[advance_copy]

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.

[mazda77]

If someone tries to intercept . . . . .

There goes their unbreakable right out the window. If they can’t get it there without interception attempts, what good is the code if it is never received without the state intact? If they are transmitting it, it has to go over the airwaves as either radio or light. Radio is simple. Light (laser) might even be less of a challenge to disrupt or corrupt.

[Flick Lives]

I just don't see how they accomplished this between an earth station and a satellite. Damn impressive.

If they're using quantum entanglement, in theory, than distances don't matter as the two particles, now "entangled", act as one even when separated. If the Chinese worked this out, it would be hack-proof as there is nothing actually transmitted between the particles as they've now been "entangled" at a quantum, non-dimensional, level.

[Cboldt]

-- I just don't see how they accomplished this between an earth station and a satellite. --

Radio frequency is photons, too.

[aquila48]

“Basically, you store an encryption key (1024 or 2048 bits) in a photon”

Basically? How do you store that many bits of info in a single photon?