If someone wasn’t a cryptographer, but does occasional security tasks at work, what is the takeaway? RSA needs to be 4096 or higher now, or that similar techniques in the future might make RSA a bad choice altogether?
Don’t worry - yet. This is either a nothingburger, or it’s going to be a nightmare for everyone, all at once (ever dealt with web PKI? you will get a chance if this is true)
But there’s no real current takeaway until we know if this approach works, and if so how extensible it is to RSA, especially 2048 bit RSA.
There are plenty of techniques in the past that make RSA a bad choice altogether.
If you are going with it anyway, yeah, 4k bits is a safe choice for making it reasonably secure right now (2k being a bare minimum), but remember, attacks always get better, never worse, and RSA has a fair share of possible attacks.
But there’s no real current takeaway until we know if this approach works, and if so how extensible it is to RSA, especially 2048 bit RSA.