Comment by ameliaquining
12 hours ago
That last sentence is not true; we have gotten much closer to building a quantum computer that can run Shor's algorithm. Organizations like Google and Cloudflare have declared a 2029 deadline to completely stop depending on the security of pre-quantum algorithms; hitting that deadline is going to cost a lot of engineering resources, but they're paying that cost because they think there's too great a chance that nation-state adversaries will have scalable quantum computers by then. See https://words.filippo.io/crqc-timeline/ and the various posts linked therein, including from the aforementioned companies.
Have they factored 21 yet? That metric hasn't changed for some time.
That's not a very useful benchmark if the thing you care about is CRQC timelines. See https://bas.westerbaan.name/notes/2026/04/02/factoring.html (which the above post links to) for an explanation of why.