1. A method of comparing a challenge verbal utterance with an enrollment verbal utterance to determine a security action, the method comprising the steps of: A) perparing an enrollment data comprising the step of: a) converting an enrollment verbal utterance into a first electrical signal; b) converting the electrical signal into a digital format; c) creating a fast Fourier transform of the signal to produce a frequency domain representation of the signal; d) taking M sample as frames of the signal for each of N frequency channel to form an M by N sample enrollment matrix Ei; e) removing all said frames with zero energy content; f) determining if at least X of the M sample have a selected minimum energy content in at least Y of the N frequency channels; g) repeating steps (a) through (f) if (f) fails, and aborting after a selected number of repeating of steps (a) through (f); h) repeating steps (a) through (f) if step (f) succeeds, until a selected number of said sample matrices Ei have been formed as E1, E2, E3,. .. ; i) forming the difference between each pair of the enrollment matrices Ei, as (E1-E2), (E1-E3), )E2-E3),. .. ; j) comparing each of the individual frames with each other of the frames by moving each said one of the frames forward and backward in time to obtain the best match; k) forming the sum, S, of the differences between each of the pairs of the matrices Ei as S={(E1-E2)+(E1-E3)+(E1-E2)+. .. } l) accepting S as an enrollment data if S&lt;EB, where EB is a selected first enrollment criterion, and if each said difference between each pair of the matrices Ei is greater than ES, ES being a selected second enrollment criterion: B) challenging the enrollment data comprising the steps of: a) converting a challenge verbal utterance into a second electrical signal; b) converting the second electrical signal into a digital format; c) creating a second fast Fourier transform of the signal to produce a frequency domain representation of the second signal; d) taking M samples of the signal for each of N frequency channels to form an M by N sample challenge matrix C; e) removing each of said frames having zero energy content; f) determining if at least X of M samples have a selected minimum energy content in at least Y of the N frequency channels; g) repeating steps (a) through (f) if (f) fails, and aborting after a selected number of repeats of steps (a) through (f); h) repeating steps (a) through (f) if step (f) succeeds, until a selected number of said sample matrices C has been formed; i) forming the difference between each pair of the enrollment matrices C, as (CE-1), (C-E2), )C-E3),. .. ; j) comparing each of the individual frames with each other of the frames by moving each said one of the forward and backward in time to obtain the best match; k) forming the sum, S, of the differences between each of the pairs of the matrices C as S={(C-E1)+(C-E2)+(C-E3)+. .. } l) accepting S as an enrollment data is S&lt;VB, VB being a selected first verification criterion and also if each said difference between each pair of the matrices C is greater than VS, VS being a selected second verification criterion: C) Enabling the security action if the challenge verbal utterance is accepted.