I mean, considering that no quantum computer has ever actually factored a number, a speedup on tiny numbers is still impressive :P
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.
Good description. Commercial fusion power seems to be in the same category currently.
The next step once you have enough thinkers working on the problem is to start pretending that commercial success is merely a few years away, with 5 or 10 years being the ideal number.
Quantum computers are still cool and things worthy of research. Its going to be a very long road though. Where we are with quantum computers is like equivalent to where we were with regular computers in the 1800s.
The hype people just make everything suck and should be ignored.
Everything else I consider pretty silly. "It can improve logistics" - I'm fairly sure computers are already as good as they can be, what dominates logistics calculations isn't an inability to optimize but the fact the real world can only conform so closely to any model you build. "It can improve finance" - same deal, really. All the other examples I see cited are problem where we've probably already got running code that is at the noise floor imposed by reality and its stubborn unwillingness to completely conform to plans.
If I had $1 to invest between AI and quantum computing I'd end up rounding the fraction of a cent that should rationally go to quantum computing and put the whole dollar in AI.
By far the most exciting possibility is one that Scott Aaronson has cited, which is, what if quantum computers fail somehow? To put it in simple and unsophisticated terms, what if we could prove that you can't entangle more than 1024 qubits and do a certain amount of calculation with them? What if the universe actually refuses to factor a thousand-digit prime number? The way in which it fails would inevitably be incredibly interesting.
It breaks only classical public-key encryption.
Public-key encryption is not necessary within a closed organization, e.g. for the personal use of an individual or group of individuals, or within a spy agency or for military applications, though it can make slightly simpler the process of key distribution, which otherwise needs an initial physical pairing between devices.
The most important application of public-key encryption is for allowing relations between parties who have never met in person, by the use of digital signatures and of Diffie-Hellman key establishment protocols.
This has been essential to enable online shopping and online banking, but not for the more traditional uses of cryptography.
The trickiest part of the circuit is they compile conditional multiplication by 4 (mod 15) into two controlled swaps. That's a very elegant way to do the multiplication, but most modular multiplication circuits are much more complex. 15 is a huge outlier on the difficulty of actually doing the modular exponentiation. Which is why so far 15 is the only number that's been factored by a quantum computer while meeting the bar of "yes you have to actually do the modular exponentiation required by Shor's algorithm".
Shor's algorithm specifies that you should pick the base (which determines the multipliers) at random. Somehow picking a rare base that is cheap to do really does start overlapping with knowing the factors as part of making the circuit. By far the biggest cheat you can do is to "somehow" pick a number g such that g^2=1 (mod n) but g isn't 1 or N-1. Because that's exactly the number that Shor's algorithm is looking for, and the whole thing collapses into triviality.
https://news.ycombinator.com/item?id=44608622 - Replication of Quantum Factorisation Records with a VIC-20, an Abacus, and a Dog (2025-07-18, 25 comments)