"Here we experimentally demonstrate the factorization of two bi-primes, 4088459 and 966887 using IBM's 5- and 16-qubit quantum processors, hence making those the largest numbers that have been factorized on a quantum device."[1]

It looks like some real progress has been made with qbit quality and stability in the last few years! I think that 21 figure held for quite a while. Maybe it still does hold and I'm misunderstanding some of the nuance.

1 - https://arxiv.org/abs/1805.10478

Yes, those are the examples of quantum methods that don't scale to cryptographic levels. The only one that can scale is shor's and the answer is still 21. https://crypto.stackexchange.com/questions/59795/largest-int...

Thanks for clarifying! TIL

That’s such a great way to communicate the current state of the field. Do you have a reference for that? And so you know what the largest number factored for algorithms that don scale into the cryptographic levels is?

> And so you know what the largest number factored for algorithms that don scale into the cryptographic levels is?

You're going to have to qualify this more, because I can factor 2^googol pretty well…