Patent US10355857

a photon source configured to generate quantum entangled bi-photons;

an optical switch operably coupled to at least four fiber optic transmission lines;

at least four remote receiver units, each coupled to one of the fiber optic transmission lines; and

a first processing component operably coupled to the optical switch;

a first server component, coupled to the first processing component;

at least four second server components, each coupled to one of the remote receiver units; and

one or more client processing systems which are operably linked to each of the at least four second server components to send data requests to the second server components and receive data from the second server components in response thereto, and to construct the public key using the received data, wherein the optical switch is configured to receive the bi-photons from the photon source and transmit each bi-photon as a first and a second quantum entangled photon along separate fiber optic transmission lines to which the optical switch is coupled, wherein the first processing component is configured to control the optical switch to determine which fiber-optic transmission line transmits the first quantum entangled photon and which fiber-optic transmission line transmits the second quantum entangled photon, and to store in a memory device associated with the first processing component information indicative of the determination, wherein each remote receiver unit comprises a second processing component configured to measure one or more quantum states of photons received over the fiber-optic transmission line to which it is coupled and to store in a memory device associated with the second processing component information indicative of the quantum state(s) measured, wherein each of the second server components is configured to respond to data requests from the one or more client processing systems for the information indicative of the quantum state(s) measured by the remote receiver unit to which it is coupled by retrieving the information indicative of the quantum state(s) measured from the memory device associated with the second processing component and transmitting the information to the one or more client processing systems, and wherein the first server component is configured to receive information from and respond to requests from the one or more client processing systems to validate that the quantum state information retrieved from each remote receiver is properly correlated with the configuration of the optical switch prepared for each entangled photon pair and transmitting the validation, or invalidation, to the one or more client processing systems, wherein each client processing system of the one or more client processing systems is configured to generate the public key by obtaining from each of the at least four remote receivers the information indicative of the quantum state(s) measured by each remote receiver, using the information obtained thereby to produce a string of random bits, and obtaining the validation or invalidation of the string of random bits from the first server component, wherein the public key is identified as being the string of random bits upon its validation by the first server component.