JP4843960B2 - Tag authentication system, authentication device, and tag authentication method - Google Patents

Description

  The present invention relates to a tag authentication system, an authentication device, and a tag authentication method.

Conventionally, authentication information such as document issuance record, issued document record, authentication record, final processing record, etc. is recorded in both the digitized document and the certifier's computer, and the authentication accompanying the digitized document There is electronic authentication that determines the validity of authentication such as document issuance, authentication progress, final status, etc. by checking the consistency between the information and authentication information in the individual computer of the certifier (for example, , See Patent Document 1). This facilitates discovery of authentication information falsification and makes it difficult to falsify authentication information.
JP-A-9-198437

An IC tag capable of rewriting data is used for various purposes. For example, use of an IC tag for a credit function, electronic money, or the like has been studied, and preventing unauthorized use is an important issue. In order to prevent unauthorized data from being written to the IC tag, it is conceivable to provide the IC tag with an encryption function for rewriting data using encrypted communication. However, such a high-function IC tag becomes expensive. Therefore, in order to safely write data to an IC tag that does not have an encryption function, data is encrypted and written. However, even if the data is encrypted and written, it cannot be prevented that the encrypted data itself is copied (dead copy) and used illegally.
In order to deal with such a problem, the authentication information of the IC tag is stored in a database on a server or the like, and the authentication information read out from the IC tag is collated, so that the unauthorized use of the IC tag having no encryption function There is a method of detecting writing or data alteration. However, with this method, if the number of IC tags increases, the database may become enormous in size. There is a digital signature as a method for avoiding this. In the digital signature, signature data for detecting falsification of data is attached to the original data, and the signature data is verified as necessary. Conventionally, RSA (Rivest-Shamir-Adleman) technology is often used for signature data, but in order to ensure safety in the future, a signature data length of 1024 bits (128 bytes) or more is used. Should. However, the current IC tag user memory is about 128 bytes or less, and such secure signature data cannot be stored.
Further, the conventional technology described above does not solve such a problem.

  The present invention has been made in view of the above circumstances, and a tag authentication system capable of protecting data held in an IC tag that does not have an encryption function without centrally managing information on the IC tag. It is an object to provide an authentication device and a tag authentication method.

In order to achieve the above object, the present invention provides a tag authentication system comprising an IC tag, a reader / writer device that reads and writes information in the IC tag, and an authentication device that verifies the validity of the IC tag. The IC tag includes storage means having a protected area that is a storage area where data cannot be rewritten and a rewritable area that is a data area where data can be rewritten, and the reader / writer device includes the IC tag In response to the unique information transmitted by the authentication information requesting means, the authentication information requesting means for reading the unique information that is unique to each IC tag from the protected area in the storage means provided in the tag and transmitting it to the authentication device , Authentication information that is information used for verifying the validity of the IC tag, and a time stamp that is information indicating a time when the authentication information is generated. An authentication information receiving means for receiving from the reader / writer device, and an authentication information request receiving means for receiving the unique information from the reader / writer device, and an authentication information receiving means for writing to a rewritable area in the storage means provided in the IC tag. Authentication information generating means for generating authentication information based on the unique information received by the authentication information request receiving means and a time stamp indicating current time information, authentication information generated by the authentication information generating means, It is a tag authentication system comprising: an authentication information transmitting means for returning the time stamp used for generating the authentication information to the reader / writer device.

Further, the present invention is the tag authentication system described above , wherein the authentication information requesting means further includes user data which is data arbitrarily used by a user from a rewritable area in a storage means included in the IC tag. Is read out and transmitted to the authentication device, the authentication information request receiving means further receives user data from the reader / writer device, and the authentication information generating means is the unique information received by the authentication information request receiving means and Authentication information is generated based on user data and a time stamp indicating information on the current time.

Further, the present invention is the above-described tag authentication system, wherein the reader / writer device receives the unique information from the protected area in the storage means provided in the IC tag, and the authentication information and time from the rewritable area in the storage means. Verification request means for reading a stamp and transmitting it to the authentication apparatus, wherein the authentication apparatus includes verification request reception means for receiving unique information, authentication information and a time stamp from the reader / writer apparatus, and the verification request reception means. A verification unit that verifies the validity of the IC tag using the received unique information, authentication information, and time stamp; and a verification result transmission unit that returns information indicating a verification result by the test verification unit to the reader / writer device. It is characterized by comprising.

Further, the present invention is the tag authentication system described above , wherein the authentication information requesting means further includes user data which is data arbitrarily used by a user from a rewritable area in a storage means included in the IC tag. Is read out and transmitted to the authentication device, the authentication information request receiving means further receives user data from the reader / writer device, and the authentication information generating means is the unique information received by the authentication information request receiving means and Authentication information is generated based on user data and a time stamp indicating current time information, and the verification request unit further reads the user data from a rewritable area in a storage unit included in the IC tag, and The verification request receiving means further receives user data from the reader / writer device, and the verification means , The unique information received by the verification request receiving unit, authentication information, time stamps, and verifies the validity of the IC tag by using the user data, and wherein the.

In addition, the present invention is the tag authentication system described above , wherein the authentication information generation unit generates the authentication information using elliptic curve cryptography.

Further, the present invention is the tag authentication system described above , wherein the storage means provided in the IC tag further stores key information, and the verification request means is further read from the storage means provided in the IC tag. The verification request receiving means further receives the key information from the reader / writer device, and the verification means receives the key information received by the verification request receiving means. Further, it is used to verify the validity of the IC tag.

Further, the present invention is the tag authentication system described above , wherein the authentication information transmitting unit further transmits key information corresponding to the authentication information to the reader / writer device, and the authentication information receiving unit further includes: The key information is received from the authentication device and written in a rewritable area in the storage means of the IC tag.

The present invention is the above tag authentication system, wherein the authentication device further includes key information storage means for storing key information and key specifying information for specifying the key in association with each other, and the IC The storage means provided in the tag further stores key specifying information, and the verification request means further transmits the key specifying information read from the storage means provided in the IC tag to the authentication device, and the verification request receiving means Further receives the key specifying information from the reader / writer device, and the verification unit reads the key information corresponding to the key specifying information received by the verification request receiving unit from the key information storage unit, The authenticity of the IC tag is verified by further using the key information.

