Systems, apparatuses, methods, and computer program products are disclosed for quantum entanglement random number generation (QERNG). An example method for QERNG includes, among other operations, generating a quantum entanglement random number based on a subset of a first set of entangled quantum particles associated with a first computing device. Each entangled quantum particle in the first set of entangled quantum particles may be entangled with a respective entangled quantum particle in a second set of entangled quantum particles associated with a second computing device. In some instances, the example method may further include generating a cryptographic key based on the quantum entanglement random number, encrypting an electronic communication based on the cryptographic key, and transmitting the encrypted electronic communication to the second computing device.

The present application relates to a method for securely transmitting a sequence of quantum states between a first participant C.sub.i and a second participant C.sub.j among a plurality of N participants, and to a device implementing said secure transmission method.

Centralized quantum capability management may be provided. A quantum network architecture may include a centralized quantum network manager. A quantum policy management may be controlled by quantum network manager. Quantum capability registration, solicitation, subscription, and discovery may be provided. Centralized quantum connection creation and management may be provided. Efficient quantum link layer services may be provided.

A communication system comprising n transmitters and a receiver, where n is an integer of at least 2, each of said n transmitters comprising a light source and an encoder such that each transmitter is adapted to output an encoded pulse of light, said receiver comprising a first element, the system further comprising a timing circuit, the timing circuit being configured to synchronise the encoded pulses output by the transmitters such that interference between a light pulse sent from the first transmitter and a light pulse from the second transmitter, interfere at the first element, each transmitter further comprising a suppressing element adapted to stop light exiting one of the transmitters such that the system is switchable between a first operation mode where two transmitters output encoded pulses and where both pulses interfere at the interference element and a second mode of operation where just one transmitter transmits light pulses to said receiver, the suppressing element being controlled to stop light exiting the other transmitter.

A system and method for quantum key distribution includes determining an intrinsic loss along a quantum channel; generating a pulse sequence; transmitting the pulse sequence via the quantum channel; receiving the pulse sequence; determining invalid signal positions and providing the invalid signal positions; determining a first reconciled signal from the first signal and the invalid signal positions, and determining a second reconciled signal from the second signal and the invalid signal positions; determining a total loss along the quantum channel from the at least one test pulse received, determining a signal loss from the total loss and the intrinsic loss, and providing the signal loss; determining a shared by error correcting the first reconciled signal and the second reconciled signal; and determining an amplified key from the shared key by shortening the shared key by a shortening amount that is determined from the signal loss.

A communications system may include a transmitter node, a receiver node, and an optical communications channel coupling the transmitter node and receiver node. The transmitter node may include a pulse transmitter and a pulse divider downstream therefrom. The receiver node may include a pulse recombiner and a pulse receiver downstream therefrom.

An example operation may include one or more of setting, by a first node, a cut-off time for a resolution of an update to a service contract received from at least one node of a plurality of second nodes over a blockchain, acquiring, by the first node, resolution parameters from a blockchain ledger, and executing a smart contract to resolve the service contract based on the update to the service contract and the resolution parameters.

Disclosed herein are technologies regarding a communication device and server which are capable of cryptographic communication based on quantum cryptography. The communication device includes: a quantum signal generation unit configured to generate a series of first quantum signals by using a first quantum filter; an optical transmission unit configured to send the series of first quantum signals to a server; and a processor configured to select the first quantum filter based on a series of randomly generated first quantum states, and to control the quantum signal generation unit to generate the series of first quantum signals by using the first quantum filter.

Disclosed herein are technologies regarding a communication device and server which are capable of cryptographic communication based on quantum cryptography. A communication device for quantum cryptography authentication includes: an optical communication unit configured to receive a series of first quantum signals generated by passing through a first quantum filter of the communication device; a quantum signal generation unit configured to generate the first quantum signals by setting up the first quantum filter in a reception path for a series of second quantum signals generated and sent by a server; and a processor configured to select the setup of the first quantum filter based on a series of randomly generated first quantum states, and to control the quantum signal generation unit to generate the first quantum signals by using the first quantum filter.

According to an embodiment, a receiver is connected to transmitters through photon communication channels and data communication channels to generate identical cryptographic keys to be shared with each transmitter. The receiver includes a sharing unit, a key distilling unit, a data communication controller, and a calculator. The key sharing unit is configured to generate a shared bit string through quantum key distribution with each transmitter via a corresponding photon communication channel. The key distilling unit is configured to generate the cryptographic keys from the respective shared bit strings. The data communication controller is configured to receive from each transmitter first information about a corresponding cryptographic key via a corresponding data communication channel. The calculator is configured to calculate the photon timeslots based on at least the first information. The data communication controller is configured to transmit the photon timeslots to the transmitters.