Abstract: A computer-implemented method of quantum-secure minting and issuing a digital coin by a central bank (CB) using a quantum cloud (QC) platform operable to facilitate an issuing authority (IA), the method includes issuing a command from the CB to the IA to mint a new digital coin, and the command includes: data indicative of a predetermined value of the coin, a unique identifier associated with the coin, and an identifier indicating which endpoint user of the QC platform is to be designated as the owner; in response to receiving the command, signing, by the IA, the coin with an ownership encryption key, wherein the ownership encryption key is known only to the QC platform and the owner; subsequent to signing the coin with the ownership encryption key, signing, by the IA, the coin with an authorising encryption key that is known only to the QC platform and the CB.

Abstract: A system and method for operating a quantum key distribution system including a receiver to receive an optical signal from a transmitter, the receiver including a first signal detection unit (1SDU) and a second signal detection unit (2SDU) for detecting events associated with single photons; an optical switch to alternate between a first switch position to direct a received optical signal to the 1SDU and a second switch position to direct a received optical signal to the 2SDU, such that the 1SDU and the 2SDU correspond to the first and second switch positions respectively; a detection time tagger to tag the events at the 1SDU and the 2SDU according to time, switch position, and signal detection unit, to introduce a correlation between a time in which an event is registered, the switch position, and the signal detection unit; and a timing recovery module connected to the detection time tagger.

Abstract: A quantum key distributed (QKD) apparatus for linking endpoint devices in a network, which includes: QKD links each including a quantum channel and a classical channel, wherein each endpoint has a QKD link; quantum transmitters to transmit quantum transmissions over a quantum channel of one of the QKD links; classical transceivers to transmit classical data over a classical channel of one of the QKD links and to receive classical data over the classical channel of said QKD link; and a controller connected to the quantum transmitters and the classical transceivers to route data generated for quantum transmission to an endpoint over a quantum channel of the QKD link of the endpoint; route classical data for classical transmission to an endpoint via a classical transceiver over a classical channel of the QKD link of the endpoint; and route classical data over the classical channel of the QKD link of an endpoint.

Abstract: A method for time synchronisation in a satellite based quantum key distribution system, by at a transmitter, emitting a first series of laser pulses (LP) encoded to form a quantum beam, emitting a second series of LP having a predetermined repeating pattern; at a receiver, receiving the first and second series of LP and determining reception times of pulses of the first and second series of LP; comparing the second series of LP to the predetermined pattern and determining the point at which the received second series of LP is most correlated to the predetermined pattern; determining a relationship fitting reception times of a plurality of the received pulses to emission times of corresponding ones of the second series of LP; and using the determined relationship to convert between reception times of the first series of LP and emission times of corresponding ones of the first series of LP.

Abstract: A computer-implemented method of creating a group key for a group of N parties using an intermediary, the method includes sharing a cryptographic key of a party with an adjacent party in an ordered ring, wherein each party has another cryptographic key of an adjacent party; generating a meeting key for the party based on combining the cryptographic key of the party with a shared cryptographic key from an adjacent party; sending the meeting key to the intermediary and receiving an intermediate key from the intermediary, wherein the intermediary computes the intermediate key by combining at least two meeting keys of corresponding parties; creating the group key by combining the cryptographic key of the party with the received intermediate key, wherein the created group key includes a combination of at least N?1 of the cryptographic keys of the parties; and using the group key with another party of the group.

Abstract: A method of operating a quantum key distribution (QKD) system including using a quantum random number generator (QRNG) to generate a random number string (RNS), and storing the RNS; providing the RNS to a first cryptographically secure pseudo-random number generator (CSPRNG) which uses random numbers of the RNS as seeds to generate respective first strings of pseudo-random numbers; using the first strings of pseudo-random numbers to encode photons or pulses transmitted by a transmitter of the QKD system; after a predetermined delay, providing the stored RNS to a second CSPRNG which uses random numbers of the RNS as seeds to generate respective second strings of pseudo-random numbers, the second CSPRNG identically configured to the first CSPRNG; using the second strings of pseudo-random numbers, together with information regarding encoded photons or pulses received by a receiver of the QKD system, to agree secure keys between the transmitter and the receiver.