The present invention is the tag authentication system described above , wherein the authentication information requesting unit further transmits key identification information read from a storage unit included in the IC tag to the authentication device, and receives the authentication information request. The means further receives key specifying information, and the authentication information generating means generates authentication information further using the key specifying information received by the authentication information request receiving means, and a key corresponding to the generated authentication information. Is written in the key information storage means in association with the key specifying information.

Further, the present invention provides the authentication apparatus used in a tag authentication system including an IC tag, a reader / writer device that reads and writes information in the IC tag, and an authentication device that verifies the validity of the IC tag. An authentication information request reception is received from the reader / writer device that is read from a protected area that is a storage area in the storage means of the IC tag that cannot be rewritten and is unique to each IC tag. And authentication information generating means for generating authentication information used for verifying the validity of the IC tag based on the unique information received by the authentication information request receiving means and the time stamp indicating the current time information; The authentication information generated by the authentication information generating means and the time stamp used for generating the authentication information are returned to the reader / writer device. And testimony information transmitting unit, an authentication apparatus, characterized in that it comprises a.

Further, the present invention provides the above-described authentication device, wherein the reader / writer device can rewrite the unique information read from the protected area in the storage means included in the IC tag and the data in the storage means. A verification request receiving means for receiving the authentication information and time stamp read from the possible area, and a verification means for verifying the validity of the IC tag using the unique information, authentication information and time stamp received by the verification request receiving means; And verification result transmitting means for returning information indicating a verification result by the verification means to the reader / writer device.

Further, the present invention is the above authentication apparatus, wherein the authentication information request receiving means is data read out from a rewritable area in a storage means provided in the IC tag and used arbitrarily by a user. The user information is received from the reader / writer device, and the authentication information generating unit is configured to authenticate information based on the unique information and user data received by the authentication information request receiving unit and a time stamp indicating current time information. The verification request receiving unit further receives user data read from the rewritable area in the storage unit included in the IC tag from the reader / writer device, and the verification unit receives the verification request. The validity of the IC tag is verified by using the unique information, authentication information, time stamp, and user data received by the means. To.

The present invention is also a tag authentication method used in a tag authentication system including an IC tag, a reader / writer device that reads and writes information in the IC tag, and an authentication device that verifies the validity of the IC tag. The IC tag includes storage means having a protect area that is a storage area where data cannot be rewritten and a rewritable area that is a data area where data can be rewritten, and authentication of the reader / writer device. The information requesting means reads out the unique information, which is information unique to each IC tag, from the protected area in the storage means provided in the IC tag and transmits it to the authentication device, and the authentication information request receiving means of the authentication device includes: The unique information is received from the reader / writer device, and the authentication information generating means of the authentication device receives the unique information received by the authentication information request receiving means and the current information Authentication information used for verifying the validity of the IC tag is generated based on the time stamp indicating the time information, and the authentication information transmitting means of the authentication device includes the authentication information generated by the authentication information generating means, The time stamp used for generating the authentication information is returned to the reader / writer device, and the authentication information receiving means of the reader / writer device receives the authentication information and the time stamp from the authentication device, and the IC tag A tag authentication method characterized by writing to a rewritable area in a storage means provided.

Further, the present invention is the above-described tag authentication method, wherein the verification request means of the reader / writer device receives the unique information from the protected area in the storage means provided in the IC tag from the rewritable area in the storage means. The authentication information and the time stamp are read and transmitted to the authentication device, the verification request reception unit of the authentication device receives the unique information, the authentication information, and the time stamp from the reader / writer device, and the verification unit of the authentication device includes: The validity of the IC tag is verified using the unique information, the authentication information, and the time stamp received by the verification request receiving unit, and the verification result transmitting unit of the authentication device transmits information indicating the verification result by the verification unit to the reader It is returned to the writer device.

Further, the present invention is the above-described tag authentication method, wherein the authentication information requesting unit is user data that is arbitrarily used by a user from a rewritable area in a storage unit included in the IC tag. And the authentication information request receiving means further receives user data from the reader / writer device, and the authentication information generating means receives the unique information received by the authentication information request receiving means, and Authentication information is generated based on user data and a time stamp indicating current time information, and the verification request unit further reads the user data from a rewritable area in a storage unit included in the IC tag, and Transmitting to the authentication device, the verification request receiving means further receives user data from the reader / writer device, the verification means, Specific information received by the serial verification request receiving unit, authentication information, time stamps, and verifies the validity of the IC tag by using the user data, and wherein the.

Further, the present invention is used in the authentication device of a tag authentication system including an IC tag, a reader / writer device that reads and writes information in the IC tag, and an authentication device that verifies the validity of the IC tag. A tag authentication method, wherein an authentication information request receiving means reads out unique information that is read from a protected area that is a storage area in the storage means of the IC tag and that cannot be rewritten and is unique to each IC tag. Based on the unique information received from the reader / writer device and received by the authentication information request receiving means and the time stamp indicating the current time information, the authentication information generating means is used to verify the validity of the IC tag. Authentication information generated by the authentication information transmitting means, and the time stamp used for generating the authentication information. The return to the reader-writer device, a tag authentication method characterized by.

Further, the present invention is the above tag authentication method, wherein the verification request receiving means can rewrite the unique information read from the protected area in the storage means provided in the IC tag and the data in the storage means. The authentication information and time stamp read from the rewritable area are received, and the verification means verifies the validity of the IC tag using the unique information, authentication information and time stamp received by the verification request receiving means, and the verification result The transmission means returns information indicating the verification result by the verification means to the reader / writer device.

Further, the present invention is the above-described tag authentication method, wherein the authentication information request receiving means is further read from a rewritable area in the storage means provided in the IC tag and used arbitrarily by the user Is received from the reader / writer device, and the authentication information generating means authenticates based on the unique information and user data received by the authentication information request receiving means, and a time stamp indicating the current time information. Information is generated, and the verification request receiving unit further receives user data read from the rewritable area in the storage unit included in the IC tag from the reader / writer device, and the verification unit receives the verification request. Verifying the validity of the IC tag using the unique information, authentication information, time stamp, and user data received by the receiving means. And butterflies.

