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Cloudflare targets 2029 for full post-quantum security
- ls612 7mo agoThe secrecy around this is precisely the opposite of what we saw in the 90s when it started to become clear DES needed to go. Yet another sign that the global powers are preparing for war.
- NitpickLawyer 7mo agoMy read of the recent google blog post is that they framed it as cryptocurrency related stuff just so they don't say the silent thing out loud. But lots of people "in the know" / working on this are taking it much more seriously than just cryptobros go broke. So my hunch is that there's more to it and they didn't want to say it / couldn't / weren't allowed to.
- IncreasePosts 7mo agoWhat is "it" that you're referring to?
- wil421 7mo ago> mitigating harvest-now/decrypt-later attacks. Most likely the NSA or someone else is ahead of the game and already has a quantum computer. If the tech news rumors are to true the NSA has a facility in Utah that can gather large swaths of the internet and process the data.
- adrian_b 7mo agoIt should be noted that quantum computers are a threat mainly for interactions between unrelated parties which perform legal activities, e.g. online shopping, online banking, notarized legal documents that use long-term digital signatures. Quantum computers are not a threat for spies or for communications within private organizations where security is considered very important, where the use of public-key cryptography can easily be completely avoided and authentication and session key exchanges can be handled with pre-shared secret keys used only for that purpose.
- dadrian 7mo agoI will bring this up at the next meeting of the secret cryptographer cabal where we decide what information to reveal to non-cryptographers.
- tptacek 7mo agoWhat do you mean? For as long as I remember (back to late 1994) people understood DES to be inadequate; we used DES-EDE and IDEA (and later RC4) instead. What "secrecy" would there have been? The feasibility of breaking DES given a plausible budget goes all the way back to the late 1970s. The first prize given for demonstrating a DES break was only $10,000.
- adrian_b 7mo agoTriple-key DES (DES-EDE) had already been proposed by IBM in 1979, in response to the criticism that the 56-bit keys of DES are far too short. So practically immediately after DES was standardized, people realized that NSA had crippled it by limiting the key length to 56 bits, and they started to use workarounds. Before introducing RC2 and RC4 in 1987, Ronald Rivest had used since 1984 another method of extending the key length of DES, named DESX, which was cheaper than DES-EDE as it used a single block cipher function invocation. However, like also RC4, DESX was kept as a RSA trade secret, until it was leaked, also like RC4, during the mid nineties. IDEA (1992, after a preliminary version was published in 1991) was the first block cipher function that was more secure than DES and which was also publicly described.
- ls612 7mo agoPeople were willing to explicitly explain why it was inadequate rather than keep it secret. That is the difference.
- tptacek 7mo agoWhat was to explain? It had a 56-bit key.
- ls612 7mo agoWas that the only thing wrong with it? The 90s was definitely before my time but I was under the impression reading about it that there were also fundamental flaws with DES which lead to the competition which ultimately produced AES.
- heliumtera 7mo agoAnd that changes what?
- Bender 7mo agoIs this still theory or are there working Quantum systems that have broken anything yet?
- moi2388 7mo agoTheory. And afaik there are still questions as to if the PQ algorithms are actually secure.
- sophacles 7mo agotbf - since we still don't know if p != np, there are still questions about if the current algorithms are secure also.
- moi2388 7mo agoFair, but recently several PQ algorithms have been shown to in fact not be secure, with known attacks, so I wouldn’t equate them
- sophacles 7mo agoInteresting. I'd like to learn more about this - where can I find info about it?
