JP2008048135A - Two-dimensional code-using system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide technique for preventing access to an address included in an illegally displayed two-dimensional code. <P>SOLUTION: A two-dimensional code using system is the system where a computer terminal is connected to a service provider device via a network. The service provider device includes: a means for converting an encryption address obtained by encrypting a self address with the use of the secret key of a CA station into a two-dimensional code, and outputting the two-dimensional code; and a means for receiving access from the computer terminal and providing a prescribed service. The computer terminal includes: a means for reading the two-dimensional code; a means for acquiring decrypted information by decrypting the two-dimensional code, and performing decoding processing with respect to the decrypted information through the use of the open key of the CA station; and a means for performing access to an address via the network when the address is acquired by the decoding processing. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a technique for reading a two-dimensional code displayed on an advertising medium or the like with a computer terminal such as a portable terminal, obtaining an address such as an e-mail address from the read two-dimensional code, and transmitting a mail addressed to the address. It is related.

  As a mobile phone service using the Internet, the QR code written in the advertisement of the service provider is read using the camera function of the mobile phone, and the mobile phone analyzes the QR code to obtain the email address, and the email A service that makes it possible to apply for a prize or apply for a service by sending an e-mail to an address has become widespread.

  Such a service has the advantage that the user can apply for the service without having to manually enter the e-mail address, and the service provider can easily obtain the user's e-mail address. There is a merit of being able to handle services.

  However, since QR codes can be easily created, a malicious person creates an image or printed material that resembles an advertisement of a well-known company, and includes information on the email address addressed to the malicious person. There is a risk of fraud such as displaying a QR code.

  When such fraud is performed, the person who touched the above image recognizes that this image belongs to a well-known company, thereby trusting the QR code on the image and reading it with a mobile phone. , Send your email to the malicious party. And not only can a malicious person obtain an email address illegally, but they can also be directed to a fake website to conduct phishing scams.

  As a countermeasure against such injustice, a method of embedding digital watermark information indicating legitimate information in a QR code can be considered. However, since the QR code is a binary image, it is difficult to take this method.

  Also, in Patent Document 1, the encrypted information obtained by encrypting the bill face information of the securities is used as a QR code, and the QR code and the bill face information are printed on the securities. There is disclosed a method for confirming the authenticity of a securities based on whether or not the information obtained by decryption is coincident with the information on the card face. However, this method cannot confirm the authenticity of the QR code itself.

As described above, there is no conventional technique for confirming whether or not the QR code itself displayed on the advertising medium is illegal, and the user can trust the QR code because of the reliability of the display medium on which the QR code is displayed. There was no choice but to judge whether it was a thing.
JP 2003-44527 A

  The present invention has been made in view of the above points, and a technique for reading a two-dimensional code displayed on an advertising medium or the like with a computer terminal, obtaining an address from the read two-dimensional code, and accessing the address An object of the present invention is to provide a technique for preventing access to an address included in an illegally displayed two-dimensional code.

  The above problem is a two-dimensional code utilization system in which a computer terminal and a service provider device are connected via a network, and the service provider device obtains its own address by encrypting it with the secret key of the CA station. An address two-dimensional encoding means for converting the encrypted address into a two-dimensional code and outputting the two-dimensional code; a service providing means for accepting access to the address from the computer terminal and providing a predetermined service; The computer terminal includes: a two-dimensional code reading unit that reads a two-dimensional code displayed on a display medium; a public key storage unit that stores a public key of the CA station; and the two-dimensional code reading unit. The decrypted information is obtained by decrypting the read two-dimensional code, and the decrypted information is recovered using the public key. Use of a two-dimensional code, comprising: a decoding means for performing an encoding process; and a network access means for accessing the address via the network when an address is obtained by the decoding process Solved by the system.

  The above address is, for example, a mail address. In this case, “accessing to an address via a network” means sending a mail to the mail address.

  In the present invention, the decrypted information is decrypted using the public key of the CA station, and when an address is obtained by the decrypting process, the address is accessed via the network. . The address obtained by the decryption process using the CA station's public key must be the address obtained from the "encrypted address encrypted with the CA station's private key", and the CA station is reliable. The address may be trusted to be that of the correct service provider corresponding to the display medium.

