Comment by tptacek
4 days ago
I don't know what you mean by "kick the tires".
If by that you mean "perfect the implementation", we already get that! The MLKEM in Go is not the MLKEM in OpenSSL is not the MLKEM in AWS-LC.
If instead you mean "figure out after some period of implementation whether the standard itself is good", I don't know how that's meant to be workable. It's the publication of the standard itself that is the forcing function for high-quality competing implementations. In particular, part of arriving at high-quality implementations is running them in production, which is something you can't do without solving the coordination problem of getting everyone onto the same standard.
Here it's important to note that nothing we've learned since Kyber was chosen has materially weakened the construction itself. We've had in fact 3 years now of sustained (urgent, in fact) implementation and deployment (after almost 30 years of cryptologic work on lattices). What would have been different had Kyber been a speculative or proposed standard, other than it getting far less attention and deployment?
("Prissy" is not the word I personally would choose here.)
I mean have a bunch of competent teams that (importantly) didn’t design the algorithm read the final draft and write their versions of it. Then they and others can perform practical analysis on each (empirically look for timing side channels on x86 and ARM, fuzz them, etc.).
> If instead you mean "figure out after some period of implementation whether the standard itself is good", I don't know how that's meant to be workable.
The forcing function can potentially be: this final draft is the heir apparent. If nothing serious comes up in the next 6 months, it will be summarily finalized.
It’s possible this won’t get any of the implementers off their ass on a reasonable timeframe - this happens with web standards all the time. It’s also possible that this is very unlikely to uncover anything not already uncovered. Like I said, I’m not totally convinced that in this specific field it makes sense. But your arguments against it are fully general against this kind of phased process at all, and I think it has empirically improved recent W3C and IETF standards (including QUIC and HTTP2/3) a lot compared to the previous method.
Again: that has now happened. What have we learned from it that we needed to know 3 years ago when NIST chose Kyber? That's an important question, because this is a whole giant thread about Bernstein's allegation that the IETF is in the pocket of the NSA (see "part 4" of this series for that charming claim).
Further, the people involved in the NIST PQ key establishment competition are a murderers row of serious cryptographers and cryptography engineers. All of them had the knowhow and incentive to write implementations of their constructions and, if it was going to showcase some glaring problem, of their competitors. What makes you think that we lacked implementation understanding during this process?
I don’t think IETF is in the pocket of the NSA. I really wish the US government hadn’t hassled Bernstein so much when he was a grad student, it would make his stuff way more focused on technical details and readable without rolling your eyes.
> Further, the people involved in the NIST PQ key establishment competition are a murderers row of serious cryptographers and cryptography engineers.
That’s actually my point! When you’re trying to figure out if your standard is difficult to implement correctly, that everyone who worked on the reference implementations is a genius who understands it perfectly is a disadvantage for finding certain problems. It’s classic expert blindness, like you see with C++ where the people working on the standard understand the language so completely they can’t even conceive of what will happen when it’s in the hands of someone that doesn’t sleep with the C++ standard under their pillow.
Like, would anyone who developed ECC algorithms have forgotten to check for invalid curve points when writing an implementation? Meanwhile among mere mortals that’s happened over and over again.
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