Patent ID: 7358847

Claim:
An integrated circuit tag that is attached to an item of merchandise, comprising: an item information storage unit that stores item information, wherein the item information includes an item price, a first discount information, a discount start time indicating a time to start discounting, and encryption information that indicates whether the item information is to be encrypted; an item information controller that provides control to change the item information; an item price calculation processor that corrects the item price based on the first discount information if the discount start time has passed; and an item information display unit that displays the item information stored, wherein if the item information controller provides control to change the item information stored based on an instruction wirelessly transmitted from a control device or the item price calculation processor corrects the item price, then the item information display unit displays the item information changed or corrected, and the item information controller is further configured to encrypt the item information at a time when the item is sold, based on an instruction from the control device if the encryption information indicates that the item information is to be encrypted.