Will you heed my warnings now?

by bwesterb • 3 months ago

89 102 3 months ago

KaiserPro• 3 months ago

Ok, 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?

fastball• 3 months ago

This is what Cloudflare[1] is doing.

[1] https://blog.cloudflare.com/post-quantum-roadmap/

rolandog2• 3 months ago

I think lobby for saner defaults (tip of the hat to Steve Gibson's term "the tyranny of the default"), configuring one's GPG config to mark certain cyphers as insecure (to prevent downgrade attacks)... and have one's (chief) information security officer write those things down as policy and maybe have a yearly onboarding workshop teaching people why it's important.

MattPalmer10863• 3 months ago

If you're a CTO, have a post quantum strategy: know what crypto you use and where it is, plan to migrate to post quantum secure ciphers over the next decade or so, or sooner if possible. If you're a lowly engineer, not very much unless you're specifically selecting technologies with crypto. In which case crypto agility (being able to switch out existing crypto when needed) is a good property to look for.

weddpros• 3 months ago

TLS can already be setup to avoid store-now-decrypt-later PQC issues. That's available today, and should be implemented. Use https://sslboard.com to inventory all your external TLS infrastructure and check for PQC readiness (creator here).

BoppreH8• 3 months ago

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.

beloch2• 3 months ago

The most important thing to realize about cryptography is that, for most methods short of a Vernam cipher or quantum key distribution, coded messages need to be treated as published with delay. Cipher text can be archived today and attacked years from now with currently undeveloped, unknown, or unpredicted resources/algorithms. Sure, perhaps nobody archived the cipher text and you're fine. You don't know that for sure. Your methods may be very strong but, if they're not provably immune to attack, you also don't know what the delay before publication truly is. It might be a very long time. It might not.

If you're transmitting credit card info that changes every few years and can be changed on demand, that's no big deal. If you're transmitting information that will remain sensitive for decades, the time to look for methods that would stand up to quantum computing was years ago. However, today is still better than years in the future. At the very least, you can choose what to send in encrypted form over public networks and what not to send.

There are people who will scoff at the notion of quantum computing ever developing to the point where it can make an impact. There are people who scoff at the effort and expense of QKD or good ol' spooks carrying briefcases full of one-time PADs. You might be right to listen to them. You might not be. It's a risk. Whether you, or your organization, can tolerate that risk is entirely dependent on you and yours.

Tyyps2• 3 months ago

About QKD: https://arxiv.org/abs/1803.04520

bwesterb8• 3 months ago

QKD is cool and all, but it just doesn't scale to the whole Internet. https://blog.cloudflare.com/you-dont-need-quantum-hardware/

bwesterb8• 3 months ago

Where available, you can migrate. Even if PQ is not yet available it helps to:

1. Make sure your dependencies are up to date. Move to a recent version of your crypto libraries. 2. Make sure your server can install multiple certificates: you'll need that unless you control all your clients. 3. Automate certificate issuance as far as possible.

Also, what you can do now is to run the following wargame: assume the CRQC arrived. What's the business impact?

For the migration itself I see three parallel streams.

1. Main push of straight-forward cases (TLS, etc.) Might need to wait a bit for software support.

2. Hard cases: crypto baked into hardware; custom protocols; keys in tight spaces (JWT in URLs); etc. You need to bubble those up soon to make decisions on how to fix them.

3. External dependencies. Barely any vendor has a PQ roadmap, so asking now is probably early, but you can figure out what to do if they don't get their stuff ready in time.

FartyMcFarter4• 3 months ago

the Shor of Damocles

Perfect.

AndrewStephens2• 3 months ago

Aaronson 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.

chii• 3 months ago

quantum computers will flourish the same day that fusion does.

bradley13• 3 months ago

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.

AshamedCaptain2• 3 months ago

And in the process immediately convert huge numbers of devices into ewaste. Then check the excuse calendar again for tomorrow's reason to deprecate yet another batch of "legacy" ciphers from openSSL.

