JP2006127163A - Privacy protecting method for ic tag and ic tag system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To collect data stored in an IC tag, while protecting the privacy of the owner of the IC tag. <P>SOLUTION: A plurality of pieces of encrypted identification information are stored in the IC tag 1, and at radio transmission from the IC tag 1, one of the identification information is selectively transmitted. In the radio transmission of identification information, different identification information is selectively transmitted for each predetermined time interval or for each predetermined number of transmissions. A tag reader 2 or an IC tag identification terminal 3 decodes the identification information and reads the unique ID of the IC tag, and identifies the IC tag in reference to an identification ID table. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a privacy protection method in an IC tag and an IC tag system.

  Conventionally, there is a method of generating identification information (hereinafter referred to as an identification ID) inside an IC tag. In this case, the IC Doug assigns an arbitrary additional ID to the IC tag unique ID to generate a redundant ID. The IC tag encrypts this redundant ID using common key information to obtain an identification ID. Then, the IC tag wirelessly transmits this identification ID to the IC tag reader. The terminal connected to the IC tag reader or the IC tag reader receives this identification ID, decrypts this identification ID with the common key information, and extracts the redundant ID. Further, the server connected to the terminal network removes the additional ID from the redundant ID and extracts the IC tag unique ID.

The IC tag can generate different identification IDs by changing the additional ID, and since only the identification ID can be wiretapped in the wireless section, it is difficult to identify individual IC tags. For this reason, a third party who eavesdrops on the radio cannot track the data stored in the IC tag by the IC tag owner or the location information of the IC tag. In addition, since the IC tag reader or the terminal connected to the IC tag reader can decode the identification ID and take out the IC tag unique ID, each IC tag can be identified. Note that Non-Patent Document 1 is disclosed as a technology related to the IC tag.
“Nikkei Electronics 2-25 2002 no. 816”, Nikkei BP Co., Ltd., February 25, 2002, p. 109-p. 137

  However, according to the above-described prior art, when the IC Doug generates the identification ID, a CPU capable of performing advanced calculations is required to encrypt with the common key information. For this reason, it is required to mount a high-performance CPU, and its use shortens the battery life and increases the running cost. At the same time, there was a problem that the unit price of the IC tag was high. Further, since the common key information is held inside the IC tag, there is a possibility that the common key information may be known to a third party when the IC tag is disassembled and analyzed.

  The present invention has been made in view of the above circumstances, and provides a privacy protection method in an IC tag and an IC tag system capable of collecting data stored in the IC tag while protecting the privacy of the owner of the IC tag. The purpose is to do.

  In order to solve the above-described problems, the present invention is an IC tag that wirelessly transmits data to an IC tag reader, and a plurality of pieces of identification information are stored in advance, and one piece of identification information is selected from the tags together with the data. Means for wirelessly transmitting to the IC tag reader.

  The present invention further comprises means for receiving from the outside the identification information generated from the identification information unique to the IC tag and the additional information based on the common key information and the encryption rule.

  The present invention is characterized by comprising: means for receiving the identification information generated based on public key information and encryption rules from identification information unique to the IC tag and additional information.

  In the present invention, when wirelessly transmitting the identification information, there is provided means for selecting and transmitting different identification information at predetermined time intervals or every predetermined number of transmissions.

  Further, the present invention is characterized by comprising: means for generating and encrypting data stored in a memory built in the IC tag and data obtained by calculating a value unique to the IC tag.

  The present invention also relates to a privacy protection method in an IC tag system comprising an IC tag that wirelessly transmits data stored in a built-in memory and an IC tag reader that receives the data or a terminal device to which the IC tag reader is connected. The IC tag is selected from a plurality of pre-stored identification information, and wirelessly transmitted to the IC tag reader together with the data; and the IC tag reader or terminal that has received the identification information And a step of identifying the received individual identification information with reference to a table held by the apparatus.

