Hi Richard,

As an independent implementer, I would like to weigh in. I believe there might be a misunderstanding here.

While it is common for software libraries to implement active Internet-Drafts, this is not a viable long-term solution. Features backed only by a rejected, long-dead draft cannot be safely maintained over time.

Furthermore, while hardware isn't my primary domain, I highly doubt any hardware manufacturer would commit resources to implementing a rejected draft.

>> The ML-KEM code points already exist in
>> the registry at Recommended=N [2], so anyone who wants to implement
>> pure ML-KEM can already do so and interoperate today, without the
>> RFC.

Henrick Wibell Hellström,
StreamSec

On 2026-07-07 04:35, Richard T. Carback III wrote:
Hi Uri,

Please read my entire comment, specifically the 4th paragraph which addressed 
this and states:

The ML-KEM code points already exist in
the registry at Recommended=N [2], so anyone who wants to implement
pure ML-KEM can already do so and interoperate today, without the
RFC.


Cheers,

Richard T. Carback III, PhD
CTO, Postquant Labs



On Jul 6, 2026, at 21:16, Blumenthal, Uri - 0553 - MITLL <[email protected]> 
wrote:

This is not about being able to implement — it’s about being able to implement 
in an interoperable way.

I do wish people would gain some IETF experience before speaking up.
--
V/R,
Uri
From: Richard T. Carback III <[email protected] <mailto:[email protected]>>
Date: Monday, July 6, 2026 at 21:08
To: [email protected] <mailto:[email protected]> <[email protected] 
<mailto:[email protected]>>
Cc: [email protected] <mailto:[email protected]> <[email protected] 
<mailto:[email protected]>>; [email protected] <mailto:[email protected]> <[email protected] 
<mailto:[email protected]>>; [email protected] <mailto:[email protected]> <[email protected] <mailto:[email protected]>>
Subject: [EXT] [TLS] Re: WG Last Call: draft-ietf-tls-mlkem-08 (Ends 2026-07-08)

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256

I do not support publishing draft-ietf-tls-mlkem-08 at this time.

I strongly urge the working group to wait a couple years for
implementations to mature and for QPUs to get closer. The
implementations are not ready, and what regulated deployments
need is nascent.

Even with "Recommended=N", publication is not neutral. The value of
an RFC, which is stated plainly in the announcement that opened this last
call [1],  is that downstream bodies rely on it: this announcement
cites liaisons from O-RAN, IEEE 802.11, and 3GPP requesting
publication because they "rely on the IETF to provide a stable
normative reference”.  That is, they want a standard to build
deployment on. An artifact that those bodies lobby for because it
will shape their decisions cannot, in the same breath, be said to
have no bearing on their decisions.

The cost of waiting is low. The ML-KEM code points already exist in
the registry at Recommended=N [2], so anyone who wants to implement
pure ML-KEM can already do so and interoperate today, without the
RFC. Thus, the substance this doc adds seems to reduce to an IETF
endorsement, which only encourages pure-only deployment in my view.

Given that the mission of the IETF is to seek the best outcome for
the whole Internet, the responsible default is caution (for now).
We are in the fortunate position of having a strictly stronger,
negligible-cost, already-Recommended=Y alternative available:
X25519MLKEM768 [2]. This has not been true for this kind of work
historically, with unfortunate and unavoidable fallout. Some
examples include:

    - RSA key-transport and static-DH suites were marked
      Recommended=N in 2018 (RFC 8447 [3]). Raccoon (2020) then
      exploited permitted-but-discouraged DH secret reuse in
      fielded stacks. CVE-2020-5929 did not even need a timing
      oracle [4] and Marvin (2023) found the 25-year-old
      Bleichenbacher timing class still live across OpenSSL,
      GnuTLS, Java, Go, Node.js, Mbed TLS, and hardware modules [5].

    - Export-grade RSA and DH, forced into stacks by 1990s
      regulation, were still enabling FREAK (CVE-2015-0204) and
      Logjam (CVE-2015-4000) twenty years later [6][7].

    - The heartbeat extension gave us Heartbleed in 2014
      (CVE-2014-0160, RFC 6520 [8]); AFAIK, the IANA
      registry still lists heartbeat as Recommended=Y [2].

