(1) MLKEM wasn't designed by NSA, but rather by a team of highly-regarded European academic cryptographers, including Bernstein's former collaborator Peter Schwabe; their submission, Kyber, was selected in an open competition in which Bernstein himself submitted a closely-related algorithm (and then contested the result, suing NIST for documents to clarify the selection.)
(2) The RFC at issue documents the possibility of running TLS with pure MLKEM rather than in a hybrid configuration with ECDH. Hybrid TLS is already the mainstream, documented, standardized method for using PQC in a TLS connection. Bernstein is canvassing opposition to any documentation of the possibility of pure MLKEM in TLS.
Every time Bernstein talks about NSA's sordid history, remember: nothing that's happening here has really anything to do with NSA. It would make more sense for Bernstein to be canvassing against SHA2, which NSA actually did design. But he can't do that, because normal people know enough about cryptography to understand how crazy a claim that is. Unfortunately, we can't yet say that about lattice cryptography, despite it being approximately as well-studied as ECC.
Two more pieces of context here: 1. The IETF allows code point registrations based purely on the existence of a specification, and the pure ML-KEM code points have already been assigned (https://www.iana.org/assignments/tls-parameters/tls-paramete...). The question at hand is whether the IETF will publish an RFC documenting the ML-KEM cipher suites [edited to make clear that ML-KEM is documented already].
2. It is also possible to publish an RFC via what's called "Independent Submission" (https://www.rfc-editor.org/authors/rfc-independent-submissio...), which is not subject to the IETF Consensus process. This is, for instance, how the GOST RFC (https://datatracker.ietf.org/doc/rfc9367/) was published. If the IETF opts not to publish this draft, the authors can still submit it to the Independent Submissions Editor.
Further the draft that this is all about does not make a recommendation for its use. The currently IETF-recommended TLS algorithms are: X25519MLKEM768, x448, x25519, secp384r1, secp256r1.
As noted by someone on the IETF list [1] there are already ML-KEM-only implementations in various libraries, so if we want interoperability then it's best to have a standard document. No one is forcing anyone to use this algorithm, and it's not even 'officially' recommended (per above).
[1] https://mailarchive.ietf.org/arch/msg/tls/SXo4iVmp0ng_vi57ce...
“People are already doing it, so we might as well rubber-stamp it even if it’s not great” introduces problems of its own: people will perceive that rubber-stamping as validating it, and now they’ll use it even more, where perhaps if you held back, they wouldn’t.
(There are counter-arguments as well, of course. A couple of relevant cases that spring to mind where a body has not aligned with usage or expectations: W3C lost control of HTML, and it was probably for the best, but they remain a relevant body in closely-related areas; and OSI licence approval is a horribly broken political process which is almost universally misunderstood and close to frozen in time, yet they haven’t suffered like they should have for their misdeeds, they pretty much got away with it. There was also that thing somewhat recently about FedRAMP rubber-stamping Microsoft Cloud despite it failing dismally, because US government agencies had already started using it too much; and I wonder what that does to their credibility.)
This is also a concern with informational/independent submissions through IETF. They are frequently perceived as having IETF/standards weight.
[1] Sadly, I know you are aware.
Null encryption used to be supported as well, and no one was forced to use it.
But when something insecure is supported by a protocol it will lead to security hiccups.
If it's dangerous it shouldn't be supported.
I recall the early-to-mid-90s when the IETF was a powerhouse, churning out foundational standards and documents monthly, and every time I read a foundational RFC for some protocol I wanted to learn, the "Security Considerations" section was intentionally left completely blank and un-considered.
I don't know if it was recklessness or expediency or a very calculated tactic (the Internet was invented by DARPA, after all) but Internet protocols were so ridiculously insecure, and based on absurd trust models that were repeatedly broken, and everything always transmitted in plaintext (because, of course, all networks were physically wired, secured, and only the good guys could tap into them).
It was an absolute Wild West clown college as the Internet transitioned to commercial and privatized use cases, and I suppose it guaranteed job security for generations of cybersecurity experts and cryptographers.
