the earlier WG document [2]
on a very widely deployed hybrid that uses the sntru-prime PQ KEM, which is now
in the RFC editor queue. The WG had a very hard time reaching consensus on how
to position these two documents, and after much debate, and an appeal, decided
to treat both hybrid KEM drafts in the same way when it comes to the IANA
recommendation for implementers (that they SHOULD be implemented) and the type
of RFC desired (informational).

    [2] https://datatracker.ietf.org/doc/draft-ietf-sshm-ntruprime-ssh/

While informational is a somewhat odd choice for this document, that is firmly
what the WG wanted and the authors/proponents of this specification are fine
with that. Changing that would likely upset quite a few WG participants for
various good and less good reasons, so we'd ask the IESG to not propose making
any changes to these aspects as they review the document. (Sometimes, holding
your nose and letting imperfect things get resolved is the correct action:-)

There may be a later WG effort to revisit how the IANA recommendations are
handled for SSH. If the WG do have cycles to consider that, then it's likely
this situation could be regularised at that point in time. Now is not the
time for that however.

*This version is dated 4 July 2022.*

## Document History

1. Does the working group (WG) consensus represent the strong concurrence of a
  few individuals, with others being silent, or did it reach broad agreement?

The WG have broad consensus.

2. Was there controversy about particular points, or were there decisions where
  the consensus was particularly rough?

See above. Once the relative positioning of this and the sntru-prime draft
was agreed, things went smoothly.

3. 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. (It should be in a separate email because this
  questionnaire is publicly available.)

No.

4. For protocol documents, are there existing implementations of the contents of
  the document? Have a significant number of potential implementers indicated
  plans to implement? Are any existing implementations reported somewhere,
  either in the document itself (as [RFC 7942][3] recommends) or elsewhere
  (where)?

Yes, implementations exist and have been noted on the WG mailing
list.

## Additional Reviews

5. Do the contents of this document closely interact with technologies in other
  IETF working groups or external organizations, and would it therefore benefit
  from their review? Have those reviews occurred? If yes, describe which
  reviews took place.

Not needed here.

6. Describe how the document meets any required formal expert review criteria,
  such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.

N/A.

7. If the document contains a YANG module, has the final version of the module
  been checked with any of the [recommended validation tools][4] for syntax and
  formatting validation? If there are any resulting errors or warnings, what is
  the justification for not fixing them at this time? Does the YANG module
  comply with the Network Management Datastore Architecture (NMDA) as specified
  in [RFC 8342][5]?

N/A.

8. Describe reviews and automated checks performed to validate sections of the
  final version of the document written in a formal language, such as XML code,
  BNF rules, MIB definitions, CBOR's CDDL, etc.

N/A.

## Document Shepherd Checks

9. Based on the shepherd's review of the document, is it their opinion that this
  document is needed, clearly written, complete, correctly designed, and ready
  to be handed off to the responsible Area Director?

Yes.

10. Several IETF Areas have assembled [lists of common issues that their
    reviewers encounter][6]. For which areas have such issues been identified
    and addressed? For which does this still need to happen in subsequent
    reviews?

N/A.

11. What type of RFC publication is being requested on the IETF stream ([Best
    Current Practice][12], [Proposed Standard, Internet Standard][13],
    [Informational, Experimental or Historic][14])? Why is this the proper type
    of RFC? Do all Datatracker state attributes correctly reflect this intent?

Informational. See the discussion at the top.

12. Have reasonable efforts been made to remind all authors of the intellectual
    property rights (IPR) disclosure obligations described in [BCP 79][7]? To
    the best of your knowledge, have all required disclosures been filed? If
    not, explain why. If yes, summarize any relevant discussion, including links
    to publicly-available messages when applicable.

Yes. Mail was sent to the authors/list on 2025-11-25. Responses have
yet to be received.

13. Has each author, editor, and contributor shown their willingness to be
    listed as such? If the total number of authors and editors on the front page
    is greater than five, please provide a justification.

