Abstract: The present invention relates to an Entropy measurement method comprising the steps of a start-up phase comprising powering on the entropy source unity, a signal emitting step comprising emitting a quantum signal characterized by an overall noise made of classical noise and quantum noise, a noise measurement step comprising measuring the statistics of overall noise through active pixels upon illumination and the statistics of classical noise through non-illuminated pixels, a quantum noise calculation step comprising calculating the quantum noise based on the difference between the overall noise and the classical noise, an health check step comprising comparing the resulting quantum noise to an expected quantum noise and/or a predetermined threshold and a health control step controlling the entropy source unit based on the result of the entropy estimation step.

Abstract: 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.

Abstract: A QKD system used to securely exchange encryption keys between an emitter (100) and a receiver (200) modified to accept an additional customization parameter. Said QKD system consists of a QKD transmitter (120) and a QKD receiver (220) capable of implementing a plurality of QKD protocols forming a family of protocols. The QKD transmitter (120) and receiver (220) connected through a quantum channel (500) consist of optical and electronic components adapted to produce and detect a stream of qubits. The qubits (520) exchanged over the quantum channel (500) are grouped into blocks (510) consisting of at least one qubit and whose length is Li (511). For each, block (510) of qubits (520), one of the QKD protocol (530), selected from the family of protocols can be implemented using the emitter (100) and transmitter (200) is used.

Abstract: 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.

Abstract: A method for providing eavesdropping detection of an optic fiber communication between two users includes the steps of exchanging both data and probe signals through at least two channels (400, 500) between the users, exchanging probe signals (143) on one channel (500 or 400) between quantum probe signal terminals, extracting a key for authentication from the probe signals, and exchanging data signals (142) between transmission units on another channel (400 or 500). A first portion of the key generated by the quantum probe signal terminals is used to authenticate the terminals, wherein a second portion of the key is dedicated to define commutation occurrences of commutation devices adapted to commutate the use of the channels (400, 500) for data (142) and probe (143) signals, thus detecting an eavesdropping event (300) which triggers an alarm (750). A further portion of the key can be used to encrypt the messages.

Abstract: A method and device for generating random numbers based on an optical process of quantum nature. According to one exemplary aspect, the method includes randomly emitting photons from a light source and absorbing the emitted photons by a photon sensor having a plurality of pixels. Furthermore, respective minimum entropy levels can be calculated for each of the pixels of the photon sensor and a randomness extractor can be associated with each of pixels based on the calculated minimum entropy level of that pixel. After this calibration, the method and device generates a number of high-entropy bits used for generating a random number.

Abstract: An apparatus and method for revealing both attack attempts performed on the single-photon detector(s) of a quantum cryptography system and Trojan horse attack attempts performed on quantum cryptography apparatus containing at least one single photon detector. The attacks detection relies on both the random modification of the setting parameters of the said single-photon detector(s) and the comparison of the measured detection probability values for each setting parameter with the expected detection probability values. The modified parameter of the single-photon detector can be its efficiency or its timing of activation for example.

Abstract: A method and device for generating random numbers based on an optical process of quantum nature. According to one exemplary aspect, the method includes randomly emitting photons from a light source and absorbing the emitted photons by a photon sensor having a plurality of pixels. Furthermore, respective minimum entropy levels can be calculated for each of the pixels of the photon sensor and a randomness extractor can be associated with each of pixels based on the calculated minimum entropy level of that pixel. After this calibration, the method and device generates a number of high-entropy bits used for generating a random number.

Abstract: A method for providing eavesdropping detection of an optic fiber communication between two users includes the steps of exchanging both data and probe signals through at least two channels (400, 500) between the users, exchanging probe signals (143) on one channel (500 or 400) between quantum probe signal terminals, extracting a key for authentication from the probe signals, and exchanging data signals (142) between transmission units on another channel (400 or 500). A first portion of the key generated by the quantum probe signal terminals is used to authenticate the terminals, wherein a second portion of the key is dedicated to define commutation occurrences of commutation devices adapted to commutate the use of the channels (400, 500) for data (142) and probe (143) signals, thus detecting an eavesdropping event (300) which triggers an alarm (750). A further portion of the key can be used to encrypt the messages.

Abstract: An apparatus and method for implementing a secure quantum cryptography system using two non-orthogonal states. For each qubit, the emitter station prepares a quantum system in one of two non-orthogonal quantum states in the time-basis to code bit values. Intra- and inter-qubit interference is then used to reveal eavesdropping attempts. Witness states are used to help reveal attacks performed across the quantum system separation.

