NSA and IETF, part 3: Dodging the issues at hand
58 comments
·November 24, 2025dhx
Amongst the numerous reasons why you _don't_ want to rush into implementing new algorithms is even the _reference implementation_ (and most other early implementations) for Kyber/ML-KEM included multiple timing side channel vulnerabilities that allowed for key recovery.[1][2]
djb has been consistent in view for decades that cryptography standards need to consider the foolproofness of implementation so that a minor implementation mistake specific to timing of specific instructions on specific CPU architectures, or specific compiler optimisations, etc doesn't break the implementation. See for example the many problems of NIST P-224/P-256/P-384 ECC curves which djb has been instrumental in fixing through widespread deployment of X25519.[3][4][5]
[1] https://cryspen.com/post/ml-kem-implementation/
[2] https://kyberslash.cr.yp.to/faq.html / https://kyberslash.cr.yp.to/libraries.html
[3] https://en.wikipedia.org/wiki/Elliptic_curve_point_multiplic...
Foxboron
> See for example the many problems of NIST P-224/P-256/P-384 ECC curves
What are those problems exactly? The whitepaper from djb only makes vague claims about NSA being a malicious actor, but after ~20 years no known backdoors nor intentional weaknesses has been reliably proven?
supernetworks_
It would be wise for people to remember that it’s worth doing basic sanity checks before making claims like no backdoors from the NSA. strong encryption has been restricted historically so we had things like DES and 3DES and Crypto AG. In the modern internet age juniper has a bad time with this one https://www.wired.com/2013/09/nsa-backdoor/.
Usually it’s really hard to distinguish intent, and so it’s possible to develop plausible deniability with committees. Their track record isn’t perfect.
With WPA3 cryptographers warned about the known pitfall of standardizing a timing sensitive PAKE, and Harkin got it through anyway. Since it was a standard, the WiFi committee gladly selected it anyway, and then resulted in dragonbleed among other bugs. The techniques for hash2curve have patched that
UltraSane
The NSA changed the S-boxes in DES and this made people suspicious they had planted a back door but then when differential cryptanalysis was discovered people realized that the NSA changes to S-boxes made them more secure against it.
chc4
They're vulnerable to "High-S" malleable signatures, while ed25519 isn't. No one is claiming they're backdoored (well, some people somewhere probably are), but they do have failure modes that ed25519 doesn't which is the GP's point.
kiray
I have been tracking this for months.
There is clearly at best, bias in moderation on the IETF list or possibly far worse.
When djb was suspended for an innocuous reason, at the same time participants were engaging in activity that would usually be met with permabans (name calling, bullying, etc.). They were not banned.
He's been up against serious adversity but continues to protect the lesser informed.
This is why djb is in the Cypherpunks Hall of Fame! [1]
Foxboron
> This is why djb is in the Cypherpunks Hall of Fame! [1]
This is a list made by you 2 weeks ago?
EDIT: Okay lol. I actually browsed the list and found multiple dubious entries, along with Trump!
Hilarious list. 10/10.
jonesjohnson
what do you expect, when the tagline at the end of the page says "In crypto we trust."?
Honestly, it's a bit sad. There are many great people on that list, but some seem a bit random and some are just straight up cryptobros, which makes the whole thing a joke, unfortunately
anonym29
Name calling, bullying (forms of systematic harassment) and attempting to instill feelings of social isolation in a target are documented techniques employed by intelligence agencies in both online and offline discourse manipulation / information warfare.
You can read up more here if you are curious: https://www.statewatch.org/media/documents/news/2015/jun/beh...
Many of the attacks against djb line up quite nicely with "discredit" operational objectives.
webdoodle
Bully and systematic harassment of cryptographers too build in backdoors too there encryption systems has been there go to strategy since the 80's.
zahllos
In context, this particular issue is that DJB disagrees with the IETF publishing an ML-KEM only standard for key exchange.
