41 pointsby jhalderm4 hours ago7 comments
  • MathMonkeyMan3 hours ago
    The title of this post changed as I was reading it. "It looks like the 'JVG algorithm' only wins on tiny numbers" is a charitable description. The article is Scott Aaronson lambasting the paper and shaming its authors as intellectual hooligans.
    • measurablefunc2 hours ago
      Scott Aaronson is the guy who keeps claiming quantum supremacy is here every year so he's like the proverbial pot calling the kettle black.
      • adgjlsfhk125 minutes ago
        the reason people pay attention to him is that he does a good job publicizing both positive and negative results, and accurately categorizing which are bullshit
  • 26 minutes ago
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  • RcouF1uZ4gsC3 hours ago
    Scott References the top comment on this previous HN discussion

    https://news.ycombinator.com/item?id=47246295

  • guy42613 hours ago
    > (yes, the authors named it after themselves) The same way the AVL tree is named after its inventors - Georgy Adelson-Velsky and Evgenii Landis... Nothing peculiar about this imh
    • johncarlosbaez2 hours ago
      Adelson-Velsky and Evgenii Landis were not the ones who named their tree the "AVL tree".

      In my "crackpot index", item 20 says:

      20 points for naming something after yourself. (E.g., talking about the "The Evans Field Equation" when your name happens to be Evans.)

    • abound3 hours ago
      Same with RSA and other things, I think the author's point is that slapping your name on an algorithm is a pretty big move (since practically, you can only do it a few times max in your life before it would get too confusing), and so it's a gaudy thing to do, especially for something illegitimate.
    • croes2 hours ago
      Named after != named by
  • kittikitti39 minutes ago
    While I think the idea that claiming one can "precompute the xr mod N’s on a classical computer" sounds impractical there are a subset of problems where this might be valid. According to computational complexity theory, there's a class of algorithms called BQP (bounded-error quantum polynomial time).

    Shor's algorithm is part of BQP. Is the JVC algorithm part of BQP, even though it utilizes classical components? I think so.

    I believe that the precomputational step is the leading factor in the algorithm's time complexity, so it isn't technically a lower complexity than Shor's. If I had to speculate, there will be another class in quantum computational complexity theory that accommodates precomputation utilizing classical computing.

    I welcome the work, and after a quick scroll through the original paper, I think there is a great amount of additional research that could be done in this computational complexity class.

    • amluto20 minutes ago
      There is a genuinely interesting complexity class called BQP/poly, which is pronounced something like “bounded-error quantum polynomial time with classical advice” (add some more syllables for a complete pronunciation).

      The JVG algorithm is not a high quality example of this or really anything else. If you think of it as “classical advice”, then it fails, because the advice depends on the input and not just the size of the input. If you think of it as precomputation, it’s useless, because the precomputation involved already fully solves the discrete log problem. And the JVG paper doesn’t even explain how to run their circuit at respectable sizes without the sheer size of the circuit making the algorithm fail.

      It’s a bit like saying that one could optimize Stockfish to run 1000x faster by giving it an endgame table covering all 16-or-fewer-piece-positions. Sure, maybe you could, but you also already solved chess by the time you finish making that table.

    • adgjlsfhk124 minutes ago
      JVC isn't BQP. it's exp time (I.e. worse than factoring without a quantum computer at all). it takes the only step of shors algorithm that is faster to run on a quantum computer and moves it to a classical computer
  • kmeisthax3 hours ago
    I mean, considering that no quantum computer has ever actually factored a number, a speedup on tiny numbers is still impressive :P
    • dehrmannan hour ago
      I didn't get the quantum hype last year. At least with AI, you can see it do some impressive things with caveats, and there are bull and bear cases that are both reasonable. The quantum hype training is promising the world, but compared to AI, it's at the linear regression stage.
      • dekhnan hour ago
        It's a variation of nerd snipe. https://xkcd.com/356/

        People get taken by the theoretical coolness and ultimate utility of the idea, and assume it's just a matter of clever ideas and engineering to make it a reality. At some point, it becomes mandatory to work on it because the win would be so big it would make them famous and win all sorts of prizes and adulation.

        QC is far earlier than "linear regression" because linear regression worked right away when it was invented (reinvented multiple times, I think). Instead, with QC we have: an amazing theory based on our current understanding of physics, and the ability to build lab machines that exploit the theory, and some immediate applications were a powerful enough quantum computer built. On the other side, making one that beats a real computer for anything other than toy challenges is a huge engineering challenge, and every time somebody comes up with a QC that does something interesting, it spurs the classical computing folks to improve their results, which can be immediately applied on any number of off-the-shelf systems.

    • adgjlsfhk1an hour ago
      The problem is that it's an exponential slowdown on large numbers.
    • Tyr423 hours ago
      Hey hey, 15 = 3*5 is factoring.
      • ashivkum2 hours ago
        my understanding is that they factored 15 using a modular exponentiation circuit that presumes that the modulus is 3. factoring 15 with knowledge of 3 is not so impressive. Shor's algorithm has never been run with a full modular exponentiation circuit.
  • coolcoder952043 minutes ago
    The 'JVG algorithm' is a perfect example of what happens when theory meets the harsh reality of polynomial scaling. It’s a recurring pattern in the field: someone manages to get a toy circuit to factor '15 = 3*5' and the hype machine instantly pivots to 'quantum supremacy.'

    As an engineer, I care about where the curve bends. If your 'supremacy' algorithm fails the moment you step out of the 'demo sandbox,' it's not a solution—it's a nerd-snipe. I'd much rather see 10 years of incremental work on error correction than 10 minutes of hype over a flawed paper.

    • 17 minutes ago
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