departing from the spirit and scope of the present invention in this example to be authenticated user 203 has a password or personal identification number pin and a token that generates a session key that is useable only once in this embodiment before practicing the invention for the first time user 203 receives an applet from server 201 the applet contains a modem and a session key issued by the server the modem demodulates and decodes the signal and includes an encryption algorithm for handling the challenge response interaction between the user and server in this example user 203 enters a password or pin code locally and inserts the sound token which generates the modulated sound into an audio input on the pc the session key automatically encrypts the password or pin ensuring a permanent password encryption state meaning that the password or pin is never transmitted over the network to the server in a clear or unencrypted state in this example user 203 is not required to enter a username server 201 sends the correct user name when it receives the correct id number from the token on the client pc only a valid server can send the correct user name therefore user 203 is entering his password safely and securely fig3 is an architectural overview 300 of interaction using the system of the invention according to another embodiment of the present invention overview 300 includes authentication server 201 network 202 and user 203 having the same description and element numbers introduced in the description of fig2 above in this example user authentication.