A method is presented for employing radio frequency (RF) identifier (ID) transponder tags (RFID tags) to create a unique identifier, termed an RFID signature, for use within a data processing system with respect to a person or an object. An interrogation signal is transmitted toward a person or an object with which a set of one or more RFID tags are physically associated. A first set of RFID tag identifiers are obtained from an interrogation response signal or signals returned from the set of one or more RFID tags. A mathematical operation is performed on the first set of RFID tag identifiers to generate an RFID signature value, which is employed as an identifier for the person or the object within the data processing system with respect to a transaction that is performed by the data processing system on behalf of the person or the object.