According to the present invention, authentication information that is unique to each IC tag and is generated using unique information that cannot be rewritten and a time stamp can be held in the IC tag. Therefore, the uniqueness of the authentication information in the IC tag can be ensured.
Further , according to the present invention, authentication information is generated using unique information of each IC tag, user data that is arbitrarily used by a user in each IC tag, and a time stamp. Therefore, highly secure authentication information can be generated.
In addition, according to the present invention, it is possible to verify the validity of an IC tag with unique authentication information. Therefore, by constantly updating the authentication information, fraud can be detected even when the authentication information in the IC tag is dead-copied and used as it is. Furthermore, when fraud is detected, it becomes possible to specify the tampering time by the time stamp. In the authentication apparatus, verification can be performed without collectively managing authentication information of each IC tag.
In addition, according to the present invention, the highly secure authentication information generated using the unique information of each IC tag, the user data that is arbitrarily used by the user in each IC tag, and the time stamp. The validity of the IC tag can be verified.
Further , according to the present invention, since the authentication information is generated using the elliptic curve encryption, the encryption strength can be increased even if the data length of the authentication information is short. Therefore, the memory means for storing the authentication information in the storage means in the IC tag can be reduced.
Further , according to the present invention, the public key of elliptic curve encryption corresponding to the authentication information can be held in the IC tag. Therefore, verification can be performed in the authentication apparatus without managing the authentication information and public key of each IC tag collectively.
In addition, according to the present invention, since the key is updated every time the authentication information is generated, safety is improved.
Further , according to the present invention, the authentication device stores the key and the key specifying information in association with each other, and further verifies the authentication information by using the key corresponding to the key specifying information received from the IC tag. Therefore, it is only necessary to store the key specifying information in the storage means in the IC tag, so that the memory capacity to be used can be reduced and the safety is enhanced.
In addition, according to the present invention, since the key information stored in the authentication apparatus is updated every time the authentication information is generated, the safety is improved.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a configuration diagram of a tag authentication system according to a first embodiment of the present invention. A reader / writer device (hereinafter referred to as “R / W device”) 2 that reads and writes information in the tag 1 is locally connected to the gateway device 3. The gateway device 3 is connected to an authentication device 5 included in the certificate authority via a network 4 such as the Internet.

  The gateway device 3 transmits / receives data to / from the authentication device 5 via the network 4 by encrypted communication. As the gateway device 3, for example, a gateway server, a router, a PDA (Personal Digital Assistants: information portable terminal), a mobile phone, or the like can be used. In the present embodiment, SSL (Secure Socket Layer), which is a protocol for encrypting and transmitting / receiving data on the Internet, is used for encrypted communication.

  The tag 1 is an IC (Integrated Circuit) tag, and here, it is assumed that it is an RFID (Radio Frequency Identification) tag that is a non-contact IC tag. An RFID tag that mainly uses a radio frequency for communication includes a data recording memory as a storage means, a data processing circuit, and an antenna for carrying data at a radio frequency, and is placed in a resin or paper container. It is manufactured in a variety of shapes, such as an encased one, a resin-encapsulated whole, or a label sandwiched between sheets of resin or paper. The power source of the RFID tag depends on a battery incorporated in the RFID tag or a necessary power is extracted from an electromagnetic wave used as a data carrier wave from the outside.

  The storage unit of the tag 1 stores unique information, user data, authentication information, a time stamp, and key data. Unique information indicating information unique to each tag is information that cannot be rewritten. For example, a tag ID that is information for uniquely identifying a tag is used. The user data is arbitrary data used by a user who uses the tag 1. For example, when the tag 1 is attached to a product, if the code of the product is used as electronic money, information on the amount can be stored as user data. The authentication information is information used for verifying the validity of the tag 1, and here, signature data indicating a digital signature is used. The time stamp is data indicating date and time information when the authentication information is generated. The key data is a key code corresponding to the authentication information.

FIG. 2 is a block diagram showing a configuration of the R / W device 2 according to the first embodiment, and only functional blocks related to the present invention are extracted. The R / W device 2 is an arbitrary device, and can be, for example, a server, a personal computer, a printer, a home appliance, a PDA, a mobile phone, or the like. The R / W device 2 includes a read / write unit 21, an authentication information request unit 22, a communication unit 23, an authentication information reception unit 24, a verification request unit 25, a verification result reception unit 26, and an operation control unit 27.
The reading / writing means 21 has a function of reading and writing information in the tag 1, and is specifically an RFID tag reader / writer. The communication unit 23 transmits / receives data to / from the gateway device 3 through an intranet, a cable, wireless communication, or the like.

  The authentication information request unit 22 transmits an authentication information generation request signal addressed to the authentication device 5 to the gateway device 3 through the communication unit 23. The authentication information generation request signal includes information indicating an authentication information generation request, and unique information and user data read from the storage unit of the tag 1 via the reading / writing unit 21. The authentication information receiving unit 24 includes authentication information generated by the authentication device 5 from the gateway device 3 via the communication unit 23, a time stamp indicating data indicating the date and time when the authentication information is generated, and a key corresponding to the authentication information. The data is received and written to the rewritable area in the storage means of the tag 1 by the reading / writing means 21.

  The verification request unit 25 transmits a verification request signal addressed to the authentication device 5 to the gateway device 3 through the communication unit 23. The verification request signal includes information indicating a verification request, unique information, user data, authentication information, time stamp, and key data read from the storage unit of the tag 1 via the reading / writing unit 21 And verification request data consisting of The verification result receiving unit 26 receives information on the verification result in the gateway device 3 via the communication unit 23. The operation control unit 27 controls the function executed by the R / W device 2 in accordance with the verification result information received by the verification result receiving unit 26.

  FIG. 3 is a block diagram showing a configuration of the authentication device 5 according to the first embodiment, and only functional blocks related to the present invention are extracted and shown. The authentication device 5 can be configured by a server, for example. The authentication device 5 includes a communication unit 51, an authentication information request reception unit 52, an authentication information generation unit 53, a clock 54, an authentication information transmission unit 56, a verification request reception unit 57, a verification unit 58, and a verification result transmission unit 59. .

