Abstract: A method for use in a quantum communication network comprising a first node, a second node and a third node, the method performed by the third node, the method comprising: receiving, from the first node, a request for authentication key data for authenticating communication with the second node; in response to the request: generating the first authentication key data; sending, to the first node, a first message comprising first authentication key data for authenticating communication between the first node and the second node, wherein the first message is authenticated using second authentication key data stored on the first node and the third node, and wherein the first message is encrypted using a first cryptographic key exchanged with the first node on the quantum communication network; and sending, to the second node, a second message comprising the first authentication key data, wherein the second message is authenticated using third authentication key data stored on the second node and the third nod

Abstract: An authentication method for quantum communication between two nodes, the method comprising: applying a hash function to a message to obtain a hash code, wherein the hash function is a Poly1305; applying a one-time pad cipher to the hash code to obtain a message authentication code (MAC); and authenticating the message exchanged between the two nodes using the MAC.

Abstract: A system for generating a biased random bit stream, wherein said biased bit stream has different predetermined probabilities of occurrence for bit “0” and bit “1”, said system comprising: a true random generator unit configured to output a true random bit stream, a pseudo random generator unit configured to output a pseudo random bit stream, said pseudo random bit stream comprising n bit words, where n is an integer of at least two; a combining unit configured to combine a bit from said true random generator unit with an n-bit word from said pseudo random generator unit to output a processed n-bit word; and an output unit configured to generate an output bit value from said processed n-bit word using a function, wherein said function is selected to control the probabilities of occurrence of the bit “0” values and bit “1” values to be the predetermined probabilities of occurrence.

Abstract: An authentication method for quantum communication between two nodes, the method comprising: applying a hash function to a message to obtain a hash code, wherein the hash function is a Poly1305; applying a one-time pad cipher to the hash code to obtain a message authentication code (MAC); and authenticating the message exchanged between the two nodes using the MAC.

Abstract: A method for use in a quantum communication network comprising a first node, a second node and a third node, the method performed by the third node, the method comprising: receiving, from the first node, a request for authentication key data for authenticating communication with the second node; in response to the request: generating the first authentication key data; sending, to the first node, a first message comprising first authentication key data for authenticating communication between the first node and the second node, wherein the first message is authenticated using second authentication key data stored on the first node and the third node, and wherein the first message is encrypted using a first cryptographic key exchanged with the first node on the quantum communication network; and sending, to the second node, a second message comprising the first authentication key data, wherein the second message is authenticated using third authentication key data stored on the second node and the third node,

Abstract: A server configured to provide a pre-shared key “PSK” with a first user node, to allow a first user node and a second user node to share a PSK, the server comprising: a network interface; an authentication unit; an encryption unit; a key management system and a quantum key distribution unit, the authentication unit being configured to receive a request for authentication, via the network interface, of a first channel between a first user node and the server, the quantum key distribution unit being configured to allow a quantum key to be distributed between the first user node and the server, the quantum key being sifted using communication over the authenticated first channel to establish a first quantum key for the first user and server, the key management system being configured to provide a first PSK for the first user to allow the first user to authenticate with the second user, the encryption unit being configured to encrypt the first PSK with the quantum key to send to the first user node via the net

Abstract: An optical emitter comprising a primary laser and a plurality of secondary lasers wherein each secondary laser is optically injection locked to said primary laser, the emitter further comprising at least one polarisation controller configured to control the polarisation of the output of at least one of the secondary lasers, the emitter further comprising a combination unit that is configured to combine the outputs of the secondary laser modules into an output signal.

Abstract: An optical device for a quantum random number generator comprising: a source of phase randomised pulses of light, the source of phase randomised pulses of light further comprising a plurality of gain-switched lasers, each gain-switched laser having an output, and each gain-switched laser being configured to emit a stream of pulses such that the phase of each pulse in the stream of pulses is randomised, and an optical pulse combiner, the optical pulse combiner being configured to receive streams of pulses from the output of each gain-switched laser, combine the streams of pulses with one another into a combined stream of pulses and direct the combined stream of pulses into at least one output of the optical pulse combiner, the at least one output of the optical pulse combiner being the output of the source of phase randomised pulses of light; wherein the source of phase randomised pulses of light is configured such that the streams of pulses of light emitted by the plurality of gain-switched lasers are tem

Abstract: A method of exchanging a combined cryptographic key between a first node and a second node, the first node and the second node being connected through a first communication and a second communication network, wherein the first communication network is a quantum communication network wherein information is encoded on weak light pulses; and the first node and the second node being configured to: exchange one or more first cryptographic keys on the first communication network; exchange one or more second cryptographic keys using the second communication network; and form the combined cryptographic key by combining the one or more first cryptographic keys and the one or more second cryptographic keys, such that the first node and the second node share knowledge of the combined cryptographic key.

