JP2007293481A - Wireless tag system, wireless tag, and reader/writer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wireless tag system, wireless tag, and reader/writer for achieving convenience in circulation and retail selling of articles using the wireless tag, convenience after purchasing, and privacy protection of an article purchaser. <P>SOLUTION: A control data section 31 is a region controlled to prevent a conventional reader/writer from reading or writing an identifier data section 32. A private/public mode switch bit 31a specifies private mode permitting only read from the reader/writer of this embodiment having a set encryption key as a common key and public mode permitting only read and write from the conventional reader/writer for performing reading/writing without using the encryption key. The encryption key for encryption or decoding is set in an encryption key section 31b. An identifier data section 32 includes a header, a domain manager, an object class, serial number and the like. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a wireless tag system including a wireless tag and a reader / writer that reads / writes from / to the wireless tag, a wireless tag, and a reader / writer.

  In recent years, a system using a wireless tag has been widely used for the purpose of speeding up distribution through linkage with an inventory management system and improving certainty. If the cost of the wireless tag is reduced in the future, it is predicted that the wireless tag will be further used at a general consumer product, so-called item level.

  The use of wireless tags at the item level has the advantage of inventory and inventory management on the product sales side, and the advantage that the purchaser can easily check the origin of the product at the time of purchase and return processing after purchase, As a secondary use of the wireless tag, there is a merit that it can be used for management of property, etc., and it is expected as a highly convenient system.

  However, conventional wireless tags place emphasis on convenience on the merchandise sales side and do not give much consideration to consumer privacy. Therefore, if you own a product with a wireless tag, it can be read from a place away from the owner without knowing the uniqueness of the identifier and the feature of using wireless, and you can know where the owner is. It has been pointed out that personal information and privacy may be infringed, such as knowing what goods are being used.

  Therefore, as a method of making the wireless tag unreadable, the wireless tag can be physically destroyed or removed so that it cannot be used according to the consumer's wish after sales, or it is put in a bag covered with aluminum foil. Measures to take self-defense measures such as carrying are proposed. Further, in the EPC / Global standards (for example, Non-Patent Documents 1 and 2) of the wireless tag standard development group, a method for making the wireless tag unreadable by methods other than the above is proposed. The outline will be described below with reference to FIGS.

  FIG. 8 is a diagram showing an example of a memory logical structure of a conventional wireless tag. An example of the memory logical structure of the wireless tag shown in FIG. 8 is shown in (Non-Patent Document 1), and includes a CRC unit 81, a data unit 82, and a password 83.

  In the CRC part 81, the 16-bit CRC of the data part 82 is set. The data part 82 includes a header, a domain manager, an object class, and a serial number in this order as four sections. The password 83 is set with an 8-bit password when using a Kill command, which is a command for permanently disabling the wireless tag.

  That is, in (Non-Patent Document 1), a Kill command is set to permanently disable the wireless tag by inputting an 8-bit password in the password 83, and the wireless tag is a reader / writer of the subsequent reader / writer. It shows how to stop responding to commands.

  FIG. 9 is a diagram showing an example of expansion of the memory logic structure of a conventional wireless tag. An extended example of the memory logic structure of the wireless tag shown in FIG. 9 is shown in (Non-Patent Document 2), and includes a header portion 91, a filter portion 92, and a domain identifier portion 93.

  The header portion 91 is 2 bits or 8 bits and represents the entire length, the identifier type, and the tag encoding structure. The domain identifier portion 93 represents an identifier in a certain domain such as a certain industry or a group of industries. The filter unit 55 is an option and is used for encoding as necessary.