Here's the thing. The existence of a standard does not mean we need to use it for most of the internet. There will also be hybrid standards, and most of the rest of us can simply ignore the existence of ML-KEM -only. However, NSA's CNSA 2.0 (commercial cryptography you can sell to the US Federal Government) does not envisage using hybrid schemes. So there's some sense in having a standard for that purpose. Better developed through the IETF than forced on browser vendors directly by the US, I think. There was rough consensus to do this. Should we have a single-cipher kex standard for HQC too? I'd argue yes, and no the NSA don't propose to use it (unless they updated CNSA).
The requirement of the NIST competition is that all standardized algorithms are both classical and PQ-resistant. Some have said in this thread that lattice crypto is relatively new, but it actually has quite some history, going back to Atjai in '97. If you want paranoia, there's always code theory based schemes going back to around '75. We don't know what we don't know, which is why there's HQC (code based) waiting on standardisation and an additional on-ramp for signatures, plus the expensive (size and sometimes statefulness) of hash-based options. So there's some argument that single-cipher is fine, and we have a whole set of alternative options.
This particular overreaction appears to be yet another in a long running series of... disagreements with the entire NIST process, including "claims" around the security level of what we then called Kyber, insults to the NIST team's security level estimation in the form of suggesting they can't do basic arithmetic (given we can't factor anything bigger than 15 on a real quantum computer and we simply don't have hardware anywhere near breaking RSA, estimate is exactly what these are) and so on.
HelloNurse
The metaphor near the beginning of the article is a good summary: standardizing cars with seatbelts, but also cars without seatbelts.
Since ML-KEM is supported by the NSA, it should be assumed to have a NSA-known backdoor that they want to be used as much as possible: IETF standardization is a great opportunity for a long term social engineering operation, much like DES, Clipper, the more recent funny elliptic curve, etc.
MYEUHD
> the more recent funny elliptic curve
Can you elaborate please?
rdtsc
Not op, but they probably meant https://en.wikipedia.org/wiki/Dual_EC_DRBG
vorpalhex
The standard will be used, as it was the previous time the IETF allowed the NSA to standardize a known weak algorithm.
Sorry that someone calling out a math error makes the NIST team feel stupid. Instead of dogpiling the person for not stroking their ego, maybe they should correct the error. Last I checked, a quantum computer wasn't needed to handle exponents, a whiteboard will do.
zahllos
ML-KEM and ML-DSA are not "known weak". The justification for hybrid crypto is that they might have classical cryptanalytical results we aren't aware of, although there's a hardness reduction for lattice problems showing they're NP-hard, while we only suspect RSA+DLog are somewhere in NP. That's reasonable as a maximal-safety measure, but comes with additional cost.
Obviously the standard will be used. As I said in a sibling comment, the US Government fully intends to do this whether the IETF makes a standard or not.
aaomidi
Except when the government starts then mandating a specific algorithm.
And yes. This has happened. There’s a reason there’s only the NIST P Curves in the WebPKI world.
zahllos
"The government" already have. That's what CNSA 2.0 means - this is the commercial crypto NSA recommend for the US Government and what will be in FIPS/CAVP/CMVP. ML-KEM-only for most key exchange.
In this context, it is largely irrelevant whether the IETF chooses or not to have a single-standard draft. There's a code point from IANA to do this in TLS already and it will happen for US Government systems.
I'd also add that personally I consider NIST P-Curves to be absolutely fine crypto. Complete formula exist, so it's possible to have failure-free ops, although point-on-curve needs to be checked. They don't come with the small-order subgroup problem of any Montgomery curve. ECDSA isn't great alone, the hedged variants from RFC 6979 and later drafts should be used.
Since ML-KEM is key exchange, X25519 is very widely used in TLS unless you need to turn it off for FIPS. For the certificate side, the actual WebPKI, I'm going to say RSA wins out (still) (I think).
jancsika
Dear some seasoned cryptographer,
Please ELI5: what is the argument for including the option for the non-hybrid option in this standard? Is it a good argument in your expert opinion?
My pea brain: implementers plus options equals bad, newfangled minus entrenched equals bad, alice only trust option 1 but bob only have option 2 = my pea brain hurt!
abhv
20+2 (conditional support) versus 7.
22/29 = 76% in some form of "yea"
That feels like "rough consensus"
jcranmer
The standard used in the C and C++ committees is essentially a 2-to-1 majority in favor. I'm not aware of any committee where a 3-to-1 majority is insufficient to get an item to pass.