- mswphd 7mo agothey're almost assuredly talking about two things (maybe 3 if they really know what they're talking about, but the third is something that people making this argument like to pretend doesn't exist). 1. the main "eye catching" attack was the [attack on SIDH](https://eprint.iacr.org/2022/975.pdf https://eprint.iacr.org/2022/975.pdf). it was very much a "thought to be entirely secure" to "broken in 5 minutes with a Sage (python variant) implementation" within ~1 week. Degradation from "thought to be (sub-)exp time" to "poly time". very bad. 2. the other main other "big break" was the [RAINBOW attack](https://eprint.iacr.org/2022/214.pdf https://eprint.iacr.org/2022/214.pdf). this was a big attack, but it did not break all parameter sets, e.g. it didn't suddenly reduce a problem from exp-time to poly-time. instead, it was a (large) speedup for existing attacks. anyway, someone popular among some people in tech (the cryptographer Dan Bernstein) has been trying (successfully) to slow the PQC transition for ~10 years. His strategy throughout has been complaining that a very particular class of scheme ("structured LWE-based schemes") are suspect. He has had several complaints that have shifted throughout the years (galois automorphism structure for a while, then whatever his "spherical models" stuff was lmao). There have been no appreciable better attacks (nothing like the above) on them since then. But he still complains, saying that instead people should use 1. NTRU, a separate structured lattice scheme (that he coincidentally submitted a scheme for standardization with). Incidentally, it had [a very bad attack](https://eprint.iacr.org/2016/127 https://eprint.iacr.org/2016/127) ~ 2016. Didn't kill PQC, but killed a broad class of other schemes (NTRU-based fully homomorphic encryption, at least using tensor-based multiplication) 2. McCliece, a scheme from the late 70s (that has horrendously large public keys --- people avoid it for a reason). He also submitted a version of this for standardization. It also had a [greatly improved attack recently](https://eprint.iacr.org/2024/1193 https://eprint.iacr.org/2024/1193). Of course, none of those are relevant to improved attacks on the math behind ML-KEM (algebraically structured variants on ring LWE). there have been some progress on these, but not really. It's really just "shaving bits", e.g. going from 2^140 to 2^135 type things. The rainbow attack (of the first two, the "mild" one) reduced things by a factor ~2^50, which is clearly unacceptable. Unfortunately, because adherents of Dan Bernstein will pop up, and start saying a bunch of stuff confidently that is much too annoying to refute, as they have no clue what the actual conversation is. So the conversation becomes 1. people who know things, who tend to not bother saying anything (with rare exceptions), and 2. people who parrot Dan's (very wrong at this point honestly, but they've shifted over time, so it's more of 'wrong' and 'unwilling to admit it was wrong') opinions. the dynamic is similar to how when discussions of vaccines on the internet occur, many medical professionals may not bother engaging, so you'll get a bunch of insane anti-vax conspiracies spread.
- 20k 7mo agoQuantum computing, and the generic term 'quantum' is gearing up to be the next speculative investment hype bubble after AI, so prepare for a lot of these kinds of articles
- bwesterb 7mo agoAt least it's time bound: hope to have this job done by 2029!
- Hasz 7mo agonah. governments around the world are hoovering up traffic today with the hope of a "cheap" (by nation state standards) quantum computer. Some of the secrets sent today are "evergreen" (i.e are still relevant 10+ years into the future), amongst a whole lot of cruft. There is massive incentive to hide the technology to keep your peers transmitting in vulnerable encryption as long as possible.
- nickspacek 7mo agoFor sure, that or just ensuring they have laws in place that grant them access to the unencrypted data we are sending to CDNs operating in their jurisdiction (when necessary for national security reasons).
- cetinsert 7mo agoYou can do PQ queries with us at qi.rt.ht! Which one do you think is PQ-secure? https://qi.rt.ht/?pq={api.,}{stripe,paypal}.com https://qi.rt.ht/?pq={api.,}{stripe,paypal}.com
- 1a527dd5 7mo agoThat is a beautiful api.
- _2fnr 7mo ago[flagged]
- jgrahamc 7mo agoCloudflare has long been doing work on PQ (sometimes in conjunction with Google) and rolled out PQ encryption for our customers. You can read about where this all started for us 7 years back: https://blog.cloudflare.com/towards-post-quantum-cryptography-in-tls/ https://blog.cloudflare.com/towards-post-quantum-cryptograph... and four years ago rolled out PQ encryption for all customers: https://blog.cloudflare.com/post-quantum-for-all/ https://blog.cloudflare.com/post-quantum-for-all/ The big change here is that we're going to roll out PQ authentication as well. One important decision was to make this "included at no extra cost" with every plan. The last thing the Internet needs is blood-sucking parasites charging extra for this.
