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).
Maybe it'll require TLS 1.4/QUIC 2, with no changes but the cipher specifications, but it can happen in two or three years. Certificates themselves don't last longer than a year anyway. Corporations running ancient software that doesn't support PQ TLS will have the same configuration options to ignore the security warnings already present for TLS 1.0/plain HTTP connections.
The biggest problem I can imagine is devices talking to the internet no longer receiving firmware updates. If the web host switches protocols, the old clients will start dying off en masses.
Leaf certificates don't last long, but root CAs do. An attacker can just mint new certs from a broken root key.
Hopefully many devices can be upgraded to PQ security with a firmware update. Worse than not receiving updates, is receiving malicious firmware updates, which you can't really prevent without upgrading to something safe first.
IPv6 deserves a prominent spot there
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.
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.
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.
To avoid the scenario where for a prolonged period of time the intelligence community has secret access to QC, researchers against that type of thing are incentivized to shout fire when they see the glimmerings of a possibly productive path of research.
If the intelligence community is going to nab the first team that has a quantum computing breakthrough, does it actually help the public to speed up research?
It seems like an arms race the public is destined to lose because the winning team will be subsumed no matter what.
Filippo Valsorda (maintainer of Golang's crypto packages, among other things) published a summary yesterday [0] targeted at relative laypeople, with the same "we need to target 2029" bottom line.
The algorithm everyone tends to be thinking of when they bring this up has literally nothing to do with any cryptography used anywhere ever; it was wildly novel, and it was interesting only because it (1) had really nice ergonomics and (2) failed spectacularly.
Sorry, I'm just very out of the loop on some of this stuff and I'm trying to play a game of catchup.
This page lists some numbers for different PQ signature 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/#dili...).
Context, two nearly identical comments from different users.
hackerman70000 at 16:09 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 :
> 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
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.
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.
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.