  Therefore, according to the present invention, it is possible to prevent a user from accessing an unauthorized address without making a determination about the reliability of the display medium as in the conventional case.

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

(System configuration)
FIG. 1 is a system configuration diagram showing an overall configuration of a system according to an embodiment of the present invention. As shown in FIG. 1, the system of the present embodiment includes a mobile terminal 10, a service provider device 20, a public key infrastructure (PKI: Public Key Infrastructure) CA (Certificate).
Authority) station 30. In the configuration of FIG. 1, communication between the mobile terminal 10 and the CA station 30 and between the mobile terminal 10 and the service provider device 20 are possible via the Internet. Further, it is assumed that the CA station 30 and the service provider device 20 are connected via an encrypted communication path. In addition, when exchanging information between the CA station 30 and the service provider device 20 offline, it is not necessary to connect the two to the network.

  The CA station 30 can be identified by the key generation management unit 31 that performs generation, update, and management (management of validity period, revocation, update date / time, etc.) of its own private key and public key, and the CA station 30 operator. The service provider's e-mail address is encrypted with the secret key of the CA station 30, and the encryption unit 32 that provides the encrypted e-mail address to the service provider apparatus 20 and the public key of the CA station 30 are distributed to the portable terminal 10 ( It has a public key distribution unit 33 to be disclosed).

  The service provider device 20 receives an email from the user's mobile terminal 10, registers the user's email address in the storage device, and performs a predetermined service (for example, user lottery processing for providing a prize, provision of new product information, etc.) ) Providing a mail address to the CA station 30 and receiving an encrypted mail address, and the encrypted mail address provided from the CA station 30 as a two-dimensional code. And having a two-dimensional encoding unit 23 for outputting.

  The mobile terminal 10 reads a two-dimensional code displayed on an advertising medium and the like, acquires a two-dimensional code image, acquires a two-dimensional code image from the two-dimensional code reading unit 11, The e-mail address decryption unit 12 that obtains the e-mail address by decrypting the two-dimensional code from the e-mail and obtaining the encrypted e-mail address and decrypting the encrypted e-mail address using the public key of the CA station 30 It has a non-volatile memory 13 for storing a key, and a mail transmitting unit 14 for transmitting a mail addressed to the mail address obtained by the mail address decrypting unit 12.

(Basic operation)
Next, the basic operation of the system of the present embodiment will be described with reference to the sequence chart of FIG. In the following operation, it is assumed that the mobile terminal 10 has a valid public key corresponding to the secret key used to generate the read encrypted mail address.

  First, the encrypted mail address acquisition unit 22 of the service provider device 20 requests the CA station 30 to encrypt the mail address of the service provider device 20 with the secret key of the CA station 30 (step 1). Here, it is assumed that registration (identification etc.) of the service provider with the CA station 30 has already been completed, and the service provider device 20 sends the email address to be encrypted to the service provider device 20 by the CA station 30. Along with authentication information for authentication, it is transmitted via an encrypted communication path.

  When the CA station 30 succeeds in authenticating the service provider device 20, the CA station 30 encrypts the received mail address with its own secret key, generates an encrypted mail address, and transmits the service provider device via the encrypted communication path. 20 (step 2).

  The two-dimensional encoding unit 23 of the service provider device 20 converts the encrypted mail address into a two-dimensional code and outputs it (step 3). The output two-dimensional code is sent to, for example, an advertisement printing apparatus, and the printing apparatus creates an advertisement including the two-dimensional code. Also, the service provider device 20 itself may add a two-dimensional code on the advertisement web page and publish the advertisement web page.

  A user who comes into contact with the advertisement and wants to receive a service using the two-dimensional code performs an operation for reading the two-dimensional code on the mobile terminal 10. For example, an operation of setting the camera provided in the mobile terminal 10 to a state where it can be photographed is performed, and the photographing button is pressed.

  By this operation, the two-dimensional code reading unit 11 acquires the two-dimensional code as an image and takes it into the storage device of the portable terminal 10 (step 4).

  Subsequently, the mail address decryption unit 12 acquires the fetched two-dimensional code from the storage device, decrypts it, acquires an encrypted mail address (step 5), and stores the encrypted mail address in the nonvolatile memory 13. Processing for decryption is performed using the stored public key of the CA station 30 (step 6).