Abstract: A quantum key distributed (QKD) apparatus for use with at least two endpoint devices, the apparatus including QKD links each having a communication medium with a quantum channel and a classical channel, wherein each endpoint has a QKD link connected to the QKD apparatus; transmitters to transmit quantum transmissions over a quantum channel of one of the QKD links; a classical transceiver component to transmit/receive classical data over a classical channel of one of the QKD links; and a controller to route data for quantum transmission to an endpoint via a transmitter assigned to the endpoint over a quantum channel of the QKD link of the endpoint, route classical data to an endpoint via a classical transceiver assigned to the endpoint over a classical channel of the QKD link of the endpoint, and route classical data over the classical channel of the QKD link of an endpoint.

Abstract: A system for performing a key exchange using a quantum key distribution protocol between first, second, and intermediary devices, wherein the intermediary device: receives first symbol set over a first quantum channel transmitted from first device and sends first receiving basis information to first device, receives second symbol set over a second quantum channel transmitted from second device and sends second receiving basis information to second device, generates first and second intermediate sets of symbols based on received first and second sets of symbols, generates third intermediate symbol set by combining first and second intermediate sets and sends third intermediate set to first and/or second device, whereby first and second devices perform the key exchange by exchanging with themselves first and second transmitting basis information and/or first and second receiving basis information to determine a final shared key based on first, second, and third intermediate symbol sets.

Abstract: A method for performing a key exchange using a quantum key distribution protocol between a first device (D1), a second device (D2), and an intermediary device (ID), wherein: ID receives first symbol set (SS1) over first quantum channel (QC1) transmitted from D1 and sends first receiving basis information (RBI1) to D1 which withholds from ID first transmitting basis information (TBI1); ID transmits second symbol set (SS2) over second quantum channel (QC2) and second transmitting basis information (TBI2) to D2 which withholds from ID second receiving basis information (RBI2); ID generates first (IS1) and second intermediate symbol (IS2) sets based on valid SS1 and SS2; wherein ID generates third intermediate symbol (IS3) set by combining IS1 and IS2 and sends IS3 set to D1 and/or D2; wherein D1 and D2 exchange TBI1 and RBI2 and/or RBI1 and TBI2 to determine a final shared key based on SS1, SS2, and IS3 sets.

Abstract: A method of aligning a quantum laser beam with a receiver, the method including: generating a quantum laser beam and a first classical, non-quantum, laser beam at a transmitter, the quantum laser beam and the first classical laser beam being substantially aligned in direction; transmitting the quantum laser beam and the first classical laser beam; and directing the quantum laser beam and first classical laser beam to a receiver; measuring the photon reception rate through the quantum laser beam at the receiver, and reporting the photon reception rate to the transmitter; at the transmitter, making a series of adjustments to the direction of the transmitted quantum laser beam and the first classical laser beam, and monitoring the reported photon reception rate; wherein, each of the series of adjustments is based, at least in part, on the effect of the preceding adjustment on the reported photon detection rate.

Abstract: A computer-implemented method of establishing a key between a first and a second device in a network including a first and a second key node, the first and second key nodes with access to a same set of keys, the method including receiving, at the first device, data representative of first key establishment data from the first key node and the second device for calculating a Bilocation Key from a selected key from the set of keys; and receiving, at the second device, data representative of second key establishment data from the first device for requesting the Bilocation Key from the second key node, wherein the Bilocation Key is calculated based on the selected key from the set of keys; and wherein the first and second devices use corresponding Bilocation Keys to each generate a Final Key based on an agreed portion of the first and second key establishment data.

Abstract: A method of encryption key provisioning that includes providing, by a quantum computing safe method, a shared secret data to a device and to a security service; using the provided shared secret data to provide a root key; and using the root key for a sequence of stages, wherein each stage includes an operation which converts a start key into a different generated key, and the same stages are carried out in parallel at the device and at the security service; wherein the root key is used as the start key for a first stage, and a generated key produced by each stage, except for the final stage, is used as a start key for a next stage of the sequence; and wherein the generated keys produced by the last stage of the sequence at the device and at the security service are symmetric keys.

