Patent ID: 8065235

Claim:
A mobile information processing device for purchasing a selected item from a store, the device comprising: a housing in a form of a wrist watch; a memory that stores information comprising: a card number reflecting a form of payment; a private key and certificate for a user of the device; a personal identification code of the user; and a public key of the store for verification purposes; a receiver configured to receive a request for a payment authorization message from a sales terminal in the store, said payment authorization message comprising a price for the selected item; a processor operatively coupled with the memory and configured to: process the request for the payment authorization message received from the sales terminal; generate a price authorization message for transmission to the sales terminal wherein the price authorization message comprises: the price of the selected item; the card number reflecting the form of payment; an e-signature of the user; and an interjacence countermeasure that ensures the user that the price authorization message is free from interjacence; transmit the price authorization message to the sales terminal; an antenna for transmission of signals to the store terminal; an input/output subsystem operatively coupled with the memory and the processor, said input/output subsystem comprising: a display driver; and a display, having several modes selectable by using a scrolling wheel, configured to: present the price to the user; and enable acceptance by the user of the price responsive to the entry of the personal identification code for the user; at least one encryption engine that protects communication between the device and the sales terminal; and the scrolling wheel configured to control the display.