The communication unit 51 transmits / receives data to / from the gateway device 3 via the network 4 by encrypted communication.
The authentication information request receiving means 52 receives an authentication information generation request signal. The authentication information generating unit 53 uses the unique information and user data included in the generation request signal received by the authentication information request receiving unit 52 and the time stamp which is data indicating the current time acquired from the clock 54. And a key corresponding to the authentication information. For generation of authentication information and key, Elliptic Curve Cryptosystem (ECC), which is one of public key encryption methods, is used. The key corresponding to the authentication information is a public key of elliptic curve encryption. is there. The authentication information transmitting unit 56 transmits the authentication information generated by the authentication information generating unit 53 and the time stamp and key data to the R / W device 2 via the communication unit 51.
The verification request receiving unit 57 receives a verification request signal. The verification unit 58 verifies the validity of the authentication information using the unique information, user data, authentication information, time stamp, and key data in the verification request data included in the verification request signal. The verification result transmission unit 59 transmits information indicating the verification result by the verification unit 58 to the R / W device 2.

FIG. 4 is a diagram illustrating a data configuration in the storage unit included in the tag 1 according to the first embodiment.
The tag 1 storage means includes a protected area in which data can be written only at the issue stage of the tag 1 and data cannot be rewritten in the field, and a rewritable area in which data can be rewritten in the field after issuance. Unique information such as a tag ID is recorded in the protect area. The rewritable area stores user data, signature data as authentication information, a time stamp indicating information on the date and time when the signature data was generated, and key data indicating a public key code corresponding to the signature data.

FIG. 5 is a diagram showing a signature generation procedure of the tag authentication system according to the first embodiment.
The authentication information request unit 22 of the R / W device 2 transmits a read request for specific information and user data to the tag 1 via the read / write unit 21 (step S110). When the tag 1 receives the read request, the tag 1 transmits the unique information stored in the protected area in the storage unit and the user data stored in the rewritable area to the R / W device 2 (step S115). The authentication information request unit 22 of the R / W device 2 transmits a signature generation request signal as an authentication information generation request signal to the gateway device 3 through the communication unit 23 (step S120). The signature generation request signal includes information indicating that it is a signature generation request, and unique information and user data received from the tag 1 via the reading / writing means 21.

  Upon receiving the signature generation request signal from the R / W device 2, the gateway device 3 transmits an SSL request for requesting establishment of SSL communication to the authentication device 5 via the network 4 (step S125). When establishing SSL communication, the communication unit 51 of the authentication device 5 returns an SSL response to the gateway device 3 (step S130). As a result, a secure session using SSL communication is established between the gateway device 3 and the authentication device 5.

  The gateway device 3 transmits the signature generation request signal received from the R / W device 2 in step S120 to the authentication device 5 using an SSL packet (step S135). The authentication information request receiving unit 52 of the authentication device 5 receives the signature generation request signal via the communication unit 51. The authentication information generation means 53 reads the current time information from the clock 54 and generates a time stamp indicating the acquired time (step S140). Next, the authentication information generating unit 53 calculates a hash value by using a hash function using the unique information and user data in the signature generation request signal received by the authentication information request receiving unit 52 and the generated time stamp as parameters. (Step S145). The authentication information generation means 53 generates signature data and a public key corresponding to the signature data from the generated hash value and random number using elliptic curve cryptography (step S150). The authentication information transmitting unit 56 transmits the time stamp, signature data, and public key to the gateway device 3 by using an SSL packet (step S155).

  The gateway device 3 extracts the time stamp, signature data, and public key received from the authentication device 5 from the SSL packet and transmits them to the R / W device 2 (step S160). When the authentication information receiving unit 24 of the R / W device 2 receives the time stamp, the signature data, and the public key via the communication unit 23, the reading / writing unit 21 rewrites the storage unit included in the tag 1. Write in the possible area (step S165). The tag 1 transmits to the R / W device 2 confirmation information indicating the writing status of whether the writing of the time stamp, the signature data, and the public key to the rewritable area of the storage means has succeeded or failed (step S170). ).

FIG. 6 is a diagram showing a signature verification procedure of the tag authentication system according to the first embodiment.
The verification request unit 25 of the R / W device 2 transmits a read request for the unique information, user data, time stamp, signature data, and public key to the tag 1 via the reading / writing unit 21 (step S210). . When the tag 1 receives the read request, the tag 1 transmits the unique information stored in the protected area in the storage means and the user data, time stamp, signature data, and public key stored in the rewritable area to the R / R Transmit to W device 2 (step S215).

  The verification request unit 25 of the R / W device 2 transmits a verification request signal addressed to the authentication device 5 to the gateway device 3 through the communication unit 23 (step S220). The verification request signal includes information indicating that the request is a verification request, unique information received from the tag 1 via the reading / writing means 21, user data, time stamp, signature data, and a public key. Data. When the gateway device 3 receives the verification request signal from the R / W device 2, the gateway device 3 performs a secure session using SSL communication between the gateway device 3 and the authentication device 5 in the same procedure as steps S125 to S130 in FIG. Establish (steps S225 to 230).

  The gateway device 3 transmits the verification request signal received from the R / W device 2 in step S220 to the authentication device 5 using an SSL packet (step S235). The verification request receiving unit 57 of the authentication device 5 receives the verification request signal via the communication unit 51. The verification unit 58 extracts a time stamp from the verification request data included in the verification request signal received by the verification request reception unit 57 (step S240). Next, the verification unit 58 calculates a hash value using a hash function using the extracted time stamp, the unique information in the verification request data, and the user data as parameters (step S245). Subsequently, the verification unit 58 extracts the public key from the verification request data (step S250). The verification means 58 uses the hash value calculated in step S245, the public key extracted in step S250, and the component included in the signature data as parameters, and the value calculated using the verification function of elliptic curve cryptography. The signature data is determined to be valid if it matches with the other components included in, and if it does not match, it is determined to be incorrect (step S255). The verification result transmission unit 59 transmits information indicating the verification result by the verification unit 58 to the gateway device 3 using an SSL packet (step S260).