- rdl 7mo agoIt will be interesting to compare PQ rollout to HTTPS rollout historically (either the "SSL becomes widespread in 2015" thing, or the deprecation SSL 3.0). Cloudflare is in an easy position to do stuff like this because it can decouple end user/browser upgrade cycles from backend upgrade cycles. Some browsers and some end user devices get upgraded quickly, so making it easy to make it optionally-PQ on any site, and then as that rollout extends, some specialty sites can make it mandatory, and then browser/device UX can do soft warnings to users (or other activity like downranking), and then at some point something like STS Strict can be exposed, and then largely become a default (and maybe just remove the non-PQ algorithms entirely from many sites). I definitely was on team "the risks of a rushed upgrade might outweigh the risks of actual quantum breaks" until pretty recently -- rushing to upgrade has lots of problems always and is a great way to introduce new bugs, but based on the latest information, the balance seems to have shifted to doing an upgrade quickly. Updating websites is going to be so much easier than dealing with other systems (bitcoin probably the worst; data at rest storage systems; hardware).
- stingraycharles 7mo ago> Updating websites is going to be so much easier than dealing with other systems (bitcoin probably the worst; data at rest storage systems; hardware). IPv6 deserves a prominent spot there
- fc417fc802 7mo agoDoes it? That one is different because IPv4 with CGNAT largely "just works" except for P2P type stuff. As a result there's a strong incentive for anyone who has a working setup to just not care. I can use myself as an example here. IPv6 is supported by all my hardware, all the software I use, and my ISP provides it. Yet my LAN intentionally remains IPv4 only with NAT. Why? Because adding IPv6 to my LAN would require nonzero effort on my part and has (at least for now) quite literally zero upside for me. If I ever need something it offers I will switch to it but that hasn't happened yet. PQC is entirely different in that the existence of a CRQC immediately breaks the security guarantee.
- valeriozen 7mo ago[flagged]
- diarrhea 7mo agohttps://news.ycombinator.com/item?id=47677483 https://news.ycombinator.com/item?id=47677483
- coldpie 7mo agoI noticed this, too. valeriozen, can you explain what happened here? Context, two nearly identical comments from different users. hackerman70000 at 16:09 https://news.ycombinator.com/item?id=47677483 https://news.ycombinator.com/item?id=47677483 : > Cloudflare pushing PQ by default is probably the single most impactful thing that can happen for adotpion. Most developers will never voluntarily migrate their TLS config. Making it the default at the CDN layer means millions of sites get upgraded without anyone making a decision valeriozen at 16:17 https://news.ycombinator.com/item?id=47677615 https://news.ycombinator.com/item?id=47677615 : > cloudflare making pq the default is the only way we get real adoption. most devs are never going to mess with their tls settings unless they absolutely have to. having it happen at the cdn level is the perfect silent upgrade for millions of sites without the owners needing to do anything
- wmf 7mo agoThey're using the same AI model?
- lexlambda 7mo ago> news.ycombinator.com:443 is using X25519, which is not post-quantum secure. This is the result of Cloudflare's test "Check if a host supports post-quantum TLS key exchange" offered on https://radar.cloudflare.com/post-quantum https://radar.cloudflare.com/post-quantum. Hoping there is already a migration plan. Fortunately many modern tools make it easy to switch to PQ, maybe someone knows which stack HN is running and if it would be possible.
- Havoc 7mo agoWow that’s a lot better browser support than expected
- Sattyamjjain 7mo ago[flagged]
- tombert 7mo agoOutside of the PQ algorithms not being as thoroughly vetted as others, is there any negatives to shifting algorithms? Like even if someone were to prove that quantum computing is a dud, is there any reason why we shouldn't be using this stuff anyway?
- MrRadar 7mo agoPost-quantum algorithms tend to be slower than existing elliptic curve algorithms and require more data to be exchanged to provide equivalent security against attacks run on non-quantum computers.
- tombert 7mo agoAny idea how much slower? Like are we talking half the speed? A quarter? 1%? Sorry, I'm just very out of the loop on some of this stuff and I'm trying to play a game of catchup.
