Abstract:
A method of detecting transient changes in the distribution of a discrete time series includes: operating in a sparse mode wherein, at sniff periods successively repeated at a first rate, at most K test phases are performed, K being an integer superior or equal to two, each test phase consisting of analyzing, by a sampling stopping time determination unit, samples of the time series captured by a sampler at sampling times according to a second rate which is higher than the first rate to provide a positive or negative result of the test phase. If the results of K successive test phases of a sniff period are each positive, the method switches to operate in a dense mode wherein the sampler is operated to continuously capture samples of the time series at sampling times according to the second sampling rate.
Abstract:
A method for recovering secret data of a cryptographic device comprises: a) determining stochastic models of leakages relating respective measurable quantities to internal states or operations of the cryptographic device, the number of greater than the number of masks used by the cryptographic device to conceal the secret data; b) sending command sequences to the device, where each command sequence causes the device to perform a cryptographic operation on at least one respective plaintext using the secret data and the masks; c) during processing of each cryptographic operation, recording a series of measurements of measurable quantities; and d) computing an estimator of secret data by maximizing the conditional joint probability of the recorded measurements given the corresponding plaintexts, averaged over all possible values of the masks. A method for evaluating the security of a cryptographic device is provided.
Abstract:
Embodiments of the invention provides a decoder for decoding a signal received through a transmission channel in a communication system, said signal carrying information symbols selected from a given alphabet and being associated with a signal vector, said transmission channel being represented by a channel matrix, wherein said decoder comprises: a sub-block division unit (301) configured to divide the received signal vector into a set of sub-vectors in correspondence with a division of a matrix related to said channel matrix; a candidate set estimation unit (305) for recursively determining candidate estimates of sub-blocks of the transmitted signal corresponding to said sub-vectors, each estimate of a given sub-block being determined from at least one candidate estimate of the previously processed sub-blocks, wherein said candidate set estimation unit is configured to determine a set of candidate estimates for at least one sub-block of the transmitted signal by applying at least one iteration of a decoding algorithm using the estimates determined for the previously processed sub-blocks, the number of candidate estimates determined for said sub-block being strictly inferior to the cardinal of the alphabet and superior or equal to two, the decoder further comprising a signal estimation unit (306) for calculating an estimate of the transmitted signal from said candidate estimates determined for said sub-blocks.
Abstract:
System for testing a protocol, which is active on an item of equipment, testing system including a monitor to continuously capture traces, corresponding to sequences of messages of protocol under test, a filter of the traces captured using formalized properties of the demands of protocol under test, to separate the traces into data and control parts, a temporary storage, and transfer module to transfer the filtered traces to a tester so as to emit verdicts by verifying whether the traces satisfy the demands of the formalized properties of the protocol under test, in the event of saturation of the tester leading to the emission of a notification of load, the transfer module interrupts the transfer of filtered traces to the tester and stores the traces at least partially in the temporary storage, particularly only their control parts, before resuming the transfer of filtered traces when the tester is again available.
Abstract:
The invention relates to a transition device between a printed transmission line on a dielectric substrate and a rectangular waveguide including a front face forming an inlet of the waveguide, a rear face parallel to the front face and forming an outlet of the waveguide, a lower face, an upper face parallel to the lower face, the upper and lower faces extending between the front and rear faces, the waveguide being a block of dielectric material whereof the faces are fully metalized except for the front face and the rear face, the transition device including: a three-dimensional cavity formed in the volume of the waveguide between the inlet of the waveguide, further forming the inlet of the cavity, and the rear face widening, the cavity being at an inlet height of the lower face of the waveguide and ending at a distance from the inlet of the cavity at an outlet height greater than the inlet height; an electrical connection extending from the transmission line along the front face of the waveguide up to the inlet of the three-dimensional cavity.
Abstract:
A system for displaying N multimedia streams, including multiple pairs of viewing spectacles and a displaying medium. The system obtains N multimedia streams, each stream including two multimedia substreams among 2×N multimedia substreams, and has N sources generating the 2×N substreams on the displaying medium. Each source has an encoder for coding two of the 2×N multimedia substreams, each substream being coded with a set of N coding modes each using a specific set of at least two states, having at least 2N possible combinations of states, each substream being coded with one of the possible combinations of states in order to visualize a given stream from the N multimedia stream. At least one pair spectacles includes a decoder for decoding, for each eyepiece, one of the substreams of the given stream and having N decoding modes corresponding to the N coding modes used for coding the substreams.
