A RADIO FREQUENCY IDENTIFICATION (RFID) SECURITY DEVICE

Abstract: A Radio Frequency Identification (RFID) tag device is configured as an electronic key. The electronic key disables the RFID Input/Output (I/O) by shorting or breaking the conductor between the RFID tag device and its resonant circuit or antenna whenever the electronic key is not inserted into a lock. This is a security measure which prevents unauthorized individuals from reading the electronic key code via a covert/concealed reading device. The circuit is completed by closing the key contacts with a matching shorting bar (normally open application), or spreading the shorted spring contacts with a nonconductive spacer (normally closed application) when the electronic key is inserted inside an electronic locking mechanism. Once the circuit is completed, the wireless transmission of data from the electronic key to the electronic locking mechanism is enabled.

Description: A RADIO FREQUENCY IDENTIFICATION (RFID) SECURITY DEVICE BACKGROUND OF THE INVENTION Field of the Invention; This invention relates generally to a Radio Frequency Identification (RFID) security device and, more specifically, to an RFID tag device configured as an electronic key which utilizes contact elements to disable the RFID I/O by shorting or breaking the RFID tag device from the antenna or resonant inductor when the key is not inserted into a locking device. Description of the Prior Art: Electronic keys have long been used to prevent unauthorized entry to restricted areas. Presently, there are several different types of electronic keys in the market place. While each of these types of keys do work, they each have certain drawbacks. One such type of an electronic key is a serial EEPROM based electronic key. Serial EEPROM based keys require 4 to 5 separate contacts in order to operate. One contact is used for each of power, ground, clock, and data. Two contacts may be used for data transfer (i.e., one as an input contact and one as an output contact). Each of the multiple contacts in the serial EEPROM based key must make proper contact in order to transfer clock and data through them. In apartment or hotel applications, users returning from a swimming pool may insert a wet key into the lock. This causes poor contact or shorts between the contacts which prevents proper transfer of data, thereby preventing the lock from opening. Furthermore, the wrong polarity of key insertion into the lock will cause damage to the lock electronics or EEPROM device, thereby rendering the key useless. Thus, moisture, polarity of insertion, and wear and/or damage to the multiple contacts are problematic in this type of electronic key. A second type of electronic key utilize access control RFID tags. In these types of keys, a card or tag is presented to a reading device to gain access to a building. In most cases, this type of electronic key is used for identification applications rather than for security. Using this type of electronic key for security (apartment and hotel locks) creates a problem since these types of keys are not very secure. Covert readers, even battery powered readers, can power-up the tag and steal its code without the owner's knowledge, even if the tag is in the owner's pocket or purse. One way to solve the problems associated with access control RFID tags is to have an encrypted electronic key. Several types of electronic keys include encryption algorithms on the die itself. Some encryption algorithms will allow the code on the electronic key to be encrypted and changed every time the key is read. While these types of electronic keys prevent unauthorized "code grabbing", they are considerably more expensive than RFID tag devices. Thus, the security comes at the expense of cost. Therefore, a need existed to provide an improved RFID security device. The improved RFID security device must not require a plurality of contacts for data transfer. The improved RFID security device must further be universal in polarity. The improved RFID security device must be resistant to environmental elements. The improved RFID security device must also be able to be used for security and must further be resistant to "code grabbing". The improved RFID security device would utilize RFID tag devices configured as electronic keys. The improved RFID security device would utilize contacts which would short or open a circuit between the RFID tag memory device and an antenna or resonant inductor whenever the RFID security device is not inserted into a lock, thereby preventing unauthorized people from reading the key via a concealed reader. SUMMARY OF THE INVENTION In accordance with one embodiment of the present invention, it is an object of this invention to provide an improved RFID security device. It is another object of the present invention to provide an improved RFID security device that does not require a plurality of contacts for data transfer. It is still another object of the present invention to provide an improved RFID security device that is universal in polarity. It is yet another object of the present invention to provide an improved RFID security device that is resistant to environmental elements. It is still a further object of the present invention to provide an improved RFID security device that is able to be used for security and must further be resistant to "code grabbing". It is yet a further object of