- MrRadar 7mo agoThis page lists some figures for ML-KEM-768 (which is the PQ key exchange algorithm that's most widely deployed today): https://blog.cloudflare.com/pq-2025/#ml-kem-versus-x25519 https://blog.cloudflare.com/pq-2025/#ml-kem-versus-x25519 This one is actually faster than X25519 (a highly optimized ECC algorithm) by about double but requires 1,184 bytes of data to be exchanged per keyshare vs 32 for X25519. In practice everyone today is using a hybrid algorithm (where you do both ECC and PQ in case the PQ algorithm has an undiscovered weakness) so an ECC+PQ key exchange will be strictly slower than an ECC-only key exchange. This page lists some numbers for different PQ signature algorithms: https://blog.cloudflare.com/another-look-at-pq-signatures/#the-algorithms https://blog.cloudflare.com/another-look-at-pq-signatures/#t... Right now the NIST has selected three different ones (ML-DSA, SLH-DSA, and Falcon a.k.a. FN-DSA) which each have different trade-offs. SLH-DSA is slow and requires a large amount of data for signatures, however it's considered the most secure of the algorithms (since it's based on the well-understood security properties of symmetric hash algorithms) so it was selected primarily as a "backup" in case the other two algorithms are both broken (which may be possible as they're both based on the same mathematical structure). ML-DSA and Falcon are both fairly fast (within an order of magnitude of Ed25519, the X25519 curve signature algorithm), but both require significantly larger keys (41x/28x) and signatures (38x/10x) compared to Ed25519. Falcon has the additional constraint that achieving the listed performance in that table requires a hardware FPU that implements IEEE-754 with constant-time double-precision math. CPUs that do not have such an FPU will need to fall back to software emulation of the required floating point math (most phone, desktop, and server CPUs have such an FPU but many embedded CPUs and microcontrollers do not). The net result is that TLS handshakes with PQ signatures and key exchange may balloon to high single- or double-digit kilobytes in size, which will be especially impactful for users on marginal connections (and may break some "middle boxes" https://blog.cloudflare.com/nist-post-quantum-surprise/#dilithiums-size https://blog.cloudflare.com/nist-post-quantum-surprise/#dili...).
- MrRadar 7mo agoAlong similar lines, Mozilla recently updated their recommended server-side TLS configuration to enable the X25519MLKEM768 post-quantum key exchange now that it's making it into actually-deployed software versions: https://wiki.mozilla.org/Security/Server_Side_TLS https://wiki.mozilla.org/Security/Server_Side_TLS At the same time they removed their "old client" compatibility profile as newer TLS libraries do not implement the necessary algorithms (or at least do not enable them by default) and slightly tweaked the "intermediate" compatibility profile to remove a fallback necessary for IE 11 on Windows 7 (now Windows 10 is the minimum compatible version for that profile).
- ossianericson 7mo agoThe CDN part is the easy half. In my work the harder problem has most often been internal service mesh, mTLS between services, any infra that doesn’t terminate at a CDN. Has a bad habit of longer certificate lifetimes and older TLS stacks, and nobody is upgrading it for you.
- weightedreply 7mo agoAny information on future CPU's with support for hardware accelerated PQC algorithms? Will all my old devices become slow when PQC is the norm and encrypted communication is no longer hardware accelerated?
- mswphd 7mo agoyou don't really need that tbh. you can get pretty good speedups using standard (vector) intrinsics. the new algorithms are (mostly) modular linear algebra (+ some concept of "noise").
- MrRadar 7mo agoOnly the asymmetric portion of the cryptography (which is only used in the handshake) will need to use PQC algorithms. Symmetric crypto algorithms (AES/ChaCha20/SHA-*), which are used after the handshake, are not as badly affected by quantum computing so they're not being replaced in the immediate term. I'm pretty sure that general purpose CPUs do not have hardware acceleration for the asymmetric crypto anyways.
- wofo 7mo agoDoes this mean we should be migrating our SSH keys to post-quantum crypto right now?