Also, (Non-patent Document 3) discloses a technique for reading using an anti-collision method such as a binary tree together with encryption when there are a plurality of wireless tags.
Auto-ID Center, TECHNICAL REPORT 860MHz / 930MHz Class I Radio Frequency Identification Tag Radio Frequency & Logical Communication Interface Specification Candidate Recommendation, Ver.1.01, `` online '', November 14, 2002, EPCglobal, `` March 14, 2005 Search by day, Internet <URL http://www.epcglobalinc.org/standards_technology/Secure/v1.0/UHF-class0.pdf> EPCglobal, EPC Tag Data Standards, Version 1.1 Rev.1.24, “online”, April 1, 2004, EPCglobal, “March 14, 2005 Search”, Internet <URL http://www.epcglobalinc.org/ standards_technology / EPCTagDataSpecificationa11rev124.pdf> Auto-ID Center, Draft protocol specification for a 900 MHz Class 0 Radio Frequency

  However, if you use a method of physically destroying or removing the wireless tag to make it unreadable, the returned goods cannot be processed and the purchaser will not be able to use it personally. However, convenience after purchase is impaired.

  Also, if you put the purchased item with a wireless tag in a bag covered with aluminum foil and bring it home, there is no problem when you return it. For example, if the purchased item is clothing, If the purchased item is a book, it will be infringed on privacy information such as what the identifier is read without the owner's awareness, what they wear, what kind of book they own. There is a possibility.

  Furthermore, in the technique described in (Non-Patent Document 1), the wireless tag that has received the Kill command cannot be read permanently, so the return process cannot be performed and the purchaser cannot use it personally. Therefore, although the problem of privacy is solved, convenience after purchase is impaired.

  In addition, in the technology described in (Non-Patent Document 2), an optional filter unit is used for encoding as necessary, but is not intended for encryption. No consideration is given to protection.

  As described above, in the past, when a wireless tag was installed in a consumer product, it would be convenient to protect privacy both in the product distribution and retail stages and in the secondary use of the product buyer. There is a problem in that convenience and safety cannot be achieved at the same time, as it is difficult to protect privacy if the convenience is impaired.

  The present invention has been made in view of the above, and aims to achieve both protection of the privacy of the product purchaser while maintaining convenience in the distribution / retail stage of the product equipped with the wireless tag and convenience after the product purchase. It is an object to obtain a wireless tag system, a wireless tag and a reader / writer that can be used.

  In order to achieve the above object, the present invention provides a wireless tag system including a wireless tag and a reader / writer that reads out the wireless tag, wherein the reader / writer uses an encryption key as a common key. A first reader / writer that performs a read operation by encrypted communication and a second reader / writer that performs a read operation by communication that does not use the encryption key, and the wireless tag includes the first reader / writer Holds a mode switching bit for designating a private mode permitting reading from the user or a public mode permitting reading from the first and second reader / writers and the encryption key for performing encryption / decryption Change of the mode specified by the encryption key part and the mode switching bit from the first reader / writer. Characterized in that it comprises a means for performing the operations write attempts.

  According to the present invention, the contents initially set in the mode switching bit are not unchanged and can be changed by the first reader / writer which is the reader / writer according to the present invention. Therefore, at the product distribution / retail stage, the wireless tag mounted on the product before sale can be read and written from any reader / writer by setting it to the public mode, so that the convenience of retailers and the like can be ensured. After the purchase of the product, the privacy of the product purchaser can be protected by changing and setting the mode of the wireless tag mounted on the product to the private mode according to the purchaser's wishes and the like. In addition, when the product purchaser returns or uses the product for the second time, the convenience after purchasing the product can be easily secured by returning the mode of the wireless tag to the public mode again.

  According to the present invention, there is an effect that it is possible to achieve both the privacy protection of the product purchaser while maintaining the convenience in the distribution / retail stage of the product equipped with the wireless tag and the convenience after the product purchase.

  Exemplary embodiments of a wireless tag system according to the present invention will be described below in detail with reference to the drawings.

  The wireless tag system according to the present invention includes a wireless tag (FIGS. 1 to 3) and a reader / writer (FIGS. 4 and 5) for writing to and reading from the wireless tag. First, the configuration of the wireless tag according to this embodiment will be described with reference to FIGS. FIG. 1 is a block diagram showing a configuration of main functions of the wireless tag in the wireless tag system according to the embodiment of the present invention. FIG. 2 is a block diagram illustrating an electrical configuration example of the wireless tag illustrated in FIG. 1. FIG. 3 is a diagram showing a memory logical structure of the wireless tag shown in FIG.

