Patent ID: 8144130

Claim:
A method for preventing unauthorized electronic or electrical eavesdropping during input of an identification (ID) number into a resistive touch screen, the input representing an ID input event, wherein each digit of the ID number is entered into the touch screen by touching a particular screen contact position associated with the digit and wherein each such touching results in a pair of instant X-axis and Y-axis voltages, the method comprising the steps of: a) between any two consecutive ID input events and relative to a constant voltage, changing independently the value of each voltage of the pair of instant X-axis and Y-axis voltages associated with a particular digit to provide a new pair of instant X-axis and Y-axis voltages; and b) enabling only an authorized entity to correlate the new pair of instant X-axis and Y-axis voltages with the particular digit, thereby preventing eavesdropping by any unauthorized entity.