Abstract: An apparatus and method for revealing both attack attempts performed on the single-photon detector(s) of a quantum cryptography system and Trojan horse attack attempts performed on quantum cryptography apparatus containing at least one single photon detector. The attacks detection relies on both the random modification of the setting parameters of the said single-photon detector(s) and the comparison of the measured detection probability values for each setting parameter with the expected detection probability values. The modified parameter of the single-photon detector can be its efficiency or its timing of activation for example.

Abstract: An apparatus and method for implementing a secure quantum cryptography system using two non-orthogonal states. For each qubit, the to emitter station prepares a quantum system in one of two non-orthogonal quantum states in the time-basis to code bit values. Intra- and inter-qubit interference is then used to reveal eavesdropping attempts. Witness states are used to help reveal attacks performed across the quantum system separation.

Abstract: An apparatus and method for implementing a secure quantum cryptography system using two non-orthogonal states. For each qubit, the emitter station prepares a quantum system in one of two non-orthogonal quantum states in the time-basis to code bit values. Intra- and inter-qubit interference is then used to reveal eavesdropping attempts.

Abstract: In a method and apparatus for synchronizing the receiver and the emitter in an autocompensating quantum cryptography system it is allowed to one of the stations (for example the emitter) to define the timing of all its operations (for example the application of a signal onto the modulator used to encode the values of the bits) as a function of a time reference. This time reference can either be transmitted using a channel from the other station (for example the receiver). It can also consist of a time reference synchronized with that of the other station through using information transmitted along a channel and a synchronization unit. Preferably a time reference unit is provided at each station. One of these time reference units functions as a master, while the other one function as a slave. The slave is synchronized with the master using information transmitted over a communication channel by a synchronization unit.

Abstract: A method and apparatus for generating true random numbers by way of a quantum optics process uses a light source to produce a beam which illuminates a detector array. The detectors of the array are associated with random numbers values. Detection of a photon by one of the detectors yields a number whose value is equal to that associated with the detector. This procedure is repeated to produce sequences of true random numbers. The randomness of the numbers stems from the transverse spatial distribution of the detection probability of the photons in the beam. If the array is made up of two detectors, the true random numbers produced are binary numbers. The process can be sped up using an array having pairs of two detectors. Using an array having more than two detectors also allows generating true random numbers of dimension higher than two. The primary object of the invention is to allow generating true random numbers by way of a quantum optics process.

Abstract: An apparatus and method for implementing a secure quantum cryptography system using two non-orthogonal states. For each qubit, the to emitter station prepares a quantum system in one of two non-orthogonal quantum states in the time-basis to code bit values. Intra- and inter-qubit interference is then used to reveal eavesdropping attempts. Witness states are used to help reveal attacks performed across the quantum system separation.

Abstract: An apparatus and method for implementing a quantum cryptography system encoding bit values on approximations of elementary quantum systems with provable and absolute security against photon number splitting attacks. The emitter encodes the bit values onto pairs of non-orthogonal states belonging to at least two sets, and such that there does not exist a single quantum operation allowing to reduce the overlap of the states in all the sets simultaneously.

Abstract: A method and apparatus for generating true random numbers by way of a quantum optics process uses a light source to produce a beam which illuminates a detector array. The detectors of the array are associated with random numbers values. Detection of a photon by one of the detectors yields a number whose value is equal to that associated with the detector. This procedure is repeated to produce sequences of true random numbers. The randomness of the numbers stems from the transverse spatial distribution of the detection probability of the photons in the beam. If the array comprises two detectors, the true random numbers produced are binary numbers. The process can be sped up using an array having pairs of two detectors. Using an array having more than two detectors also allows generating true random numbers of dimension higher than two. The primary object of the invention is to allow generating true random numbers by way of a quantum optics process.

Abstract: An apparatus and method for implementing a quantum cryptography system encoding bit values on approximations of elementary quantum systems with provable and absolute security against photon number splitting attacks. The emitter encodes the bit values onto pairs of non-orthogonal states belonging to at least two sets, and such that there does not exist a single quantum operation allowing to reduce the overlap of the states in all the sets simultaneously.

Abstract: A method and apparatus for generating true random numbers by way of a quantum optics process uses a light source to produce a beam which illuminates a detector array. The detectors of the array are associated with random numbers values. Detection of a photon by one of the detectors yields a number whose value is equal to that associated with the detector. This procedure is repeated to produce sequences of true random numbers. The randomness of the numbers stems from the transverse spatial distribution of the detection probability of the photons in the beam. If the array comprises two detectors, the true random numbers produced are binary numbers. The process can be sped up using an array having pairs of two detectors. Using an array having more than two detectors also allows generating true random numbers of dimension higher than two. The primary object of the invention is to allow generating true random numbers by way of a quantum optics process.