  As shown in FIG. 1, the wireless tag according to this embodiment includes a power supply unit 11, a storage unit 12, a modem unit 13, a command interpretation unit 14, an encryption / decryption unit 15 as main functional blocks. And a control unit 16 for controlling the operations and processes.

  In FIG. 1, a power supply unit 11 supplies operating power to each unit by a built-in battery or by a mechanism that converts electromagnetic waves received from a reader / writer into drive power. The storage unit 12 stores necessary information in the form of the memory logical structure shown in FIG. The modem 13 demodulates the radio wave received from the reader / writer, takes in the command, gives it to the control unit 16, modulates the transmission signal to the reader / writer received from the control unit 16 and places it on the radio wave. To send and receive. The command interpreter 14 interprets a command received from the reader / writer. The encryption / decryption unit 15 performs encryption / decryption according to the command received from the reader / writer and the stored contents of the storage unit 12.

  The functions of the wireless tag shown in FIG. 1 include, for example, a CPU 21, a ROM 22, a RAM 23, a rewritable nonvolatile memory 24, a power supply circuit 25, a cryptographic processing circuit 26, and an RF circuit 27 as shown in FIG. And the antenna 28.

  The power supply circuit 25 corresponds to the power supply unit 11 shown in FIG. 1, but here is a circuit that converts electromagnetic waves received from a reader / writer into drive power. That is, FIG. 2 shows a configuration example of a passive wireless tag.

  The entirety of the RF circuit 27 and the antenna 28 corresponds to the modem unit 13 shown in FIG. The RAM 23 performs temporary storage as a work area for the CPU 21. The rewritable nonvolatile memory 24 is, for example, FeRAM, and corresponds to the storage unit 12 shown in FIG. The encryption processing circuit 26 corresponds to the encryption / decryption unit 15 shown in FIG. The CPU 21 implements the functions of the command interpreter 14 and the controller 16 shown in FIG. 1 using the RAM 23 as a work area in accordance with a control program stored in the ROM 22.

  That is, the CPU 21 interprets the command received from the reader / writer according to the control program stored in the ROM 22 as the command interpreter 14 shown in FIG. Further, the CPU 21 writes and reads data to and from the rewritable nonvolatile memory 24 and RAM 23 according to a control program stored in the ROM 22 as the control unit 16 shown in FIG. 1, and also receives commands received from the reader / writer. In response to this, a random number is generated, and the encryption processing circuit 26 is controlled to perform decryption and verification of the session key, encryption of the identifier, and the like.

  The memory logical structure of the wireless tag shown in FIG. 1 includes a control data part 31, an identifier data part 32, and a user data part 33, as shown in FIG.

  The control data section 31 is an area for controlling a conventional reader / writer so that the identifier data section 32 cannot be read and written, and is configured by a private / public mode switching bit 31a and an encryption key section 31b.

  The private / public mode switching bit 31a includes a private mode in which reading / writing is allowed from a reader / writer according to this embodiment having a set encryption key as a common key, and a conventional read / write without using an encryption key. A bit of “0” or “1” that designates a public mode in which reading / writing from a reader / writer is permitted is set. Eventually, when the private / public mode switching bit 31a is in the public mode, the control data unit 31 does not function.

  In the encryption key part 31b, the above encryption key for performing encryption / decryption is set. This is an encryption key (common key) required for a reader / writer that performs reading in the private mode.

  The identifier data part 32 includes a header, a domain manager, an object class, a serial number, and the like. The user data section 33 is an area for storing user data as an option.

  Next, the configuration of the reader / writer according to this embodiment will be described with reference to FIGS. FIG. 4 is a block diagram showing a configuration of main functions of the reader / writer in the wireless tag system according to the embodiment of the present invention. FIG. 5 is a block diagram showing an example of the electrical configuration of the reader / writer shown in FIG.

  As shown in FIG. 4, the reader / writer according to this embodiment includes, as main functional blocks, a power supply unit 41, a storage unit 42, a modem unit 43, a response interpretation unit 44, and an encryption / decryption unit 45. A display unit 46, an operation unit 47, a host interface unit 48, and a control unit 49 for controlling them.

