Satellite-relayed intercontinental quantum network

Understand

We perform decoy-state quantum key distribution between a low-Earth-orbit satellite and multiple ground stations located in Xinglong, Nanshan, and Graz, which establish satellite-to-ground secure keys with ~kHz rate per passage of the satellite Micius over a ground station.

• The satellite thus establishes a secure key between itself and, say, Xinglong, and another key between itself and, say, Graz.
• Then, upon request from the ground command, Micius acts as a trusted relay.
• It performs bitwise exclusive OR operations between the two keys and relays the result to one of the ground stations.