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[31.187.164.63]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-b935ac74adasm550662866b.27.2026.03.03.00.28.34 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Tue, 03 Mar 2026 00:28:34 -0800 (PST) From: Thom Wiggers Message-Id: Content-Type: multipart/alternative; boundary="Apple-Mail=_650BE9CB-8C8A-4041-87E2-3FC2773814A2" Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3864.400.21\)) Date: Tue, 3 Mar 2026 09:28:23 +0100 In-Reply-To: To: Loganaden Velvindron References: <577ecff2-a791-4573-9665-7885cdfd7227@cs.tcd.ie> X-Mailer: Apple Mail (2.3864.400.21) Message-ID-Hash: XCNXOK4DWEDK4LRNZHZZDF7CHAMFOK5F X-Message-ID-Hash: XCNXOK4DWEDK4LRNZHZZDF7CHAMFOK5F X-MailFrom: thom@thomwiggers.nl X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; header-match-tls.ietf.org-0; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header CC: "" X-Mailman-Version: 3.3.9rc6 Precedence: list Subject: =?utf-8?q?=5BTLS=5D_Re=3A_Proposed_Text_on_hybrid_vs_non-hybrid_=7C_Re=3A_WG?= =?utf-8?q?_Last_Call=3A_draft-ietf-tls-mlkem-05_=28Ends_2026-02-27=29?= List-Id: "This is the mailing list for the Transport Layer Security working group of the IETF." Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: --Apple-Mail=_650BE9CB-8C8A-4041-87E2-3FC2773814A2 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 Hi Loganaden, > Op 3 mrt 2026, om 05:35 heeft Loganaden Velvindron = het volgende geschreven: >=20 > Alternatively, if NIST could support hybrids officially, a lot of the > current issues would go away ? NIST don=E2=80=99t mind hybrids. It=E2=80=99s SDOs in e.g. Canada and = the UK that are sending strong messaging that =E2=80=9Cdouble=E2=80=9D = migrations are potentially very costly and risky, and thus urge people = to consider a direct-to-pure-PQ migration. There is also one particular = set of purchasing requirements for US National Security systems (CNSA) = that mandates pure PQC [1], where my impression [2] is strongly that = this is not just to avoid =E2=80=9Cdouble migration=E2=80=9D but perhaps = even more so to simply reduce the number of algorithms they need to keep = track of. People who mind hybrids mostly appear to do so for =E2=80=9Csoft=E2=80=9D = reasons rather than =E2=80=9Chard=E2=80=9D technical reasons. Arguing = how practical/fast/small hybrids are, and that they shouldn=E2=80=99t = mind them, isn=E2=80=99t really a convincing argument for them. Regards, Thom [1] CNSA 2.0 has one exception for when hybrids are absolutely necessary = for compatibility reasons: my understanding is that this caveat exists = basically just for IKEv2. [2] Clearly I=E2=80=99m not an American nor do I work for the NSA, so I = can=E2=80=99t speak for them= --Apple-Mail=_650BE9CB-8C8A-4041-87E2-3FC2773814A2 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=utf-8 Hi Loganaden,

Op 3 mrt 2026, om 05:35 heeft Loganaden Velvindron = <loganaden@gmail.com> het volgende geschreven:

Alternatively, if NIST could support = hybrids officially, a lot of the
current issues would go away = ?

NIST don=E2=80=99t mind = hybrids. It=E2=80=99s SDOs in e.g. Canada and the UK that are sending = strong messaging that =E2=80=9Cdouble=E2=80=9D migrations are = potentially very costly and risky, and thus urge people to consider a = direct-to-pure-PQ migration.  There is also one particular set of = purchasing requirements for US National Security systems (CNSA) that = mandates pure PQC [1], where my impression [2] is strongly that this is = not just to avoid =E2=80=9Cdouble migration=E2=80=9D but perhaps even = more so to simply reduce the number of algorithms they need to keep = track of.

People who mind hybrids mostly appear = to do so for =E2=80=9Csoft=E2=80=9D reasons rather than =E2=80=9Chard=E2=80= =9D technical reasons. Arguing how practical/fast/small hybrids are, and = that they shouldn=E2=80=99t mind them, isn=E2=80=99t really a convincing = argument for = them.

Regards,

Thom


[1] CNSA 2.0 has one exception for = when hybrids are absolutely necessary for compatibility reasons: my = understanding is that this caveat exists basically just for = IKEv2.
[2] Clearly I=E2=80=99m not an American nor do I = work for the NSA, so I can=E2=80=99t speak for = them
= --Apple-Mail=_650BE9CB-8C8A-4041-87E2-3FC2773814A2--