Tyyps2• 3 months ago

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.

ipython• 3 months ago

I hard disagree with your assertion that moving to more secure encryption isn't difficult. It is insanely difficult, especially at global scale.

bwesterb8• 3 months ago

It'll be a 90/10 rule: 90% of the upgrades will be straightforward. It's important the 10% that'll be hard early. For many it's probably already too late.

sharkjacobs• 3 months ago

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.

emil-lp• 3 months ago

But Duke Nukem was developed with visible progress.

We are still not factoring 21, let alone 35, let alone numbers with thousands of digits.

watwut• 3 months ago

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.

notarobot123• 3 months ago

"The Shor of Damocles" - what a metaphor.

I thought it was a typo at first but wikipedia explained:

The Sword of Damocles is an ancient Greek moral anecdote, an allusion to the imminent and ever-present peril faced by those in positions of power.

Shor's algorithm is a quantum algorithm for finding the prime factors of an integer

Obscurity4340• 3 months ago

It applies to those subject to a capricious arbitrary power as well. Like living under a shitty parent, the same threat(s) they settle on to control them becomes the dangling Sword till its forecefully removed and they are neutered

amelius• 3 months ago

Tl;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.

dwedge• 3 months ago

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

Ardren3• 3 months ago

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

FartyMcFarter4• 3 months ago

I said this about LLMs a few years ago, and now here we are.

L-four• 3 months ago

Yeah 70 years ago right.

sanxiyn3• 3 months ago

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 that this is sort of like dismissing the Manhattan Project as hopelessly stalled in 1944, on the ground that so far it hasn't produced even a tiny nuclear explosion... If there's a reason why you think it can't work beyond a certain scale, say so. But don't fixate on one external benchmark and ignore everything happening under the hood, if the experts are telling you that under the hood is where all the action now is, and your preferred benchmark is only relevant later.

toxik• 3 months ago

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.

Ardren3• 3 months ago

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".

tgv2• 3 months ago

dismissing the Manhattan Project as hopelessly stalled in 1944

Then again, there are enough examples of failed projects. Why should this be comparable to the Manhattan project? In 1944, it was only two years underway, whereas Shor's algorithm is over 30. Tons of articles have been published on quantum computing, while the A bomb was kept as secret as possible, making learning from other countries, sometimes even from colleagues, impossible. In 1942, an atomic explosion was still hypothetical, whereas quantum computing had its first commercial service 7 years ago. Etc.

So, while in principle lack of progress doesn't guarantee failure, a comparison to the Manhattan Project is stylistic bullshit.

bwesterb8• 3 months ago

The abacus thing is pretty funny, but it's dangerously uninformed. https://bas.westerbaan.name/notes/2026/04/02/factoring.html

Ardren3• 3 months ago

Is there a better benchmark to use?

Honest question.

How can a lay person track the real word progress of quantum computers?

sehansen3• 3 months ago

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`?

alephnerd3• 3 months ago

It's still being implemented or defined.

The worry about "harvest and decrypt" in a 5 year timeframe is primarily from a nation state/natsec perspective.

If you are being targeted by a nation state as a line level engineer, harvest and decrypt is the least of your worries.

i_think_so7• 3 months ago

I am reminded of a certain comedian who lost his job hosting an awards ceremony because he had once said something on stage that people didn't like....

...8 years previously.[1]

Long, long ago in a datacenter far away, breaking 3DES used to be the province of expensive bespoke hardware owned by only the elite nation states. Today it is so trivial that the gpu in your second hand laptop can do it "at scale".

5 years ago ChatGPT was a wet dream.

We should be very conservative in our planning where future security is concerned. The only thing we can be sure of is that Murphy's Law is looking for every chance to make us look foolish.