That's fine.

14. Document any remaining I-D nits in this document. Simply running the [idnits
    tool][8] is not enough; please review the ["Content Guidelines" on
    authors.ietf.org][15]. (Also note that the current idnits tool generates
    some incorrect warnings; a rewrite is underway.)

The remaining I-D nits warnings are erroneous.

15. Should any informative references be normative or vice-versa? See the [IESG
    Statement on Normative and Informative References][16].

Those are fine.

16. List any normative references that are not freely available to anyone. Did
    the community have sufficient access to review any such normative
    references?

N/A.

17. Are there any normative downward references (see [RFC 3967][9] and [BCP
    97][10]) that are not already listed in the [DOWNREF registry][17]? If so,
    list them.

N/A.

18. Are there normative references to documents that are not ready to be
    submitted to the IESG for publication or are otherwise in an unclear state?
    If so, what is the plan for their completion?

N/A.

19. Will publication of this document change the status of any existing RFCs? If
    so, does the Datatracker metadata correctly reflect this and are those RFCs
    listed on the title page, in the abstract, and discussed in the
    introduction? If not, explain why and point to the part of the document
    where the relationship of this document to these other RFCs is discussed.

N/A.

20. 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 aspects of the document requiring IANA assignments are
    associated with the appropriate reservations in IANA registries. Confirm
    that any referenced IANA registries have been clearly identified. Confirm
    that each newly created IANA registry specifies its initial contents,
    allocations procedures, and a reasonable name (see [RFC 8126][11]).

The IANA code-points are already allocated. See the discussion
at the top wrt the recommendation for implementers.

21. List any new IANA registries that require Designated Expert Review for
    future allocations. Are the instructions to the Designated Expert clear?
    Please include suggestions of designated experts, if appropriate.

N/A.

# Document Shepherd Write-Up for Group Documents

This document [1] defines hybrid KEMs that use the ML-KEM algorithm.  It has
been implemented and is starting to (or will soon) see widespread deployment.

    [1] https://datatracker.ietf.org/doc/draft-ietf-sshm-mlkem-hybrid-kex/

The main point of interest is how this is coupled with the earlier WG document [2]
on a very widely deployed hybrid that uses the sntru-prime PQ KEM, which is now
in the RFC editor queue. The WG had a very hard time reaching consensus on how
to position these two documents, and after much debate, and an appeal, decided
to treat both hybrid KEM drafts in the same way when it comes to the IANA
recommendation for implementers (that they SHOULD be implemented) and the type
of RFC desired (informational).

    [2] https://datatracker.ietf.org/doc/draft-ietf-sshm-ntruprime-ssh/

While informational is a somewhat odd choice for this document, that is firmly
what the WG wanted and the authors/proponents of this specification are fine
with that. Changing that would likely upset quite a few WG participants for
various good and less good reasons, so we'd ask the IESG to not propose making
any changes to these aspects as they review the document. (Sometimes, holding
your nose and letting imperfect things get resolved is the correct action:-)

There may be a later WG effort to revisit how the IANA recommendations are
handled for SSH. If the WG do have cycles to consider that, then it's likely
this situation could be regularised at that point in time. Now is not the
time for that however.

*This version is dated 4 July 2022.*

## Document History

1. Does the working group (WG) consensus represent the strong concurrence of a
  few individuals, with others being silent, or did it reach broad agreement?

The WG have broad consensus.

2. Was there controversy about particular points, or were there decisions where
  the consensus was particularly rough?

See above. Once the relative positioning of this and the sntru-prime draft
was agreed, things went smoothly.

3. 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. (It should be in a separate email because this
  questionnaire is publicly available.)

No.

4. For protocol documents, are there existing implementations of the contents of
  the document? Have a significant number of potential implementers indicated
  plans to implement? Are any existing implementations reported somewhere,
  either in the document itself (as [RFC 7942][3] recommends) or elsewhere
  (where)?

