Abstract: A method for a quantum key distribution from a first target node to a second target node across a network via an entanglement-based protocol, including the following steps: transferring entangled particles from a load node to the first target node and to at least one intermediate node; generating a quantum key with the entangled particles transferred to the first target node and the at least one intermediate node; transmitting the quantum key to the second target node on a first path located on the network with a stage of secure quantum key transmission agreement starting from the at least one intermediate node by encrypting intervals of binary nodes with pre-shared quantum keys; and providing a secure communication with the quantum keys between the first target node and the second target node on a second path located on the network.

Abstract: A system and a method for entanglement-based quantum key distribution (QKD) are provided. The photons used for quantification of security and forming of the raw key can be reallocated, and wasted photons’ information may be recycled. Accordingly, a system for quantum key distribution including a photon source configured to generate entangled photon pair including first and second photons and two receiving units configured to receive separately the first and second photons is provided.

Abstract: A method for a quantum key distribution from a first target node to a second target node across a network via an entanglement-based protocol, including the following steps: transferring entangled particles from a load node to the first target node and to at least one intermediate node; generating a quantum key with the entangled particles transferred to the first target node and the at least one intermediate node; transmitting the quantum key to the second target node on a first path located on the network with a stage of secure quantum key transmission agreement starting from the at least one intermediate node by encrypting intervals of binary nodes with pre-shared quantum keys; and providing a secure communication with the quantum keys between the first target node and the second target node on a second path located on the network.

Abstract: A method and circuit for operating a liquid crystal device, LCD, based polarisation rotator. The method comprises the steps of tracking a capacitance value of the LCD rotator; and controlling a driver setting to the LCD rotator based on the tracked capacitance value to achieve temperature independent operation.

Abstract: A method and circuit for operating a liquid crystal device, LCD, based polarisation rotator. The method comprises the steps of tracking a capacitance value of the LCD rotator; and controlling a driver setting to the LCD rotator based on the tracked capacitance value to achieve temperature independent operation.