The gateway device 3 transmits the verification result information received from the authentication device 5 to the R / W device 2 (step S265). When the verification result receiving unit 26 of the R / W device 2 receives the verification result information via the communication unit 23, the verification result receiving unit 26 displays the verification result on a display (not shown) provided in the R / W device 2 (step S270). ). The operation control unit 27 controls a function executed by the R / W device 2 according to the verification result.
For example, the R / W device 2 is a printer, and the tag 1 is provided for the toner. If the verification result information indicates that it is valid in step S270, the operation control means 27 of the R / W device 2 provides all printing functions such as full-color printing. On the other hand, when the verification result information indicates fraud, the operation control means 27 provides only a part of printing functions such as monochrome printing. In this way, by providing a tag 1 on a pure product part or consumable part of a certain product, all functions are provided when verified as a genuine product, and some parts are used when a product other than a genuine product is used. Only the functions can be provided, or the provision of all functions can be restricted, and the user can be encouraged to use genuine parts and consumables.

Next, a tag authentication system according to the second embodiment will be described.
In the tag authentication system according to the second embodiment, the tag 1 stores a key ID for specifying a key instead of key data. Hereinafter, other embodiments will be described focusing on differences from the above-described embodiments.

  The configuration of the tag authentication system according to the second embodiment is the same as the configuration of the tag authentication system according to the first embodiment shown in FIG. 1, but in this embodiment, instead of the authentication device 5, the authentication device 5a. Is used. The data structure in the storage means included in the tag 1 is the same as the data structure according to the first embodiment shown in FIG. 4, but in the rewritable area, instead of the key data indicating the public key code. The key ID for specifying the public key is stored.

FIG. 7 is a block diagram showing the configuration of the authentication device 5a according to the second embodiment. In this figure, the same parts as those of the authentication device 5 in the first embodiment shown in FIG.
The authentication information generating unit 53a authenticates using the unique information, user data and key ID included in the generation request signal received by the authentication information request receiving unit 52, and a time stamp which is data indicating the time acquired from the clock 54. Information and a key corresponding to the authentication information are generated. Further, the authentication information generation unit 53a writes the generated key and the key ID in association with each other in the key information storage unit 55. The authentication information transmitting unit 56a transmits the authentication information generated by the authentication information generating unit 53a and the time stamp to the R / W device 2. When the verification request receiving unit 57 receives a verification request signal including verification request data including unique information, user data, authentication information, a time stamp, and a key ID, the verification unit 58a corresponds to the key ID in the verification request data. The obtained key is read from the key information storage means 55. Further, the validity of the authentication information is verified using the read key and the unique information, user data, authentication information, and time stamp in the verification request data.

FIG. 8 is a diagram showing a signature generation procedure in the tag authentication system according to the second embodiment.
The authentication information request unit 22 of the R / W device 2 transmits a read request for the unique information, user data, and key ID to the tag 1 via the reading / writing unit 21 (step S310). When the tag 1 receives the read request, the tag 1 transmits the unique information stored in the protected area in the storage means and the user data and key ID stored in the rewritable area to the R / W device 2 (Step S1). S315). The authentication information request unit 22 of the R / W device 2 transmits a signature generation request signal as an authentication information generation request signal to the gateway device 3 through the communication unit 23 (step S320). The signature generation request signal includes information indicating that it is a signature generation request, unique information received from the tag 1 via the reading / writing means 21, user data, and a key ID.

  The gateway device 3 that has received the signature generation request signal from the R / W device 2 establishes a secure session using SSL communication between the authentication devices 5a, and receives the signature generation request signal received from the R / W device 2 as an SSL. The procedure of steps S325 to S335 transmitted by the packet to the authentication device 5a is the same as the procedure of steps S125 to S135 of FIG.

  Subsequently, after the authentication information request receiving unit 52 of the authentication device 5a receives the signature generation request signal, the authentication information generation unit 53a generates a time stamp, and the generated time stamp and the uniqueness in the signature generation request signal The procedure of steps S340 to S345 for calculating a hash value using a hash function with information and user data as parameters is the same as steps S140 to S145 in FIG. After calculating the hash value, the authentication information generation unit 53a generates a random number based on the key ID in the received signature generation request signal (step S350). The authentication information generation unit 53a generates signature data and a public key corresponding to the signature data from the generated hash value and random number using elliptic curve cryptography (step S355). The authentication information transmitting unit 56a transmits the time stamp and the signature data to the gateway device 3 by using an SSL packet (step S360). The authentication information generation unit 53a writes the key ID and the generated public key in association with each other in the key information storage unit 55 (step S365).

  The gateway device 3 transmits the time stamp and signature data received from the authentication device 5a to the R / W device 2 (step S370). When the authentication information receiving unit 24 of the R / W device 2 receives the time stamp and the signature data via the communication unit 23, the reading / writing unit 21 causes the authentication information receiving unit 24 to store the rewritable area in the storage unit included in the tag 1. Writing is performed (step S375). The tag 1 transmits a time stamp to the rewritable area of the storage unit and confirmation information indicating a writing state indicating whether writing of the signature data has succeeded or failed to the R / W device 2 (step S380).

FIG. 9 is a diagram showing a signature verification procedure in the tag authentication system according to the second embodiment.
The verification request unit 25 of the R / W device 2 transmits a request to read the unique information, user data, time stamp, signature data, and key ID to the tag 1 (step S410). The tag 1 transmits the unique information stored in the protected area in the storage means and the user data, time stamp, signature data, and key ID stored in the rewritable area to the R / W device 2. (Step S415). The verification request unit 25 of the R / W device 2 transmits a verification request signal addressed to the authentication device 5a to the gateway device 3 through the communication unit 23 (step S420). The verification request signal includes information indicating a verification request and verification request data including unique information received from the tag 1, user data, time stamp, signature data, and key ID.

  The gateway device 3 that has received the verification request signal from the R / W device 2 establishes a secure session using SSL communication between the authentication devices 5a, and receives the verification request signal received from the R / W device 2 as an SSL packet. The procedure of steps S425 to S435 transmitted to the authentication device 5a is the same as the procedure of steps S225 to S235 in FIG.

  The verification request receiving means 57 of the authentication device 5a receives the verification request signal, and the verification means 58a receives the time stamp extracted from the verification request data included in the verification request signal, the unique information and the user data in the verification request data. The procedure of steps S440 to S445 for calculating the hash value using the hash function as a parameter is the same as the procedure of steps S240 to S245 in FIG. Subsequently, the verification unit 58a reads the public key corresponding to the key ID in the verification request data from the key information storage unit 55 (step S450).