  Further, according to the present invention, the identification information stored in advance in the IC tag is decrypted with a common key, and in the step of identifying the identification information, the IC tag reader or the terminal device obtains the identification information with the common key. Decoding is performed to identify the received individual identification information.

  In the present invention, the identification information stored in advance in the IC tag is decrypted with a public key, and in the step of identifying the identification information, the IC tag reader or the terminal device has a secret key corresponding to the public key. In this case, the identification information is decrypted to identify the received individual identification information.

According to the present invention, when a plurality of identification information of an IC tag is stored in advance in the IC tag, and the IC tag wirelessly transmits, one of the plurality of identification information is selected and wirelessly transmitted to the IC tag reader. Since different identification information is transmitted to the wireless section if the time is different, it becomes difficult for a third party to track a specific IC tag. Therefore, data stored in the IC tag can be collected while protecting the privacy of the owner of the IC tag.
According to the present invention, the IC tag connects the IC tag reader or the IC tag reader by receiving the identification information generated based on the common key information and the encryption rule from the identification information unique to the IC tag and the additional information. The terminal can use the common key information that generated the identification information to decrypt the identification information and obtain identification information unique to the IC tag. For this reason, even if the same IC tag has a different time, different identification information is transmitted to the wireless section, making it difficult for a third party to track a specific IC tag. At this time, the IC tag reader or the terminal to which the IC tag reader is connected has a table for identifying each received identification information, but here, only the common key information needs to be possessed, so the table management cost Can be reduced.

According to the present invention, the IC tag connects the IC tag reader or the IC tag reader by receiving the identification information generated based on the public key information and the encryption rule from the identification information unique to the IC tag and the additional information. The terminal can decrypt the identification information using the secret key information and obtain identification information unique to the IC tag. For this reason, even if the same IC tag has a different time, different identification information is transmitted to the wireless section, making it difficult for a third party to track a specific IC tag. Further, by using the public key information, it is not necessary to keep the key for storing the identification information in the IC tag, so that the operation cost can be reduced.
Furthermore, according to the present invention, when the identification information is wirelessly transmitted, the identification information of the IC tag is selected according to the usage scene of the IC tag by selecting and transmitting different identification information at a predetermined time interval or every predetermined transmission. It is possible to control the interval at which changes, and the security effect is further increased.

  In addition, according to the present invention, the IC tag reader or the terminal connected to the IC tag reader can be obtained by generating and encrypting data stored in the IC tag and data obtained by calculating a value unique to the IC tag. The unique value can be decoded by performing a subtraction, addition, or exclusive OR operation. As a result, when collecting data in the IC tag, it is possible to make it difficult to estimate data easily even if communication is wiretapped in the wireless section between the IC tag and the IC tag reader and in the IC tag reader. . In addition, since encryption is performed by a simple operation such as addition, subtraction, or exclusive OR in the IC tag, it can be realized by a CPU with relatively low performance, and power consumption can be reduced.

FIG. 1 is a diagram showing an example of the configuration of an IC tag system using the IC tag of the present invention.
The IC tag system includes an IC tag 1, an IC tag reader 2, an IC tag identification terminal 3, an IC tag setting terminal 4, and an IC tag setting machine 5. The IC tag 1 has a function of wirelessly transmitting identification information (hereinafter referred to as an identification ID) to an IC tag reader 2 from a built-in RF transmission unit (not shown). The IC tag reader 2 transmits the identification ID received wirelessly from the IC tag 1 to the IC tag identification terminal 3, and the IC tag identification terminal 3 obtains an ID unique to the IC tag from the identification ID received from the IC tag reader 2. Has function.
On the other hand, the IC tag setting device 5 uses various parameters or identification IDs of the IC tag 1 based on information from the IC tag setting terminal 4 using an LF (low frequency) signal generated by a magnetic coil. With the ability to send to. The IC tag 1 sets parameters in the IC tag 1 along with various parameters received from the IC tag setting machine 5 by the LF signal, and stores the identification ID received from the IC tag setting machine 5 via the LF signal. For this reason, in addition to the normal configuration, the IC tag 1 includes an LF signal receiving unit, and the IC tag setting machine 5 includes an LF signal transmitting unit.