the present invention to provide an improved RFID security device that utilizes RFID tag devices configured as electronic keys. It is still a further object of the present invention to provide an improved RFID security device that utilizes contacts which would short or open a circuit between the RFID tag memory device and an antenna or resonant inductor whenever the RFID security device is not inserted into a lock thereby preventing unauthorized people from reading the key via a concealed reader. It is still another object of the present invention to provide the above objects at a reduced cost compared to encrypted devices. BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS In accordance with one embodiment of the present invention, a Radio Frequency Identification (RFID) security device is disclosed. The RFID security device is an electronic key. The electronic key uses an RFID tag device for storing data on the key. An energizing circuit is coupled to the RFID tag device for providing energy to the RFID tag device and to read the data on the electronic key. The energizing circuit may be a tuned resonant circuit or an antenna. A key contact is coupled, to the energizing circuit. The key contact is used for enabling and disabling the energizing circuit. Once the electronic key is enabled, transmission of the data from the electronic key may occur. In accordance with another embodiment of the present invention, a Radio Frequency Identification (RFID) security device is disclosed. The RFID security device uses an electronic locking mechanism and an electronic key. The electronic key has an RFID tag device for storing data. An energizing circuit is electrically coupled to the RFID tag device when the electronic key is coupled to the electronic locking mechanism. The energizing circuit may be a tuned resonant circuit or an antenna. The energizing circuit is used for providing energy to the RFID tag device in order to read the data on the electronic key when the electronic key is coupled to the electronic locking mechanism. A key contact is coupled to the energizing circuit for enabling the energizing circuit when the electronic key is coupled to the electronic locking mechanism. The electronic locking mechanism uses a reading device for reading the data transferred from the electronic key when the electronic key is coupled to the electronic locking mechanism. A first inductive element is coupled to the reading device for transmitting a signal to the energizing circuit of the electronic key when the electronic key is coupled to the electronic locking mechanism. A second inductive element is coupled to the first inductive element. Shorting members are coupled to the second inductive element for coupling the second inductive element to the electronic key to form the energizing circuit of the electronic key. The foregoing and other objects, features, and advantages of the invention will be apparent from the following, more particular, description of the preferred embodiments of the invention, as illustrated in the accompanying drawing. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a simplified electrical schematic of a first embodiment of the present invention. Figure 2 is a simplified electrical schematic of a second embodiment of the present invention. Figure 3 is a simplified electrical schematic of a third embodiment of the present invention. Figure 4 is a simplified electrical schematic of a fourth embodiment of the present invention. Figure 5 is a simplified electrical schematic of a fifth embodiment of the present invention. Figure 6 A is a top view of one implementation of the present invention. Figure 6B is an end view of one embodiment of the implementation depicted in Figure 6A. Figure 6C is an end view of a second embodiment of the implementation depicted in Figure 6A. Figure 7 A is a top view of another implementation of the present invention. Figure 7B is an end view of one embodiment of the implementation depicted in Figure 7A. Figure 7C is an end view of a second embodiment of the implementation depicted in Figure 7A. Figure 8 A is a top view of another implementation of the present invention. Figure 8B is a side view of the implementation depicted in Figure 8 A. Figure 8C is an end view of the implementation depicted in Figure 8 A. Figure 9 is a simplified electrical schematic of another embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to Figure 1, a first embodiment of an improved electronic key 10 (hereinafter key 10) is shown. The key 10 uses a Radio Frequency Identification (RFID) tag device 12. The RFID tag device 12 is programmed to store data on the key 10. When the key 10 is inserted into a locking mechanism (not shown), the data stored on the RFID tag device 12 will be read by a reading device (not shown) in the locking mechanism. If the proper electronic key 10 has been inserted into the locking mechanism, the locking mechanism will be released. In order to read the data on the RFID tag device 12, an energizing circuit 14 is coupled to RFID tag device 12. The energizing circuit 14 is used to provide energy to the RFID tag device 12 and to convey the data signal back to the reader. The energizing device may be a tuned resonant circuit or an antenna. In the embodiment depicted in Figure 1, the energizing circuit 14 is a tuned resonant circuit 14. The reading device of the locking mechanism will send