Quantum computing bombshells that are not April Fools

(scottaaronson.blog)

95 points | by Strilanc 5 hours ago

7 comments

  • freetonik 16 minutes ago
    I worked at a quantum computing company that builds superconducting QC chips (so, not really applicable to one of the “bombshells” from the article). My team was designing the software stack which allows to control the QC, run quantum jobs/algorithms, and calibrate the parameters.

    I’ve made two attempts to explain the work we’ve been doing and to explain the current realistic state of the industry:

    1. A talk at PyCon: https://youtu.be/tT1YLP5T71Y

    2. A free ebook “ Quantum Computing For Software Engineers” https://leanpub.com/quantum-computing-for-software-engineers

    The company I left a few months ago is planning its IPO this year. Like almost all other quantum companies, it’s gonna be a SPAC merger, not a pure IPO. Those traded companies mentioned in the other comments are mostly SPACs as well.

  • tombert 2 hours ago
    Here's hoping that my stock for D-Wave ends up being worth something.

    Quantum computing seems super cool, but I've been a little skeptical of it actually ever yielding anything useful. I would love to be wrong, it seems neat, and I have read through a few books on the subject and played with simulators, so I'm not completely talking out of my ass here, but quantum as a whole has kind of felt like vaporware to me.

    As I said, I have stock in D-Wave, obviously it would be in my best interest for quantum to end up as cool as it seems.

    • bawolff 1 hour ago
      D-Wave is not making the type of quantum computers these breakthroughs would apply to, even if scaled up, as far as i know.
    • crispyambulance 1 hour ago
      I got some too. Obviously the principles behind quantum computing are perfectly sound. It's just those pesky engineering obstacles.

      One of the companies around today or in the near future will be the one who makes it work at a practical scale. It will have enormous impact, but I think it will be a slow-burn kind of thing as making effective use of quantum computers will take a long time to evolve, IMHO.

      Unfortunately, Google and IBM are also working on this stuff and they have deep pockets. They might do it, but even if they don't they may very well decide to acquire whoever does.

      These stocks (IONQ, RGTI, QBTS, XNDU) are a sort of thinking-man's LOTTO ticket which will have its numbers called anytime within the next 5 to 20 years (probably closer to 20). I think they're worthwhile to hold in affordable quantities to see what happens. It might hit big, or it might fizzle out for a variety of reasons. There will also be some hype-driven market sugar-rushes along the way that are an opportunity to rake in a modest profit. This has happened already with IONQ, RGTI and QBTS earlier this year. It will certainly happen again when the patagonia-vest people get jazzed about something.

    • esseph 2 hours ago
      You can rent Quantum computing time from IBM cloud today:

      https://www.ibm.com/quantum/products

      https://quantum.cloud.ibm.com/docs/en/guides/plans-overview

      I have NOT used it, but the idea is interesting.

      • AlexCoventry 1 hour ago
        You can rent it, but it's basically worthless at this stage.
  • amluto 2 hours ago
    One thing I find rather amazing about all of this is the degree to which the Bitcoin community has tried, for years, to claim that quantum computers will be another other than a complete break.

    Sure, it takes a pretty nice quantum computer or a pretty good algorithm or a degree of malice on the part of miners to break pay-to-script-hash if your wallet has the right properties, but that seems like a pretty weak excuse for the fact that the entire scheme is broken, completely, by QC.

    Does there even exist a credible post-quantum proof protocol that could be used to “rescue” P2SH wallets?

    • int32_64 2 minutes ago
      > the Bitcoin community has tried, for years, to claim that quantum computers will be another other than a complete break.

      Who specifically is claiming this? Satoshi literally mentioned the need to upgrade if QC is viable on bitcointalk in 2010.

    • Strilanc 1 hour ago
      The best proposal I have heard for rescuing P2SH wallets after cryptographically relevant quantum computers exist is to require vulnerable wallets to precommit to transactions a day ahead of time. The precommitment doesn't reveal the public key. When the public key must be exposed as part of the actual transaction, an attacker cannot redirect the transaction for at least one day because they don't have a valid precommitment to point to yet.
      • warkdarrior 1 hour ago
        24-hour latency to make a payment? What is this, the 20th century?
        • Strilanc 41 minutes ago
          This is for rescue, not for payment. Once you've moved the coins to quantum-secure wallet, the delay would no longer be needed.

          ...probably some people would be very inconvenienced by this. But not as inconvenienced as having the coins stolen or declared forever inaccessible.

    • bawolff 58 minutes ago
      On the brightside at least we'll have a clear indicator for when quantum computers actually arrive.
    • Mistletoe 17 minutes ago
      If Bitcoin is broken then your bank encryption and everything else is broken also.

      As far as I know quantum computers still can't even honestly factor 7x3=21, so you are good. And the 5x3=15 is iffy about how honest that was either.

      https://news.ycombinator.com/item?id=45082587

      Bitcoin uses 256-bit encryption, it's a universe away from 5x3=15.

  • ChrisArchitect 2 hours ago
    Related:

    Discussion on the Google one,

    Safeguarding cryptocurrency by disclosing quantum vulnerabilities responsibly

    https://news.ycombinator.com/item?id=47582418

  • GeoSys 1 hour ago
    So does BTC need to hard fork? Good luck getting to a consensus again ...
    • r4indeer 36 minutes ago
      If QC gets to the point where breaking RSA and ECC in the real world is actually going to happen, I'd imagine you will find a consensus rather quickly.
  • pmarreck 2 hours ago
    Can quantum computing do even basic math yet? I think this was the holdup. Or perhaps I'm missing the point.
    • qnleigh 22 minutes ago
      This is a good question, and currently the answer is no. Quantum computers can only run very short, simple algorithms right now, because the qubits they're built out of are noisy. You need a lot of error correction, which the community is working on.

      The thing is, unlike ordinary computers, quantum computers can factor numbers about as easily as they can multiply them. So as soon as they can multiply two large integers, they'll also be able to factor the result and break RSA encryption based on keys of that size.

      This blog post gives a good sense of the state of the art and what progress might look like:

      Why haven't quantum computers factored 21 yet? https://algassert.com/post/2500

      • Foobar8568 16 minutes ago
        And isn't the response already known in the validation process?
        • qnleigh 7 minutes ago
          I don't understand your question. Can you elaborate?
    • bawolff 52 minutes ago
      > I think this was the holdup

      It isn't...

    • GeoSys 1 hour ago
      It doesn't do basic math ... just the hard one :)
    • aaron695 16 minutes ago
      [dead]
    • georgeburdell 23 minutes ago
      You are. It’s like trying to take the train to your farm job
      • qnleigh 20 minutes ago
        This comment is wildly inappropriate and violates the community guidelines here. I suggest you delete it.
  • socketcluster 1 hour ago
    Maybe it's a good time to start promoting my 5 year old, lightweight, hand-crafted, battle-tested, quantum-resistant blockchain: https://capitalisk.com/

    It's about 5000 lines of custom code. Crypto signature library written from scratch.

    • EdwardDiego 1 hour ago
      > Crypto signature library written from scratch.

      That's a sentence every white hat cryptography enthusiast loves to hear lol.

      • socketcluster 12 minutes ago
        It's a very simple signature algorithm. They're welcome to try and crack it. If there is an issue with it, it shouldn't be hard to identify within those few hundred lines. Nobody found any issues in the last 5 years though.

        Isn't it a good thing that there exists at least one blockchain in the world which isn't based on the same crypto library used by tens of thousands of projects? What if those handful of libraries have a backdoor?

        Strange how finance people always talk about hedging but in tech, nobody is hedging tech.