  The verification means 58a uses the hash value calculated in step S445, the public key read in step S445, and the component included in the signature data as parameters to calculate the signature data using the verification function of the elliptic curve cryptography. The signature data is determined to be valid if it matches with the other components included in, and if it does not match, it is determined to be incorrect (step S455).

  The verification result transmission means 59 of the authentication device 5a transmits information indicating the verification result to the gateway device 3 by an SSL packet, and the R / W device 2 receives the verification result information from the gateway device 3 and displays the verification result. The steps S460 to S470 for controlling the function executed by the R / W device 2 according to the verification result are the same as the steps S260 to S270 in FIG.

In the second embodiment described above, the public key is stored in the key information storage unit 55 in correspondence with the key ID, but is associated with the unique information, the user ID included in the user data, and the like. The public key may be stored.
Further, the key ID may be changed every time the public key is generated. In this case, the authentication device 5a transmits a key ID for specifying a new public key in step S360 of FIG. 8, and in step S375, the R / W device 2 uses the key ID received from the gateway device 3 as the tag 1 Write in the storage means.

  In the tag authentication system according to the first and second embodiments described above, every time the R / W device 2 is turned on every time communication with the tag 1 becomes possible, a specific function of the R / W device 2 is executed. The signature verification procedure shown in FIG. 6 or FIG. 8 and the signature generation procedure shown in FIG. 5 or FIG.

Next, signature generation and verification using elliptic curve cryptography will be described.
When generating a signature, first, a hash value e of plaintext M, which is a source for generating a signature, is calculated using a hash function H. Note that the plaintext M corresponds to the unique information and user data included in the signature generation request signal and the time stamp in the above embodiment.

  Hash value e = hash function H (M)

  Next, the signature S and the public key S are calculated using the signature generation function f using the hash value e, the random number d, and the random number k as parameters. The signature S is a 160-bit value composed of components r and s each having 20 bytes, and the public key S is a 160-bit value composed of components x and y each having 20 bytes.

  When verifying the signature, plaintext M ′, signature S, and public key Q are used. First, the hash value e ′ of the plaintext M ′ is calculated using the hash function H. This plaintext M ′ corresponds to unique information, user data, and time stamp included in the signature verification request data in the signature verification request signal.

  Hash value e ′ = H (M ′)

  Next, the verification value v is calculated using the verification function g using the hash value e ′, the public key Q, and s, which is a component of the signature S = (r, s), as parameters. The public key Q corresponds to a public key corresponding to the key ID included in the signature verification request data or a public key included in the signature verification request data. The signature S corresponds to signature data included in the signature verification request data.

  Verification value v = Verification function g (e ′, Q, s)

  If the calculated verification value v matches r, which is a component of signature S = (r, s), it is determined that the signature is valid, and if not, the signature is determined to be invalid.

In the above embodiment, the gateway device 3 performs encrypted communication with the authentication device 5 and the authentication device 5a. However, the R / W device 2 directly uses the authentication device 5 and the authentication device without using the gateway device 3. It is also possible to perform encrypted communication with 5a.
In addition, the authentication device 5 and the authentication device 5a may encrypt and transmit a time stamp, a public key, or a key ID. For example, the authentication device 5 encrypts the time stamp and the public key with the public key of the tag 1 and transmits it. The R / W device 2 decrypts the time stamp and the public key with the secret key of the tag 1 and writes them in the tag 1.
Further, an encryption algorithm ID for specifying an encryption algorithm used for signature data may be further stored in the storage means in the tag 1. The R / W device 2 transmits a signature data generation request signal including the encryption algorithm ID read from the tag 1 and a verification request time signal. The authentication information generating unit 53 of the authentication device 5 and the authentication information generating unit 53a of the authentication device 5a generate signature data by the encryption algorithm specified by the received encryption algorithm ID, and the verification unit 58 of the authentication device 5 and the authentication The verification means 58a of the device 5a verifies the signature data with the encryption algorithm specified by the received encryption algorithm ID.
Further, position information indicating the position of the tag 1 may be used instead of the time stamp.

  According to the above embodiment, unique signature data is generated using the unique information and the time stamp. Therefore, it is possible to detect falsification of the IC tag by constantly updating the signature data. For example, when an IC tag is added to a product to improve security, it is necessary to detect unauthorized writing of data to the IC tag. This can be achieved by verifying signature data in the IC tag. In addition, it is inevitable to dead copy the normal rewritable area of the IC tag as it is, but by constantly updating the signature data with uniqueness, it is possible to avoid illegal use of the copied information. can do. Even when there is unauthorized use, it is possible to specify the tampering time by the time stamp. In addition, since signature data is generated using elliptic curve cryptography, the encryption strength can be increased and the memory capacity for storing the signature data can be reduced even if the data length of the signature data is short.

  The R / W device 2, the gateway device 3, the authentication device 5 and the authentication device 5a described above have a computer system inside. The authentication information requesting means 22, the authentication information receiving means 24, the verification requesting means 25 and the verification result receiving means 26 of the R / W device 2 described above, the gateway device 3, the authentication information request receiving means 52 of the authentication device 5, the authentication information Generation unit 53, authentication information transmission unit 56, verification request reception unit 57, verification unit 58, verification result transmission unit 59, and authentication information request reception unit 52 of authentication device 5a, authentication information generation unit 53a, authentication information transmission The operation processes of the means 56a, the verification request receiving means 57, the verification means 58a, and the verification result transmitting means 59 are stored in a computer-readable recording medium in the form of a program, and the computer system reads this program. By executing this, the above processing is performed. The computer system here includes an OS and hardware such as peripheral devices.

  In addition to ROM, “computer-readable recording medium” refers to a portable medium such as a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, a hard disk built in a computer system, a non-volatile memory, etc. This is a storage device. Furthermore, the “computer-readable recording medium” refers to a volatile memory (RAM) inside a computer system that becomes a client or a system when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. In addition, those holding programs for a certain period of time are also included.

Further, the “computer system” includes a homepage providing environment (or display environment) if a WWW system is used.
The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Furthermore, the “computer-readable recording medium” dynamically holds a program for a short time like a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line. In this case, a volatile memory in a computer system serving as a server or a client in that case, and a program that holds a program for a certain period of time are also included. The program may be a program for realizing a part of the functions described above, and may be a program capable of realizing the functions described above in combination with a program already recorded in a computer system.