The IETF document only documents how and where to put the MLKEM values into TLS. MLKEM itself is specified in FIPS203 and it just references that for the actual cryptographic details. The IETF document is in fact quite short:
https://www.ietf.org/archive/id/draft-ietf-tls-mlkem-08.html
(This doesn't mean the document is a stub or pointless or something like that, you do need a "what goes where".)
DJB himself has consistently advocated for Classic McEliece in any application which can accept its performance characteristics (which are excellent except for the ginormous public keys), and spent many bytes trying to convince people that the set of applications that can is wider than they suspect.
> Unfortunately, we can't yet say that about lattice cryptography, despite it being approximately as well-studied as ECC.
DJB is not just a mathematician looking over theoretical equations. He's also an expert in the real world _implementation_ of cryptography where most security failures can be expected to occur.
For some mathematician's brilliant cryptography scheme, how easy would it be for implementers to develop constant time / constant power computer algorithms to avoid side channel leakage? Have these computer algorithms been developed, are they easy to implement securely or are implementers going to continually mess it up?
See [1] and [2] for answers. Summary: Technology is not ready.
That said, personally speaking, his behavior as a software publisher (packaging & whatnot) is something I'd call… let's go with "subpar" and leave it at that. So while I do believe it's a fair argument, I'm not accepting it, because from my perspective he isn't putting in the necessary work to really understand software publishing.
One very big problem I have with Bernstein's recent activism is the way he writes to an audience you can just very clearly tell he thinks little of. He's assuming everybody who pays attention to this stuff has paid basically no attention at all to any cryptography he himself didn't write about. It's a bad argument, but that's not my big issue; my big issue is that he's making fools of his supporters. Not OK.
For most users however, side channel resistance is a very important property that shouldn't be considered an optional after-thought. If standards bodies made it mandatory to consider side channel resistance when standardising cryptography schemes, the choice of what scheme(s) to standardise could look quite different, and thus general use of cryptography would have improved security by default. If some types of users don't care about side channel resistance, then great, make use of non-side-channel-resistant cryptography optional for them to use. Don't standardise it the other way around.
For example:
FIPS 186-5 sB.1 states: "Other (constant time) algorithms that produce an equivalent result may be used."[1]
NIST SP 800-186 sE.4 states: "If one is concerned about side-channel leakage, one should compute the inverse using a constant-time algorithm."[2]
RFC 8032 s8.1 states: "Note that the example implementations in this document do not attempt to be side-channel silent."[3]
A better standard may, for example, _require_ [4] be implemented in order for an implementation to claim conformance with the standard. Not as an optional after-thought. If there are users wanting to trade off side channel resistance for performance gains, then write a new standard to that effect and remove the requirement to implement [4].
A better standardisation process may, for example, only accept candidate algorithms _if_ they are side channel resistant. This opens up the standard to as many use cases as possible. No cutting corners to pretend performance is better for one implementation because it trades off side channel resistance for performance, and no pretending side channel sensitive use cases don't exist.
[1] https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.186-5.pdf
[2] https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.S...
[3] https://www.rfc-editor.org/info/rfc8032/#section-8.1
[4] https://en.wikipedia.org/wiki/Elliptic_curve_point_multiplic...
Cryptographers can be good, bad, be more or less knowledgeable about applied cryptography, and possibly have agendas.
(If my subtext wasn't clear, by the way: the implementation history of ECC is godawful.)
> the implementation history of ECC is godawful
You do know that new cryptographic code can be godawful, then?
I was happy to see the lead of Europe’s PQC team also voted with the cryptographers.
How can you say that???
It seems to be literally only for their claim to need it that pure MLKEM is being requested..!
A summary at https://blog.cr.yp.to/20251004-weakened.html, or just see e.g. https://keymaterial.net/2025/11/27/ml-kem-mythbusting for an opposite voice stating the same...
The optionality of MLKEM by itself is of a similar shape to standardizing a lame DRBG that 'obviously' no one would use and anyone who would use would use the appendix parameter generation scheme that would have rendered it secure (although still slow). The reality of it was that once it was standardized NSA was able to secretly compel its use.