DJB's argument that this isn't good enough would, by itself, be enough for me to route his objections to /dev/null; it's so tedious and snipey that it sours the quality of his other arguments by mere association. And overall, it gives the impression of someone who is more interested in derailing the entire process than in actually trying to craft a good standard.
pfortuny
You are turning “consensus” into “majority” and those it not the same.
jcranmer
There was a recent discussion within the C committee over what exactly constituted consensus owing to a borderline vote that was surprisingly ruled "no consensus" (and the gravitas of the discussion was over the difference between a "no" and an "abstain" vote for consensus purposes). The decision was that it had to be a ⅔ favor/(favor + against), and ¾ (favor + neutral) / (favor + against + neutral). These are the actual rules of the committee now for determining consensus. Similar rules exist for the C++ committee.
If there is any conflation going on, I am not the one doing it.
vorpalhex
We're talking about a landmine in a crypto spec and you're bikeshedding about consensus ratios.
We should talk about the NSA designed landmine.
f33d5173
A consensus is 100%. A rough consensus should be near 100%. 2/3 is a super majority. That's a very different standard.
philipwhiuk
For an employee at NIST who operates a NIST email address to claim they have no association with NIST is farcical:
https://web.archive.org/web/20251122075555/https://mailarchi...
amszmidt
”No association” and “I am not a representative” are quite different things to say.
philipwhiuk
You represent your organisation regardless of whether you cloak yourself in an alternate email
amszmidt
An employee doesn’t act as an official representative of their employer nor do they speak for the employee in any official capacity. That is what the message says.
The informal also didn’t cloak their identity (implies some malicious intent), they simple did not use their work email. Nothing wrong with that.
conception
I’m sorry, can you state which organization you are speaking for with this comment? It wasn’t immediately clear.
throw0101c
[flagged]
hosteur
What is your agenda?
6581
That's not what the message you linked claims at all. Maybe you missed the "in this message" at the end of the sentence?
philipwhiuk
No not really - I don’t think choosing to post from an alternative email removes the association issue that the original intent is trying to capture.
throw0101a
Perhaps related: from 2022, on his (FOIA?) lawsuit against the government:
* https://news.ycombinator.com/item?id=32360533
From 2023, "Debunking NIST's calculation of the Kyber-512 security level":
GauntletWizard
The NSA has railroaded bad crypto before [1]. The correct answer is to just ignore it, to say "okay, this is the NSA's preferred backboard crypto standard, and none of our actual implementations will support it."
It is not acceptable for the government to be forcing bad crypto down our throats, it is not acceptable for the NSA to be poisoning the well this way, but for all I respect DJB, they are "playing the game" and 20 to 7 is consensus.
0xbadcafebee
tl;dr DJB is trying to stop the NSA railroading bad crypto into TLS standards, the objections deadline is in two days, and they're stonewalling him
This /. story fills in the backstory: https://it.slashdot.org/story/25/11/23/226258/cryptologist-d...
Normal practice in deploying post-quantum cryptography is to deploy ECC+PQ. IETF's TLS working group is standardizing ECC+PQ. But IETF management is also non-consensually ramming a particular NSA-driven document through the IETF process, a "non-hybrid" document that adds just PQ as another TLS option.g-mork
Handforth Parish council Internet edition. You have no authority here, djb! No authority at all
ants_everywhere
D. J. Bernstein is very well respected and for very good reason. And I don't have firsthand knowledge of the background here, but the blog posts about the incident have been written in a kind of weird voice that make me feel like I'm reading about the US Government suppressing evidence of Bigfoot or something.
Stuff like this
> Wow, look at that: "due process".... Could it possibly be that the people writing the law were thinking through how standardization processes could be abused?"
is both accusing the other party of bad faith and also heavily using sarcasm, which is a sort of performative bad faith.
Sarcasm can be really effective when used well. But when a post is dripping with sarcasm and accusing others of bad faith it comes off as hiding a weak position behind contempt. I don't know if this is just how DJB writes, or if he's adopting this voice because he thinks it's what the internet wants to see right now.