  In FIG. 4, a power supply unit 41 supplies operation power to each unit by a built-in battery or an external power supply. The storage unit 42 stores necessary information such as an encryption key that is a common key and an operation mode. The control unit 49 stores the encryption key in the storage unit 42 by the following two methods. That is, (1) the control unit 49 displays the encryption key input by the user from the operation unit 47 on the display unit 46 and stores it in the storage unit 42 in response to the user's confirmation operation. (2) The control unit 49 stores the encryption key received from the host such as a PC via the host interface unit 48 in the storage unit 42.

  The control unit 49 controls transmission / reception with the wireless tag. That is, under the control of the control unit 49, the modem unit 43 modulates a command from the control unit 49 and transmits the modulated radio wave to the radio tag. When the radio tag is a passive type, the power conversion unit 43 The response electromagnetic wave from the wireless tag is demodulated and passed to the capture control unit 49.

  The control unit 49 gives the received response to the response interpretation unit 44, interprets it, reads the encryption key from the storage unit 42 as necessary based on the interpretation result, and gives it to the encryption / decryption unit 45 for encryption. Decoding is performed, and a command is transmitted from the modem unit 43.

  The reader / writer function shown in FIG. 4 has, for example, a CPU 50, a ROM 51, a RAM 52, a rewritable nonvolatile memory 53, a power supply circuit 54, and a host interface control circuit 55 as shown in FIG. The encryption processing circuit 56, the display circuit 47, the input unit 58, the RF circuit 59, and the antenna 60 are realized.

  The entirety of the RF circuit 59 and the antenna 60 corresponds to the modulation / demodulation unit 43 shown in FIG. The power supply circuit 54 corresponds to the power supply unit 41 shown in FIG. The input unit 58 corresponds to the operation unit 47 illustrated in FIG. 4 and includes buttons, a keyboard, a touch panel, and the like that receive user operation inputs. The display circuit 47 corresponds to the display unit 46 shown in FIG. 4 and includes a display such as an LCD. The rewritable nonvolatile memory 53 corresponds to the storage unit 42 shown in FIG. 4 and can be configured by an EEPROM or a replaceable SD card. The host interface control circuit 55 corresponds to the host interface unit 48 shown in FIG. 4, and controls the connection between the CPU 50 and a host such as a PC connected by a LAN or a wireless LAN. The encryption processing circuit 56 corresponds to the encryption / decryption unit 45 shown in FIG. 4 and is used by the CPU 50 to accelerate the encryption processing.

  The CPU 50 implements the functions of the response interpreter 44 and the controller 49 shown in FIG. 4 by using the RAM 52 as a work area in accordance with a control program stored in the ROM 51.

  That is, the CPU 50 interprets the response received from the wireless tag as the response interpretation unit 44 shown in FIG. 4 according to the control program stored in the ROM 41. Further, as the control unit 49 shown in FIG. 4, the CPU 50 stores the encryption key input from the input unit 58 or the host interface control circuit 55 in the rewritable nonvolatile memory 53 and rewrites it according to the control program stored in the ROM 51. Data is written to and read from the non-volatile memory 53 and RAM 52, random numbers are generated in response to responses received from the wireless tag, and the encryption key circuit 56 is controlled to decrypt, verify, and identify the session key Let's do encryption etc.

  Next, a basic operation example of the wireless tag system according to this embodiment configured as described above will be described with reference to FIGS. FIG. 6 is a flowchart illustrating a communication procedure in which the reader / writer illustrated in FIG. 4 reads the identifier of the wireless tag when the private mode and the encryption key are set in the wireless tag illustrated in FIG. FIG. 7 is a flowchart for explaining a communication procedure in which the reader / writer shown in FIG. 4 returns the setting of the wireless tag to the public mode when the wireless tag shown in FIG. 1 is set in the private mode.

  In the example shown in FIG. 6, the reader / writer 61 is a reader / writer according to this embodiment having the configuration shown in FIG. 4, and the encryption set in the wireless tag 62 according to this embodiment having the configuration shown in FIG. The case where a key is used as a common key and encrypted and transmitted / received similarly to the wireless tag 62 is shown.

