- cross-posted to:
- hackaday@ibbit.at
- cross-posted to:
- hackaday@ibbit.at
If you are to believe the glossy marketing campaigns about ‘quantum computing’, then we are on the cusp of a computing revolution, yet back in the real world things look a lot less dire. At least if you’re worried about quantum computers (QCs) breaking every single conventional encryption algorithm in use today, because at this point they cannot even factor 21 yet without cheating.
In the article by [Craig Gidney] the basic problem is explained, which comes down to simple exponentials. Specifically the number of quantum gates required to perform factoring increases exponentially, allowing QCs to factor 15 in 2001 with a total of 21 two-qubit entangling gates. Extrapolating from the used circuit, factoring 21 would require 2,405 gates, or 115 times more.
underlying article: https://algassert.com/post/2500


This “everything” was meant as an exaggeration. But it comes close for nearly every article (or press release disguised as an article) in the press.
QC has well-founded expected applications within chemistry, factorisation and optimization. Anything else is hyperbole at this point.
Tell this to the people who try to sell it as the one big computational solution.
I am! Tell me who it is, and I’ll kick their butts.