JP4839751B2 - RFID tag - Google Patents

Description

  The present invention relates to an RFID (Radio Frequency IDentification) tag, and more particularly to access control to a memory in the RFID tag.

  In Patent Document 1, in order to ensure the security of each user's data when the RFID tag is used by a plurality of users, the built-in memory is divided into a plurality of memory areas, and a password is individually set for each memory area. An RFID tag that can be used is disclosed.

  Patent Document 2 discloses an IC card corresponding to a plurality of communication methods. The IC card includes a plurality of signal interfaces that adjust signals in different ways for communication with a card terminal, and an adjustment determination unit that determines whether or not a signal adjusted by one signal interface is appropriately adjusted. And a switching control unit that switches a signal interface to be adjusted from one signal interface to another signal interface when the adjustment determination unit determines NO.

  According to the method of Patent Document 1, when accessing a password-protected memory area, it is necessary to input a password, which makes processing complicated.

JP 2002-259927 A JP 2004-192253 A

  The present invention provides a new scheme for data protection of memory in RFID tags.

The present invention includes a memory unit having a plurality of memory areas, and with an external device, different RFID tag at least a first communication mode corresponding to the standard and the communication unit capable of communicating with the second communication mode, a memory area to allow access from an external device of the multiple memory areas, and a memory access control unit for controlling in accordance with a communication mode between the communication unit and the external device, the communication unit, When communication with the external device is started, communication is performed in the first communication mode, and when a predetermined mode transition command is received from the external device in communication in the first communication mode, the second switching to communication in a communication mode, to provide an RFID tag you wherein a.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a block diagram showing a configuration of an embodiment of an RFID tag according to the present invention. The RFID tag 1 communicates with an external device 2 wirelessly. The external device 2 is, for example, a tag reader that reads data stored in the RFID tag 1, a tag writer that writes data to the RFID tag 1, or a reader / writer that has both functions.

  The RFID tag 1 includes an antenna 50 for wireless communication with the external device 2 and a chip 10 connected to the antenna. The RFID tag 1 according to this embodiment conforms to two types of RFID tag standards, ISO15693 (or ISO18000) (proximity type) and ISO14443 (proximity type). Since both ISO15693 (or ISO18000) and ISO14443 use a carrier wave of 13.56 MHz, the antenna 50 is common to both standards.

  The chip 10 is an integrated circuit chip in which the radio wave (HF) interface 20, the control circuit 30, and the memory 40 are integrated.

  The radio wave interface 20 is a circuit for interfacing between an analog high frequency communication channel of the antenna 50 and a digital circuit such as the control circuit 40. The first signal processing circuit 22 and the second signal processing circuit 24 in the radio wave interface 20 are circuits that perform signal processing on signals transmitted to and received from the external device 2 in accordance with the RFID tag standard. The first signal processing circuit 22 performs signal processing according to ISO15693 (or ISO18000), and the second signal processing circuit 24 performs signal processing according to ISO14443. In addition, the power extraction circuit 26 extracts power serving as a power supply voltage to be supplied to each circuit in the chip 10 from AC power input from the external device 2 via the antenna 50. The clock extraction circuit 28 extracts a system clock supplied to each circuit in the chip 10 from the high frequency signal input from the antenna 50. As the first signal processing circuit 22, the second signal processing circuit 24, the power extraction circuit 26, and the clock extraction circuit 28, conventionally known ones can be used.

  The control circuit 30 controls each circuit in the chip 10 and processes such as a response to the external device 2 in accordance with commands and data indicated by the digital signal supplied from the first signal processing circuit 22 or the second signal processing circuit 24. I do. For example, the control circuit 30 reads the data at the address specified from the external device 2 from the memory 40 and returns it to the external device 2, or writes the data input from the external device 2 to the specified address in the memory 40. Sloppy. The control circuit 30 executes processing according to a command group defined by ISO15693 (or ISO18000) or a command group defined by ISO14443 or a proprietary standard based thereon.

