Comment by rolandog

> [...] no one has managed to factor a larger number than 21.

Small correction: no one has PUBLICLY managed to factor a larger number than 21.

There could be advances (foreign and domestic) that just don't get published because they represent having an upper-hand with regards to cryptography. So, from Game Theory perspective, not making waves is in the interest of nation states. They'll even try to be dismissive about concerns.