[sweis]

The record for factoring using a quantum computer is 21. Don't read that as 21 bits. 3*7. This has been the record for 12 years and that is arguably a result that is "cheating" with a priori knowledge of the factors.

There are some other examples of people factoring special-form composites that are particularly easy to factor on quantum computers, but those are basically stunts with no impact.

To threaten RSA, quantum computers need to increase the number qubits 6 orders of magnitude and improve the error correction at least 2 orders of magnitude. Check out this blog post for an illustration of where we are at: https://sam-jaques.appspot.com/quantum_landscape