Google says that it will fully transition to post-quantum cryptography by 2029. I think this is a good move, not because I think we will have a useful quantum computer anywhere near that year, but because crypto-agility is always a good thing.
Slashdot thread.
Zsolt • April 6, 2026 1:25 PM
“not because I think we will have a useful quantum computer anywhere near that year”
Google’s move might signal that they’re not a 100% sure that there won’t be “a useful quantum computer anywhere near that year”.
Clive Robinson • April 7, 2026 2:02 AM
@ Bruce,
With regards,
“I think this is a good move, not because I think we will have a useful quantum computer anywhere near that year, but because crypto-agility is always a good thing.”
The problem I have with this is that the message being pushed is effectively “Quatum Crypto ONLY solutions”.
This is anything but “agile”, in fact it’s much more than “fragile” it’s a significant risk.
Put simply we “don’t know enough” which is why some proposed algorithms that appeared good came up as duds.
This is because we are in at best the very early stages of our understanding, and we should be thinking of how to have “resilience” rather than “all in” as our touch stone on this.
Because we might find that there is no secure post-QC algorithm by way of what we currently understand and that we will have to find an entirely different approach.
In fact we are seeing the potential first stages of new fundamental work in this area currently, but os this going to make a difference to “time lines”?
Probably not… We are at the stage of using “Engineering and Technology” that are in effect “established” to “knock the noise out” and how far that is going to go and how quickly is going to be a shock to many,
lurker • April 7, 2026 2:44 AM
@Clive Robinson, ALL
Comment from a senior theoretical physicist at Caltech:
“We just have to build these machines and see if they work.”
A bit like fusion reactors, or as Peter Gutman says, physics experiments.
Anonymous • April 7, 2026 7:02 AM
@lurker
Adding to that: If it wasn’t for engineers, physicists would be glorified philosophers.
Clive Robinson • April 8, 2026 12:41 AM
@ lurker, Anonymous,
With regards the,
“senior theoretical physicist at Caltech”
Note “theoretical” sometimes known as maths “model makers”…
Where as the other types of physicists 😉 have to work with the practical realities of the universe those “theoretical models” fail to capture or even address. Thus are seen as not theoretical but applied physicists or “model breakers” much to the chagrin of the model makers (who appear to get up set when their “strings are found to be springs” or similar 😉
Hence the comment of,
“We just have to build these machines and see if they work.”
Is a very grudging acknowledgement that the laws of nature do not bend to fit their models, and in fact the opposite has to be true… That their models have to bend within the laws of nature, and often don’t even outside of small ranges…
It is one of the reasons why Sir Issac came up with infinitesimals in the first place…
Winter • April 8, 2026 1:29 AM
@Clive
Where as the other types of physicists 😉 have to work with the practical realities of the universe those “theoretical models” fail to capture or even address.
Physics is probably the science with the most theoretical revolutions, where theorists like Carnot, Maxwell, Planck, Einstein, Bohr, Heisenberg, and Schrodinger (and many others) changed the course of science in decisive ways.
But there are indeed also theoretical endeavors in directions that did and don’t lead to fruitful results. For instance, String theory has lead to a lot of interesting mathematical results[1], but as yet no strings at all. This fails to a such a “not-even-wrong” level that it gives rise to an Anti-String movement in Physics.
[1] Personally, I am still impressed by the AdS/CFT result even though we don’t live in an AdS universe. And de Sitter was one of those theorists.
https://en.wikipedia.org/wiki/AdS/CFT_correspondence
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Sidebar photo of Bruce Schneier by Joe MacInnis.
Cley Faye • April 6, 2026 10:23 AM
I’m curious if this will lead to more people looking into it, both for usage and issues, if there’s a stronger incentive to “break” things.