System architecture and method of authenticating a user

A non-transitory computer-readable medium encoded with a computer-readable program which, when executed by a first processor, will cause a computer to execute a method of authenticating a user, the method comprising:

• training a plurality of models;
• sending, by the computer, an acoustic signal;
• receiving, by the computer, a reflected acoustic signal, wherein the reflected acoustic signal comprises information about a signature;
• receiving, by the computer, motion data about the information about the signature;
• comparing the information about the signature to a model to generate a plurality of scores;
• and
• deciding, based on the plurality of scores, if the information about the signature is within a predetermined tolerance levels wherein the plurality of scores comprise:
• a first score corresponding to a measure of similarity between a hand geometry of the user and a hand geometry in the model,
• a second score corresponding to a measure of similarity between a hand movement of the user and a hand movement in the model, and
• a third score corresponding to a measure of similarity between the motion data of a second hand movement of the user and a predetermined second hand movement in the model.