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Comment by tptacek | Hacker News Reader

The sleight of hand here is to equate publicly reducing the key size, which was known (presumably at the time as well) to be a weakening of the system, with a supposed weakness injected cryptically into the S-boxes --- which we now know is the opposite of what happened.

Further, the truncated version of DES that got standardized far outlasted its expected lifetime --- the National Bureau of Standards expected DES to have a useful lifetime of about 5 years. And even at the time it was understood that you could expand the keysize by tripling up the DES core.

I think there's a really big difference between publicly weakening a standard, in effect telling the world "we want a standard that is adequate for commercial purposes but inadequate for military purposes, so as to retain our national edge", and doing what they did with Dual-EC, where it was impossible (apparently) for people to reason about what NSA was up to.

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> and doing what they did with Dual-EC, where it was impossible (apparently) for people to reason about what NSA was up to.

Schneier was clearly able to reason about what NSA was up to, and told everyone in 2007 not to use Dual-EC, 6 years before the Snowden revelations.

I believe you have admitted that you thought that “Dual-EC has a backdoor” was a wild conspiracy theory until the Snowden revelations? Which makes the “impossible (apparently)” part a classic case of projection.

The (apparently) was a dunk on me.

(I thought nobody should use Dual EC! But that was my reason for thinking it wasn't an NSA backdoor, because it was too dumb to be one. I underestimated the industry's capacity for "dumb". Also: I was dumb! I am dumb a lot.)

And now you believe it’s impossible for any of the NIST PQC submissions to have been backdoored or weakened. I feel safer already. :D

NIST didn't design any of the PQC submissions. It did design Dual EC.

NIST didn’t design Dual-EC, NSA did. But NIST did the really hard work, which involved slapping their organization’s name on it, and not asking any inconvenient questions.

Thankfully we found a better way that ensures cryptographic security, which is to get former NSA interns to write the PQC standards, instead of proper NSA employees.

As a shorthand for this site, I'm not distinguishing between the two organizations. Which former NSA interns are you talking about? You can get their names from the pq-crystals.org site. Which one should we not be trusting?

Is it maybe Tancrede Lepoint? He always seemed shady to me. Or Peter Schwabe?

A wonderful question that exposes me to legal action if I answer.

A better question: why do you think so many of your cryptographic feline friendz were so excited about isogenies for the past decade? Where do you think they all obtained that identical enthusiasm from? Why do you think SIKE made it so far in the contest and only got eliminated through luck?

Your theory here is that NSA coordinated an action whereby the PQC standard selected could be broken by anybody in the world with a Python script, based on research disclosed to the public in the 1990s.

I'm guessing this isn't a conversation that's going to take us into Richelot isogenies.

You obviously know that the Python script wasn’t submitted to NIST along with the draft standard.

Is Dual-EC-DRBG fine because we never saw the FVEY Python exploit that breaks it?

I think my theory here is that NSA coordinated an action whereby they figured no one was reading obscure algebraic geometry papers from 1997. In our low-attention-span world, it’s not the worst plan.

(Hell, folks didn’t realize TAOSSA contained 0day for a long time. Simply putting something in front of the public doesn’t mean they’ll read or comprehend it.)

It is literally the worst plan, because it leaves every PQC-protected system in the world exposed to everybody in the world. It's a theory that depends on NSA just wanting to watch the world burn.

Dual EC isn't broken by an exploit script. It's broken with a secret key.

> It is literally the worst plan, because it leaves every PQC-protected system in the world exposed to _everybody in the world_.

No, it leaves every SIKE-protected system in the world exposed to _everybody who reads obscure algebraic geometry papers from 1997._ We got really lucky that the two dorks who do read those papers decided to share their insights.

For all you know, there’s a paper sitting at the Institute For Advanced Study that would let you write a marvelous pq-crystals-shattering Python script, but they’ll never tell you the combination to the safe.

(Again: TAOSSA contained 0day exploits, and few noticed for a decade.)

You seem to believe the only thing preventing people from exploiting Dual EC is not having read the right cryptography papers. No; the reason why that's not the case is plainly evident from Dual EC's structure (if that were true, the NSA would presumably have no need of Dual EC!). Our premises are too far apart to usefully discuss this.

I thought PQC systems were wrapping classical encryption within the PQC protection so even if you broke PQC you'd still be left having to crack classical. Of course some hypothetical future QC could then accomplish this task so the future proofing goal of PQC would be violated.

The proposal is to do exactly this (hybrid schemes using a pre and a post quantum scheme).

However in this context the debate is just over the PQ scheme (not the overall system). Also, NSA are not planning to mandate a hybrid system for government use. Others may do the same.

Of the SCW hosts, I'm actually the NSA plant. You got me.

What people on these threads aren't prepared to grok is that cryptography engineers (even the older ones) are gothy af, and the isogeny graph diagrams all looked like black magic stuff out of the Lesser Key of Solomon. Sorry, there isn't more to it than that.

I don't know if I count as a "feline friend", but: SIDH kept the DH shape. Being able to upgrade the protocols we had relatively closely is appealing. "Structure is useful but seems precarious" wasn't exactly secret knowledge.

I never understood the Dual-EC backdoor. What was the point? Who would be dumb enough to use that as their CSPRNG when so many simpler, faster, and less sus options were available?

I supposed they did (allegedly) pay RSA Security to make this the default choice in BSAFE but that seems like an awful lot of work to hack one product.

That was my take too, but in fairness to everyone else who was right about this, once you stepped back and looked at the design for what it was, rather than as a weird concoction that happened to spit out random numbers, it was extremely obvious what the purpose of the design was. Another thing happening with me and Dual EC: I just know a lot more about cryptography today than I did 13 years ago. (I'm not a cryptographer; I'm a vulnerability person that happens to specialize a bit in cryptography vulnerabilities. It's a great rhetorical hedge.)

Another thing I was very certain (and certainly wrong) about was that no competent team was using BSAFE in 2010. The more I've learned about cryptography the less confidence I've held onto in industry cryptography practices outside of Google, Apple, and Microsoft. I would have assumed the major networking vendors were playing at roughly the same level. Yikes, no.

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