[1] https://www.bbc.com/news/entertainment-arts-46479017

BoppreH8• 3 months ago

I have another comment[1] on this post with more practical instructions, but the `ssh-keygen` is a good question. The cryptography community is still focused on migrating encryption/key exchange algorithms, for fear of data being captured today and decrypted in the future. So OpenSSH 10.0+ already enables ML-KEM by default.

SSH keys, on the other hand, are authentication and would require an online Quantum Computer to break, so we have more time. Authentication is also (usually) more complicated, so there are still disagreements on what to do with the Web PKI for example. To give you a concrete target, Google, Microsoft, and CloudFlare have self-imposed deadlines of 2029 for their PQC migrations.

In practice, PQC migration means updating your software, bugging your vendors to ensure they have this on their roadmaps, and making sure your own code is flexible in respect to algorithms used.

[1] https://news.ycombinator.com/item?id=47959556

alephnerd3• 3 months ago

Cloudflare should have finished it's PQC migration already.

BoppreH8• 3 months ago

Late edit: PQC migration also includes sometimes changing configuration files/library invocations to enable the new algorithms, and ensuring that your processes still work during the migration, where you might have both pure classical and PQC/hybrid at the same time.

bwesterb8• 3 months ago

SSH is working on a drop-in as we speak. TLS is further along: most stacks already support X25519MLKEM768 (by default!) to counter store-now/decrypt-later. PQ certs are not widely supported yet, but that's being sped up as we speak.

endymion-light2• 3 months ago

I'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.

Razengan• 3 months ago

* it feels as if CERN began advertising itself as a marketing stunt*

Quantum AI harvesting antimatter

endymion-light2• 3 months ago

I suppose in spirit of the article - it's as if the manhattan project in 1944 was telling the world that theoretically it's 6-12 months away from igniting the entire upper atmosphere.

YouWhy• 3 months ago

Re the "Manhattan project in 1944" argument - I am very cautious about the "modulo engineering scaling" carve-out -- unlike the uranium manufacturing pipeline of World War 2, that involved massively scaling up a known process, on the face of it there's no uncontroversial process/architecture to scale up in this case.

On the face of it, even relatively "point-target" goals of this kind could take many decades if at all; GaN for blue diodes come in mind as an example of a field that was stuck for a generation -- until it wasn't.

codethief3• 3 months ago

I am very cautious about the "modulo engineering scaling" carve-out

As OP said elsewhere[0, 1]:

Once you understand quantum fault-tolerance, asking “so when are you going to factor 35 with Shor’s algorithm?” becomes sort of like asking the Manhattan Project physicists in 1943, “so when are you going to produce at least a small nuclear explosion?”

In other words (IIUC): Some problems (here: scaling fault tolerance) seem to be easier than others.

[0] https://scottaaronson.blog/?p=9665#comment-2029013

[1]: See also https://news.ycombinator.com/item?id=47959531 for a very similar quote.

brador• 3 months ago

Sounding the alarm while presenting no data or science, as a member of the National academy of sciences, is doing a disservice to the position, to science, to the self.

Show the data, the charts, let people decide for themselves.

codethief3• 3 months ago

Sounding the alarm while presenting no data or science

One needs to read OP's blog post in the context of his other posts from the last couple months (many of which have been discussed here on HN in one way or another), where he does discuss the science.

nh23423fefe• 3 months ago

Demanding information one won't read or understand.

boh• 3 months ago

People are starting to catch on to the AI scare mongering, let the quantum computer scare mongering begin. We should probably start giving these companies lots of money lest other countries beat us to it.

BoppreH8• 3 months ago

Many people in this thread are skeptical about quantum computers, and that's fair. This migration is a big part of my current job, and even I think that there's a non negligible chance that we won't see commercially available quantum computers anytime soon.

The problem is that we're not trying to predict the exact future, we're hedging against possible developments. If there's a 50/50 chance of quantum computers being widely deployed for cryptoanalysis, then there's a 50% chance of this migration being useless. But you don't want to bet your security on a coin toss! So, we migrate.