  Then, the mail address decryption unit 12 determines whether or not the decryption is successful (step 7). Here, it is determined whether or not the decryption is successful by checking whether or not the information (character string) obtained by the decryption process is in the form of a mail address. For example, check whether one @ mark is included in a character string of a predetermined length including English characters, or whether an @ mark and a predetermined domain name (ne, ga, jp, etc.) are included. To do. If this check is successful, it is determined that the e-mail address has been successfully decrypted. It is possible to determine that the decryption has succeeded by such a check because the information other than the “encrypted mail address encrypted by using the secret key of the CA station 30” is decrypted by the public key of the CA station 30. This is because it is considered very unlikely that an email address will be accidentally processed.

  If the mail address decrypting unit 12 determines that the decryption is successful, the mail address decrypting unit 12 passes the information (mail address) obtained by the decrypting process to the mail transmitting unit 14, and the mail transmitting unit 14 is in a state in which mail can be transmitted. (Step 8).

  For example, a mail application is started, a mail text input screen including a mail transmission instruction button is displayed on the screen of the display unit provided in the mobile terminal 10, and mail is transmitted as soon as the user inputs a transmission instruction. At this time, the mail address obtained by the decryption process may be displayed on the screen so that the user can confirm the contents of the mail address.

  Then, the user inputs the mail text as necessary and instructs mail transmission. Thereby, the mail transmission part 14 transmits mail to the mail address obtained from the encrypted mail address (step 9). If it is determined in step 7 that the e-mail address has not been successfully decrypted, the process is terminated without setting the e-mail transmission unit 14 to the e-mail transmission enabled state.

  As described above, in this embodiment, when it is determined that the encrypted mail address has been successfully decrypted with the public key, the mail is transmitted. Successful decryption of the encrypted mail address with the public key indicates that the mail address has been encrypted with the secret key of the CA station 30. Since the mail address encrypted with the secret key of the CA station 30 may be trusted, the mail address before encryption corresponds to the advertising medium by successfully decrypting the encrypted mail address with the public key. It can be judged that it is correct. If the decryption is not successful, there is a possibility that the mail address is not encrypted with the secret key of the CA station 30 but an illegal mail address. In this embodiment, it is possible to prevent a mail from being sent to such an illegal mail address.

  In the above example, whether or not the decryption is successful is determined by whether or not the information obtained as a result of decrypting the encrypted mail address with the public key is in the form of the mail address. Instead, the information obtained by the decryption process may be regarded as a mail address and the mail address transmission process may be performed. In this case, if the decryption is successful, the email can be sent, but if the decryption is not successful and meaningless information is obtained, the email transmission fails. It is possible to prevent transmission.

  In the above example, the mail address is shown as a two-dimensional code. However, address information other than the mail address such as a URL may be used as a two-dimensional code, and access to the address may be performed. In that case, a function unit having a function suitable for access to the address may be used as the mail transmission unit 14.

  When there are a plurality of service providers, it is possible to use a different CA station for each service provider. In such a case, the mobile terminal 10 acquires public keys from the plurality of CA stations, and performs decryption processing using each of the plurality of public keys one by one at the time of decryption processing. An error is displayed if the decryption process is not successful with the key.

(Detailed processing related to key update)
In general, an expiration date is set for the private key / public key pair of the CA station 30, and when the expiration date expires, the CA station 30 updates the key by generating a new private key / public key pair. . Regardless of the expiration date, if the encryption strength is compromised, the key may be revoked and the private key / public key pair may be updated. However, there are various methods for updating the key, and the method described here is merely an example.

  FIG. 3 shows a flowchart of the operation of the service provider device 20 related to such key update.

  The CA station 3 holds the updated private key / public key pair and the update date / time, and has a function of responding to the information about the update including the key update date / time information in response to an inquiry from another device. Suppose you are. In addition, the service provider device 20 stores the update date and time in the storage device every time the encrypted mail address is updated.

