15. A method for authenticating a speaker, the method comprising: receiving reference speech input comprising a reference passphrase to form a reference recording; determining a reference set of feature vectors for the reference recording, the reference set of feature vectors having a time dimension and comprising a plurality of frames; receiving test speech input comprising a test passphrase to form a test recording; determining a test set of feature vectors for the test recording, the test set of feature vectors having the time dimension and comprising a plurality of frames; classifying each frame in the reference set of feature vectors and the test set of feature vectors as one of a voiced frame or a silent frame to form a voiced reference set of feature vectors and a voiced test set of feature vectors; comparing the voiced reference set of feature vectors to the voiced test set of feature vectors to determine a length ratio; determining whether the test passphrase is different from the reference passphrase based on the length ratio; correlating the voiced reference set of feature vectors with the voiced test set of feature vectors over the time dimension; comparing the voiced reference set of feature vectors to the voiced test set of feature vectors to determine whether the test passphrase matches the reference passphrase; determining a set of reference fundamental frequency values for the reference recording, wherein determining a reference fundamental frequency comprises determining a voice feature of the reference recording as a function of a time period T; determining a set of test fundamental frequency values for the test recording, wherein determining a test fundamental frequency comprises determining a voice feature of the test recording as a function of the time period T; identifying a set of local peak fundamental frequency values in the set of reference fundamental frequency values and the set of test fundamental frequency values; excluding the set of local peak fundamental frequency values from the set of reference fundamental frequency values and the set of test fundamental frequency values to form a modified set of reference fundamental frequency values and a modified set of test fundamental frequency values; comparing the modified set of reference fundamental frequency values to the modified set of test fundamental frequency values to determine whether a speaker of the test speech input matches a speaker of the reference speech input; and authenticating the speaker of the test speech input in response to determining that the reference passphrase matches the test passphrase and that the speaker of the test speech input matches the speaker of the reference speech input; wherein the reference set of feature vectors comprises Mel Cepstrum feature vectors, and wherein the test set of feature vectors comprises Mel Cepstrum feature vectors.
15. A method for authenticating a speaker, the method comprising: receiving reference speech input comprising a reference passphrase to form a reference recording; determining a reference set of feature vectors for the reference recording, the reference set of feature vectors having a time dimension and comprising a plurality of frames; receiving test speech input comprising a test passphrase to form a test recording; determining a test set of feature vectors for the test recording, the test set of feature vectors having the time dimension and comprising a plurality of frames; classifying each frame in the reference set of feature vectors and the test set of feature vectors as one of a voiced frame or a silent frame to form a voiced reference set of feature vectors and a voiced test set of feature vectors; comparing the voiced reference set of feature vectors to the voiced test set of feature vectors to determine a length ratio; determining whether the test passphrase is different from the reference passphrase based on the length ratio; correlating the voiced reference set of feature vectors with the voiced test set of feature vectors over the time dimension; comparing the voiced reference set of feature vectors to the voiced test set of feature vectors to determine whether the test passphrase matches the reference passphrase; determining a set of reference fundamental frequency values for the reference recording, wherein determining a reference fundamental frequency comprises determining a voice feature of the reference recording as a function of a time period T; determining a set of test fundamental frequency values for the test recording, wherein determining a test fundamental frequency comprises determining a voice feature of the test recording as a function of the time period T; identifying a set of local peak fundamental frequency values in the set of reference fundamental frequency values and the set of test fundamental frequency values; excluding the set of local peak fundamental frequency values from the set of reference fundamental frequency values and the set of test fundamental frequency values to form a modified set of reference fundamental frequency values and a modified set of test fundamental frequency values; comparing the modified set of reference fundamental frequency values to the modified set of test fundamental frequency values to determine whether a speaker of the test speech input matches a speaker of the reference speech input; and authenticating the speaker of the test speech input in response to determining that the reference passphrase matches the test passphrase and that the speaker of the test speech input matches the speaker of the reference speech input; wherein the reference set of feature vectors comprises Mel Cepstrum feature vectors, and wherein the test set of feature vectors comprises Mel Cepstrum feature vectors. 17. The method of claim 15 , wherein correlating the reference set of feature vectors with the test set of feature vectors over the time dimension is performed using a derivative dynamic time warping process, wherein the derivative dynamic time warping process is applied to the voiced reference set of feature vectors and the voiced test set of feature vectors; and wherein determining a set of reference fundamental frequency values for the reference recording and determining a set of test fundamental frequency values for the test recording is performed using a YIN process, wherein the YIN process is applied to the reference recording and the test recording.