Quantum Key Distribution (QKD) has been around for some years now. An American company that has been on the leading edge of QKD is called
MagiQ Technologies.
I've only ever heard of it being done over optical fiber, and it is really pretty cool. Basically, you store an encryption key (1024 or 2048 bits) in a photon and transmit that quantum state to another system. As noted in the article if someone tries to intercept it, the quantum state changes right out from under them.
I just don't see how they accomplished this between an earth station and a satellite. Damn impressive.