  The mail address encryption unit 22 of the service provider device 20 periodically inquires of the CA station 30 and acquires key update date / time information (steps 11 to 13). Then, the mail address encryption unit 22 of the service provider device 20 compares the date and time when the previous encrypted mail address was updated with the key update date and time acquired from the CA station (step 14). If the encrypted mail address update date / time is later than the key update date / time, it is determined that the encrypted mail address need not be updated (No in step 15), and the process returns to step 11.

  If the encrypted mail address update date / time is before the key update date / time, it is determined that the two-dimensional code needs to be updated because the key has been updated after the encrypted mail address update (in step 15). Yes) Newly request the CA station 30 to encrypt the mail address, obtain the encrypted mail address encrypted with the updated secret key, generate a two-dimensional code from the encrypted mail address, and output it (Step 16). In this way, the two-dimensional code is updated.

  Next, FIG. 4 shows a flowchart of the operation of the mobile terminal 10 including the operation related to the key update. In the example of FIG. 4, the two-dimensional code read by the mobile terminal 10 is a mail address with the latest secret key. It is assumed that it is generated from an encrypted mail address obtained by encryption.

  When the portable terminal 10 receives an operation for reading a two-dimensional code (step 21), the portable terminal 10 checks whether or not access to the CA station 30 is possible (step 22). That is, it tries to access the CA station 30 and checks whether the access is successful. When the portable terminal 10 is outside the wireless communication area, the access to the CA station 30 is unsuccessful, and an error is displayed (step 23).

  If the access to the CA station 30 is successful, the mail address decryption unit 12 determines whether or not the public key needs to be updated (step 24). Specifically, as in the case of the service provider device 20, information related to the update including the key update date / time is acquired from the CA station 30, and the date / time when the previous public key was updated is compared with the key update date / time. . If the public key update date / time is after the key update date / time of the CA station 30, it is determined that the public key need not be updated (No in step 24), and the two-dimensional code reading process is performed without updating the public key. move on. If the public key update date / time is before the key update date / time, it is determined that the public key needs to be updated because the CA station 30 has updated the key after the public key update (Yes in step 24). ) The updated public key is downloaded from the CA station 30 and the public key in the nonvolatile memory 13 is updated (step 25).

  Thereafter, as described above, the two-dimensional code reading unit 11 of the mobile terminal 10 reads the two-dimensional code (step 26), the mail address decrypting unit 12 acquires the encrypted mail address information from the two-dimensional code (step 27), A public key is acquired from the non-volatile memory 13 (step 28), and the encrypted mail address is decrypted using the public key (step 29). If the information obtained by the decryption process is in the form of a mail address, it is determined that the decryption is successful (Yes in Step 30), and the mail address is passed to the mail transmission unit 14 (Step 31). Thereafter, the mail transmission unit 14 transmits mail based on an instruction from the user. If it is determined in step 30 that the decoding is unsuccessful, an error is displayed on the screen (step 23).

  The above processing is based on the premise that the read encrypted mail address is encrypted with the latest secret key. However, even after the public key expires, the two-dimensional code printed on the actual advertising medium may also be generated from the email address encrypted with the private key before the expiration date. . Hereinafter, the processing of the mobile terminal in consideration of such a possibility will be described with reference to the flowchart of FIG.

  After accepting the two-dimensional code reading operation (step 41), the mobile terminal 10 reads the two-dimensional code (step 42), decrypts it to obtain the encrypted mail address, and uses the public key currently held in the nonvolatile memory. Then, a process for decrypting the encrypted mail address is performed (step 43), and the success / failure of the decryption is determined (step 44). If unsuccessful (No in step 44), an attempt is made to access the CA station 30 (step 45). If it cannot be accessed, an error is displayed (step 46). If access is possible, the portable terminal 10 checks whether or not the public key needs to be updated in the same manner as in FIG. 4 (step 47).

  If no update is required (No in step 47), that is, if the current public key is valid, an error is displayed (step 46). This is because the decryption was unsuccessful even though the public key was valid. In step 47, if the public key needs to be updated, the public key is updated (step 48), and the process from the decryption process of the encrypted mail address in step 43 is performed again using the updated public key. .

  If it is determined in step 44 that the decryption has succeeded, the mail address obtained by the decryption is transferred to the mail transmitting unit 14 as in step 31 of FIG. 4 (step 49).