Abstract: An emitter configured to output a sequence of periodic light pulses with different polarisations, the emitter comprising: a beam splitter configured to divide the pulses of a first sequence of pulses, such that each pulse is split between a first path and a second path, the first sequence of pulses having a varying phase and a first polarisation; a polarisation rotator configured to rotate the polarisation state of pulses in one of the first path or the second path with respect to the polarisation state of pulses in the other path; a time delay component configured to provide a time delay such that the first sequence of pulses in the first arm are delayed by one period with respect to the first sequence of pulses in the second arm; an optical combination component configured to combine the delayed first sequence of pulses from the first path with the first sequence of pulses from the second path to produce an output sequence of pulses where each pulse in the output sequence is a combination of a pulse from

Abstract: An emitter configured to output a sequence of periodic light pulses with different polarisations, the emitter comprising: a beam splitter configured to divide the pulses of a first sequence of pulses, such that each pulse is split between a first path and a second path, the first sequence of pulses having a varying phase and a first polarisation; a polarisation rotator configured to rotate the polarisation state of pulses in one of the first path or the second path with respect to the polarisation state of pulses in the other path; a time delay component configured to provide a time delay such that the first sequence of pulses in the first arm are delayed by one period with respect to the first sequence of pulses in the second arm; an optical combination component configured to combine the delayed first sequence of pulses from the first path with the first sequence of pulses from the second path to produce an output sequence of pulses where each pulse in the output sequence is a combination of a pulse from th

Abstract: An optical emitter comprising a primary laser and a plurality of secondary lasers wherein each secondary laser is optically injection locked to said primary laser, the emitter further comprising at least one polarisation controller configured to control the polarisation of the output of at least one of the secondary lasers, the emitter further comprising a combination unit that is configured to combine the outputs of the secondary laser modules into an output signal.

Abstract: An optical module includes: a quantum photonic integrated circuit; a temperature controller; and a housing configured to house the photonic integrated circuit and the temperature controller. The photonic integrated circuit is attached to the temperature controller, such that the photonic integrated circuit is in thermal communication with the temperature controller, and the temperature controller is attached directly to the housing, such that the temperature controller is in direct thermal communication with the housing.

Abstract: An optical system, comprising: an emitter configured to output a first optical signal along a first optical path to an interference unit and to output a second optical signal along a second optical path to the interference unit, the interference unit being configured to interfere the first and second optical signals, wherein the coherence length of the optical signal is longer than the path difference between first and second optical paths, and there is a path difference between the first and second paths of at least 1 km.

Abstract: An optical system, comprising: an emitter configured to output a first optical signal along a first optical path to an interference unit and to output a second optical signal along a second optical path to the interference unit, the interference unit being configured to interfere the first and second optical signals, wherein the coherence length of the optical signal is longer than the path difference between first and second optical paths, and there is a path difference between the first and second paths of at least 1 km.

Abstract: A node for a quantum communication network, said node comprising: a quantum transmitter, said quantum transmitter being adapted to encode information on weak light pulses; a quantum receiver, said quantum receiver being adapted to decode information from weak light pulses; at least three ports adapted to communicate with at least one other node; and an optical switch, said optical switch being configured to selectively connect the quantum transmitter and receiver to the ports such that the switch controls which of the ports is in communication with the quantum transmitter and quantum receiver.

Abstract: The present invention relates to an amorphous pyrrolidine derivative as a PPAR agonist and a preparation method thereof.

Abstract: An optical module includes: a quantum photonic integrated circuit; a temperature controller; and a housing configured to house the photonic integrated circuit and the temperature controller. The photonic integrated circuit is attached to the temperature controller, such that the photonic integrated circuit is in thermal communication with the temperature controller, and the temperature controller is attached directly to the housing, such that the temperature controller is in direct thermal communication with the housing.

Abstract: A system for generating a biased random bit stream, wherein said biased bit stream has different predetermined probabilities of occurrence for bit “0” and bit “1”, said system comprising: a true random generator unit configured to output a true random bit stream, a pseudo random generator unit configured to output a pseudo random bit stream, said pseudo random bit stream comprising n bit words, where n is an integer of at least two; a combining unit configured to combine a bit from said true random generator unit with an n-bit word from said pseudo random generator unit to output a processed n-bit word; and an output unit configured to generate an output bit value from said processed n-bit word using a function, wherein said function is selected to control the probabilities of occurrence of the bit “0” values and bit “1” values to be the predetermined probabilities of occurrence.

Abstract: An optical source including: a phase-randomised light source including a master light source configured to intermittently generate master light pulses; a slave light source optically coupled to the master light source and configured to receive the master light pulses, and that generates a sequence of slave light pulses during each period of time that a master light pulse is received; and an interferometer optically coupled to the slave light source and configured to receive sequences of slave light pulses, delay the received sequences by the first time interval to form delayed sequences of slave light pulses, interfere the received sequences with the delayed sequences, such that pulses from a received sequence interfere with adjacent pulses of the delayed sequence, and output interfered pulses including first and second output pulses that have a first and second predetermined amplitude respectively and a predetermined relative phase between them.