Yes, implementations exist and have been noted on the WG mailing
list.

## Additional Reviews

5. Do the contents of this document closely interact with technologies in other
  IETF working groups or external organizations, and would it therefore benefit
  from their review? Have those reviews occurred? If yes, describe which
  reviews took place.

Not needed here.

6. Describe how the document meets any required formal expert review criteria,
  such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.

N/A.

7. If the document contains a YANG module, has the final version of the module
  been checked with any of the [recommended validation tools][4] for syntax and
  formatting validation? If there are any resulting errors or warnings, what is
  the justification for not fixing them at this time? Does the YANG module
  comply with the Network Management Datastore Architecture (NMDA) as specified
  in [RFC 8342][5]?

N/A.

8. Describe reviews and automated checks performed to validate sections of the
  final version of the document written in a formal language, such as XML code,
  BNF rules, MIB definitions, CBOR's CDDL, etc.

N/A.

## Document Shepherd Checks

9. Based on the shepherd's review of the document, is it their opinion that this
  document is needed, clearly written, complete, correctly designed, and ready
  to be handed off to the responsible Area Director?

Yes.

10. Several IETF Areas have assembled [lists of common issues that their
    reviewers encounter][6]. For which areas have such issues been identified
    and addressed? For which does this still need to happen in subsequent
    reviews?

N/A.

11. What type of RFC publication is being requested on the IETF stream ([Best
    Current Practice][12], [Proposed Standard, Internet Standard][13],
    [Informational, Experimental or Historic][14])? Why is this the proper type
    of RFC? Do all Datatracker state attributes correctly reflect this intent?

Informational. See the discussion at the top.

12. Have reasonable efforts been made to remind all authors of the intellectual
    property rights (IPR) disclosure obligations described in [BCP 79][7]? To
    the best of your knowledge, have all required disclosures been filed? If
    not, explain why. If yes, summarize any relevant discussion, including links
    to publicly-available messages when applicable.

Yes. Mail was sent to the authors/list on 2025-11-25. Responses have
yet to be received.

13. Has each author, editor, and contributor shown their willingness to be
    listed as such? If the total number of authors and editors on the front page
    is greater than five, please provide a justification.

That's fine.

14. Document any remaining I-D nits in this document. Simply running the [idnits
    tool][8] is not enough; please review the ["Content Guidelines" on
    authors.ietf.org][15]. (Also note that the current idnits tool generates
    some incorrect warnings; a rewrite is underway.)

The remaining I-D nits warnings are erroneous.

15. Should any informative references be normative or vice-versa? See the [IESG
    Statement on Normative and Informative References][16].

Those are fine.

16. List any normative references that are not freely available to anyone. Did
    the community have sufficient access to review any such normative
    references?

N/A.

17. Are there any normative downward references (see [RFC 3967][9] and [BCP
    97][10]) that are not already listed in the [DOWNREF registry][17]? If so,
    list them.

N/A.

18. Are there normative references to documents that are not ready to be
    submitted to the IESG for publication or are otherwise in an unclear state?
    If so, what is the plan for their completion?

N/A.

19. Will publication of this document change the status of any existing RFCs? If
    so, does the Datatracker metadata correctly reflect this and are those RFCs
    listed on the title page, in the abstract, and discussed in the
    introduction? If not, explain why and point to the part of the document
    where the relationship of this document to these other RFCs is discussed.

N/A.

20. 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 aspects of the document requiring IANA assignments are
    associated with the appropriate reservations in IANA registries. Confirm
    that any referenced IANA registries have been clearly identified. Confirm
    that each newly created IANA registry specifies its initial contents,
    allocations procedures, and a reasonable name (see [RFC 8126][11]).

The IANA code-points are already allocated. See the discussion
at the top wrt the recommendation for implementers.

21. List any new IANA registries that require Designated Expert Review for
    future allocations. Are the instructions to the Designated Expert clear?
    Please include suggestions of designated experts, if appropriate.

N/A.