JP2002533846A - Radio frequency identification (RFID) security system with RF emulation circuit - Google Patents

Abstract

(57) Summary Radio frequency identification (RFID) security (10) uses an electronic key (12) to store data. By providing and using a readout mechanism (14), when the electronic key (12) is connected to the readout mechanism (14), a modulated signal having data stored in the electronic key (12) is read out. When an RF emulation circuit (16) is connected to the reading mechanism (14) and the electronic key (12) is connected to the reading mechanism (14), the RF energy signal is emulated by the electronic key (12) and read. It enables the mechanism (14) to read data stored in the electronic key (12).

Description

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates generally to radio frequency identification (RFID) security devices, and more particularly to RFID security systems, wherein the RFID tag and its complementary reader / interrogator utilize an RF emulation circuit, The hard wire secure bus is replaced with an RF unit for data communication.

Electronic keys have long been used to prevent unauthorized entry into restricted areas. Currently, there are various different types of electronic keys on the market. While each of these types of keys works, each has certain disadvantages.

One such type of electronic key is a serial EEPROM-based electronic key. Serial EEPROM based keys require 4-5 additional contacts for operation. One contact is used for each of power, ground, clock, and data. Two contacts may be used for data transmission (ie, one as an input contact and one as an output contact). Serial E
The multiple contacts of each of the EPROM-based keys need to be properly contacted to transmit clock and data through them. In an apartment or hotel application, a user returning from the swimming pool may insert a wet key into the lock. This causes inadequate contacts or shorts between contacts and prevents proper transmission of data, thereby preventing the opening of the lock. In addition, locks with the wrong polarity
Inserting the key in) can cause damage to the lock electronics or the EEPROM device, thereby rendering the key unusable. Thus, moisture, insertion polarity and wear and / or damage of the multiple contacts are problems for such types of electronic keys.

A second type of electronic key is used for access control RFID tags.
In these types of keys, a card or tag exists for a reading device to gain access to the building. In most cases, this type of electronic key is used as an identification application rather than security. The use of such types of electronic keys for security (apartment and hotel locks) creates problems because such types of keys are not very reliable. Even if the tag is in the owner's pocket or purse, the secret reader,
Even a battery powered reader can power up the tag, and its code is stolen without the owner's knowledge.

[0005] One way to solve the problem associated with access control RFID tags is to have an encrypted electronic key. Some types of electronic keys include an encryption algorithm on the die. Some encryption algorithms allow the code on the electronic key to be encrypted and changed each time the key is read. While these types of electronic keys prevent unauthorized "code grabbing", they are significantly more expensive than RFID tag devices. Therefore, security causes an increase in cost.

[0006] Accordingly, there is a need to provide an improved RFID security device. Improved RFID security does not require multiple contacts for data transmission. Improved RFID security devices need to be more versatile in polarity. Improved R
FID security devices must withstand environmental factors. Improved RFID security devices can also be used for security and must also withstand “code grabbing”. An improved RFID security device is a low cost solution that solves the above-mentioned problems. The improved RFID security system provides an electronic key and readout mechanism R
Replace section F with a simpler, lower cost circuit.

[0007] In one embodiment of the present invention, it is an object of the present invention to provide an improved RFID security device.

Another object of the present invention is to provide an improved RFID security device that does not require multiple contacts for data transmission.

It is yet another object of the present invention to provide an improved RFID security device that is versatile in polarity.

[0010] It is yet another object of the present invention to provide an improved RFID security device that is resistant to environmental factors.

Yet another object of the present invention is to provide an improved RFID security device that can be used for security and that is more resistant to “code grabbing”.

Yet another object of the present invention is to provide an improved RFID security device, which is a low cost solution to solving the above problems.

Yet another object of the present invention is to provide an improved RFID security system that replaces the RF portion of the electronic key and readout mechanism with a low cost circuit.

