RFID device with dual frequency interrogation for enhanced security and method of preventing counterfeiting of RFID devices

#The invention relates generally to radiofrequency identification devices (RFID) and systems, and more particularly, to RFID devices with enhanced security features to prevent counterfeiting. The invention further relates to RFID devices that have high and low frequency authentications, and methods associated with the devices incorporated within a plurality of objects which are tagged with RFID devices and monitored for security purposes.

#Radiofrequency identification employs electromagnetic fields to automatically identify objects that incorporate RFID tags. An RFID tag includes electronically stored information in the form of electronic registers that store data that may allow the tag to be uniquely identified among a plurality of other RFID tags. RFID tags are utilized within many different commercial settings. Examples of uses of RFID tags include tags for livestock, RFID tagged pharmaceuticals, RFID tags for component identification of objects within a manufacturing process, and others.

#The active tags intermittently transmit an ID signal for authentication. A battery assisted passive tag also has an integral battery power source, but is not activated unless in the presence of an RF signal generated by an RFID reader. A passive tag has no onboard power source and rather, uses the radiofrequency energy transmitted by the reader to power the tag. Further, tags may be read only or read/write. For read-only tags, a pre-assigned serial number and other data may be incorporated in the read-only register(s) of the tags. Read/write tags are those in which object specific data is written into the tag by a user/administrator.

#FIG. 1 is a schematic diagram of an RFID device of the invention including a high-frequency RFID tag and a low frequency authenticator; and

#FIG. 2 is a plan view of an example gaming board with a plurality of electromagnetic coils placed at pre-configured known locations on the gaming board in which RFID tagged gaming chips or tokens can each be interrogated and authenticated despite very close spacing of many chips/token on the gaming board, and therefore the precise location of each chip can be determined during game play; and

#FIG. 3 is a fragmentary cross sectional view of an example chip or token incorporating the RFID device and optionally incorporating a vector magnetometer device therein.

#In a preferred embodiment of the invention, it includes a RFID device with enhanced security features to prevent counterfeiting. The RFID device has a dual RFID structure including a high frequency RFID transponder and a complementing low-frequency authenticator. The low-frequency authenticator has an RF transponder function that utilizes a different low frequency RF transmission protocol, such as one produced from a MEMs device or an ASIC device in combination with RFID architecture.

#Referring to FIG. 1, the RFID device 10 of the invention is illustrated in a preferred embodiment. In one application, the device 10 may be incorporated within an object such as a gambling chip C. The gaming chip has an outer shell or cover which protects the transponder 12 and authenticator 30. The device 10 may also be referred to herein as a secure dual frequency RFID tag, or “secure RFID tag”. The secure RFID tag has two primary components, namely, a high frequency RFID transponder 12 that incorporates standard architecture and a low frequency authenticator 30. The gaming chip has an outer shell or cover which protects the transponder 12 and authenticator 30. The gaming chip C may also have one or more protective layers to providing cushioning for the electronic components. The transponder 12 has a number of components/functions illustrated in the schematic diagram, these components/functions including: an antenna 14, a modulator 16, a fixed capacitance 18, a power generation element 20, a unique serial number 22 within a data register, a fixed inductance 24, and one or more additional data registers 26. The authenticator 30 is also illustrated with a number of components/functions including: an antenna 32, a modulator 34, an adjustable capacitance 36, a power generation element 38, an authentication code generator 40, and a fixed inductance 42.

#The RFID transponder 12 functions according to existing high-frequency RFID protocol.