Abstract: The present invention provides a quantum communication system and associated methods for securely establishing a cryptographic key between two or more transmitters and a receiver. Each transmitter emits qubit signals from a light source within defined time windows, characterized by specific bases and modes controlled by a transmitter controller. The receiver utilizes an interference device with multiple inputs to receive qubit signals and outputs to generate an interference signal, which is detected by multiple detectors. A receiver controller sends information on detected outputs to transmitters and provides feedback based on spectral characteristics. Simultaneously, the system adjusts subsequent qubit signal characteristics based on this spectral feedback, enabling the establishment of a cryptographic key between transmitters using the detected signals. This adjustment optimizes the cryptographic key rate, enhancing security and efficiency in quantum communication protocols.

Abstract: The present invention provides a quantum communication system and associated methods for securely establishing a cryptographic key between two or more transmitters and a receiver. Each transmitter emits qubit signals from a light source within defined time windows, characterized by specific bases and modes controlled by a transmitter controller. The receiver utilizes an interference device with multiple inputs to receive qubit signals and outputs to generate an interference signal, which is detected by multiple detectors. A receiver controller sends information on detected outputs to transmitters and provides feedback based on spectral characteristics. Simultaneously, the system adjusts subsequent qubit signal characteristics based on this spectral feedback, enabling the establishment of a cryptographic key between transmitters using the detected signals. This adjustment optimizes the cryptographic key rate, enhancing security and efficiency in quantum communication protocols.

Abstract: A quantum communication system and associated methods are described for securely establishing a cryptographic key between multiple transmitters and a receiver. Each transmitter emits qubit signals from a light source within defined time windows, characterized by specific bases and modes controlled by a transmitter controller. The receiver utilizes an interference device with multiple inputs to receive qubit signals and outputs to generate an interference signal, which is detected by multiple detectors. A receiver controller sends information on detected outputs to transmitters and provides feedback based on temporal characteristics. Simultaneously, the system adjusts subsequent qubit signal characteristics based on this temporal feedback, enabling the establishment of a cryptographic key between transmitters using the detected signals. This adjustment optimizes the cryptographic key rate, enhancing security and efficiency in quantum communication protocols.