On one hand MLKEM by itself seems like a better choice than DUAL-EC, on the other hand that fact should make it much easier for a powerful attacker to cause a target to use it if you do have an attack that exploits this fact.
MLKEM was selected out of myriad other options through a NIST process which was directly influenced by NSA (including in manners that NIST failed to disclose and actively mislead the group about). I think this makes the commentary regarding NSA highly relevant. While it seems less like that NSA already knows of a total break in MLKEM (and indeed their influence could have been in a strengthening direction...) it's possible that their influence was motivated by things like that ease of undetectably compromising specific implementations through techniques like dopant adulteration or specialized side channel weaknesses.
If your plan it to tamper with chip mfgr or hit them with a very well aimed e-beam (e.g. to cause ion migration) after the fact then having a non-hybrid scheme is pretty obviously going to make your life much easier... Or perhaps they've taken a route similar to the one they took with Crypto AG-- this time positioning themselves as a fabless silicon vendor to sell MLKEM RTL to a market that doesn't have an implementation but already has many robust ECC implementations to choose from.
...and that's without getting into the unknown possibility of a cryptoanalytic breakthrough.
I don't think it's even safe to say that NSA would only consider NOBUS backdoors-- I don't think any of us can know how inadvisably arrogant the relevant decision makers may be and what they might consider NOBUS. Given how DUAL_EC went in Netscreen's products I think it's reasonable to argument that there is no such thing as a NOBUS backdoor when push comes to shove. Capping DES's key size is candidate example of a very much non-NOBUS weakness that NSA felt comfortable with, as one needed a particularly amount of strength to exploit it which they believed that only they had. Today, of course, a child's video game device can crack DES as a direct product of that part of their influence.
Not a great track record when fear of "store and decrypt later" attacks is much of what motivates the use of PQ key agreement today.
The consistent aggression five-eyes affiliated cryptographic-intelligence groups have had for hybrid schemes is truly difficult to comprehend-- given that practically everyone else considers them obviously prudent in all cases where the resource costs permit -- and I think this justifies the utmost concern and caution. And in terms of caution hybrid schemes are table stakes.
A major theme of DJB's cryptographic security advocacy is that cryptographic security is often as much about what you don't offer as it is what you do. A completently engineered security product is misuse resistant and it's not completely clear to me that a standard which offers the choice of a non-hybrid mlkem qualifies as misuse resistant.
That said, there are plenty of drafts that are in no way misuse resistant. :)
He’s been moderated during the last call because of his email disclaimer/footnote, and apparently refuses to respond on list during this time. Seems like he’s playing a few steps ahead where he can (yet again) cry foul on the system and cry foul on vote rigging. Despite him being a key instigator. I’ve already seen at least one poster reference a RFC explaining how IETF consensus works and how its not a pure numbers game (5 for and 100 against can still be consensus, depending on the circumstances; the inverse also applies).
What’s his next step if the authors publish as an information RFC? He can’t stop that, right?
This is a slightly complicated question. There are several main routes to an Informational RFC.
* Through the IETF Stream, either through the Working Group (what is happening now) or via sponsorship by an Area Director. The former is what is happening now (this document is not up for Proposed Standard). I don't think the latter is likely to happen if TLS WG decides not to publish. If the TLS WG does decide to publish, then there are a number of steps afterward (AD review, IETF Last Call, IESG Review), plus potential avenues for appeal at some of these stages.
* Through the Independent Submissions Editor (ISE) (though in another comment wbl says that the ISE is not going to publish cryptography standards https://news.ycombinator.com/item?id=48812844). This is essentially at the sole discretion of the ISE and can't be appealed.
In either case, if the document makes it through all these gates and is eventually published as an RFC, then that's pretty much it, as RFCs aren't changed once published.
Informational RFCs still need to pass through the IETF consensus process, changing the intended status isn't a procedural bypass. However, the authors can just publish it elsewhere, it makes no difference at all for the codepoint allocations. Only distinction is that it doesn't get the somewhat intangible (but existent) "RFC sheen".
