Patent ID: 8497836

Claim:
A method comprising: receiving, by a user identifier circuit, a button pressure signature specifying a sequence of button pressure values sampled by a pressure-sensitive detector circuit at prescribed time intervals while a corresponding identified button of a user input device is pressed by a user, the identified button being one of a plurality of buttons on the user input device, the pressure-sensitive detector circuit configured for measuring, at the prescribed time intervals, variable pressure applied by the user during a single user input via the corresponding identified button and in response generating the sequence of button pressure values as a representation of the variable pressure over time; the user identifier circuit identifying the user of the user input device based on the button pressure signature, the plurality of said buttons arranged as a device keyboard, enabling identification of the user based on the corresponding button pressure signature from any one of the buttons; and the user identifier circuit outputting a message identifying the identified button and the identified user.