  In FIG. 6, in the reader / writer 61, the control unit 49 receives a user input from the operation unit 47 or receives an identifier read instruction from the host interface unit 48 to generate a read start command and generate a modulation / demodulation unit 43. The modulation / demodulation unit 43 modulates it and places it on a radio wave and transmits it to the surroundings (R1, S1).

  In the wireless tag 62 set in the private mode existing within the reach of the radio wave, the modem unit 13 demodulates the content of the received radio wave and gives it to the control unit 16 via the power source unit 11. If the power supply unit 11 is a passive type, it generates operating power from the received radio wave of the modem unit 13 and supplies it to each unit. If it is an active type, it supplies operating power to each unit from the built-in battery.

  The control unit 16 gives the received content received from the modem unit 13 to the command interpretation unit 14. When the received content received from the modem unit 13 is a read start command as a result of interpretation by the command interpreter unit 14, the control unit 16 generates a random number (T1) and responds as a challenge from the modem unit 13 (response). Are transmitted (T2, S2).

  In the reader / writer 61, the response data received and demodulated by the modem unit 43 is input to the response interpretation unit 44 via the control unit 49 and interpreted. Based on the interpretation result, the control unit 49 generates a session key (R2), encrypts the response and session key using the encryption key shared by the encryption / decryption unit 45 (R3), and the modulation / demodulation unit 23 is modulated and placed on radio waves and transmitted to the surroundings (R4, S3).

  In the wireless tag 62 set in the private mode existing within the reach of the radio wave, the modem unit 13 demodulates the content of the received radio wave and gives it to the control unit 16 via the power source unit 11. The control unit 16 gives the received content received from the modem unit 13 to the command interpretation unit 14. As a result of interpretation by the command interpretation unit 14, the control unit 16 determines that the received data needs to be decrypted in this example, causes the encryption / decryption unit 15 to perform decryption, and stores the decrypted data in the storage unit 12. It is checked against the random number (T3).

  When the authentication is successful, the control unit 16 of the wireless tag 62 causes the encryption / decryption unit 15 to decrypt the session key (T4), and encrypts the identifier using the decrypted session key (T5). Then, the modem unit 13 transmits the data (T6, S4). Although not shown in FIG. 7, when authentication fails, most of the access is from a conventional reader / writer. Therefore, the modem 13 does not transmit that the authentication has failed, but protects privacy. From the viewpoint, no transmission is made here, and no response is made.

  In the reader / writer 61, the received data (encrypted tag identifier) of the modem unit 43 is input to the response interpretation unit 44 via the control unit 49 and interpreted. Based on the interpretation result, the control unit 49 gives the received data (encrypted wireless tag identifier) of the modem unit 43 to the encryption / decryption unit 45 and decrypts it with the session key to obtain the wireless tag identifier. (R5).

  Then, the control unit 49 of the reader / writer 61 transmits the data to the host PC or the like via the host interface unit 48 in accordance with the operation mode preset in the storage unit 42 or in a format that can be determined by the user on the display unit 46. The information indicated by the identifier is displayed or both or one of them is performed.

  In addition, it goes without saying that various modes other than the above can be used for the communication procedure in which the reader / writer reads the identifier of the wireless tag using the encrypted data. As shown, the session key is generated after the reader / writer receives a random number from the wireless tag. However, when the reader / writer first generates a session key and sends a read command, the generated session key is generated. May be sent encrypted with a common key, or a wireless tag may generate a session key.

  In FIG. 6, the number of wireless tags is shown as one for convenience of explanation, but even when there are a plurality of wireless tags, an anti-collision method such as a binary tree as shown in (Non-Patent Document 3) is used. By using it together with encryption, it can be read by the same processing.

  Next, in the wireless tag system according to this embodiment, the reader / writer changes the private / public mode switching bit 31a in the memory logic structure of the wireless tag from the public mode to the private mode, and conversely, from the private mode. You can change to public mode.

  First, the change from the public mode to the private mode is performed on, for example, a product equipped with the wireless tag shown in FIG. 1, and the reader / writer shown in FIG. 4 sends an encryption key write command without performing encryption. Then, the wireless tag shown in FIG. 1 that has received it interprets the private / public mode switching bit 31a from the public mode to the private mode, and writes the received encryption key in the encryption key unit 31b. Yes.