  Hereinafter, the embodiment of the present invention shown in FIG. 1 will be described in detail. First, the IC tag setting terminal 4 generates a random number using the built-in software, and creates a table based on the generated random value. Here, this table is referred to as an identification ID table 20. FIG. 2 shows an example of the data structure of the identification ID table 20. The IC tag setting terminal 4 sets the generated random number in the identification ID field and records it in association with the unique ID of the IC tag. Here, both the identification ID and the IC tag unique ID are shown in hexadecimal.

Here, since the identification IDs shown in the identification ID table 20 must all be different values, the generated random number value is discarded if it matches one of the identification IDs already recorded in the identification ID table 20, Do not use. The random number value is stored only when all the identification IDs recorded in the identification ID table 20 do not match.
On the other hand, the user brings the IC tag 1 close to the IC tag setting machine 5 and manually applies the IC tag unique ID of the IC tag 1 to the IC tag setting terminal 4. The IC tag setting terminal 4 sends one or a plurality of identification IDs associated with the input IC tag unique ID to the IC tag setting machine 5, and the IC tag setting machine 5 converts the received identification ID into the LF signal. To the IC tag 1. The IC tag 1 stores the identification ID received from the IC tag setting machine 5. Alternatively, in the manufacturing process of the IC tag 1, the IC tag 1 can be obtained by burning one or a plurality of identification IDs associated with the IC tag unique ID by the identification ID table 20 into the ROM in the IC tag 1 by the ROM writer. It is also possible to store the identification ID.

Subsequently, the IC tag setting terminal 4 transmits the identification ID table 20 to the IC tag identification terminal 3. The IC tag 1 transmits one of the stored identification IDs to the IC tag reader 2. Further, the IC tag reader 2 transmits the received identification ID to the IC tag identification terminal 3. Here, the IC tag identification terminal 3 searches the identification ID table 20 using the received identification ID as a key, and acquires the associated IC tag unique ID.
For example, according to the identification ID table 20 shown in FIG. 2, when the identification ID “ABOABOBAB” is received, the IC tag unique ID is recognized as “00000001”.

  Another embodiment of the present invention will be described. First, the user brings the IC tag 1 close to the IC tag setting device 5 and manually supplies the IC tag unique ID of the IC tag to the IC tag setting terminal 4. The IC tag setting terminal 4 adds a 32-bit additional ID generated by a random number to the 32-bit IC tag unique ID input by the user as shown in FIG. 4 (a), A 64-bit identification ID is generated from the common key information (b). The common key information is uniquely determined by the system administrator or the administrator of the IC tag setting terminal 4 and the IC tag identification terminal 3.

The IC tag setting terminal 4 sends one or a plurality of identification IDs generated here to the IC tag setting machine 5, and the IC tag setting machine 5 sends the received identification ID to the IC tag 1 by an LF signal. As a result, the IC tag 1 stores the identification ID received from the IC tag setting machine 5.
Alternatively, by adding an additional ID to the IC tag unique ID during the manufacturing process of the IC tag 1 and burning one or a plurality of identification IDs encrypted by the common key information into the ROM in the IC tag 1 with the ROM writer, the IC tag 1 can also store an identification ID.

  Subsequently, the IC tag setting terminal 4 transmits the common key information to the IC tag identification terminal 3. The IC tag 1 transmits one of the stored identification IDs to the IC tag reader 2. The IC tag reader 2 transmits the received identification ID to the IC tag identification terminal 3. As shown in FIG. 4, the IC tag identification terminal 3 decrypts the received identification ID (32 bits) with the common key information, and acquires the IC tag unique ID (16 bits) (c).

