Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Willow, Our Quantum Chip

blog.google

Post reply on HN
Print view View original

431–440 of 557 posts

Re: Willow, Our Quantum Chip

#431

Post by bsaul »

kortilla wrote: post #420
ReptileMan wrote: post #335

Earlier quoted context omitted.

Perfect forward secrecy doesn't work that well when NSA motto is - store everything now decrypt later. If they intercept the ephemeral key exchange now they can decrypt the message 10 or 50 years later.

Diffie Hellman doesn’t ever send the key over the wire, that’s the point. There is nothing to decrypt in the packets that tells you the key both sides derived. Unless they break ECDHE, it doesn’t matter if RSA gets popped.

wouldn't be surprised if ecdhe isn't quantum resistant.

Re: Willow, Our Quantum Chip

#432

Post by coppsilgold »

kortilla wrote: post #332
qnleigh wrote: post #249

Earlier quoted context omitted.

You need to distinguish between "physical qubits" and "logical qubits." This paper creates a single "first-of-a-kind" logical qubit with about 100 physical qubits (using Surface Code quantum error correction). A paper from Google in 2019 estimates needing ~20 million physical qubits ("How to factor 2048 bit RSA integers in 8 hours using 20 million noisy qubits" - https://arxiv.org/abs/1905.09749 ), though recent adva…

> quantum computers would be able to retroactively break any public keys that were stored Use a key exchange that offers perfect forward secrecy (e.g. diffie Hellman) and you don’t need to worry about your RSA private key eventually being discovered.

Perfect forward secrecy requires the exchange of ephemeral keys. If you use either ECC or RSA for this and the traffic is captured a quantum computer will break it.

All perfect forward secrecy means is that you delete your own ephemeral private keys, the public keys stay in the record. And a quantum computer will recover the deleted private keys.

Also, none of the currently accepted post-quantum cryptographic algorithms offer a Diffie-Hellman construction. They use KEM (Key Encapsulation Mechanism).

Re: Willow, Our Quantum Chip

#433

Post by vixen99 »

wasabi991011 wrote: post #35
jawns wrote: post #8

> It lends credence to the notion that quantum computation occurs in many parallel universes, in line with the idea that we live in a multiverse I see the evidence, and I see the conclusion, but there's a lot of ellipses between the evidence and the conclusion. Do quantum computing folks really think that we are borrowing capacity from other universes for these calculations?

I was also really taken aback by this quote. I have no idea who put it there, but I can assure you the actual paper contains no such nonsense. I would have thought whoever writes the google tech blogs is more competent than bottom tier science journalists. But in this case I think it is more reasonable to assume malice, as the post is authored by the Google Quantum AI Lead, and makes more sense as hype-boosting buzzw…

Presumably the 'nonsense' is the supposed link between the chip and MW theory.

Let me add a recommendation for David Wallace's book The Emergent Multiverse - a highly persuasive account of 'quantum theory according to the Everett Interpretation'. Aside from the technical chapters, much of it is comprehensible to non-physicists. It seems that adherents to MW do 'not know how to refute an incredulous stare'. (From a quotation)

Re: Willow, Our Quantum Chip

#434

Post by crishoj »

Take the announcement with a grain of salt. From German physicist Sabine Hoffenfelder:

> The particular calculation in question is to produce a random distribution. The result of this calculation has no practical use. > > They use this particular problem because it has been formally proven (with some technical caveats) that the calculation is difficult to do on a conventional computer (because it uses a lot of entanglement). That also allows them to say things like "this would have taken a septillion years on a conventional computer" etc. > > It's exactly the same calculation that they did in 2019 on a ca 50 qubit chip. In case you didn't follow that, Google's 2019 quantum supremacy claim was questioned by IBM pretty much as soon as the claim was made and a few years later a group said they did it on a conventional computer in a similar time.

https://x.com/skdh/status/1866352680899104960

Re: Willow, Our Quantum Chip

#435

Post by krick »

xnx wrote: post #98

Is anyone else even close to Google in this space? (e.g. on the "System Metrics" the blog defines)

I would be very grateful if somebody can point to an actually good blogpost/video that would summarize the current state of the domain. I mean, I remember some "quantum annealing" providers as far as some 10 years ago (I mean, as a service, as such D-Wave exists for 25 years now), but I never actually learned if they are truly useful for anything (like, real numbers, what amount of computation these thing can perform and if it's truly cheaper/faster than throwing a bunch of GPUs on it). From time to time there are some news feturing dope photos, about some new chip from IBM, that is useful for nothing, but a big breakthrough for reasons I don't understand.

