The United States of America, As Represented by the Director, National Security Agency

The United States of America As Represented by the Director of the National Security Agency

The U.S. Goverment As Represented by the Director, National Security Agency

Adolf Cusmariu

A device for and method of determining a coherence measurement for a signal that includes a digitizer for digitizing the signal, a transformer connected to the digitizer, a first squarer connected to the transformer, a second squarer connected to the digitizer, an adder connected to the first squarer and the second squarer, a subtractor connected to the first squarer and the second squarer, a standard-deviation function block connected to the subtractor, a mean generator connected to the adder, a first multiplier connected to the standard-deviation function block, and a divider connected to the output of the mean generator and the first multiplier.

Device for determining a coherence measurement for a digital signal that does not require spectral estimation

A method of assessing security of an information access system by selecting at least one verification mechanism, estimating an error tradeoff plot showing false acceptance rate versus false rejection rate for each verification mechanism, selecting a corresponding false acceptance rate and false rejection rate pair from each error plot, combining the false acceptance rates to determine intrusion protection, combining the false rejection rates to determine denial protection, and combining intrusion protection and denial protection as the assessment of the information access system.

Method of assessing security of an information access system

A method of measuring the degree of enhancement made to a voice signal by receiving the voice signal, identifying formant regions in the voice signal, computing stationarity for each identified formant region, enhancing the voice signal, identifying formant regions in the enhanced voice signal that correspond to those identified in the received voice signal, computing stationarity for each formant region identified in the enhanced voice signal, comparing corresponding stationarity results for the received and enhanced voice signals, and calculating at least one user-definable statistic of the comparison results as the degree of enhancement made to the received voice signal.

Method of measuring degree of enhancement to voice signal

The present invention is a novel method of performing spectral analysis on a digital signal. The received signal is segmented into a number of data blocks, which may be disjoint or overlapping. For each data block, the signal is differentiated, and the Gram-Schmidt process is used to obtain orthogonality between a signal and its derivative. The complex extension leads to computation of phase using either the inverse tangent function or the complex logarithm. Finally, frequency estimation follows through differentiation of the unwrapped phase.

Method of estimating digital signal frequency

A method of comparing voice samples to reduce false alarms by receiving a first voice sample, generating a model of the first voice sample, reordering the first voice sample, generating a model of the reordered first voice sample; receiving a second voice sample; generating a model of the second voice sample; reordering the second voice sample, generating a model of the reordered second voice sample, comparing at least one pairings of the models, and determining if the first voice sample matches the second voice sample if the model comparisons are within a user-definable threshold.

Method of comparing voice signals that reduces false alarms

A method of identifying file format, converting file from assumed format and bit ordering to user-definable format, dividing file into blocks, determining frequencies of occurrence in blocks, creating first set of frequencies of occurrence less than and equal to most frequently occurring integer, creating second set of frequencies of occurrence greater than the most frequently occurring integer, creating third set of differences in first sets, creating fourth set of differences in second sets, replacing third and fourth sets with polarity indicators, summing polarity indicators, determining sum percentages, pairing percentages, determining pairing maximum number, determining statistics, determining maximum of statistics, assigning result to converted file, selecting another format and bit ordering and returning to third step, identifying converted file with maximum statistic, and determining format and bit ordering of file to be that of assumed format associated with converted file identified in last step.

Method of identifying digital audio signal format

A method of identifying duplicate voice recording by receiving digital voice recordings, selecting one of the recordings; segmenting the selected recording, extracting a pitch value per segment, estimating a total time that voice appears in the recording, removing pitch values that are less than and equal to a user-definable value, identifying unique pitch values, determining the frequency of occurrence of the unique pitch values, normalizing the frequencies of occurrence, determining an average pitch value, determining the distribution percentiles of the frequencies of occurrence, returning to the second step if additional recordings are to be processed, otherwise comparing the total voice time, average pitch value, and distribution percentiles for each recording processed, and declaring the recordings duplicates that compared to within a user-definable threshold for total voice time, average pitch value, and distribution percentiles.

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Eldersburg, MD, United States of America

Adolf Cusmariu