I don't get this. The challenge (which the authors don't actually name, and which they take a long time to even describe) is key distribution. Apparently their

I don't get this. The challenge (which the authors don't actually name, and which they take a long time to even describe) is key distribution. Apparently their solution is for Alice and Bob to each have a quantum object that is entangled with the other. But now they have the same problem, but harder: how to distribute entangled quantum objects. What have I missed?