ML-KEM -- Module-Lattice-Based Key-Encapsulation Mechanism
ML-DSA -- Module-Lattice-Based Digital Signature Algorithm
solo PQ -- Using post-quantum crypto on its own
ECC+PQ -- Using post-quantum crypto as a layer on top of traditional elliptical curve cryptography (ECC)
So what's at stake here, is that the PQ crypto is not proven yet, and had recent implementation vulnerabilities (Kyberslash 1 & 2).
In the NSA's defense, combining cryptosystems also creates attack surfaces, timing problems, additional complexity, etc. Perhaps they know something we don't. They have sometimes acted to strengthen public cryptography, as with the DES S-boxes and differential cryptanalysis. Of course, they also weakened the key-space...
Is this true? The NSA pushed for weaker cryptography it could break versus stronger cryptography our adversaries couldn't?
Four days ago: https://news.ycombinator.com/item?id=48760490
Because they weren't (supposedly) able to break the encryption
> than to attack the algorithms
You have an opportunity to introduce new, broken, algorithms; they exploited it with DES, tried to exploit it with ECC, why wouldn't they try it with post-quantum (which they've kind of been pushing)?
(I'm only somewhat cryptography-literate and so I would myself default to a hybrid, though that opinion might change the first time I bother banging together an MLKEM implementation.)
You are if you're considering a cypher that's extremely likely to be secure.
In this case we're ok to introduce something with a chance to be quantum-resistant before it's been studied enough, because we want a chance of being quantum-resistant soon.
But that's only ok if you add it to the existing, reliable, systems.
Were there not the issue of quantum computers we wouldn't even be considering to use different cyphers at this time.
«- 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»
(https://mailarchive.ietf.org/arch/msg/tls/ol2otAvtdDrdz_xY0_...)
Apart from that, the crux of this is the codepoint allocation in the named group registry. [https://www.iana.org/assignments/tls-parameters/tls-paramete...] The requirement for that allocation (with "recommended=N" - which is what this draft has) is "Specification Required", not "IETF consensus". "Specification" for IANA registries doesn't mean IETF documents, it means:
[…] must be documented in a permanent and readily
available public specification, in sufficient detail so that
interoperability between independent implementations is possible.
As such I don't understand why the authors are so intent at ramming this through the IETF process when they could just put the same document whereever. The process has been sufficiently and publicly fraught enough to destroy any "reputation" that might (or might not) come associated with it being published as IETF RFC.
[ed.: referenced wrong registry, it's named groups, not cipher suites. Makes no difference, same registration procedure.]
FTR, the only [preliminary] entry with recommended=Y for PQ crypto is:
4588 X25519MLKEM768 Combining X25519 ECDH with ML-KEM-768 https://datatracker.ietf.org/doc/html/draft-ietf-tls-ecdhe-mlkem-05
The hybrid code point you reference is "preliminary" in the sense that when the RFC for hybrid ECC/ML-KEM is published (it's already been approved, https://datatracker.ietf.org/doc/draft-ietf-tls-ecdhe-mlkem/), it will replace the reference in the registry. However, it will have the same code point and the same semantics. If, for some reason, the IETF were to change the semantics, a new code point would have to be assigned for interop reasons.
If the document is dropped by the IETF, nothing at all would happen. It's already a valid code point registration, and indeed the authors could have just published the document, registered the code points, and stopped (see: https://datatracker.ietf.org/doc/draft-barnes-tls-this-could...).
If the authors decided to later pick up the document somewhere else, then they could probably get the reference changed to whatever that was, as long as the semantics were identical.
Yes, sorry, I was just covering against people nitpicking on the document status :)
Participants in disputes and RFCs literally call their comments “!vote” in true hacker notation, to repeatedly and clearly emphasize that “vote count” is never a factor in the process of establishing consensus.
(Elections are, however, regularly held, and votes counted, for positions such as Administrator, and the ArbCom seats, but that’s for people, not article content.)