  This is a measure for protecting the privacy of the product purchaser because the wireless tag shown in FIG. 1 attached to the pre-sale product in the distribution stage or retail stage is normally set in the public mode. . In this way, it is possible to easily take measures for protecting the privacy of the product purchaser.

  Conversely, the change from the private mode to the public mode is performed when the wireless tag set to the private mode as described above needs to be returned to the public mode for, for example, a return process or secondary use. This is a measure for ensuring the convenience of the product purchaser. Hereinafter, a description will be given with reference to FIG.

  In FIG. 7, the reader / writer 61 transmits a write start command to the wireless tag 62 (R11, S11). The wireless tag 62 interprets the received write start command, generates a random number (T11), and responds to the reader / writer 61 as a challenge (T12, S12). The reader / writer 61 encrypts the challenge with the encryption key (R12) and responds as a response (R13, S13).

  The wireless tag 62 decrypts and matches the received response (T13). When authentication fails, although not shown, a response to that effect is possible, but in principle, no response is made as described above. When the authentication is successful, as shown in the figure, a session key is generated (T14), encrypted with an encryption key (T15), and the encrypted session key is transmitted as a response (T16, S14).

  The reader / writer 61 decrypts the received session key with the encryption key (R14), encrypts the write data using the decrypted session key, in this example, the command to return to the public mode (R15), and encrypts it. The written data is transmitted (R16, S15).

  The wireless tag 62 decrypts the received encrypted write data with the session key (T17), recognizes that it is a command for returning to the public mode, and switches the private / public mode switch bit to the public mode and sets it ( R18).

  It goes without saying that the reader / writer can change the private / public mode switching bit of the wireless tag from the private mode to the public mode and set various modes other than the above. In the wireless tag system according to the embodiment, it is possible to safely return to the public mode.

  As can be understood from the above description, the assumed usage of the wireless tag system according to this embodiment is as follows.

  The private / public mode switching bit 31a in the memory logic structure of the wireless tag shown in FIG. 1 is set to a bit (“1” bit or “0” bit) indicating the public mode according to the agreement at the time of shipment from the factory. The mode of the wireless tag shown in FIG. 1 mounted on a product before sale at the stage or retail stage is a public mode.

  When the wireless tag shown in FIG. 1 is in the public mode, the control data unit 31 in the memory logical structure of the wireless tag shown in FIG. 1 does not function. Reading is enabled, and writing to the user data section 33 is enabled in response to a write command that does not perform encryption.

  In this writing operation, the setting of the private / public mode switching bit 31a can be rewritten from the public mode to the private mode. However, in this case, it is necessary to write the encryption key in the encryption key unit 31b, and this can be performed only by the reader / writer shown in FIG. 4, so that it does not have a common encryption key according to this embodiment after all. In the reader / writer, the setting of the private / public mode switching bit 31a cannot be rewritten from the public mode to the private mode.

  Accordingly, in the distribution stage and the retail stage, the identifier data unit 32 is read from an arbitrary reader / writer, as in the conventional wireless tag, with respect to the wireless tag shown in FIG. Since writing to the user data section 33 can be performed, convenience in the distribution stage and retail stage can be ensured as in the conventional case.

  Then, after the purchase of the product equipped with the wireless tag shown in FIG. 1, the purchaser who intends to use the product for the secondary use can set the encryption key as follows: (1) Using the reader / writer shown in FIG. 4, set the private / public mode switching bit 31a to the private mode and request to write the encryption key to the encryption key part 31b. (2) Owned by the purchaser 4 Write the encryption key on the spot using the reader / writer shown in Fig. 4 built in a mobile phone or PDA. (3) Wrap it in aluminum foil so that it cannot be read in the public mode setting. Various methods such as writing an encryption key can be selected at home or at home using a reader / writer shown in FIG.