Contrast these with one of IETF's finer moments: RFC 6176
prohibiting SSLv2 outright in 2011 [9]. Five years later DROWN
(CVE-2016-0800) used still-deployed SSLv2 to break TLS for roughly
a third of HTTPS servers [10]. While a "MUST NOT" did not
decommission everything, it did substantially reduce the impact
(and personally saved my infrastructure at the time).

In terms of **when** publication might make sense, I propose two
gates, both of which should hold:

1. A demonstrated CRQC.
2. ML-KEM available in more than one independently validated FIPS
    140-3 or similarly vetted module with published
    side-channel-resistance results.

An available CRQC diminishes the security of ECDSA to the cost to
run the attack (which is not likely to be trivial [11]). At which
point the PQC side protects. It will likely be a few years or more
before such CRQCs become common place.

High quality vetted implementations of the core primitives are
necessary for regulated deployments, and they should exist in some
quantity before an IETF endorsement for pure constructions. I did
read that much of this thread argued maturity in terms of whether
an ephemeral key exchange tolerates a bug. I believe that this is
the wrong yardstick for many deployments that are hard to fix
after the fact. Regulated systems like financial infrastructure
and anything under Common Criteria or FIPS evaluations often run
their cryptography inside validated boundaries and certified HSMs,
and they patch on validation timelines, not software timelines, so
I think it prudent to discourage pure-only option for these at the
moment.

No one can predict the future, but we do know the past. Endorsing
a pure mode now is an unnecessary risk when we have safe low-cost
alternatives.

In summary, for these reasons I believe that publishing this now
is not in the best interests of the internet. If the working group
does publish now, then at minimum the Security Considerations
should state the hybrid preference in the document body rather
than by reference to the registry column, and should note
explicitly that deployments bound by module-validation
requirements face a materially different risk profile with
standalone ML-KEM than with the hybrid groups.

I write as an implementer of post-quantum primitives (an early PQ
Ratchet, WOTS+/SHRINCS) and as someone who works with downstream
operators bound by module-validation and regulatory constraints.
It is from this perspective that this document looks premature.

Sincerely,

Richard T. Carback III, PhD
CTO, Postquant Labs

References
[1]  WG Last Call: draft-ietf-tls-mlkem-08 (J. Salowey, 2026-06-24)
      -- the announcement that opened this thread; the liaison quotes
      above are from it:
      <https://mailarchive.ietf.org/arch/msg/tls/ol2otAvtdDrdz_xY0_eKcuY1om0/>
      Full thread:
      
<https://mailarchive.ietf.org/arch/browse/tls/?q=%22WG%20Last%20Call%3A%20draft-ietf-tls-mlkem-08%22>
[2]  IANA TLS Supported Groups registry (MLKEM512/768/1024 =
      Recommended N; X25519MLKEM768 = Y) and TLS ExtensionType
      registry (heartbeat = Recommended Y):
      <https://www.iana.org/assignments/tls-parameters/tls-parameters.xhtml>
      
<https://www.iana.org/assignments/tls-extensiontype-values/tls-extensiontype-values.xhtml>
[3]  RFC 8447, IANA Registry Updates for TLS and DTLS (Recommended
      column): <https://www.rfc-editor.org/rfc/rfc8447.html>
      (updated by RFC 9847:
      <https://www.rfc-editor.org/rfc/rfc9847.html>)
[4]  Raccoon Attack: <https://raccoon-attack.com/> ; F5
      CVE-2020-5929; OpenSSL CVE-2020-1968:
      <https://nvd.nist.gov/vuln/detail/CVE-2020-1968>
[5]  Marvin Attack (timing Bleichenbacher, affected-implementation
      list): <https://people.redhat.com/~hkario/marvin/>
[6]  FREAK, CVE-2015-0204:
      <https://nvd.nist.gov/vuln/detail/CVE-2015-0204>
[7]  Logjam, CVE-2015-4000 (weakdh.org):
      <https://weakdh.org/> ;
      <https://nvd.nist.gov/vuln/detail/CVE-2015-4000>
[8]  Heartbleed, CVE-2014-0160 (RFC 6520 Heartbeat extension):
      <https://nvd.nist.gov/vuln/detail/CVE-2014-0160> ;
      <https://www.rfc-editor.org/rfc/rfc6520.html>
[9]  RFC 6176, Prohibiting Secure Sockets Layer (SSL) Version 2.0:
      <https://www.rfc-editor.org/rfc/rfc6176.html>
[10] DROWN Attack (CVE-2016-0800; ~33% of HTTPS servers):
      <https://drownattack.com/> ;
      <https://nvd.nist.gov/vuln/detail/CVE-2016-0800>
[11] Quantum Doom Clock, which references several analyses:
      <https://quantumdoomclock.com/>



