First of all, this sort of paper pops up fairly frequently and, so far, none have stood up to peer review for long. There's probably an error somewhere in thei

First of all, this sort of paper pops up fairly frequently and, so far, none have stood up to peer review for long. There's probably an error somewhere in their proof. Second, long distance communication and scalable networks cannot rely on direct point-to-point links. You can't build everyone a point to point link with each other and individual links, even for classical signals, can only extend for a few hundred kilometers before signal-to-noise drops so far that any known communication protocol breaks down completely. Yes, commercial quantum systems built to date do rely on point-to-point links, but quantum memory and quantum repeater networks (currently enjoying rapid improvement in research) will allow chained entanglement swapping through untrusted nodes, allowing quantum crypto to work in network topologies very similar to the existing internet. The method in the linked paper does not appear to permit this and would have to rely on trusted nodes at best. In other words, even if it there isn't an error in their proof, they need to show that their technology can be expanded beyond trusted-point-to-trusted-point links in order for it to be of practical use.