  The memory 40 is a semiconductor memory such as an EEPROM (Electronically Erasable and Programmable Read Only Memory) or a ROM (Read Only Memory). The memory 40 is divided into a plurality of banks (areas), and the control circuit 30 controls reading and writing in units of banks. In the illustrated example, the memory 40 is divided into four banks, but this is only an example. Further, the memory 40 may include an EEPROM portion and a ROM portion.

  In the RFID tag 1 configured as described above, the control circuit 30 determines a bank that allows access from the external device 2 among the banks of the memory 40 according to the communication mode that can be established with the external device 2. select. An example of the selection rule is shown in FIG.

  In the example of FIG. 2, in the first communication mode compliant with ISO15693 (or ISO18000), the external device 2 is permitted to use only the bank 1 out of the four banks shown in FIG. On the other hand, in the second communication mode based on ISO14443, the external device 2 is permitted to use all four banks.

  For such memory access control, the control circuit 30 performs state control by state transition as shown in FIG. That is, first, when the wireless tag 1 is in the power off state (102), when the power is turned on by receiving power supply from the external device 2 (112), the control circuit 30 conforms to ISO15693 (or ISO18000). The control operation in the first communication mode (104) is executed. In the first communication mode, the control circuit 30 selects the first signal processing circuit 22 as a digital signal supply source, and operates in accordance with the digital signal from the circuit 22. In the first communication mode, the control circuit 30 prohibits the external device 2 from accessing the banks 2 to 4 of the memory 40. That is, in the first communication mode, the control circuit 30 cancels execution of the command when the target address of the read command or write command from the external device 2 belongs to the banks 2 to 4. At this time, the control circuit 30 may return an error code to the external device 2. In the first communication mode, when an instruction to read or write to an address in the bank 1 is given from the external device 2, the control circuit 30 executes the instruction.

  Thereafter, the control circuit 30 turns off the power supply (116) until it receives the transition command (114) indicating the transition to the second communication mode from the external device 2 or the power supply from the external device 2 is cut off. Until then, the state of the first communication mode is maintained.

  When receiving the shift command (114) from the external device 2, the control circuit 30 shifts to the second communication mode (106). In the second communication mode, the control circuit 30 selects the second signal processing circuit 24 as a digital signal supply source, and operates according to the digital signal from the circuit 24. In the second communication mode, the control circuit 30 permits all read or write requests from the external device 2 to the banks 1 to 4. When the wireless tag 1 is in the second communication mode and the power is turned off (116), the wireless tag 1 shifts to the power off state (102). Note that a return command for shifting from the second communication mode to the first communication mode is defined, and when this return command is transmitted from the external device 2, the control circuit 30 shifts to the first communication mode. May be.

  In the above embodiment, the first signal processing circuit 22 for the first communication mode and the second signal processing circuit 24 for the second communication mode are provided separately. However, two identical signal processing circuits are provided. The communication mode may be shared. In this case, the control circuit 30 operates the common signal processing circuit in accordance with the first communication mode when the power is turned on, and operates in accordance with the second communication mode when the transition command is received. Control such as switching operation parameters of the signal processing circuit may be performed.

  If the RFID tag 1 described above is used, the memory area permitted to access the external device 2 can be switched by switching the communication mode, so that password setting for protection, password input for releasing protection, etc. It is not necessary to perform such processing. Further, in the present embodiment, the memory bank that can be accessed by the external device 2 changes according to the RFID tag standard to which the external device 2 corresponds. Therefore, by using the external device 2 having a different tag standard for each purpose / use, The memory area can be easily used properly.

  For example, if the external device 2 conforming to ISO 15693 (or ISO 18000) is used, only the bank 1 can be used, and the external device 2 conforming to ISO 14443 (however, the first request command and the migration command must be issued by ISO 15693 or ISO 18000). ), The banks 1 to 4 can be used.

  Further, according to the present embodiment, since an area in which two communication modes (in other words, RFID tag standards) can be used in common is provided in the memory 40, the external devices 2 respectively corresponding to different communication modes can Data can be exchanged or shared using a common area.