On Wed, 2026-06-24 at 08:00 -0700, Joseph Salowey via Datatracker
wrote:
This message initiates a new Working Group Last Call for draft-ietf-

tls-mlkem[1], which defines standalone ML-KEM key establishment for

TLS 1.3. The main question before the working group is: "Should the

working group publish a document specifying stand alone ML-KEM?". If

there is rough consensus then we will push to refine and publish the

document; otherwise, we will stop discussing the draft and not

progress it. Please respond to this call indicating whether you

support publishing a document specifying a stand alone ML-KEM. Please

refrain from further discussion on this topic as most arguments have

been discussed multiple times.



Why are we holding this consensus call now?



Significant developments have occurred both within this document and

in the broader TLS ecosystem to address the concerns raised in the

last WGLC. Therefore, the third consensus call is warranted. We ask

the working group to consider document publication in light of these

recent changes:



- Promotion of Hybrids in draft-ietf-tls-ecdhe-mlkem: Following a

separate consensus call, the WG agreed to promote the X25519MLKEM768

hybrid group to Recommended: Y in the IANA registry. Consequently,

the IANA registry will reflect a clear community preference for a

hybrid because Recommended: Y clearly indicates this while the

standalone ML-KEM groups defined in this draft remain Recommended: N.

The updated security considerations in [1] reference the IANA

registry to emphasize this preference.



- Key Share Reuse Prohibited in draft-ietf-tls-rfc8446bis: The WG

recently reached consensus to explicitly prohibit key share reuse

across connections in TLS 1.3. The new text changes the guidance from

SHOULD NOT to a strict MUST NOT. This resolves the concerns regarding

static key reuse and its associated privacy and forward-secrecy risks

for ML-KEM.



- Nadim updated the ProVerif model of TLS 1.3 to evaluate KEM and

hybrid KEM groups in TLS 1.3. This supports other results which show

that KEMs are secure when used in TLS 1.3 and that hybrid groups are

secure even if one of the components is compromised.



- Liaisons: We received liaison statements from multiple SDOs

including  O-RAN[2], IEEE 802.11[4] and from 3GPP[3]  expressing

support for the publication of draft-ietf-tls-mlkem as an RFC as they

rely on the IETF to provide a stable normative reference.



Please note that a third-party IPR disclosure exists [5] against this

document regarding patents related to the underlying ML-KEM

algorithm. This IPR declaration has not changed since the last WGLC.

As a reminder, per BCP 79, the IETF takes no stance on the validity

of patent claims, and the working group may decide to proceed with a

technology despite IPR disclosures if it decides that such use is

warranted.



Conduct Reminder: Given the heated nature of previous discussions on

this topic, participants are strongly reminded to adhere to the IETF

Code of Conduct (BCP 54) and the TLS WG's Mail List Procedures. Keep

feedback professional, technical, and focused on the document's text.



This working group last call will end on 2026-07-08.



Joe and Sean



[1] https://datatracker.ietf.org/doc/draft-ietf-tls-mlkem/

[2] https://datatracker.ietf.org/liaison/2198/

[3] https://datatracker.ietf.org/liaison/2151/

[4] https://datatracker.ietf.org/liaison/2148/

[5]

https://datatracker.ietf.org/ipr/search/?submit=draft&id=draft-ietf-tls-mlkem



_______________________________________________

TLS mailing list -- [email protected]

To unsubscribe send an email to [email protected]





_______________________________________________
TLS mailing list -- [email protected]
To unsubscribe send an email to [email protected]

Attachment: smime.p7s
Description: S/MIME Cryptographic Signature

_______________________________________________
TLS mailing list -- [email protected]
To unsubscribe send an email to [email protected]

Reply via email to