Radio frequency identification (RFID) tag, portable terminal, and server for RFID tag

摘要

A hierarchical structure is established among a plurality of RFID tags (100), such that ID numbers can be read only from RFID tags which belong to a particular layer. RFID tag (100) can control whether permission should be given to read its ID number therefrom to protect the ID number. Data held in the RFID tag (100) can be read from the outside. RFID tag (100) comprises a memory circuit (150) having a function of holding data, and a logic circuit (140) having a function of processing a control command received from outside. Memory circuit (150) stores an own ID nmber (151) for identifying the RFID tag itself, and a parent ID number (152) for identifying a second RFID tag. When RFID tag (100) receives an ID number read command (400) which contains first data (403) as a parameter from outside, the logic circuit (140) outputs the own ID number (151) to outside only when the first data (403) matches the parent ID number (152).