According to one embodiment of the present invention, a radio frequency identification (RFID) security system is disclosed. The RFID security system uses an electronic key to store data. A readout mechanism is provided and, when the electronic key is coupled to the readout mechanism, used to read out a modulated signal having data stored in the electronic key. An RF emulation circuit is coupled to the readout mechanism and, when the electronic key is coupled to the readout mechanism, emulates an RF energy signal into the electronic key to cause the readout mechanism to read data stored on the electronic key. enable.

The above and other objects, features, and advantages of the present invention will be apparent from the following description, and more particularly, from the description of the preferred embodiments of the invention as illustrated in the accompanying drawings.

Referring to FIG. 1, an improved RFID security system 10 (hereinafter referred to as system 10) is shown. The system 10 includes a radio frequency identification (RFID)
) Use the tag device 12. The RFID tag device 12 is configured as an electronic key and is programmed to store data on the electronic key. RFID tag 12
Is connected to the readout mechanism 14 via the RF emulation circuit 16, R
The data stored in the FID tag device 12 is read by the reading mechanism 14. If a suitable RFID tag 12 is inserted into the readout mechanism 14, the readout mechanism 14 releases the locking device (not shown) or performs other operations according to the particular application.

In order to read data on the RFID tag device 12, it is necessary to connect an activated circuit to the RFID tag device 12 and the reading mechanism 14. In the present invention, the RF portions of both the RFID tag device 12 and the readout mechanism 14 replace lower cost circuitry. The present invention uses an RF emulation circuit 16. Using an RF emulation circuit 16, an RF energy carrier signal is
Emulate the tag device 12. The "modulated" signal is then sent back to readout mechanism 14. Readout mechanism 14 may filter the carrier signal to read data stored on RFID tag device 12.

Referring now to FIG. 2 (same numbers and symbols represent the same elements), the RFI
One embodiment of a method for configuring a D-tag device 12 as an electronic key 18 is shown. The electronic key basically comprises two main components: an RFID tag device 12 and a contact device 20. As described above, the RFID tag device 12 is used to store data and is read by the reading mechanism 14. RF
The ID tag device 12 is connected to the contact device 20. The contact device 20 is used to connect the RFID tag device 12 to the RF emulation circuit 16. When the electronic key 18 is connected to the RF emulation circuit 16, the RF emulation circuit 16 emulates an RF energy carrier signal and transmits the signal to the RFID tag device 12. The RFID tag device 12 is activated and activated by the incoming RF energy carrier signal. Upon activation of the RFID tag device 12, the device modulates the incoming RF energy carrier signal and returns the content in memory. The “modulated” signal is then sent back to the readout mechanism 14. The reading mechanism 14 may then filter the carrier signal and read the data stored on the RFID tag device 12.

Referring to FIG. 3 (same numbers and symbols represent like elements), one embodiment of the RF emulation circuit 16 is shown. The RF emulation circuit 16 replaces the LC circuits of both the prior art electronic key and readout mechanism, thereby allowing for a simplified electronic key 18 and a simplified readout mechanism 14. These simplified electronic keys 18 and simplified readout mechanism 14 form part of the present invention. In the embodiment shown in FIG. 3, the RF emulation circuit 16 uses a switching element 22. In a preferred embodiment of the present invention, switching element 22 is a transistor. Resistor 24 has a first terminal connected to switching element 22 and a second terminal connected to voltage source Vcc. Second resistor 26 has a first terminal connected to switching element 22 and a second terminal connected to contact device 28. The electronic key 18 (FIGS. 1 and 2) is
(FIGS. 1 and 2), the RF emulation circuit 16 is connected to the electronic key 18.
(FIGS. 1 and 2) use a contact device 28.