Next, still another embodiment of the present invention will be described. Here, the IC tag identification terminal 3 generates secret key information and corresponding public key information, and transmits the public key information to the IC tag setting terminal 4. The secret key information is uniquely determined by the system administrator or the administrator of the IC tag setting terminal 4 and the IC tag identification terminal 3.
Next, the user brings the IC tag 1 close to the IC tag setting machine 5 and inputs the IC tag unique ID of the IC tag to the IC tag setting terminal 4. As a result, the IC tag setting terminal 4 adds a 32-bit additional ID generated by a random number to the 32-bit IC tag unique ID input by the user as shown in FIG. A bit identification ID is generated (b).

Subsequently, the generated identification ID or IDs are sent to the IC tag setting device 5, and the IC tag setting device 5 transmits the received identification ID to the IC tag 1 using an LF signal. Thus, the IC tag 1 can store the identification ID received from the IC tag setting machine 5.
Alternatively, in the manufacturing process of the IC tag 1, an additional ID is added to the IC tag unique ID, and one or more identification IDs encrypted using the public key information are burned into the ROM in the IC tag 1 by the ROM writer. The IC tag 1 can also store the identification ID by inserting it.

  On the other hand, the IC tag 1 transmits one of the stored identification IDs to the IC tag reader 2. Subsequently, the IC tag reader 2 transmits the received identification ID to the IC tag identification terminal 3. As shown in FIG. 2, the IC tag identification terminal 3 decrypts the received identification ID (32 bits) with the secret key information, and acquires the IC tag unique ID (16 bits) (c).

Next, still another embodiment of the present invention will be described. First, the user brings the IC tag 1 close to the IC tag setting machine 5. At this time, the user operates the IC tag setting terminal 4 to set a trigger (trigger) for changing the identification ID and its frequency.
Here, as a trigger, a predetermined time interval or a predetermined number of transmissions can be set. In the case of a predetermined time interval, the frequency is specified as the number of seconds, which is a time interval. The trigger and frequency are transmitted to the IC tag 1 by LF transmission from the IC tag setting terminal 4, and the IC tag 1 can change the way of changing the identification ID based on this setting.

  For example, when the frequency is 1000 seconds at a predetermined time interval, the IC tag 1 changes the identification ID transmitted to the IC tag reader 2 every 1000 seconds by timer monitoring. In other words, the same identification ID is transmitted until 1000 seconds elapse. Further, when the number of times indicated by the predetermined number of transmissions is 5, the IC doug 1 counts whether or not the identification ID has been transmitted 5 times to the IC tag reader 2 by a counter. When the ID is transmitted five times, the identification ID is changed, the changed identification ID is transmitted five times, and this is repeated a predetermined number of times. In other words, the same identification ID is transmitted when the counter value is between “0” and “5”.

FIG. 3 shows an operation sequence for IC tag identification. As shown in FIG. 3, first, the IC tag 1 selects one of a plurality of stored identification IDs with respect to the IC tag reader 2 (S31). Then, a wireless transmission command trigger that holds the selected identification ID is generated (S32). Next, it is determined whether the transmission of intermittent radio pulses has elapsed for a number of seconds indicated by a predetermined time interval, or whether the transmission of intermittent radio pulses has been performed by the number indicated by a predetermined number of transmissions ( S33) When a predetermined time interval has passed or when a predetermined number of transmissions have been transmitted, another different identification ID is selected and read from among a plurality of identification IDs (S34), and a radio signal including the identification ID is transmitted. . At this time, the count of the number of seconds indicated by the predetermined time interval or the number of transmission times indicated by the predetermined number of transmissions is reset.
The IC tag reader 2 receiving the identification ID from the IC tag 1 (S35) or the IC tag identification terminal 3 to which the IC tag reader is connected refers to the identification ID table 20, or decrypts based on the common key information and the secret key information. To identify the IC tag (S36).

