JP4546124B2 - Information tag response control method - Google Patents

Description

  The present invention relates to a response control method for an information tag (RFID tag) that performs non-contact communication using a carrier wave in a radio frequency band.

  Conventionally, RFID tag data is in an environment where it is easy to be stolen from outside without being noticed by the owner due to non-contact. If it is a normal device, it is sufficient to encrypt the data. However, in the case of the RFID tag, since the CPU capability is low, complicated calculation is difficult.

  Analysis is difficult if the data structure of the command or response is not known, but depending on how the response to the command is performed, the possibility of data being analyzed is increased by repeated testing.

  An authentication device or an authentication method for ensuring such security has been proposed (for example, Patent Document 1).

However, this proposal cannot be applied because the CPU capability is high in a mobile phone, and the RFID tag has a low CPU capability as described above.
JP 2002-342288 A

  As described above, in the RFID tag (information tag), there is a problem that the possibility of data analysis is increased by repeatedly performing a test depending on how to respond to a command.

  An object of the present invention is to provide an information tag response control method in which data analysis is difficult.

  According to the information tag response control method of the present invention, when a command is received, the command is analyzed, and if the command cannot be analyzed by this analysis processing, if it is a sequence error, or if it is a command error, it is stored in advance. A response length is set using a random number table, response data is created, and the created response data is transmitted.

  According to the information tag response control method of the present invention, it is possible to make data analysis difficult by controlling a response that is difficult to distinguish between no response, error response, and normal response.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows a schematic configuration of an RFID tag (information tag) 10 according to the information tag response control method of the present invention.

  The RFID tag 10 includes a CPU 1 that performs overall control, a ROM that stores a program and a random number table, which will be described in detail later, a RAM 3 that temporarily stores information, a modulation / demodulation circuit 4 that performs modulation and demodulation, and an antenna 7. It consists of a connected analog circuit 5 and a power generation circuit 6. The power generation circuit 6 generates power and supplies power to each circuit.

  Next, the response control operation of the RFID tag 10 of the present invention in such a configuration will be described with reference to the flowchart of FIG.

  First, it is assumed that the RFID tag 10 receives a radio frequency carrier wave, the power generation circuit 6 generates power, and the power supply is turned on.

  At that time, the CPU 1 first performs I / O initialization (ST1).

  Subsequently, the CPU 1 checks whether a command has been received (ST2), and enters a command reception standby state if no command has been received yet.

  When receiving the command in step ST2, the CPU 1 performs a command analysis process (ST3).

  Here, when the analysis of the command is impossible as a result of the analysis process of step ST3, the CPU 1 proceeds to step ST9, and when the command can be analyzed, the CPU 1 proceeds to the next step (ST4).

  If the command can be analyzed, the CPU 1 checks whether it is a sequence error (ST5). If it is a sequence error, the process proceeds to step ST9. If it is not a sequence error, the process proceeds to the next step.

  If it is not a sequence error, the CPU 1 checks whether it is a command error (ST6). If it is a command error, the process proceeds to step ST9. If it is not a command error, the process proceeds to the next step.

  If it is not a command error, the CPU 1 executes the command (ST7) and creates a response (ST8).

  On the other hand, if the command cannot be analyzed in step ST4, or if a sequence error occurs in step ST5, or if a command error occurs in step ST6, the CPU 1 sets a response length using a random number table prepared in advance in the ROM 2 ( Further, response data is created from this random number table (ST10).

  Then, the CPU 1 performs a response transmission process of the response created in step ST8 or the response data created in step ST10 (ST11), and returns to step ST2.

  As described above, in this embodiment, when a sequence other than a predetermined sequence or command is received, a response length is set using a random number table, and a response is set using a random number table. Create data.

  Here, as a comparison with the operation of the present embodiment, the response control operation of the conventional RFID tag will be described with reference to the flowchart of FIG. The same steps are assigned to the same operations, and the description is omitted.

  That is, conventionally, when command analysis is impossible in step ST4, the process proceeds to the command reception standby state in step ST2. If it is a sequence error in step ST5, a sequence error response determined by the specification is created (ST21), and response response processing is performed. If a command error is detected in step ST6, a command error response determined by the specification is created (ST22), and a response transmission process is performed.

  Thus, conventionally, since a response determined by the specification is created and a response transmission process is performed, the possibility of data analysis increases.

  As described above, according to the embodiment of the present invention, it is possible to provide an RFID tag in consideration of data security.

  Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention in the implementation stage. In addition, the embodiments may be appropriately combined as much as possible, and in that case, the combined effect can be obtained. Furthermore, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, the problem described in the column of the problem to be solved by the invention can be solved, and the effect described in the column of the effect of the invention Can be obtained as an invention.

The block diagram which shows schematic structure of the RFID tag which concerns on the response control method of the information tag of this invention. The flowchart for demonstrating the response control operation | movement of the RFID tag of this invention. The flowchart for demonstrating the response control operation | movement of the conventional RFID tag.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... CPU, 2 ... ROM, 3 ... RAM, 4 ... Modulation / demodulation circuit, 5 ... Analog circuit, 6 ... Electric power generation circuit, 7 ... Antenna, 10 ... RFID tag.

Claims (1)

When the command is received, this command is analyzed and processed.
If analysis of the command is impossible in this analysis process, or in the case of a sequence error, or in the case of a command error, the response length is created and the response data is created using a pre-stored random number table,
A response control method for an information tag, wherein the generated response data is transmitted.

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