As a software engineer with a good amount of freedom to choose what tools I want to use, what can I do presently to move towards post-quantum cryptography? AFAIK the hashes and symmetric cyphers that are in wide use are already resistant, leaving mainly public-key cryptography as the problem. Is there, for instance, a drop in replacement for `ssh-keygen -t ed25519`?
Will you heed my warnings now?
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Re: Will you heed my warnings now?
#22Ok, maybe I'm missing something here. So we know that quantum computers hold a real risk of being able to break a lot of encryption. We also know that changing cyphers is hard (because reasons) But what I don't see is what I can practically do now, as either someone who is a CTO/Big Cheese™ or a lowly engineer?
> But what I don't see is what I can practically do now, as either someone who is a CTO/Big Cheese™ or a lowly engineer?
Migrate! The major TLS and OpenSSH applications already support PQC, for example.
1. Make sure you have the required dependencies (e.g., openssl 3.5+ is when a lot of PQC algorithms got support).
2. Make sure the client/server software is up to date (this might be all that's needed, e.g., OpenSSH 10.0+ enables PQC in-transit encryption by default, and so does Chrome 131+).
3. Enable PQC support in the configuration (e.g., "ssl_ecdh_curve X25519MLKEM768;" in Nginx).
If you are the developer of anything that's explicitly using RSA or ECC (or god forbid Diffie-Hellman), you can also migrate your own software, or at least make the algorithm selectable at initialization time instead of hardcoded. If you have vendors, ask them for their PQC migration roadmaps.
Note that with encrypted data you want to protect yourself against attackers that are capturing data today and waiting to break it in the future (Harvest-Now, Decrypt-Later). So migrating encryption is more urgent than migrating authentication.
Re: Will you heed my warnings now?
#23> Shor of Damocles What is the biggest number factored using Shor's algorithm? Last time I looked it was very unimpressive. Edit: It's gotten worse. 21 from 2012. "Replication of Quantum Factorisation Records with an 8-bit Home Computer, an Abacus, and a Dog" say the factorization of 35 in 2019 actually failed. https://eprint.iacr.org/2025/1237
I will let Scott Aaronson speak. (See https://scottaaronson.blog/?p=9668 ) > Sometimes these days, I'll survey the spectacular recent progress in fault-tolerance, 2-qubit gate fidelities, programmable hundred-qubit systems, etc., only to be answered with a sneer: "What's the biggest number that Shor's algorithm has factored? Still 15 after all these years? Haha, apparently the emperor has no clothes!" I've commented…
I talked to a guy who did his doctoral degree on quantum computing and he was not worried at all. In fact he thought it was wildly overhyped, and like cold fusion, self driving cars, or string theory, always just around the corner. Just give us five more years and another grant, please.
Re: Will you heed my warnings now?
#24Aaronson know his stuff but I am not sure he hasn’t considered the fact that, in this current hype cycle, the quantum researchers breathlessly reporting to him on a breakthrough just around the corner are just lying to him and themselves. I have been hearing about one more technical hurdle to solve before quantum algorithms become feasible since before I graduated. That was in 1996.
Are you saying this because it's an evergreen joke or because you really think there hasn't been meaningful progress in the field since 1996? Duke Nukem Forever was release fifteen years ago. Some things never happen until they suddenly do. The wolf really does eat the boy at the end of The Boy Who Cried Wolf.
The Boy Who Cried Wolf is a story about a boy who have seen a wolf, successfully threatened the wolf away by causing a commotion in a disbelieving village. One day the disbelieving village refused to show up, boy was eaten and thus proven correct.
But as it happens in real life politics too, people who were just proven they were wrong continued to blame the boy.
The story is told from the point of view of a villagers trying to hide their culpability by blaming the victim.
Re: Will you heed my warnings now?
#25Tl;dr: > if quantum computers start breaking cryptography a few years from now, don’t you dare come to this blog and tell me that I failed to warn you. This post is your warning.
If quantum computers broke cryptography I think going to some guy's blog and complaining that he failed to warn me would be pretty low down on my todo list
Re: Will you heed my warnings now?
#26> Shor of Damocles What is the biggest number factored using Shor's algorithm? Last time I looked it was very unimpressive. Edit: It's gotten worse. 21 from 2012. "Replication of Quantum Factorisation Records with an 8-bit Home Computer, an Abacus, and a Dog" say the factorization of 35 in 2019 actually failed. https://eprint.iacr.org/2025/1237
I said this about LLMs a few years ago, and now here we are.
Yeah 70 years ago right.
Re: Will you heed my warnings now?
#27> Shor of Damocles What is the biggest number factored using Shor's algorithm? Last time I looked it was very unimpressive. Edit: It's gotten worse. 21 from 2012. "Replication of Quantum Factorisation Records with an 8-bit Home Computer, an Abacus, and a Dog" say the factorization of 35 in 2019 actually failed. https://eprint.iacr.org/2025/1237
I will let Scott Aaronson speak. (See https://scottaaronson.blog/?p=9668 ) > Sometimes these days, I'll survey the spectacular recent progress in fault-tolerance, 2-qubit gate fidelities, programmable hundred-qubit systems, etc., only to be answered with a sneer: "What's the biggest number that Shor's algorithm has factored? Still 15 after all these years? Haha, apparently the emperor has no clothes!" I've commented…
> If there's a reason why you think it can't work beyond a certain scale, say so
I'm not saying it can't work. Just that in 14 years no one has managed to factor a larger number than 21. Seemingly focus has shifted to other factoring algorithms that don't have performance improvements over conventional computing.
I'm not the one implying that Shor's algorithm will breaking encryption in "a few years from now".
Re: Will you heed my warnings now?
#28I'm sure eventually i'll eat my words - but Quantum still seems like a massive marketing gimmick. The technology itself is incredibly interesting, but it feels as if CERN began advertising itself as a marketing stunt - there's just something about the way I see quantum marketed + advertised right now that doesn't seem to align with reality.
Re: Will you heed my warnings now?
#29Earlier quoted context omitted.
This is true, practical quantum computing is always "just a couple of years away". At the same time, moving to more secure encryption really isn't difficult. How many times have algorithms been deprecated over the past 20 or so years? It's time to do it again. Let's just make sure that the NSA hasn't worked in any backdoors. At latest since Snowdon, anything they work on is suspect.
There is no clear evidence that the risk of "a practical post quantum computer would arrive in the next 5 years" is greater than "post quantum scheme X is broken" for any scheme X. The only way to go is hybridation and it is quite hard from an engineering point apparently.
There is evidence of the opposite: graph singular isogeny mumbo jumbo algorithm was proven to be easily broken on an ordinary computer.
Hybrid encryption is as simple as running one encryption and then the other. Problem is mostly that post quantum keys are large.
Re: Will you heed my warnings now?
#30I'm sure eventually i'll eat my words - but Quantum still seems like a massive marketing gimmick. The technology itself is incredibly interesting, but it feels as if CERN began advertising itself as a marketing stunt - there's just something about the way I see quantum marketed + advertised right now that doesn't seem to align with reality.
> * it feels as if CERN began advertising itself as a marketing stunt*
Quantum AI harvesting antimatter