[mac3n]

There is at least one [science fiction] short story where this happens. Greg Egan, maybe?

There is a fast quantum factorization method, Shor's Algorithm. As far as we know, it is not yet practical. However, there is ongoing work on post-quantum cryptography that would be safe against such attacks.

The most likely users for a fast factorization algorithm that could break RSA encryption are nation-states. They would obviously keep this capability secret.

Nation-states have compromised many systems anyway, without needing to break this kind of cryptography. We are not really set up to handle this either.