  The wireless tag shown in FIG. 1 can be read from the reader / writer who has set the encryption key without having to worry about being read by a partner who does not know the encryption key after the private mode is set. Can use the RFID tag identifiers to ensure convenience such as organizing belongings and using them for searching. In the case of returning the product, it is possible to return to the public mode by the communication procedure for writing using the encryption key shown in FIG. 8, so that the return processing can be performed smoothly.

  In the above description, the information is disclosed using the encryption key as the key of the common key system, but it goes without saying that the encryption key can be easily extended to the key of the public key encryption system.

  As described above, the wireless tag system, the wireless tag, and the reader / writer according to the present invention maintain the convenience at the distribution / retail stage of the product equipped with the wireless tag and the convenience of the product purchaser while maintaining the convenience after the product purchase. This is useful for balancing privacy protection.

The block diagram which shows the structure of the main function of the wireless tag in the wireless tag system by one embodiment of this invention 1 is a block diagram showing an example of the electrical configuration of the wireless tag shown in FIG. The figure which shows the memory logical structure of the radio | wireless tag shown in FIG. The block diagram which shows the structure of the main function of the reader / writer in the radio | wireless tag system by one embodiment of this invention Block diagram showing an example of the electrical configuration of the reader / writer shown in FIG. FIG. 4 is a flowchart for explaining a communication procedure in which the reader / writer shown in FIG. 4 reads the identifier of the wireless tag when the private mode and the encryption key are set in the wireless tag shown in FIG. FIG. 4 is a flowchart for explaining a communication procedure in which the reader / writer shown in FIG. 4 returns the setting of the wireless tag to the public mode when the wireless tag shown in FIG. 1 is set in the private mode. The figure which showed the memory logical structure example of the conventional wireless tag The figure which showed the example of expansion of the memory logic structure of the conventional wireless tag

Explanation of symbols

11 wireless tag power supply unit 12 wireless tag storage unit 13 wireless tag modulation / demodulation unit 14 wireless tag command interpretation unit 15 wireless tag encryption / decryption unit 16 wireless tag control unit 21 wireless tag CPU
22 Radio tag ROM
23 Wireless tag RAM
24 wireless tag rewritable nonvolatile memory 25 wireless tag power supply circuit 26 wireless tag encryption processing circuit 27 wireless tag RF circuit 28 wireless tag antenna 31 control data part 31a private / public mode switching bit 31b encryption key part 32 identifier Data section 33 User data section 41 Reader / writer power supply section 42 Reader / writer storage section 43 Reader / writer modulation / demodulation section 44 Reader / writer response interpretation section 45 Reader / writer encryption / decryption section 46 Reader / writer Display unit 47 Reader / writer operation unit 48 Reader / writer host interface unit 49 Reader / writer control unit 50 Reader / writer CPU
51 Reader / Writer ROM
52 Reader / Writer RAM
53 Reader / Writer Rewritable Non-volatile Memory 54 Reader / Writer Power Circuit 55 Reader / Writer Host Interface Control Circuit 56 Reader / Writer Encryption Processing Circuit 57 Reader / Writer Display Circuit 58 Reader / Writer Input 59 Reader / RF circuit of lighter 60 Reader / writer antenna 61 Reader / writer 62 Wireless tag

Claims (3)

In a wireless tag system including a wireless tag and a reader / writer that reads out the wireless tag,
The reader / writer is
A first reader / writer that performs a read operation by encryption communication using an encryption key as a common key;
A second reader / writer that performs a reading operation by communication without using the encryption key,
The wireless tag is
A mode switching bit for designating a private mode for permitting reading from the first reader / writer or a public mode for permitting reading from the second reader / writer, and the mode for performing encryption / decryption A memory having an encryption key part for holding the encryption key;
And a means for executing a change of a mode designated by the mode switching bit by a reading operation from the first reader / writer. A memory having a private mode for permitting reading by encryption communication using an encryption key as a common key, or a mode switching bit for designating a public mode for permitting reading by communication without using the encryption key;
And a means for executing a change of a mode designated by the mode switching bit by a reading operation from a reader / writer accessible in the private mode. Means for performing a read operation by encrypted communication using the encryption key set in the corresponding wireless tag as a common key;
A reader / writer comprising: means for performing a reading operation by communication without using the encryption key.

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