That's the unfortunate truth of security, sometimes the protections are never triggered. But you still need them.

i_think_so7• 3 months ago

Can you talk about what algorithms you're migrating to?

BoppreH8• 3 months ago

Disclaimer: what follows is my opinion.

There's a good consensus that for key exchange/encryption (TLS, SSH, age, etc) the way forward is ML-KEM 768 together with some classical algorithm, like X25519. The public keys are larger (1 KB), but that's usually ok unless you're working on very small microcontrollers. And you should migrate quickly because of harvest-now-decrypt-later attacks.

For signatures, things are harder because there are tradeoffs. Some algorithms have large signatures (10+ KB), others require keeping state and have catastrophic consequences if subkeys are reused. And the systems around it are also more complicated: in a certificate, should you put a classical and a PQC signature together? Or should the PQC signature go in an extension? Should the extension be marked as critical and fail loudly on old clients, or should new clients have a special case to always check it if PQC signature validation is available? Or should we abandon the certificate chains and move to Merkle Tree Certificates[1]?

So signatures/authentication are still up for debate. Unless your team is on the bleeding edge of either crypto research or security risks, then there's not much to do than wait for better consensus to form.

[1] https://postquantum.com/security-pqc/googles-merkle-tree-mtc...

mert-kurttutan• 3 months ago

There are different types of skepticism when it comes to Quantum Computing (QC). One can be skeptic about its feasibility, namely achieving Fault Tolerant Scalable Quantum Computer (for instance Gil Kalai).

Or, they can be skeptic its applications on the real world.

I am on the second camp, very much. It has mainly two important application areas: Breaking Some Public Key cryptography and Simulating Quantum System.

I think the 1st one is very real, we need to be serious and careful on the migration.

The second area is, I think, extremely overhyped.

One should ask what cases there are for investing in QC that makes financial sense. I can think of couple of areas where quantum effects are important enough to justify this. Better designs for Enzymes and Solid State Batteries. The case for enzyme designs is weakened even more if you check the recent paper by Garnet Chan: https://bsky.app/profile/dulwichquantum.bsky.social/post/3mh...

Unless we see collorobaration between IBM/Google and BYD/CATL/Tesla that will lead to next gen solid state batteries, I would say it wont have substantial impact on the real world. One also has to consider that QC is not the only method to simulation strongly coupled Quantum Systems, there are already other methods, tensor network, Deep Learning based, etc.

Lastly, the QCs will be coming in the future. SO, yhey kind of need to hurry up since current benchmarks for EV batteries are improving every year. There is also the issue of translating lab result into production environment.

All of these factors are eating away the relevance of QCs when it comes to real world applications.

I think we are essentially left with a situation where the only practical application of the technology (QC) is to steal stuff on the internet.

i_think_so7• 3 months ago

Does djb ever frequent HN? Can we summon him with the correct incantations?

I'd really like to know what his current work on the subject entails, but when I try googling his stuff all I find are years-old papers, more recent meta discussion, and him making a few comments about other peoples' work.

I was sure that by now he'd have at least collaborated on some avant-garde PQ algo that was as different from the NSA approved stuff as chacha20-poly1305 was from AES. I was hoping for a PQ-NaCl folks would be using soon, not the libpqcrypto that seems to lack traction among devs (for reasons I do not understand). I am disappoint.

(It's probably all tucked away in some corner of the web that a layman like me will never find. Sigh.)

Edit: Hah! I gave up on looking for papers or repos and decided to just read his blog instead. Well would'ya look at that! It's non-stop PQ ranting of the kind we've come to love and cherish from DJB. No new repos or code with his imprimatur that I can see so far but better than I was expecting. Looks like I've got some reading to do....

I should have subscribed to his rss feed years ago. And his "microblog" too! https://microblog.cr.yp.to/

projektfu• 3 months ago

My only concern is that in the rush to implement PQC everywhere, less well-tested/battle-hardened algorithms get used and everything becomes insecure to someone who has found the master key.

Will you heed my warnings now?

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