Trusted nodes in a network perform secure out-of-band symmetric encryption key delivery to user devices. A first trusted node receives a request from a first user device to deliver symmetric encryption keys to the first user device and a second user device, as a pair of user devices. The first trusted node delivers a second symmetric encryption key to the second user device, via trusted nodes. The first trusted node receives confirmation of delivery of the second symmetric encryption key. Responsive to the confirmation of delivery, the first trusted node delivers the first symmetric encryption key to the first user device.

An apparatus for enhancing secret key rate exchange over quantum channel in QKD systems includes an emitter system with a quantum emitter and a receiver system with a quantum receiver, wherein both systems are connected by a quantum channel and a service communication channel. User interfaces within the systems allow to define a first quantum channel loss budget based on the distance to be covered between the quantum emitter and the quantum receiver and the infrastructure properties of the quantum channel as well as a second quantum channel loss budget associated to the loss within the realm of the emitter system. The emitter system is adapted to define the optimal mean number of photons of coherent states to be emitted based on the first and the second quantum channel loss budgets.

Devices, systems, and methods for ambient-temperature quantum information buffering, storage, and communication are provided enabling receiving a quantum communication (for example, photons holding quantum information, e.g., qubits), storing the qubits in a room-temperature scalable quantum memory device, selectively retrieving the qubits, performing filtering, and extracting the quantum communication with a controllable delay.

The present disclosure relates to a quantum key distribution network apparatus and an operation method for a quantum key distribution network, for independently operating a data transfer path and a quantum key consumption path on which a quantum key is consumed to encrypt corresponding data in a quantum key distribution network.

A method for generating digital quantum chaotic orthonormal wavepacket signals includes the following steps: construct a N-dimensional Hermitian matrix ; calculate N eigen-wavefunctions .sub.j of a quantum Hamiltonian system with the Hamiltonian by some numerical calculation methods, wherein the Hamiltonian is the Hermitian matrix ; extract some or all of the eigen-functions .sub.j with obvious chaos features as quantum chaotic eigen-wavefunctions according to a chaos criterion; generate some semi-classical digital quantum chaotic wavepacket signals .sub.j(n) with the same mathematical form as the quantum chaotic eigen-wavefunctions and length N from the selected quantum chaotic eigen-wavefunctions according to the mathematical correspondence between the classical signal and the wavefunction in quantum mechanics. By combining the quantum state chaotic transition theory and the classical time-frequency analysis, some semi-classical quantum chaotic wavepacket digital signals are generated according to the mathematical correspondence between the classical time-frequency signal and the wavefunction in quantum mechanics.

In some example embodiments, there is provided an apparatus. The apparatus may include a frequency shifter configured to shift a reference signal to a portion of an optical spectrum separate from another portion of the optical spectrum being used by a signal of interest; and a polarization rotator configured to provide the reference signal shifted and rotated by the polarization rotator. The apparatus may also include a modulator configured to modulate the signal of interest with coherent state information from which quantum key information is derivable. Related systems, methods, and articles of manufacture are also disclosed.

One embodiment described herein provides a system and method for ensuring data and computation security. During operation, a server receives a key-negotiation request from a client and authenticates the client. In response to the client authenticating the server, the server negotiates, via a quantum-key-distribution process, a secret key shared between the client and the server; and stores the secret key in a trusted-computing module.

Quantum channel routing utilizing a quantum channel measurement service is disclosed. A quantum channel router that is communicatively coupled to a plurality of quantum channels receives a message from a sender that is directed to a receiver. Each quantum channel is configured to convey a quantum message from a sender to a receiver. The quantum channel router identifies a quantum channel to which the receiver listens. The quantum channel router determines a message size of the message. It is determined that transmission of the message would exceed a maximum channel capacity of the quantum channel at a current point in time, and in response, the quantum channel router does not transmit the first message onto the first quantum channel at the current point in time.

A tamper detecting component for a quantum communication system is a trusted node, configurable as a first endpoint trusted node, a middle-trusted node and a second endpoint trusted node. The trusted node has a tamper detection module and a secure memory. The tamper detection module deletes critical system parameters responsive to detecting physical tampering. The trusted node, as the first endpoint trusted node, exchanges a quantum key, encrypts data and transmits encrypted data. The trusted node as the middle-trusted node exchanges a quantum key, exchanges another quantum key, decrypts and re-encrypts data and transmits encrypted data. The trusted node as the second endpoint trusted node exchanges a quantum key, and decrypts data.

A quantum communication system has a plurality of trusted nodes. Each trusted node has a quantum key controller, and a quantum transmitter or a quantum receiver. The trusted nodes are configurable as first and second endpoint trusted nodes and middle-trusted nodes between endpoint trusted nodes. The first endpoint trusted node encrypt data comprising a first key, using a first quantum key. Each middle-trusted node decrypts, using a preceding quantum key, and re-encrypts using a succeeding quantum key. The second endpoint trusted node decrypts using a quantum key, so that the first and second endpoint trusted nodes each have the first key.