- crote 7mo agoOpenSSH has supported post-quantum key agreement since 2022, and since 10.1 (October 2025) you'll get a warning if your connection isn't using it. It doesn't require rotating your keys, just upgrading the software on both sides. Post-quantum signatures will require rotating your keys, but that's less urgent.
- TacticalCoder 7mo agoTangential question... Seen that many are already moving to QC-resistant cryptography and that more are shifting by the day... I've got a question: what are the implications of quantum computers going to be if we consider that the entirety of cryptography will have moved to quantum-resistant cryptography? In other words: I only ever read about quantum computing when it's to talk about breaking cryptography. But what if all cryptography moves to quantum-resistant scheme, all of it... Then what are the uses of quantum computing? Protein folding? Logistics? Basically, so far, quantum computing research has the effect of many companies and projects adding quantum-resistant cryptographic schemes. If, say, we've got a $10 million quantum computer that can break one 256 bit elliptic curve key in an hour... Great, EC is broken. But what if browsers, SSH, auth, etc. just about everything moves to PQ schemes... Then what are those quantum computers useful for? I understand that breaking even a single EC 256 bit key in a few hours on a $$$ machine is a very big deal. But what else are they going to be useful for? For breaking ECC doesn't help humanity. It doesn't bring anything. It only destroys. EDIT: for example I read stuff like: "Estimates are about three years to break a single 256 bit EC key on a 10 000 qbits quantum computer". What's a 10 000 qbits quantum computer going to be used for when everybody shall have moved to quantum-resistant algos?
- phicoh 7mo agoWe can assume that organizations like NSA have collected a huge amount of traffic that is protected by RSA or EC. So they well have plenty of use for those quantum computers.
- snowwrestler 7mo agoTo start, I am NOT an expert on the underlying technologies. But I have some exposure to the topic at let’s say more like an ecosystem level. There are tons of hypothesized applications for quantum computing based on the expectation it will provide better simulation of quantum effects for e.g. chemistry, and offer major speedups of highly parallel simulation problems like nuclear plasma or some things in finance. Easy to Google to learn more about these. But keeping the focus squarely on the military and intelligence services, one answer to your question is that everyone is not going to switch to post-quantum cryptography instantaneously. It’s going to take a while, especially for a long tail of “infrastructure” type things like networking gear, “internet of things,” industrial sensors, etc. Things that national intelligence services might like to break into to enable breaking into other things. Quantum breaks may also still succeed against stored encrypted data from before the switch to PQ. And for at least a couple decades, national intelligence services have been scaling up their storage resources. So they might have a “backlog” they can work through. Finally, things don’t have to last forever. Everything the military / government builds has an expected lifespan, and it only has to be valuable during that life span. And risks can be rare but huge in national security. So if quantum code-breaking computers only help the NSA learn a few very important things for a limited time, that still might be “worth it” to them. Or if a quantum computer doesn’t break any important cryptography, but helps advance the engineering and enables better quantum computers in the future for other anpplications—again, still might be worth it.
- nalekberov 7mo agoYet, the same Cloudflare wants to control entire internet traffic single-handedly. The Internet was not created for this. One could argue that 'but they are very good at preventing DDoS attacks' — yes they are; however, they have always loved control and kept their technology proprietary to lock their customers into their systems. And one day, a single line of code disrupted many services on the web. Centralization and monopolies are much bigger threats to the future of the internet, IMHO. (Which always follows the same pattern: give your customers free or unbelievably cheaper services, even at a loss, lock them in, then jack up the price.)
- teaearlgraycold 7mo agoMullvad has PQ encryption available today. I recommend everyone use them, they're a 10/10 company.
- dfordp11 7mo ago[dead]
- bdeol22 7mo ago2029 is plausible at Cloudflare's edge; the long tail is boring enterprise TLS configs someone last touched in 2017.
- bwesterb 7mo agoYeah, it's rough. Important to understand now for each product / system what the business impact is if it's not upgraded in time.
- bdeol22 7mo agoAgreed. The migrations that stall are usually missing an explicit owner for each TLS surface, not missing algorithms. Business impact is the forcing function once you know who gets paged.