The first resistor 24 and the second resistor 26 form a voltage divider circuit. The switching element 22 together with the first resistor 24 and the second resistor 26 forms a drive circuit,
The carrier signal is simulated to the RFID tag device 12 (FIGS. 1 and 2). With careful selection of the resistors 24 and 26 and the on-resistance of the switching element 22, the RF emulation circuit 16 can operate the RFID tag device 12 with sufficient current and voltage for powering up and proper operation of the RFID tag device 12.
1 and 2) can be driven.

The RFID tag device 12 (FIGS. 1 and 2)
, The internal clock of the RFID tag device operates in synchronization with the carrier signal and “modulates” the carrier signal using the data stored in the RFID tag device 12. This modulated RF signal is
The data is supplied to the simplified RFID reader 14 via the RF emulation circuit 16. In the embodiment shown in FIG. 3, a square wave is superimposed on the carrier signal at point B by the on-resistance of the RFID tag device 12 (see FIG. 6A). The readout mechanism 14 (FIGS. 1 and 2) can then demodulate the signal, extract the tag data stream, and obtain the data stored on the RFID tag device 12.

As an example, an RFID tag device 12 has an on-resistance of
Assume that we have 0 k ohm off resistance. The first resistor 24 and the second
Has a resistance of 10 k ohms. The voltage source provides a 5 volt voltage level. In operation, the switching element 22 causes the readout mechanism 14 (
1 and 2). The carrier signal has a high voltage level and a low voltage level that activates and deactivates switching element 22 (ie, the carrier signal may have a voltage level of 0 to 5 volts). When switching element 22 is activated, the voltage at point B is a square wave having a voltage level of 0 volts. When deactivating the switching element, the voltage at point B is 4.2 volts, the off-resistance level of RFID tag device 12, or R
The on-resistance level of the FID tag device 12 is any of 1.7 volts. FIG. 6A shows the modulated carrier signal. The signal is demodulated to extract the data content of the memory within the RFID tag device 12. Simplified reader 1
4 also has a microcontroller (or processor) for decoding the demodulated signal. FIG. 6 shows the modulated signal and the demodulated signal respectively.
See A and FIG. 6B. A simple filter or comparator circuit may be used to filter the carrier signal within the simplified reader 14. The 1.7 to 4.2 volt data stream (see FIG. 6B) is then driven to the data decode circuit (microcontroller) without amplification.
I can do it.

Referring to FIG. 4 (same numbers and symbols represent the same elements), a second embodiment of the RF emulation circuit 16 is shown. As described above, the RF emulation circuit 1
6 replaces the LC circuit of both the prior art electronic key and readout mechanism, thereby enabling a simplified electronic key 18 (FIGS. 1 and 2) and readout mechanism 14 (FIGS. 1 and 2) To These form part of the invention. In the embodiment shown in FIG. 4, the RF emulation circuit 16 uses a single resistor 30. The resistor has a first terminal connected to the output of readout mechanism 14 (FIGS. 1 and 2), and a second terminal connected to the input of readout mechanism 14 (FIGS. 1 and 2).
The second terminal of the resistor 30 is also connected to the contact circuit 28. Electronic key 18 (
When the reading mechanism 14 (FIGS. 1 and 2) is inserted into the reading mechanism 14 (FIGS. 1 and 2), the contact circuit 28 connects the RF emulation circuit 16 to the electronic key 18 (FIGS.
). The operation of the embodiment shown in FIG. 4 operates in a manner similar to the operation disclosed in FIG. The carrier signal is transferred to the resistor 30.
The voltage level at point B is again one of three voltage levels. A simple filter or comparator circuit may be used to filter the carrier signal. When the RFID tag device 12 is activated, the modulated signal
Appears in A data signal can be obtained by demodulating the output signal. Next, the obtained signal is transferred to the data decoding circuit without amplification.