Abstract: A computer-implemented method of secure quantum safe (QS) payments using a quantum cloud payment platform, the method, performed by the quantum cloud payment platform, comprising: receiving one or more quantum safe deposit payment transactions from one or more endpoint devices of one or more registered users, each QS deposit payment transaction of a user comprising data representative of a deposit fiat cash value; transferring each of the deposit fiat cash values from a bank account associated with a user and linked to the QS payment account of the user to a quantum cloud account for pooling each of the deposit fiat cash values; for each deposit fiat cash value transferred in relation to a user of an endpoint device, performing: converting said each deposit fiat cash value to a corresponding number of quantum money tokens; linking said number of quantum money tokens to the QS payment account of the user; and sending said number of quantum money tokens to the endpoint device of the user for updating an electro

Abstract: Method(s), system(s), apparatus are provided for quantum safe quantum streaming between a first endpoint device and second endpoint device via a server of a quantum cloud platform. Splitting, at the first endpoint device, a data item into a plurality of data shards that allow reconstruction of the data item. Encrypting, at the first endpoint device, each of the data shards separately using a first cryptographic key shared between the first endpoint device and the second endpoint device. Establishing, between the first endpoint device and the server, a first plurality of secure channels with the server of the quantum cloud platform using a second cryptographic key, the second cryptographic key shared between the endpoint and the server. Transmitting, from the first endpoint device to the server, the plurality of encrypted shards towards the second endpoint device via the server over the plurality of secure channels.

Abstract: A method of scheduling encryption key delivery communication sessions in a satellite quantum key distribution system comprising a constellation of one or more satellites and a plurality of user ground stations comprises producing a list of user ground stations requiring encryption keys. For each satellite of the constellation of satellites, determining a region of the earths surface within which the satellite can carry out encryption key delivery communication sessions to user ground stations using a quantum optical communications link during a scheduling period. Obtaining a cloud cover map. Comparing the locations of the listed user ground stations, the determined regions of the earths surface for the constellation of satellites, and the cloud cover map, to identify listed user ground stations to which encryption key delivery can be carried out by the constellation of satellites during the scheduling period.

Abstract: Method(s), system(s), apparatus are provided for storing one or more data item(s) in a quantum-safe (QS) network. The QS network comprising one or more QS server(s) and a repository for storing and accessing said data item(s). Each QS server comprising a hardware security module (HSM) for storing an identical set of quantum distributed (QD) keys. The identical set of QD keys having been distributed to each of said QS server(s) in a quantum-safe manner. The QS server(s) are configured to communicate securely with each other and the repository using one or more available QD keys from the identical set of QD keys. A QS server performs generating a quantum reference (QREF) locator based on input data associated with a data item for storage and an available QD key selected from the set of QD keys, and sending the QREF locator along with the data item encrypted with the available QD key to the repository for storage.

Abstract: Methods, apparatus, and systems are provided for performing a quantum key distribution (QKD) protocol between a first device, a second device, and an intermediary device. The intermediary device transmitting: a first secret symbol string over a first quantum channel to the first device; a first basis set over a first communication channel to the first device. The intermediary device; a second secret symbol string over a second quantum channel to the second device; a second basis set over a second communication channel to the second device. The intermediary device generating a third symbol string based on combining the first and second secret symbol strings and transmitting to the second device, via the second communication channel, data representative of the third symbol string.

Abstract: Methods, apparatus, and systems are provided for operating a distributed ledger network (100), the distributed ledger network (100) comprising a plurality of nodes (102a-102n, 104a-04m), the plurality of nodes comprising a group of nodes (104), wherein each node in the group of nodes (104) includes functionality for acting as a trusted third party node on a distributed ledger transaction, the method comprising: performing an operating performance test on one or more selected nodes (104a-104m) of the group of nodes (104), wherein the operating performance test comprises sending a plurality of test messages to each selected node (104a-104m) over a predetermined time period; receiving operating performance data associated with each selected node (104a-104m) in relation to the operating performance test; aggregating operating performance statistics for each selected node (104a-104m) based on the received operating performance responses; and indicating to the distributed ledger network (100) those selected nodes (