It is a block diagram of the tag authentication system by the 1st Embodiment of this invention. It is a block diagram which shows the structure of the R / W apparatus by 1st Embodiment. It is a block diagram which shows the structure of the authentication apparatus by 1st Embodiment. It is a figure which shows the data structure in the memory | storage means with which the tag by 1st Embodiment is provided. It is a figure which shows the signature production | generation procedure of the tag authentication system by 1st Embodiment. It is a figure which shows the signature verification procedure of the tag authentication system by 1st Embodiment. It is a block diagram which shows the structure of the authentication apparatus by 2nd Embodiment. It is a figure which shows the signature production | generation procedure of the tag authentication system by 2nd Embodiment. It is a figure which shows the signature verification procedure of the tag authentication system by 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Tag 2 ... R / W apparatus 3 ... Gateway apparatus 4 ... Network 5, 5a ... Authentication apparatus 21 ... Reading / writing means 22 ... Authentication information request means 23, 51 ... Communication means 24 ... Authentication information receiving means 25 ... Verification Request means 26 ... Verification result receiving means 27 ... Operation control means 52 ... Authentication information request receiving means 53, 53a ... Authentication information generating means 54 ... Clock 55 ... Key information storage means 56, 56a ... Authentication information transmitting means 57 ... Verification request reception Means 58, 58a ... Verification means 59 ... Verification result transmission means

Claims (13)