Referring to FIG. 5 (similar numbers and symbols represent similar elements), a readout mechanism 14 used in the present invention is shown. The readout mechanism 14 greatly simplifies RFID readers currently used to read RFID tag devices. When the electronic key is connected to the reading mechanism 14, the data stored in the electronic key is read using the reading mechanism 14. When the electronic key 18 (FIG. 2) is connected to the reading mechanism 14 via the RF emulation circuit 16 (FIGS. 1 to 4), the reading mechanism 14 stores the electronic key 18 (FIG. 2) using a processor. A data stream containing the data obtained is read. In the embodiment shown in FIG. 5, the processor is a microcontroller. Timing device 34 includes processor 32 and R
It is connected to the F emulation circuit 16. The timing device 34 is used to supply a clock signal to both the processor 32 and the RF emulation circuit 16. Timing device 34 can be an oscillator or any other type of device that can generate a clock signal. The signal passing circuit 36 (that is, the demodulator) is connected to the processor 32 and the RF emulator circuit 16. The signal passing circuit 36 is used for demodulating and filtering the carrier signal as well as transferring the data stream to the processor 32 without amplification.
The comparator circuit or low pass filter connected to the reference signal is
Note that these are two examples. In a preferred embodiment of the present invention, a low-pass filter is used.

While the invention has been shown and described in part with reference to the preferred embodiments of the invention,
Those skilled in the art will appreciate that these and other variations can be made in form and detail without departing from the spirit and scope of the invention.

[Brief description of the drawings]

FIG. 1 is a simplified electrical block diagram of the present invention.

FIG. 2 is a simplified electrical block diagram of one embodiment of the present invention.

FIG. 3 is a simplified electrical schematic of one embodiment of an RF emulation circuit used in the present invention.

FIG. 4 is a simplified electrical schematic of a second embodiment of the RF emulation circuit used in the present invention.

FIG. 5 is an electrical block diagram of a simplified readout mechanism used in the present invention.

FIG. 6A is a timing diagram of a modulated RF energy carrier signal.

FIG. 6B is a timing diagram of a demodulated baseband data signal.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Sollers, Peter United States of America Arizona 85225, Chandler, East Flint Street 1110 F-term (reference) 2E250 AA01 BB08 DD06 FF26 FF35 5B035 BB09 CA01 CA08 CA23 5B058 CA14 CA17 YA11

Claims (20)