out a carrier signal. The tuned resonant circuit 14 is tuned to the frequency of the carrier signal. The tuned resonant circuit 14 will take the energy from the carrier signal to power the RFID tag device 12. This will allow the reading device of the locking mechanism to read the data stored on the RFID tag device 12. The tuned resonant circuit 14 is comprised of an inductive element 16 and a capacitive element 18. The inductive element 16 may be any type of inductor such as an antenna or a coil. A contact device 20 is coupled to the tuned resonant circuit 14. The contact device 20 is used for enabling and disabling the tuned resonant circuit 14. In the embodiment depicted in Figure 1, the contact device 20 is a normally open contact. When the key 10 is inserted into the electronic locking mechanism, a shorting bar in the electronic locking mechanism will close the contact device 20 thereby completing the tuned resonant circuit 14. Once the tuned resonant circuit 14 is complete, the powering of the RFID tag device 12 and transmission of the data from the key 10 to the electronic locking mechanism is enabled. Referring to Figure 2 wherein like numerals and symbols represent like elements, a second embodiment of the key 10 is shown. This embodiment is very similar to the embodiment depicted in Figure 1. The only difference is that the contact device 20 is used to create an open circuit between the entire tuned resonant circuit 14 and the RFID tag device 12. The key 10 in Figure 2 functions in the same manner as the key 10 shown in Figure 1. In the embodiment depicted in Figure 2, the contact device 20 is a normally open contact. When the key 10 is inserted into the electronic locking mechanism, a shorting bar in the electronic locking mechanism will close the contact device 20 thereby completing the tuned resonant circuit 14. Once the tuned resonant circuit 14 is complete, the powering of the RFID tag device 12 and transmission of the data from the key 10 to the electronic locking mechanism is enabled. Referring to Figure 3 wherein like numerals and symbols represent like elements, a third embodiment of the key 10 is shown. This embodiment is very similar to the embodiment depicted in Figures 1 and 2. The main difference is that the capacitive element 18 is located on the RFID tag device 12. The key 10 in Figure 3 functions in the same manner as the key 10 shown in Figures 1 and 2. In the embodiment depicted in Figure 3, the contact device 20 is a normally open contact. When the key 10 is inserted into the electronic locking mechanism, a shorting bar in the electronic locking mechanism will close the contact device, 20 thereby completing the tuned resonant circuit 14. Once the tuned resonant circuit 14 is complete, the powering of the RFID tag device 12 and transmission of the data from the key 10 to the electronic locking mechanism is enabled. Referring to Figure 4 wherein like numerals and symbols represent like elements, a fourth embodiment of the key 10 is shown. This embodiment is very similar to the embodiment depicted in Figure 3. The main difference is that in the energizing circuit 14, the inductive element 16 is an antenna. In the preferred embodiment of the present invention, the antenna is a microwave antenna. The key 10 in Figure 4 functions in the same manner as the key 10 shown in Figures 1-3. Referring to Figure 5 wherein like numerals and symbols represent like elements, a fifth embodiment of the key 10 is shown. This embodiment is very similar to the embodiment depicted in Figure 4. The main difference is that the contact device 20 is a normally closed contact device. The normally closed contact device 20 will create a short between the terminals of the energizing circuit 14 thereby disabling the key 10. In this embodiment, when the key 10 is inserted into the electronic locking mechanism (not shown), a nonconductive spacer will spread the shorted contact device 20 apart thereby enabling the energizing circuit 14. Once the energizing circuit 14 is enabled, the powering of the RFID tag device 12 and the transmission of the data from the key 10 to the electronic locking mechanism is enabled. It should be noted that in the embodiment depicted in Figure 5, tuned inductors may be used instead of the antenna. The tuned inductor will function in the same manner as that described in Figures 1-3. Referring to Figure 6A wherein like numerals and symbols represent like elements, a sixth embodiment of the key 10 is shown. This embodiment is very similar to the embodiment depicted in Figures 3 and 4 wherein the capacitive element is found on the RFID tag device 12, and similar to Figures 1 and 2 wherein the capacitive element 18 is installed on a module external to the RFID tag device 12. In the embodiment depicted in Figure 6A, the contact device 20 uses a pair of normally open contact elements. The pair of contact elements may be on one or more sides of the key 10. Furthermore, as may be seen in Figure 6B, the contact device 20 may protrude from the key 10 or, as may be seen in Figure 6C, the contact device 20 may be embedded in the key 10 such that the contact elements are flush with the key 10. When the key 10 is inserted into the electronic locking mechanism, a shorting bar in the electronic locking mechanism will close the contact device 20 thereby completing the energizing circuit 14. The energizing circuit 14 may be a