But I don't really have a feel of what's going on, really. How many quantum computers there are, is there anything that is actually capable of performing anything more than just being an ongoing research prototype? Some educated guesses about how far can be some non-public projects by now? Like, is it possible that some secret CIA project is further ahead than what we know, or if it's even more unlikely and farther away than fusion power? Or maybe it's even more comparable to cold fusion?

I know, that this kinda exists as an idea, and apparently somebody's working on it, but that's pretty much it.

Re: Willow, Our Quantum Chip

#436

Post by coppsilgold »

minitech wrote: post #424
kortilla wrote: post #419

Earlier quoted context omitted.

I’m talking specifically about RSA being eventually broken. If just RSA is broken and you were using ECDHE for symmetric keying, then you’re fine. The point is that you can build stuff on top of RSA today even if you expect it to be broken eventually if RSA is only for identity verification.

The relevant RSA break is sufficiently powerful quantum computers, which also break ECDH (actually, ECDH is easier than classically equivalent-strength RSA for quantum computers[1]), so no, you’re not fine. [1] https://security.stackexchange.com/questions/33069/why-is-ec...

I would actually expect RSA to see a resurgence due to this. Especially because you can technically scale RSA to very high levels potentially pushing the crack date to decades later than any ECC construction. With the potential that such a large quantum computer may never even arrive.

There are several choices with scaling RSA too, you can push the primes which slows generation time considerably. Or the more reasonable approach is to settle on a prime size but use multiple of them (MP-RSA). The second approach scales indefinitely. Though it would only serve a purpose if you are determined to hedge against the accepted PQC algorithms (Kyber/MLKEM, McEliece) being broken at some point.

Re: Willow, Our Quantum Chip

#437

Post by demaga »

navaati wrote: post #86
deanCommie wrote: post #57

Earlier quoted context omitted.

What if we are? And by injecting entropy into it, we are actually hurrying (in small insignificant ways) the heat death of those universes? What if we keep going and scale out and in the future it causes a meaningful impact to that universe in a way that it's residents would be extremely unhappy with, and would want to take revenge? What if it's already happening to our universe? And that is what black holes are? Or…

Getting strong vibes of Asimov’s novel "The Gods Themselves" here ! For those who haven’t read it I recommend it. It’s a nice little self-contained book, not a grandiose series and universe, but I love it.

This is exactly it, love that book.

Re: Willow, Our Quantum Chip

#438

Post by attentionmech »

attentionmech wrote: post #404

What does it mean when they say that the computations are happening in multiverse? I didn't know we are that advanced already :)

I don't know why i got downvoted. "It lends credence to the notion that quantum computation occurs in many parallel universes, in line with the idea that we live in a multiverse, a prediction first made by David Deutsch." -- this is from the article itself.

Re: Willow, Our Quantum Chip

#439

Post by ReptileMan »

kortilla wrote: post #420
ReptileMan wrote: post #335

Earlier quoted context omitted.

Perfect forward secrecy doesn't work that well when NSA motto is - store everything now decrypt later. If they intercept the ephemeral key exchange now they can decrypt the message 10 or 50 years later.

Diffie Hellman doesn’t ever send the key over the wire, that’s the point. There is nothing to decrypt in the packets that tells you the key both sides derived. Unless they break ECDHE, it doesn’t matter if RSA gets popped.

Diffie Hellman to the best of my understanding also relies on the same hard problems that make the public key cryptography possible. If you trivialize factoring of big numbers, you break both RSA and the original DHE. Not sure how it will work for elliptic curves, but my instinct tells me that if you make the fundamental ECC problem easy, the exchange will also go down.

Re: Willow, Our Quantum Chip

#440

Post by ravenhappy »

vessenes wrote: post #228
npalli wrote: post #205

Earlier quoted context omitted.

> Worth spending a little time doing some long tail strategizing I’d say. Yup, like Bitcoin going to zero.

I'm a little more in my wheelhouse here -- without an algo change, Grover's algorithm would privilege quantum miners significantly, but not any more than the industry has seen in the last 13 years (C code on CPU -> GPU -> Large Geometry ASIC -> Small Geometry ASIC are similarly large shifts in economics for miners probably). As to faking signatures and, e.g. stealing Satoshi's coins or just fucking up the network wit…

You fool! And I say that affectionately. Another fool says: the security of Bitcoin relies on the inability to (among other things) derive a private key from a public key. This is just basic cryptography, like Turning vs enigma. This machine can "calculate" solutions to problems in time frames that break the whole way that cryptocurrency works. You better believe that what we hear about is old. These types of systems, and there must be non-public versions, could solve a private key from a public key, in easy less than O(fu) time.

EDIT: it's like rainbow hashes, but every possible variation is a color, not granular like binary, but all and any are included.

Post reply on HN