  In this embodiment, since the second communication mode (ISO 14443) is faster than the first communication mode (ISO 15693 or ISO 18000), the security of the banks 2 to 4 can be enhanced. That is, for example, as one method of making a copy of an RFID tag, there is a method of emulating the RFID tag processing by software. The copy product of this method simulates the operation of a regular product by executing a program according to a clock reproduced from radio waves received from an external device. For this reason, it becomes difficult to simulate the operation of ISO 14443 faster than ISO 15693 or ISO 18000. Thus, since it becomes difficult to simulate the operation in the second communication mode, the protection of the banks 2 to 4 that can be accessed only in the second communication mode is strengthened.

  As an example of the application field of the RFID tag 1 described above, consumables (replacement parts) management of an image forming apparatus such as a copying machine or a multifunction machine can be given.

  Conventionally, a storage medium is attached to replaceable consumables such as a toner cartridge and a photosensitive drum cartridge in the image forming apparatus, and data is read / written from / to the storage medium. An image forming operation can be performed. For example, in the consumable storage medium, data on the amount of consumption of the consumable is written from the image forming apparatus. In addition, in order to allow the consumables to operate under appropriate conditions, for example, identification information of the consumables and various control parameters for optimal functioning of the consumables are previously stored in the consumables manufacturing factory. Writing to the storage medium is also performed. In recent years, the use of RFID tags as recording media to be mounted on consumables has been progressing. Since the wireless tag can read and write data without contact, there is an advantage that restrictions on the structure of the device are relaxed compared to reading and writing with a wired connection method.

  In this way, it is considered that the RFID tag attached to the consumables is also used for distribution management of the consumables. For example, by reading the RFID tag at a logistics base such as a factory, warehouse, sales office, port, airport, or transportation company's logistics center, which consumables are present at which logistics base, or which logistics base has passed It is conceivable to manage such as.

  However, control parameters such as image quality adjustment parameters are also written in the consumable RFID tag, and if this is changed at a place other than the correct organization such as a factory, the consumable can function in an optimal state. Therefore, there is a possibility that it may be disadvantageous for the user. Therefore, it is important that data in the RFID tag is not accidentally rewritten at a distribution base or the like.

  In order to solve such a problem, there is a problem if the RFID tag 1 of the present embodiment is adopted as an RFID tag to be attached to a consumable, and it is rewritten or read at a distribution base or the like like a control parameter. Data is stored in the banks 2 to 4, and data for physical distribution management is stored in the bank 1. In this case, a tag reader, tag writer, or reader / writer (hereinafter, abbreviated as “reader / writer”) provided at each distribution base conforms to ISO15693 (or ISO18000), and a reader / writer incorporated in the image forming apparatus. Is based on ISO14443. When the RFID tag 1 is controlled by the state transition as shown in FIG. 3, the reader / writer and the like provided in the image forming apparatus perform an initial call (request command) to the RFID tag 1 in addition to the operation conforming to ISO14443. The shift command (114) is provided with a function for transmitting by a communication method compliant with ISO15693 (or ISO18000). After issuing the migration command, the reader / writer and the like perform communication conforming to ISO14443. ISO15693 or ISO18000 (proximity type) is slower in communication speed than ISO14443 (proximity type), but has a longer communicable distance. Therefore, as in the case of reading and writing at a distribution base, the target consumable is packed and the reader -It can also be used when a writer or the like cannot be brought too close. On the other hand, if the image forming apparatus is designed so that a reader / writer or the like is provided near the attached RFID tag of the consumable item, it can support ISO 14443, and can read and write at high speed. This is advantageous. In addition, as for ISO15693 or ISO18000 (proximity type), any manufacturer or reader that conforms to this standard can basically read or write an RFID tag of this standard. As described above, ISO 15693 or ISO 18000 is highly versatile, so that it is easy to introduce equipment such as readers / writers at various distribution bases including overseas bases. A base having a reader / writer that conforms to this standard can easily participate in the consumables distribution system. On the other hand, ISO14443 can have a unique command system when security such as an IC card is required. Therefore, by making the reader / writer of the image forming apparatus and the second signal processing circuit 24 of the RFID tag 1 of this unique standard, it is possible to make it difficult for a general reader / writer to access the RFID tag 1. is there.