Next, still another embodiment of the present invention will be described. Here, it is assumed that the measurement data “0111101” is stored in the IC tag 1, the storage area is 8 bits, and the key unique to the IC tag is “01001011”.
In this case, an exclusive OR operation of “0111101” of the measurement data and the key “01001011” unique to the IC tag is performed to generate “00110110”, which is stored in the memory in the IC tag 1. This value is transmitted wirelessly to the IC tag reader 2 and sent to the IC tag identification terminal 3. The IC tag identification terminal 2 performs exclusive OR operation on the received “001110110” with the unique key “01001011” of the IC tag 1 to restore the measurement data “0111101”.

  As described above, according to the present invention, a plurality of IC tag identification information is stored in advance in the IC tag 1, and when the IC tag wirelessly transmits, one of the plurality of identification information is selected and wirelessly transmitted to the IC tag reader 2. This makes it difficult for a third party to track a specific IC tag, because even if the same IC tag 1 has different times, different identification information is transmitted to the radio section. . Therefore, data stored in the IC tag can be collected while protecting the privacy of the owner of the IC tag. In addition, the IC tag 1 does not require a high-performance CPU for encryption, so that the problem that the battery life is shortened, the running cost is increased, and the unit price of the IC tag is increased can be avoided. In addition, since it is not necessary to hold key information used for encryption inside the IC tag, there is a chance that the IC tag is disassembled and analyzed and the common key information is made known to a third party. Further, by using the public key information, it is not necessary to keep the key for storing the identification information in the IC tag, so that the operation cost can be reduced.

It is a figure which shows an example of a structure of the IC tag system containing the IC tag of this invention. It is a figure which shows the data structure of the identification ID table concerning this invention embodiment. It is a figure which shows the operation | movement sequence concerning this invention embodiment. It is a figure which shows the flow of the encryption and decoding process concerning embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... IC tag, 2 ... IC tag reader, 3 ... IC tag identification terminal, 4 ... IC tag setting terminal, 5 ... IC tag setting machine, 20 ... Identification ID table

Claims (8)

An IC tag that wirelessly transmits data to an IC tag reader,
A plurality of pieces of identification information stored in advance, means for selecting one of the pieces of identification information and wirelessly transmitting it to the IC tag reader together with the data;
An IC tag comprising: Means for receiving from the outside the identification information generated based on the common key information and the encryption rule from the identification information unique to the IC tag and the additional information;
The IC tag according to claim 1, further comprising: Means for receiving the identification information generated from the identification information unique to the IC tag and the additional information based on public key information and encryption rules from the outside;
The IC tag according to claim 1, further comprising: When wirelessly transmitting the identification information, means for selecting and transmitting different identification information at predetermined time intervals or every predetermined number of transmissions;
The IC tag according to any one of claims 1 to 3, further comprising: Means for generating and encrypting data stored in a memory built in the IC tag and data obtained by calculating a value unique to the IC tag;
The IC tag according to claim 1, further comprising: A privacy protection method in an IC tag system comprising an IC tag that wirelessly transmits data stored in a built-in memory, and an IC tag reader that receives the data or a terminal device to which the IC tag reader is connected,
Selecting one of a plurality of pieces of identification information in which the IC tag is stored in advance, and wirelessly transmitting to the IC tag reader together with the data;
Identifying the received individual identification information with reference to a table of the IC tag reader or terminal device that has received the identification information;
A privacy protection method in an IC tag system, comprising: The identification information stored in advance in the IC tag is decrypted with a common key,
The privacy protection according to claim 6, wherein in the step of identifying identification information, the IC tag reader or terminal device decrypts the identification information with the common key to identify the received individual identification information. Method. The identification information stored in advance in the IC tag is decrypted with the public key,
7. The step of identifying identification information, wherein the IC tag reader or terminal device decrypts the identification information with a secret key corresponding to the public key, and identifies the received individual identification information. The privacy protection method according to 1.

Images