A tag authentication system comprising an IC tag, a reader / writer device that reads and writes information in the IC tag, and an authentication device that verifies the validity of the IC tag,
The IC tag is
A storage means having a protect area that is a storage area where data cannot be rewritten and a rewritable area that is a storage area where data can be rewritten;
The reader / writer device is
Reading out the unique information , which is information unique to each IC tag, and the encryption algorithm identification information for specifying the encryption algorithm used for verifying the validity of the IC tag from the protected area in the storage means provided in the IC tag, and An authentication information requesting means for transmitting to the authentication device;
Corresponding to the unique information transmitted by the authentication information requesting means, authentication information that is information used for verifying the validity of the IC tag, and a time stamp that is information indicating the time when the authentication information was generated Authentication information receiving means that receives from the authentication device and writes to a rewritable area in the storage means of the IC tag;
Verification request means for reading out the unique information and the encryption algorithm identification information from the protected area in the storage means included in the IC tag, and reading the authentication information and the time stamp from the rewritable area in the storage means and transmitting them to the authentication device; Prepared,
The authentication device
Authentication information request receiving means for receiving unique information and encryption algorithm identification information from the reader / writer device;
Encryption algorithm identification information received by the authentication information request receiving means by calculating a hash value from a hash function using the unique information received by the authentication information request receiving means and a time stamp indicating the current time information as parameters. Authentication information generating means for generating authentication information from the calculated hash value using the encryption algorithm specified by
Authentication information transmitting means for returning the authentication information generated by the authentication information generating means and the time stamp used for generating the authentication information to the reader / writer device ;
Verification request receiving means for receiving unique information, encryption algorithm identification information, authentication information and time stamp from the reader / writer device;
A hash value is calculated from a hash function using the unique information and time stamp received by the verification request receiving unit as parameters, and using an encryption algorithm specified by the encryption algorithm identification information received by the verification request receiving unit, Verification means for verifying the validity of the IC tag using the calculated hash value and the authentication information received by the verification request receiving means;
Verification result transmission means for returning information indicating a verification result by the verification means to the reader / writer device ;
A tag authentication system characterized by this. The authentication information requesting unit further reads out user data, which is data arbitrarily used by the user, from the rewritable area in the storage unit included in the IC tag, and transmits the user data to the authentication device.
The authentication information request receiving means further receives user data from the reader / writer device,
The authentication information generating means generates authentication information based on the unique information and user data received by the authentication information request receiving means, and a time stamp indicating current time information,
The verification request unit further reads user data from a rewritable area in a storage unit included in the IC tag and transmits the user data to the authentication device,
The verification request receiving means further receives user data from the reader / writer device,
The verification means verifies the validity of the IC tag using the unique information, authentication information, time stamp, and user data received by the verification request receiving means.
The tag authentication system according to claim 1 . The authentication information generating means, the tag authentication system according to claim 1 or claim 2, characterized in that to generate the authentication information using elliptic curve cryptography. The storage means included in the IC tag further stores key information,
The verification request unit further transmits key information read from the storage unit included in the IC tag to the authentication device,
The verification request receiving means further receives key information from the reader / writer device,
The verification means further verifies the validity of the IC tag using the key information received by the verification request receiving means;
The tag authentication system according to claim 3 . The authentication information transmitting means further transmits key information corresponding to the authentication information to the reader / writer device;
The authentication information receiving means further receives key information from the authentication device and writes it in a rewritable area in the storage means provided in the IC tag.
The tag authentication system according to claim 4 . The authentication device further includes key information storage means for storing key information and key specifying information for specifying the key in association with each other,
The storage means included in the IC tag further stores key specifying information,
The verification request unit further transmits key identification information read from the storage unit included in the IC tag to the authentication device,
The verification request receiving means further receives key specifying information from the reader / writer device,
The verification unit reads key information corresponding to the key specifying information received by the verification request receiving unit from the key information storage unit, and further verifies the validity of the IC tag using the read key information.
The tag authentication system according to claim 3 . The authentication information requesting means further transmits the key specifying information read from the storage means included in the IC tag to the authentication device,
The authentication information request receiving means further receives key specifying information,
The authentication information generating means generates authentication information by further using the key specifying information received by the authentication information request receiving means, and associates the key information corresponding to the generated authentication information with the key specifying information and Write to information storage means,
The tag authentication system according to claim 6 . An authentication device used in a tag authentication system comprising an IC tag, a reader / writer device that reads and writes information in the IC tag, and an authentication device that verifies the validity of the IC tag,
An encryption algorithm that is read from a protected area that is a storage area that cannot be rewritten in the storage means included in the IC tag, and is used for verification of the validity of the IC tag and unique information that is unique to each IC tag Authentication information request receiving means for receiving encryption algorithm identification information to be specified from the reader / writer device;
Encryption algorithm identification information received by the authentication information request receiving means by calculating a hash value from a hash function using the unique information received by the authentication information request receiving means and a time stamp indicating the current time information as parameters. Authentication information generating means for generating authentication information used for verifying the validity of the IC tag from the calculated hash value using the encryption algorithm specified by
Authentication information transmitting means for returning the authentication information generated by the authentication information generating means and the time stamp used for generating the authentication information to the reader / writer device;
Specific information and encryption algorithm identification information read from the protected area in the storage means included in the IC tag from the reader / writer device, authentication information read from the rewritable area where data in the storage means can be rewritten, and A verification request receiving means for receiving a time stamp;
A hash value is calculated from a hash function using the unique information and time stamp received by the verification request receiving unit as parameters, and using an encryption algorithm specified by the encryption algorithm identification information received by the verification request receiving unit, Verification means for verifying the validity of the IC tag using the calculated hash value and the authentication information received by the verification request receiving means;
Verification result transmission means for returning information indicating the verification result by the verification means to the reader / writer device;
An authentication device comprising: The authentication information request receiving means further receives from the reader / writer device user data that is read from a rewritable area in the storage means of the IC tag and is arbitrarily used by a user,
The authentication information generating means generates authentication information based on the unique information and user data received by the authentication information request receiving means, and a time stamp indicating current time information,
The verification request receiving unit further receives user data read from a rewritable area in a storage unit included in the IC tag from the reader / writer device,
The verification means verifies the validity of the IC tag using the unique information, authentication information, time stamp, and user data received by the verification request receiving means.
The authentication apparatus according to claim 8 . A tag authentication method used in a tag authentication system comprising an IC tag, a reader / writer device that reads and writes information in the IC tag, and an authentication device that verifies the validity of the IC tag,
The IC tag is
A storage means having a protect area that is a storage area where data cannot be rewritten and a rewritable area that is a storage area where data can be rewritten;
The authentication information requesting means of the reader / writer device identifies the unique information that is unique to each IC tag and the encryption algorithm used to verify the validity of the IC tag from the protected area in the storage means of the IC tag. And reading the encryption algorithm identification information to be sent to the authentication device,
The authentication information request receiving means of the authentication device receives the unique information and the encryption algorithm identification information from the reader / writer device,
The authentication information generation unit of the authentication device calculates a hash value from a hash function using the unique information received by the authentication information request receiving unit and a time stamp indicating the current time information as parameters, and the authentication information request Using the encryption algorithm specified by the encryption algorithm identification information received by the receiving means , generating authentication information used for verifying the validity of the IC tag from the calculated hash value ,
The authentication information transmitting means of the authentication device returns the authentication information generated by the authentication information generating means and the time stamp used for generating the authentication information to the reader / writer device,
Authentication information receiving means of said reader writer device receives the authentication information and the time stamp from the authentication device, writes in a rewritable region of the storage means provided in the said IC tag,
The verification request unit of the reader / writer device reads the unique information and the encryption algorithm identification information from the protected area in the storage unit included in the IC tag, and reads the authentication information and the time stamp from the rewritable area in the storage unit, Sent to the authentication device,
The verification request receiving means of the authentication device receives unique information, encryption algorithm identification information, authentication information and a time stamp from the reader / writer device,
The verification unit of the authentication device calculates a hash value from the hash function using the unique information and time stamp received by the verification request receiving unit as parameters, and is specified by the encryption algorithm identification information received by the verification request receiving unit. And verifying the validity of the IC tag using the calculated hash value and the authentication information received by the verification request receiving means,
A verification result transmission unit of the authentication device returns information indicating a verification result by the verification unit to the reader / writer device;
A tag authentication method characterized by the above. The authentication information requesting unit further reads out user data, which is data arbitrarily used by the user, from the rewritable area in the storage unit included in the IC tag, and transmits the user data to the authentication device,
The authentication information request receiving means further receives user data from the reader / writer device;
The authentication information generating means generates authentication information based on the unique information and user data received by the authentication information request receiving means, and a time stamp indicating current time information,
The verification request unit further reads user data from a rewritable area in the storage unit included in the IC tag and transmits the user data to the authentication device,
The verification request receiving means further receives user data from the reader / writer device;
The verification unit verifies the validity of the IC tag using the unique information, authentication information, time stamp, and user data received by the verification request reception unit,
The tag authentication method according to claim 10 . A tag authentication method used in the authentication device of a tag authentication system, comprising: an IC tag; a reader / writer device that reads and writes information in the IC tag; and an authentication device that verifies the validity of the IC tag. ,
The authentication information request receiving means is read from the protected area, which is a storage area where data cannot be rewritten in the storage means provided in the IC tag, and the unique information that is unique to each IC tag and the validity of the IC tag. Receiving from the reader / writer device encryption algorithm identification information for specifying an encryption algorithm used for verification ;
The authentication information generation means calculates a hash value from the hash function using the unique information received by the authentication information request reception means and the time stamp indicating the information of the current time as parameters, and is received by the authentication information request reception means Using the encryption algorithm specified by the encrypted algorithm identification information, generating authentication information used to verify the validity of the IC tag from the calculated hash value ;
Authentication information transmission means returns the authentication information generated by the authentication information generation means and the time stamp used to generate the authentication information to the reader / writer device ,
The verification request receiving means has the unique information and algorithm ID read from the protected area in the storage means provided in the IC tag, and the authentication information and time stamp read from the rewritable area in which data in the storage means can be rewritten. Receive
An encryption algorithm specified by the encryption algorithm identification information received by the verification request receiving unit, wherein the verification unit calculates a hash value from the hash function using the unique information and time stamp received by the verification request receiving unit as parameters. And verifying the validity of the IC tag using the calculated hash value and the authentication information received by the verification request receiving means,
A verification result transmission unit returns information indicating a verification result by the verification unit to the reader / writer device;
A tag authentication method characterized by the above. The authentication information request receiving means further receives from the reader / writer device user data that is read from a rewritable area in the storage means provided in the IC tag and is arbitrarily used by a user,
The authentication information generating means generates authentication information based on the unique information and user data received by the authentication information request receiving means, and a time stamp indicating current time information,
The verification request receiving means further receives user data read from the rewritable area in the storage means included in the IC tag from the reader / writer device,
The verification unit verifies the validity of the IC tag using the unique information, authentication information, time stamp, and user data received by the verification request reception unit,
The tag authentication method according to claim 12 .

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