In order to detect a replay attack in a speaker recognition system, at least one feature is identified in a detected magnetic field. It is then determined whether the at least one identified feature of the detected magnetic field is indicative of playback of speech through a loudspeaker. If so, it is determined that a replay attack may have taken place.

Techniques are disclosed for determining the presence of pulse jams in an identification friend or foe (IFF) system. In an embodiment, a plurality of jamming pulse rates are determined. Each of the plurality of jamming pulse rates is a count of jamming pulses entering the IFF system during a corresponding integration period. Each of the plurality of jamming pulse rates is a count of jamming pulses associated with non-valid signals entering the IFF system. An average jamming pulse rate is computed based on the plurality of jamming pulse rates. The average jamming pulse rate is then compared against a pulse jam threshold to determine whether a pulse jam is present (or not present) in the IFF system.

A method of detecting a replay attack on a voice biometrics system comprises: receiving an audio signal representing speech; detecting a magnetic field; determining if there is a correlation between the audio signal and the magnetic field; and if there is a correlation between the audio signal and the magnetic field, determining that the audio signal may result from a replay attack.

A communication system including an analog front end and an automatic gain controller. The analog front end includes at least one amplifier for amplifying a received analog signal and an analog to digital converter that converts the analog signal to digital samples. The automatic gain controller includes comparator circuitry, counter circuitry, and a gain controller. The comparator circuitry compares each of the digital samples with an upper threshold and a lower threshold. The counter circuitry counts a high count number of the digital samples having magnitudes that are greater than the upper threshold during each count window and counts a low count number of the digital samples having magnitudes that are less than the lower threshold during the count window. The gain controller adjusts a gain of the at least one amplifier by an amount based on the high count number and the low count number.

Systems and associated methods for detecting a set of spectrum sensing falsification (SSF) attacks in a geographic database (GDB) driven cognitive radio (CR) system. Viewing the GDB as a type of non-orthogonal compressive sensing (CS) dictionary, the composite power spectral density (PSD) estimate at a candidate CR is approximated by a small number of sensor nodes listed in the GDB. In a dense CR network, the PSD estimate at a CR may contain a composite mixture of spectrally overlapping signals. An implementation of an optimized, greedy algorithm orthogonal matching pursuit (OMP) returns a set of sensor nodes which are suspected to be in the vicinity of the CR. A sufficient match between the PSD estimate reported by a candidate CR and the PSD that is sparsely approximated from the SNs in its area provides confidence (trust) metrics which may be used to detect potential SSF attacks.

A method for automatic detection of antenna site conditions, ASC, at an antenna site, AS, of an antenna, A, the method comprising the steps of providing (S1) signal source observations, SSO, derived from signals received by the antenna, A, from at least one signal source, SS, and transforming (S2) the signal source observations, SSO, into images fed to a trained image-processing artificial intelligence, AI, model which calculates antenna site conditions, ASC, at an antenna site, AS, of the respective antenna, A.

A communication system receives a jammed signal including a sequence of complex numbers encoding one or combination of symbols transmitted by multiple transmitters. The system transforms the sequence of complex numbers into an image of real numbers having at least two columns and multiple rows, with real values of real and imaginary parts of each complex number forming different columns but the same row of the first image, processes the image with a neural network trained to suppress the wideband signal in the received signal, and detects the symbols transmitted by the transmitters from the de jammed signal.

A method of detecting a replay attack on a voice biometrics system comprises: receiving an audio signal representing speech; detecting a magnetic field; determining if there is a correlation between the audio signal and the magnetic field; and if there is a correlation between the audio signal and the magnetic field, determining that the audio signal may result from a replay attack.

Methods and systems for network jamming detection and remediation are provided. Exemplary methods include: detecting by a base unit network jamming, the base unit being disposed in a residence; and issuing an alert in response to the detected network jamming, the alert being last least one of: sounding an audible alarm, showing a visual alarm indication, communicating with law enforcement, and communicating with an alarm monitoring station.

Methods and apparatus for providing a comprehensive decision support system to include predictions, recommendations with consequences and optimal follow-up actions in specific situations are described. Data is obtained from multiple disparate data sources, depending on the information deemed necessary for the situation being modeled. The decision support system provides a prediction or predictions and a recommendation or a choice of recommendations based on the correlative analysis and/or other analyses. Also described are methods and apparatus for developing application specific decision support models. The decision support model development process may include identifying multiple disparate data sources for retrieval of related information, selection of classification variables to be retrieved from the data sources, assignment of weights to each classification variable, selecting and/or defining rules, and selecting and/or defining analysis functions.