Quantum-authenticated clock signal

A time distribution system comprising:

• a quantum channel configured to transfer photons between a source device and a receiver device;
• a communication channel configured to facilitate communication between the source device and the receiver device;
• said source device operably coupled to an external clock source, said source device configured to transmit a photon pulse over the quantum channel according to a time characteristic of the external clock source, said source device configured to communicate a time of transmission of the photon pulse to the receiver device via the communication channel;
• said receiver device with a receiver device clock, said receiver configured to detect an arrival time of one or more photons of the photon pulse and to return one or more photons of the photon pulse to the source device via the quantum channel;
• and
• wherein said receiver device is configured to determine a receiver synchronized clock that is synchronized to the external clock source based on a time of flight of the photon pulse sent by the source device, the arrival time of the one or more photons detected in the receiver device, and the time of transmission of the photon pulse communicated from the source device to the receiver device.

A device comprising:

• a quantum channel interface configured to receive and transmit photons with respect to a source device, wherein the source device is operably coupled to a trusted clock source, said quantum channel interface configured to attenuate photons received ;
• a communication channel configured to communicate information with the source device;
• a photon detector configured to detect an arrival of one or more photons of a photon pulse received from the source device;
• and
• a controller operably coupled to the photon detector and the communication channel, said controller configured to receive time of transmission information for the photon pulse via the communication channel, said controller configured to store an arrival time of the one or more photons detected by the photon detector, said controller configured to determine a clock output synchronized to the trusted clock source, wherein the clock output is determined based on a time of flight of the photon pulse sent by the source device, the arrival time of the one or more photons detected by the photon detector, and the time of transmission information of the photon pulse received from the source device.