It's an open question in mathematics/CS, that's all we know. If you want to know more, get to mathing :)

if you want a little more in depth explanation of the whole multiplication thing Ican recommend TAOCP volume 2. it has a section called 'How fast can we multiply?' it should provide more insight. there is a paper from djb (Daniel J Bernstein),which I can also recommemd: https://cr.yp.to/lineartime/multapps-20080515.pdf

Scroll down, there is a huge ad but the article continues.

Ask Sol 5.6 for the answer