  For this reason, it is preferable to use ISO15693 (or ISO18000) for physical distribution management and ISO14443 for use in an image forming apparatus.

  In this case, it is also preferable that the bank 1 holds a code for product management such as an EPC (Electronic Product Code) proposed by an auto-ID center which is an international non-profit organization. . This enables individual identification of consumables at each distribution base. Further, the image forming apparatus reads this code, so that the image forming apparatus can recognize which number of consumables is mounted.

  With the above configuration, the distribution base can access only bank 1 and can protect data in banks 2 to 4. Further, when a consumable is mounted on the image forming apparatus, the protected banks 2 to 4 can also be used.

  Further, in the RFID tag 1 of the present embodiment, the bank 1 can be used for both physical distribution management and image forming apparatus, so the range of use of the RFID tag 1 is expanded. For example, when consumable usage count data is written to the RFID tag 1 from the reader / writer of the image forming apparatus, since this data is important data, it is written in one of the protected banks 2 to 4, but the same data is written. Write to bank 1 as well. Thus, for example, when the usage amount count data of the bank 1 is read by a reader / writer conforming to ISO 15693 held by the collection worker at the time of collection of the consumable item, it can be easily confirmed whether the consumable item can still be used. . Since the correct usage amount count data is stored in the banks 2 to 4, if the usage amount count data of the bank 1 is simply used for simple confirmation, even if it is tampered with, it becomes a big problem. Must not.

  If the bank 1 is shared by the distribution management and the image forming apparatus, the data written in the bank 1 at the distribution base can be read and used by the image forming apparatus.

  Further, according to the present embodiment, a function as a general-purpose logistic tag and a function as a security memory used in the image forming apparatus can be realized as one tag chip.

  As described above, the application example of the image forming apparatus to the consumables has been described. However, the RFID tag 1 of the present embodiment is not limited to such an example, and can be applied to various fields. For example, it is possible to use the RFID tag memory area for each phase while using a common RFID tag in the phase of logistics management of replacement parts and the phase in which the replacement parts are actually used.

  In the above embodiment, since the RFID tag 1 is activated in the first communication mode compliant with ISO15693 or ISO18000 when the power is turned on, the external device 2 for reading and writing in the second communication mode (ISO14443) is also provided. At the time of the first call to the RFID tag 1, a function for transmitting a command conforming to ISO15693 or ISO18000 was required. This has an aspect of improving the security for the banks 2 to 4 because the RFID tag 1 cannot be accessed by a general reader / writer conforming to ISO14443.

  The above embodiment is merely an example, and various modifications can be considered within the scope of the technical idea of the present invention.

  For example, in the above embodiment, when a command for shifting from the first communication mode to the second communication mode is received from the external device 2, the RFID tag 1 authenticates whether the external device 2 is valid. You may do it. For the authentication, an existing authentication method such as password authentication or SHA (Secure Hash Algorithm) authentication may be used. In any method, this authentication is not successful unless the external device 2 knows secret key information or a password that is not known unless it is a valid external device. If the authentication is not successful, the RFID tag 1 does not shift to the second communication mode, and therefore does not allow the external device 2 to access the banks 2 to 4. Thus, by requesting authentication for the transition to the second communication mode, the banks 2 to 4 can be protected more firmly. Further, if the key information can be individually set for each bank in the memory 40, data protection for each bank is possible.

  In the above embodiment, since the RFID tag 1 is activated in the first communication mode conforming to ISO15693 or ISO18000 when the power is turned on, the external device 2 accessing the banks 2 to 4 needs to correspond to it. On the other hand, the RFID tag 1 may be accessible even by the external device 2 that supports only the second communication mode. For example, the control circuit 30 simultaneously monitors the input signal from the first signal processing circuit 22 and the input signal from the second signal processing circuit 24 at the time of power-on, and requests the start of communication. The signal processing circuit 22 or 24 that can interpret the command (request command or the like) from the input signal is selected, and thereafter, it operates in the communication mode corresponding to the selected signal processing circuit 22 or 24. Instead of simultaneous parallel monitoring, the control circuit 30 can determine the communication mode by sequentially determining whether the command can be detected from the input signals from the signal processing circuits 22 and 24. Good.