Which is why I'm noting the alienation of "IETF believers", which I should maybe clarify I count myself as. The IETF is a lot of people doing a lot of good work. It does include a bunch of questionable actors, anything from ignorant, incompetent, ulterior motives, to outright malicious. But all in all it has brought us the internet as it exists today and I can't help feeling a little, well, alienated by DJB's writs.
[ed.:] https://blog.cr.yp.to/20251004-weakened.html#agreement says:
Anyway, IETF hasn't attempted to issue such a rule. On the contrary, IETF claims that WG decisions are not taken by voting: "Decisions within WGs, as with the broader IETF, are taken by 'rough consensus' and not by voting." This begs the question of what IETF thinks "rough consensus" means. Letting chairs make arbitrary decisions is a violation of due process.
More to the point, IETF can't override the definition of "consensus" in the law. That definition requires general agreement. Adoption of this draft was controversial, and didn't reach general agreement.
DJB making legal-ish arguments (or the idea that the IETF could be sued over a definition of "rough consensus") is absolutely inane to me. The choice of words of the IETF in defining its own processes for itself is not a legal one. And apart from that, which country's laws would that be? (I'm also quite skeptical about such a definition existing in a relevant manner to begin with.)
I, too, don't support the IETF (hence the quote on the web page, which I can't find now). But I happen to know enough about the people involved in this particular drama that I can see through his arguments here, and whether he realizes it or not, he's operating in supremely bad faith this time.
I've met him in person, once, at a CCC event about a decade ago, and as someone clueless about cryptography all I can say to that is that he certainly had (has?) a my-way-or-the-highway personality.
> I, too, don't support the IETF
Out of curiosity, how would you maintain e.g. TLS? Something more academic? Raw "throw it all out there, best-wins"? Another SDO (e.g. ITU)? Other more formal international processes?
I would maintain TLS the same way WireGuard and OpenSSH are maintained. Both have superior track records. I'm generally an opponent of all security and (especially) cryptographic standards bodies.
Hmm. This doesn't entirely connect for me… WireGuard and OpenSSH are first and foremost implementations. Are you implying people should follow a "primary" implementation? Does WireGuard even have a protocol specification? (searches - ah, yes, it does. I do know there have been a very number of "further" implementations [e.g. on FreeBSD], though I'm not sure if they're derivative or clean-room.)
But then isn't this just replacing IETF processes with whatever community or corporate processes those projects have? Wouldn't that just be "get shit into {the Linux kernel,OpenBSD}"? They've gotten better but both of those communities have their shortcomings. (For Linux, it's not the social interactions anymore, at this point it's the significant corporate interests.)
The problem with cryptographic standards bodies is that committee-based design has a long track record of weakening protocols. Originally, part of the ethos of the IETF was that it was merely providing interop for things that were already happening; rough consensus around real implementations. But that attitude expired decades ago; things are now designed de novo in working groups.
Through a herculean effort, TLS-WG managed through that fucked process to drastically improve TLS in 1.3. It did that in part because a team of cryptographers and cryptography engineers camped on the working group and made sure the outcome was sane. And they nearly failed! Banks fought hard to try to keep static handshakes in the new version, so they could do compliance intercepts.
Unfortunately, fully documenting PQC cryptography isn't as glamorous a task as defining the next generation's version of TLS. And yet, we've got a somewhat diverse team of cryptographers on the working group lined up against Bernstein on this.
The gist of it is that standards organizations like the IETF depend on a specific carve-out in US antitrust law (in order for it to be legal for American companies like Cisco and Google to participate in them), and that carve-out includes a specific definition of what "standards organizations" and "consensus" are. So even if the IETF uses different words to describe its processes, those processes still have to comply with the legal definition that separates a "standards organization" from, like, an illegal cartel.
If the link goes down, the content is available in many other places across the web under the title "The Gentleman's Guide To Forum Spies (spooks, feds, etc.)"
https://www.itu.int/en/ITU-T/tutorials/202203/Documents/Rein...