Abstract:
A method for selecting beams in a Millimeter-Wave MIMO system, using at least a transmitter antennas codebook indexing a plurality of beam patterns and a receiver antennas codebook indexing a plurality of beam patterns, at least one beam pattern being selected among said transmitter antennas codebook and at least one beam pattern being selected among said receiver antennas codebook, said selected beam patterns forming one or more pair of beams, said pair forming a channel for transmitting information between the transmitter and receiver antennas, with at least the following steps: sounding only a subset of beam pair, measuring a transmission quality parameter of said subset beam pairs to be indexed in an matric, using a learning model to select the beam pair having the maximum value of transmission quality parameter to form the channel for transmitting information between the transmitter and receiver antennas.
Abstract:
A channel sensing device for detecting preamble transmission by observing a channel sensing sequence of a length smaller than or equal to a maximum given length, the channel sensing device being implemented in a receiver, the channel sensing sequence includes one or more samples. The channel sensing device is configured to: receive input parameters comprising a target reliability metric, a receiver noise profile, the maximum given length, a received power, and a probability of there being a preamble; determine channel sensing parameters given the input parameters and according to the inimization of the average energy consumption per given length, the channel sensing parameters comprising a number of channel sensing phases, and a number of samples, a receiver power consumption value, and a preamble detection threshold corresponding to each of the channel sensing phases; perform a first channel sensing phase comprising: observing a batch of samples of the one or more samples by consuming the receiver power consumption value corresponding to the first phase channel sensing phase; applying a hypothesis test comprising the comparison of a value derived from the observed samples with the preamble detection threshold corresponding to the first channel sensing phase; deciding on the presence of a preamble or on performing a subsequent channel sensing phase based on the comparison and/or whether the number of channel sensing phases is greater than one; a subsequent channel sensing phase comprising: observing a batch of samples by consuming the receiver power consumption value corresponding to the channel sensing phase; applying a hypothesis test comprising the comparison of a value derived from all of the so far observed samples with the preamble detection threshold; deciding on the presence of a preamble or on performing a subsequent channel sensing phase based on the comparison and/or on a condition related to a number of performed channel sensing phases compared with the number of channel sensing phases.
Abstract:
N-type polymer based electrochemical devices include one or more source electrodes, one or more drain electrodes, one or more channels, a gate electrode, and an electrolyte solution are disclosed. The channels include one or more n-type polymers and one or more enzymes. The gate electrode includes one or more n-type polymers and one or more enzymes. The source and the drain electrodes are electrically connected by the corresponding channel. The electrolyte solution contains one or more metabolites capable of reacting with the one or more enzymes in the channel and the gate electrode and is in electrical contact with the channel and the gate electrode. Saturation current that flows through the channel increases when the metabolites react with the enzymes to produce electrons, which are directly transferred to the n-type polymers at the gate electrode and the channel. Methods of making and using the n-type electrochemical device are also disclosed.
Abstract:
A free-space optical communication system includes a transmitter and a receiver, the transmitter being configured to transmit an encrypted message to the receiver at the mid-infrared domain, the transmitter comprising a master mid-infrared optical source configured to generate a mid-infrared signal and a chaos generator configured to generate a chaotic signal by applying external optical feedback to the master mid-infrared optical source, the transmitter being configured to determine an encrypted message from an original message by applying a message encryption technique to the original message and to send the encrypted message to the receiver through an optical isolator, the receiver comprising a slave mid-infrared optical source similar to the master mid-infrared optical source the slave mid-infrared optical source being configured to recover the chaotic signal from the encrypted message by applying chaos synchronization, the receiver further comprising a first detector configured to detect the encrypted message, a second detector configured to detect the chaotic signal, and a message recovery unit configured to recover the original message from the encrypted message detected by the first detector and the chaotic signal detected by the second detector.