tuned resonant circuit or an antenna. Once the tuned resonant circuit 14 is complete or in the alternative, the RFID tag device 12 is coupled to the antenna, the transmission of the data from the key 10 to the electronic locking mechanism is enabled. Referring to Figure 7A wherein like numerals and symbols represent like elements, a seventh embodiment of the key 10 is shown. This embodiment is very similar to the embodiment depicted in Figures 6A-6C. In the embodiment depicted in Figure 7 A, the contact device 20 also uses a pair of normally open contact elements. However, in this embodiment, one contact element is placed on one side of the key 10 and the second contact element is placed on a second side of the key 10. As with the previous embodiment, the contact device 20 may protrude from the key 10, Figure 7B, or, as may be seen in Figure 7C, the contact device 20 may be embedded in the key 10 such that the contact elements are flush with the key 10. Like previous embodiments, when the key 10 is inserted into the electronic locking mechanism, a shorting bar in the electronic locking mechanism will close the contact device 20 thereby completing the energizing circuit 14. The energizing circuit 14 may be a tuned resonant circuit or an antenna. Once the tuned resonant circuit 14 is complete, or in the alternative, the RFID tag device 12 is coupled to the antenna, the transmission of the data from the key 10 to the electronic locking mechanism is enabled. Referring to Figure 8A wherein like numerals and symbols represent like elements, an eighth embodiment of the key 10 is shown. This embodiment is very similar to the embodiment depicted in Figures 7A-7C. The main difference in the embodiment depicted in Figure 8 A is that the contact device 20 uses a pair of normally closed contact elements 22. The normally closed contact elements 22 are generally a pair of normally closed spring contact elements. In this embodiment, the key 10 is hollow. When the key 10 is inserted into the electronic locking mechanism, a nonconductive spacer will be inserted into the hollow key 10. The nonconductive spacer will spread apart the pair of normally closed contact elements 22 thereby enabling the energizing circuit 14. The energizing circuit 14 may be a tuned resonant circuit or an antenna. Once the energizing circuit 14 is complete, or unshorted, the transmission of the data from the key 10 to the electronic locking mechanism is enabled. Referring now to Figure 9 wherein like numerals and symbols represent like elements, another embodiment of the present invention is shown. In this embodiment an RFID security system 30 (hereinafter system 30) is shown. The system 30 uses an electronic key 10 and an electronic locking mechanism 40. In this embodiment, the electronic key 10 has an RFID tag device 12 which is programmed to store data on the key 10. The RFID tag device 12 further may have the capacitive element 18 located thereon. However, the capacitive element 18 may be located on the die, module, or may not even be required if using an antenna. The contact device 20 is coupled to the RFID tag device 12. In the embodiment depicted in Figure 9, the contact device 20 is a normally open contact. In this embodiment, the contact device 20 uses a pair of contact elements. One contact element is placed on one side of the key 10 and the second contact element is placed on a second side of the key 10. As with the embodiment depicted in Figures 7A-7C, the contact device 20 may protrude from the key 10, Figure 7B, or, as may be seen in Figure 7C, the contact device 20 may be embedded in the key 10 such that the contact elements are flush with the key 10. The electronic locking mechanism 40 uses a reading device 42 for reading the data stored on the RFID tag device 12 of the key 10. The reading device 42 is coupled to an inductive element 44. The reading device 42 will send out a carrier signal via the inductive element 44. The energizing circuit 14 of the electronic key 10, which is located inside the electronic locking mechanism, receives the carrier signal. The energizing circuit 14 will take the energy from the carrier signal and power the RFID tag device 12. This will allow the reading device 42 of the electronic locking mechanism 40 to-read the data stored in the RFID tag device 12. In the embodiment depicted in Figure 9, the electronic locking mechanism 40 further has a second inductive element 16. Like in previous embodiments, the second inductive element 16 in combination with the capacitive element 18 form the energizing circuit 14. A connecting element 46 is coupled to the second inductive element 16. When the key 10 is inserted into the electronic locking mechanism 40, the connecting element 46 in the electronic locking mechanism 40 will connect to the contact device 20 thereby completing the energizing circuit 14. Once the energizing circuit 14 is complete, it will take the energy from the carrier signal emitted from the inductive element 44 to power the RFID tag device 12. The transmission of the data from the key 10 to the electronic locking mechanism 40 is enabled thereby allowing the reading device 42 of the electronic locking mechanism 40 to read the data stored in the RFID tag device 12. While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in form and details may be made therein without departing from the spirit and scope of the invention.