  In the above, the memory 40 is divided into four banks, but this is only an example. The present invention can be applied to any memory that is divided into two or more banks.

  In the above, one of the banks 1 to 4 can be shared in the first communication mode and the second communication mode, but there may be two or more such shared banks.

  In the above description, a bank that can be accessed in both the first communication mode and the second communication mode is provided. However, an aspect in which such a shared bank is not provided is also within the scope of the present invention.

  In the above example, the RFID tag 1 corresponds to two communication modes (wireless tag standards). When there are three or more communication modes, the basic control is the same as in the case of two. That is, the control circuit 30 of the RFID tag 1 determines the banks that are permitted to be used by the external device 2 in the memory 40 according to the communication mode that is used by the external device 2, and other than the banks that permit these uses. Access to is prohibited.

  In the above example, as an example of the communication mode, a mode compliant with ISO15693 (or ISO18000) and a mode compliant with ISO14443 are illustrated, but other wireless tag standards may be used as a matter of course.

  Further, in the above-described embodiment, in the first communication mode, both reading and writing of the banks 2 to 4 are not allowed for the external device 2, but about one to a plurality of predetermined banks among the banks 2 to 4. Reading may be permitted. As described above, the control of permission and prohibition of access to the memory area (bank) in the present invention includes control at the operation content level such as reading and writing.

  Further, in the above embodiment, the RFID tag 1 is of a type that receives power supply from the external device 2, but it will be apparent that the present invention can also be applied to a battery built-in type RFID tag.

It is a block diagram which shows the structure of embodiment of the RFID tag which concerns on this invention. It is a figure which shows an example of the selection rule of the memory bank which permits the access from an external device. It is a figure which shows the state transition of the RFID tag of embodiment.

Explanation of symbols

  1 RFID tag, 2 external device, 10 chip, 20 radio wave interface, 22 first signal processing circuit, 24 second signal processing circuit, 26 power extraction circuit, 28 clock extraction circuit, 30 control circuit, 40 memory, 50 antenna.

Claims (8)

A memory unit having a plurality of memory areas;
With an external device, a different RFID tag at least a first communication mode corresponding to the standard and the communication unit capable of communicating with the second communication mode,
A memory area to allow access from an external device of the multiple memory areas, and the memory access control unit for controlling in accordance with a communication mode between the communication unit and the external device,
Equipped with a,
The communication unit performs communication in the first communication mode at the start of communication with the external device, and receives a predetermined mode transition command from the external device in communication in the first communication mode. , Switch to communication in the second communication mode,
RFID tag you wherein a. The RFID tag according to claim 1, wherein
It said memory access control unit in the plurality of the first communication mode in the communication mode and the second communication mode, permits access to the common memory area,
An RFID tag characterized by the above. The RFID tag according to claim 2, wherein
The memory access control unit permits the external device to access two or more memory areas in the second communication mode, and accesses the external device in the second communication mode in the first communication mode. Access to the external device is not permitted to an area other than the common memory area among two or more memory areas that are permitted to
An RFID tag characterized by the above. The RFID tag according to claim 3, wherein
The RFID tag, wherein the second communication mode has a higher communication speed than the first communication mode. The RFID tag according to claim 3, wherein
The memory access control unit authenticates the external device, and permits switching from the first communication mode to the second communication mode only when the authentication is successful.
An RFID tag characterized by the above.   4. The RFID tag according to claim 3, wherein the first communication mode is a method based on an ISO standard. 5.   7. The RFID tag according to claim 6, wherein an identification code of an object to which the RFID tag is added is stored in the common memory area.   4. The RFID tag according to claim 3, wherein the second communication mode is a method compliant with ISO standards.

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