  In addition to the above processing, both the pre-update public key and the post-update public key are held in the mobile terminal 10, and if decryption fails with the post-update public key, the pre-update public key is May be used to attempt decoding.

  According to such processing, even if the portable terminal 10 holds the public key corresponding to the secret key even from the two-dimensional code based on the encrypted mail address encrypted using the expired secret key. You can get an email address. The process of FIG. 5 is inferior from the viewpoint of encryption strength as compared with the process shown in FIG. 4, but has the advantage that the possibility that an email address cannot be obtained from a two-dimensional code without fraud is reduced. In order to avoid using a public key that has passed for a long time after the expiration date, the key update date and time is received from the CA station 30 before the process of reading the two-dimensional code, and the previous mobile terminal 10 If the public key update date and time in is before a predetermined period of time before the key update date and time of the CA station 30, after the key is updated, the process after the two-dimensional code reading process may be executed.

(About realization)
The mobile terminal 10 according to the present embodiment has a program for executing the processing shown in FIG. 4 or the like installed as an application on a small PC or mobile phone having a computer configuration including a storage device such as a CPU and a memory. This can be realized. The service provider device 20 can also be realized by installing a program in a computer.

  In the case of a mobile phone, a method of adding various functions by downloading and installing an application program created in Java (registered trademark) language from a server is widespread, but the program in this embodiment is also this program. It is possible to install on a mobile phone in such a manner. In this case, for example, the mobile phone accesses a predetermined Web server and downloads the program from the Web server.

  Further, the type of the two-dimensional code used in the present embodiment is not limited, but for example, a QR code can be used. QR code can set the level of error correction. Since QR codes are not always displayed on a display medium that provides easy-to-read and clear images, the level of error correction should be set high so that accurate information can be obtained even when reading errors occur. Is desirable. However, when the level of error correction is high, the amount of information that can be used as an encrypted mail address in the two-dimensional code is reduced. Therefore, it is desirable to use a two-dimensional code with a large amount of information that can be embedded.

  The present invention is not limited to the above-described embodiment, and various modifications and applications can be made within the scope of the claims.

1 is a system configuration diagram showing the overall configuration of a system in an embodiment of the present invention. It is a sequence chart for demonstrating the basic operation | movement of a system. It is a flowchart of operation | movement of the service provider apparatus 20 relevant to the update of a key. 4 is a flowchart of the operation of the mobile terminal 10. 12 is another example of a flowchart of the operation of the mobile terminal 10.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Mobile terminal 11 Two-dimensional code reading part 12 Mail address decoding part 13 Non-volatile memory 14 Mail transmission part 20 Service provider apparatus 21 Service provision part 22 Encrypted mail address acquisition part 23 Two-dimensional encoding part 30 CA station 31 Key generation Management unit 32 Encryption unit 33 Public key distribution unit

Claims (3)

A two-dimensional code utilization system in which a computer terminal and a service provider device are connected via a network,
The service provider device includes:
Address two-dimensional encoding means for converting the encrypted address obtained by encrypting its own address with the secret key of the CA station into a two-dimensional code and outputting the two-dimensional code;
Service providing means for accepting access to the address from the computer terminal and providing a predetermined service;
The computer terminal is
Two-dimensional code reading means for reading the two-dimensional code displayed on the display medium;
Public key storage means for storing the public key of the CA station;
Decryption means for obtaining decrypted information by decrypting the two-dimensional code read by the two-dimensional code reading means, and performing decryption processing on the decrypted information using the public key;
A two-dimensional code utilization system comprising: network access means for accessing the address via the network when an address is obtained by the decoding process. The decoding means of the computer terminal is
It is determined whether the information obtained by the decryption process is in the form of an address for performing network access, and when the information is in the form of an address for performing network access, the information obtained by the decryption process To the network access means,
2. The two-dimensional code utilization system according to claim 1, wherein an error is displayed on the display means of the computer terminal when the address format is not for network access. The computer terminal is
Obtain public key update information from the CA station via the network, and based on the update information, determine whether the public key stored in the public key storage means is the latest public key, and update the latest public key. The two-dimensional unit according to claim 1, further comprising means for downloading the latest public key from a CA station and updating the public key stored in the public key storage means when it is determined that the key is not a key. Code usage system.

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