1. A non-invasive method of recognizing the identity of a human or animal by recognizing non-visible internal tissue having a substantially stable unique distinguishing characteristic comprising the following steps: a) generating an electrical oscillating signal; b) converting said electrical oscillating signal of step (a) to an acoustic energy beam, said acoustic energy beam having at least one frequency in the range between 100 KHz and 10 MHz; c) transmitting said acoustic energy beam through an external accessible surface to said non-visible internal tissue; d) receiving an emitted acoustic energy beam from said non-visible internal tissue, said emitted acoustic energy beam responsive to said transmitted acoustic energy beam; e) converting said emitted acoustic energy beam to an emitted electrical signal; f) forming a current representative pattern of said non-visible internal tissue having said substantially stable unique distinguishing characteristic in response to said emitted electrical signal, said forming of said current representative pattern comprising: (i) generating at least one amplitude versus time plot, wherein the amplitude and interpeak distance of an echo peak is in response to said emitted electrical signal; (ii) determining a minimum threshold amplitude value parallel to an x-axis and normal to a y-axis of said plot, thereby dividing said plot into selecting and eliminating areas; (iii) calculating at least one ratio of said peaks in the selecting area to provide a representative pattern; and g) comparing a previously produced and stored master representative pattern of said non-visible internal tissue with said current representative pattern of same.