Claims: What is Claimed is: 1. A Radio Frequency Identification (RFID) security device comprising: a key wherein said key comprises: an RFID tag device for storing data on said key; an energizing circuit coupled to said RFID tag device for providing energy to said RFID tag device to read said data on said key; and a key contact coupled to said energizing circuit for enabling and disabling said energizing circuit. 2. A Radio Frequency Identification (RFID) security device in accordance with Claim 1 wherein said energizing circuit comprises: a resonance inductor; and a resonance capacitor coupled to said resonance inductor. 3. A Radio Frequency Identification (RFID) security device in accordance with Claim 2 wherein said resonance inductor is a coil. 4. A Radio Frequency Identification (RFID) security device in accordance with Claim 2 wherein said resonance inductor is an antenna. 5. A Radio Frequency Identification (RFID) security device in accordance with Claim 2 wherein said resonance Capacitor is located on said RFID tag device. 6. A Radio Frequency Identification (RFID) security device in accordance with Claim 1 wherein said energizing circuit is an antenna. 7. A Radio Frequency Identification (RFID) security device in accordance with Claim 1 wherein said key contact is a normally open contact for disabling said energizing circuit when said key is not inserted into a mechanism for reading. 8. A Radio Frequency Identification (RFID) security device in accordance with Claim 7 wherein said normally open contact is located on an outer first side of said key. 9. A Radio Frequency Identification (RFID) security device in accordance with Claim 7 wherein said normally open contact is located on an outer first side and on an outer second side of said key for allowing universality of direction for insertion of said key. 10. A Radio Frequency Identification (RFID) security device in accordance with Claim 1 wherein said key contact is a normally closed contact for shorting and disabling said energizing circuit when said key is not inserted into a mechanism for reading. 11. A Radio Frequency Identification (RFID) security device in accordance with Claim 10 wherein said normally closed contact is located on inside of said key. 12. A Radio Frequency Identification (RFID) security device in accordance with Claim 10 wherein said normally closed contact is located outside of said key. 13. A Radio Frequency Identification (RFID) security device comprising: an electronic locking mechanism; an electronic key wherein said electronic key comprises: an RFID tag device for storing data on said electronic key; an energizing circuit electrically coupled to said RFID tag device when said electronic key is coupled to said electronic locking mechanism for providing energy to said RFID tag device and to read said data on said electronic key when said electronic key is coupled to said electronic locking mechanism; and a key contact coupled to said energizing circuit for enabling said energizing circuit when said electronic key is coupled to said electronic locking mechanism. 14. A Radio Frequency Identification (RFID) security device in accordance with Claim 13 wherein said energizing circuit comprises: a resonance capacitor; and a resonance inductor. 15. A Radio Frequency Identification (RFID) security device in accordance with Claim 14 wherein said resonance inductor is located in said electronic locking mechanism and is coupled to said resonance capacitor when said electronic key is coupled to said electronic locking mechanism. 16. A Radio Frequency Identification (RFID) security device in accordance with Claim 14 wherein said resonance inductor and resonance capacitor are located in said electronic locking mechanism and are coupled to said RFID tag device when said electronic key is coupled to said electronic locking mechanism. 17. Radio Frequency Identification (RFID) security device in accordance with Claim 14 wherein said resonance inductor is a coil. 18. A Radio Frequency Identification (RFID) security device in accordance with Claim 14 wherein said resonance inductor is an antenna. 19. A Radio Frequency Identification (RFID) security device in accordance with Claim 14 wherein said resonance capacitor is located on said RFID tag device. 20. A Radio Frequency Identification (RFID) security device in accordance with Claim 13 wherein said energizing circuit is an antenna. 21. A Radio Frequency Identification (RFID) security device in accordance with Claim 13 wherein said key contact is a normally open contact for disabling said energizing circuit when said electronic key is not coupled to said electronic locking mechanism. 22. A Radio Frequency Identification (RFID) security device in accordance with Claim 21 wherein said normally open contact is located on an outer first side of said electronic key. 23. A Radio Frequency Identification (RFID) security device in accordance with Claim 21 wherein said normally open contact is located on an outer first side and on an outer second side of said electronic key for allowing universality of direction for insertion of said electronic key into said electronic locking mechanism. 24. A Radio Frequency Identification (RFID) security device in accordance with Claim 13 wherein said electronic locking mechanism comprises: a reading device for reading data transferred from said electronic key when said electronic key is coupled to said electronic locking mechanism; and a first inductive element coupled to said reading device for transmitting a signal to said energizing circuit of said electronic key when said electronic key is coupled to said electronic locking mechanism. 25. A Radio Frequency Identification (RFID) security device in accordance with Claim 24 wherein said electronic locking mechanism further comprises: a second inductive element magnetically coupled to said first inductive element; and connecting members coupled to said second inductive element for coupling said second inductive element to said electronic key to form said energizing circuit.

Inventors: KUZDAS ADRIAN C, LEE YOUBOK, SORRELLS PETER, KUZDAS, ADRIAN, C., LEE, YOUBOK, SORRELLS, PETER
Applicants: MICROCHIP TECH INC, MICROCHIP TECHNOLOGY INCORPORATED
Application year: 1999
Main classification: E05B49
IPC codes: E05B49, G06K19, G07C9, H04B5