[Claims] An electronic key for storing data, and a reading mechanism, wherein when the electronic key is connected to the reading mechanism, an RF clock signal is generated, and the data stored in the electronic key is transmitted. A readout mechanism for demodulating and reading out the modulated signal comprising: an RF emulation circuit connected to the readout mechanism, wherein when the electronic key is connected to the readout mechanism, the RF energy carrier signal Emulating the electronic key to enable the electronic key to modulate the RF energy carrier signal and to enable the readout mechanism to read data stored in the electronic key. A radio frequency identification (RFID) security system comprising: 2. The electronic key, wherein the electronic key is an RFID tag device for storing data in the electronic key, and a key contact connected to the RFID tag device, wherein the electronic key is connected to the reading mechanism. The radio frequency identification (RFID) security system of claim 1, comprising: a key contact for connecting the RFID tag device to the RF emulation circuit. 3. The method according to claim 1, wherein said readout mechanism is a processor, and wherein said electronic key is connected to said readout mechanism, for reading out a demodulated baseband data signal having said data stored in said electronic key. A timing device connected to the processor and the RF emulation circuit, the timing device supplying a clock signal to the processor and the RF emulation circuit; and a timing device connected to the processor and the RF emulation circuit. A signal passing circuit connected to the processor for extracting the demodulated baseband data signal and transmitting the demodulated baseband data signal to the processor so that the processor can read the data stored in the electronic key. And a signal passing circuit. FID) security system. 4. The radio frequency identification (RFID) security system according to claim 3, wherein said signal passing circuit is a low pass filter. 5. The radio frequency identification (RFID) security system according to claim 3, wherein said signal passing circuit is a comparator. 6. The RF emulation circuit includes: a switching device connected to the readout mechanism; a voltage divider circuit connected to the switching device; and a voltage source connected to the voltage divider circuit. The radio frequency identification (RFID) security system of claim 1. 7. The radio frequency identification (RFID) of claim 6, wherein the RF emulation circuit further comprises a contact connected to the voltage divider circuit for connecting the electronic key to the RF emulation circuit. ) Security system. 8. The switching device has a first terminal connected to the voltage divider circuit, a second terminal connected to the readout mechanism, and a third terminal connected to ground. 7. The radio frequency identification (RFID) security system of claim 6, wherein the system is a transistor. 9. A voltage divider circuit comprising: a first resistor having a first terminal connected to the switching device and a second terminal connected to the voltage source; and a resistor connected to the switching device. The radio frequency identification (RFID) security system of claim 6, comprising: a second resistor having a first terminal and a second terminal connected to the readout mechanism. 10. The radio frequency identification (RFID) security system according to claim 1, wherein said RF emulation circuit comprises a resistor connected to said readout mechanism. 11. The RF emulation circuit further comprises a contact connected to the resistor for connecting the electronic key to the RF emulation circuit.
A radio frequency identification (RFID) security system according to claim 10. 12. A radio frequency identification (RFID) security system, the system comprising an electronic key for storing data, wherein the electronic key is an RFID tag device for storing the data in the electronic key. And a key contact connected to the RFID tag device, wherein the key contact connects the RFID tag device to an RF emulation circuit when the electronic key is connected to a readout mechanism. A readout mechanism for demodulating and reading out a modulated signal having the data stored in the electronic key when the electronic key is connected to the readout mechanism; If the readout mechanism is a processor and the electronic key is connected to the readout mechanism, the demodulated data having the data stored in the electronic key. A processor for reading a baseband data signal, a timing device connected to the processor and the RF emulation circuit, wherein the timing device supplies a clock signal to the processor and the RF emulation circuit. A signal passing circuit connected to the RF emulation circuit, wherein the demodulated baseband data signal is extracted, and the processor reads the data stored in the electronic key. A signal passing circuit for transmitting a signal to the processor, the system comprising: an RF emulating circuit connected to the readout mechanism, wherein the RF key is connected to the readout mechanism. By emulating the energy carrier signal into the electronic key, the electronic key It makes it possible to modulate the RF energy carrier signal, makes it possible to read the data which the read mechanism is stored in the electronic key comprises a RF emulation circuit, a radio frequency identification (RFID) security systems. 13. The signal passing circuit according to claim 12, wherein the signal passing circuit is a low-pass filter.
A radio frequency identification (RFID) security system according to claim 1. 14. The radio frequency identification (RFID) security system according to claim 12, wherein said signal passing circuit is a comparator. 15. The RF emulation circuit includes: a switching device connected to the readout mechanism; a voltage divider circuit connected to the switching device; and a voltage source connected to the voltage divider circuit. A radio frequency identification (RFID) security system according to claim 12. 16. The radio frequency identification (RFID) of claim 15, wherein the RF emulation circuit further comprises a contact connected to the voltage divider circuit for connecting the electronic key to the RF emulation circuit. ) Security system. 17. The transistor, wherein the switching device has a first terminal connected to the voltage divider circuit, a second terminal connected to the readout mechanism, and a third terminal connected to ground. 16. The radio frequency identification (RFID) security system of claim 15, wherein: 18. The voltage divider circuit, wherein a first resistor having a first terminal connected to the switching device and a second terminal connected to the voltage source, is connected to the switching device. 16. The radio frequency identification (RFID) security system of claim 15, comprising: a second resistor having a first terminal and a second terminal connected to the readout mechanism. 19. The radio frequency identification (RFID) security system according to claim 12, wherein said RF emulation circuit comprises a resistor connected to said readout mechanism. 20. The radio frequency identification (RFID) security system according to claim 19, wherein said RF emulation circuit further comprises a contact connected to said resistor for connecting said electronic key to said RF emulation circuit. .