Personally, I would prefer a style where he says only what he means without irony and expresses his feelings directly. If showing contempt is essential to the piece, then the Linus Torvalds style of explicit theatrical contempt is probably preferable, at least to me.
I understand others may feel differently. The style just gives me crackpot vibes and that may color reception of the blog posts to people who don't know DJT's reputation.
amiga386
It's very simple.
ECC is well understood and has not been broken over many years.
ML-KEM is new, and hasn't had the same scrutiny as ECC. It's possible that the NSA already knows how to break this, and has chosen not to tell us, and NIST plays the useful idiot.
NIST has played the useful idiot before, when it promoted Dual_EC_DRBG, and the US government paid RSA to make it the default CSPRNG in their crypto libraries for everyone else... but eventually word got out that it's almost certainly an NSA NOBUS special, and everyone started disabling it.
Knowing all that, and planning for a future where quantum computers might defeat ECC -- it's not defeated yet, and nobody knows when in the future that might happen... would you choose:
Option A): encrypt key exchange with ECC and the new unproven algorithm
Option B): throw out ECC and just use the new unproven algorithm
NIST tells you option B is for the best. NIST told you to use Dual_EC_DRBG. W3C adopted EME at the behest of Microsoft, Google and Netflix. Microsoft told you OOXML is a valid international standard you should use instead of OpenDocument (and it just so happens that only one piece of software, made by Microsoft, correctly reads and writes OOXML). So it goes on. Standards organisations are very easily corruptable when its members are allowed to have conflicts of interest and politick and rules-lawyer the organisation into adopting their pet standards.
jcranmer
> Standards organisations are very easily corruptable when its members are allowed to have conflicts of interest and politick and rules-lawyer the organisation into adopting their pet standards.
FWIW, in my experience on standardization committees, the worst example I've seen of rules-lawyering to drive standards changes is... what DJB's doing right now. There's a couple of other egregious examples I can think of, where people advocating against controversial features go in full rules-lawyer mode to (unsuccessfully) get the feature pulled. I've never actually seen any controversial feature make it into a standard because of rules-lawyering.
glenstein
Thank you, that seems to be the whole ball game for me right there. I understood the sarcastic tone as kind of exasperation, but it means something in the context of an extremely concerning attempt to ram through a questionable algorithm that is not well understood and risks a version of an NSA backdoor, and the only real protection would be integrity of standards adoptions processes like this one. You've really got to stick with the substance over the tone to be able to follow the ball here. Everyone was losing their minds over GDPR introducing a potential back door to encrypted chat apps that security agencies could access. This goes to the exact same category of concern, and as you note it has precedent!
So yeah, NSA potentially sneaking a backdoor into an approved standard is pretty outrageous, and worth objecting to in strongest terms, and when that risk is present it should be subjected to the highest conceiveable standard of scrutiny.
In fact, I found this to be the strongest point in the article - there's any number of alternatives that might (1) prove easier to implement, (2) prove more resilient to future attacks (3) turn out to be the most efficient.
Just because you want to do something in the future doesn't mean it needs to be ML-KEM specifically, and the idea of throwing out ECC is almost completely inexplicable unless you're the NSA and you can't break it and you're trying to propose a new standard that doesn't include it.
How is that not a hair on fire level concern?
jonstewart
He’s smart and prolific, for sure, but I lost respect for him several years ago.
johnisgood
Why, if I might respectfully ask?
jonstewart
Sure! First, while I’m in no position to judge cryptographic algorithms, the success of cha-cha and 25519 speak for themselves. More prosaically, patriecia/critbit trees and his other tools are the right thing, and foresighted. He’s not just smart, but also prolific.
However, he’s left a wake of combative controversy his entire career, of the “crackpot” type the parent comment notes, and at some point it’d be worth his asking, AITA? Second, his unconditional support of Jacob Appelbaum has been bonkers. He’s obviously smart and uncompromising but, despite having been in the right on some issues, his scorched earth approach/lack of judgment seems to have turned his paranoia about everyone being out to get him into a self-fulfilling prophecy.
For context, djb has been doing and saying these things since he was a college student: