JP7260093B2 - Information processing system - Google Patents

Description

The present invention relates to an information processing system.

Currently, there is no mechanism for guaranteeing that recorded data has not been altered in recording devices for surveillance cameras.

On the other hand, with the spread of smartphones and personal computers, anyone can edit video data. In addition, by using new artificial intelligence technologies such as deep learning, it has become easier to edit with a natural finish that cannot be easily distinguished by the human eye.

Therefore, considering that recorded data from surveillance cameras will be used as evidence in criminal investigations, it is important to check whether the recorded data submitted as evidence is in its original state (unedited state) recorded by the recording device. If it cannot be determined, the admissibility of the evidence may be judged to be low.

In Patent Document 1, when using a rental car or car sharing service, a user of the service takes an image of a vehicle provided for the service with a camera, and transmits the image data as evidence data to a server for storage. A system has been proposed in which the image data as proof data can be used as materials for solving the trouble when a trouble occurs between the service user and the service provider.

JP 2018-151825 A

However, the system of Patent Document 1 does not have a mechanism to guarantee that image data as evidence data has not been altered. In such a case, it cannot be denied that the image data as evidence data may be altered at will on the server side.

The present invention has been made in consideration of the above points. SUMMARY OF THE INVENTION It is an object of the present invention to provide a mechanism for ensuring that image data has not been altered.

An information processing system according to a first aspect of the present invention includes:
a registration device for registering image data;
a verification device that verifies whether or not the image data has been altered;
with
The registration device
an image information transmission unit that transmits a first transaction in which image information is stored to a blockchain network;
a first specific information storage unit that embeds and stores in the image data a two-dimensional code in which first specific information for specifying the first transaction registered in the blockchain is encoded;
a tampering prevention data transmitting unit configured to transmit a second transaction storing tampering prevention data including a hash value of the image data in which the two-dimensional code is embedded and the first specific information to a blockchain network;
has
The verification device is
The first transaction on the blockchain is identified based on the first identification information extracted by decoding the two-dimensional code embedded in the image data to be verified, and the image information is obtained from the identified first transaction. an image information acquisition unit;
The second transaction on the blockchain is searched using the first specific information extracted by decoding the two-dimensional code embedded in the image data to be verified as a search key, and if there is no hit, the image to be verified an alteration-prevented data acquisition unit that determines that data has been altered, and acquires alteration-prevented data from the hit second transaction if there is a hit;
The hash value of the image data to be verified is compared with the hash value included in the alteration prevention data obtained from the second transaction on the blockchain to determine whether or not the image data to be verified has been altered. Department and
have

According to this aspect, since the first transaction in which the image information is stored is registered in the blockchain at the time of registration, it is substantially impossible to modify the image information afterwards. In addition, since the two-dimensional code encoded with the specific information (first specific information) of the first transaction is embedded in the image data, the image data and the specific information (first specific information) of the first transaction can be easily linked. can be managed In addition, since the second transaction in which the alteration-prevented data including the hash value of the image data embedded with the two-dimensional code and the first specific information is stored in the block chain, the alteration-prevented data is subsequently altered. is also virtually impossible. Then, at the time of verification, the first transaction registered on the blockchain is specified based on the first specifying information extracted by decoding the two-dimensional code embedded in the target image data, and from the first transaction By viewing and visually confirming the acquired image information, the viewer can directly verify that the image data has not been altered based on the content of the image information. In addition, by confirming that the hash value of the target image data matches the hash value included in the alteration prevention data acquired from the second transaction registered on the blockchain, the target image data Must not be altered (for example, the two-dimensional code of correct image information must not be abused and embedded in other (fake) image data (the two-dimensional code must not be illegally cut and pasted) ) can be guaranteed.

Further, according to this aspect, for example, even if the property or file name of the file is arbitrarily changed due to the operation of the operating system (OS) or the like when copying the image data, at the time of verification, The second transaction registered on the blockchain by searching for the second transaction on the blockchain using the first specific information extracted by decoding the two-dimensional code embedded in the target image data as a search key. is specified, and based on the hash value included in the alteration prevention data acquired from the second transaction, it is possible to guarantee that the target image data has not been altered.

An information processing system according to a second aspect of the present invention includes:
a registration device for registering image data;
a verification device that verifies whether or not the image data has been altered;
with
The registration device
an image information transmission unit that transmits a first transaction in which image information is stored to a blockchain network;
a first specific information storage unit that embeds and stores in the image data a two-dimensional code in which first specific information for specifying the first transaction registered in the blockchain is encoded;
a tampering prevention data transmission unit configured to transmit a second transaction storing tampering prevention data including a hash value of the image data embedded with the two-dimensional code to a blockchain network;
The second specification information for specifying the second transaction registered in the blockchain is stored in the property or file name of the file that does not affect the hash value of the image data in which the two-dimensional code is embedded. a storage unit;
has
The verification device is
The first transaction on the blockchain is identified based on the first identification information extracted by decoding the two-dimensional code embedded in the image data to be verified, and the image information is obtained from the identified first transaction. an image information acquisition unit;
Modification to identify the second transaction on the blockchain based on the second identification information extracted from the property or file name of the file of the image data to be verified, and to acquire the alteration prevention data from the identified second transaction a prevention data acquisition unit;
The hash value of the image data to be verified is compared with the hash value included in the alteration prevention data obtained from the second transaction on the blockchain to determine whether or not the image data to be verified has been altered. Department and
have

According to this aspect, since the first transaction in which the image information is stored is registered in the blockchain at the time of registration, it is substantially impossible to modify the image information afterwards. In addition, since the two-dimensional code encoded with the specific information (first specific information) of the first transaction is embedded in the image data, the image data and the specific information (first specific information) of the first transaction can be easily linked. can be managed In addition, since the second transaction that stores the tamper-prevented data including the hash value of the image data embedded with the two-dimensional code is registered in the blockchain, it is practically impossible to tamper with the tamper-prevented data afterwards. It becomes possible. Further, since the specific information of the second transaction (second specific information) is stored in the property or file name of the file of the image data, the image data and the specific information of the second transaction (second specific information) can be easily identified. Can be linked and managed. Then, at the time of verification, the first transaction registered on the blockchain is specified based on the first specifying information extracted by decoding the two-dimensional code embedded in the target image data, and from the first transaction By viewing and visually confirming the acquired image information, the viewer can directly verify that the image data has not been altered based on the content of the image information. In addition, by confirming that the hash value of the target image data matches the hash value included in the alteration prevention data acquired from the second transaction registered on the blockchain, the target image data Must not be altered (for example, the two-dimensional code of correct image information must not be abused and embedded in other (fake) image data (the two-dimensional code must not be illegally cut and pasted) ) can be guaranteed.

An information processing system according to a third aspect of the present invention is the information processing system according to the first or second aspect,
The registration device
further comprising an image data transmission unit that transmits a third transaction in which the image data embedded with the two-dimensional code is stored to a blockchain network;
The alteration-prevented data transmission unit transmits to the blockchain network a second transaction in which alteration-prevented data is stored, further including third identification information for identifying the third transaction registered in the blockchain;
The verification device is
Image data acquisition for identifying a third transaction on the blockchain based on the third identification information included in the tamper-proof data obtained from the second transaction on the blockchain, and obtaining image data from the identified third transaction It further has a part.

According to this aspect, at the time of registration, the third transaction in which the image data embedded with the two-dimensional code is stored is registered in the blockchain, so it is substantially impossible to modify the image data afterwards. It becomes possible. Then, at the time of verification, the first transaction registered on the blockchain is specified based on the first specifying information extracted by decoding the two-dimensional code embedded in the target image data, and from the first transaction By browsing and visually confirming the acquired image information, and by browsing and visually confirming the image data acquired from the third transaction registered on the blockchain, the content of the image information and image data Based on this, it is possible for the viewer to directly verify that the image data has not been altered with a higher degree of certainty.

An information processing system according to a fourth aspect of the present invention is the information processing system according to any one of the first to third aspects,
The registration device has a private key, the verification device has a public key corresponding to the private key,
The image information transmission unit transmits a first transaction storing the image information encoded with the private key to a blockchain network,
The image information acquisition unit acquires the image information stored in the first transaction on the blockchain by decrypting it with the public key.

According to this aspect, even when using a public blockchain, viewing of image information registered on the blockchain can be limited to specific viewers who have public keys.

An information processing system according to a fifth aspect of the present invention is the information processing system according to any one of the first to third aspects,
The registration device has a private key, the verification device has a public key corresponding to the private key,
The alteration-prevented data transmission unit transmits a second transaction storing the alteration-prevented data encoded with the private key to a blockchain network,
The alteration-prevented data acquisition unit decrypts and acquires the alteration-prevented data stored in the second transaction on the blockchain with the public key.

According to this aspect, even when using a public blockchain, it is possible to restrict viewing of alteration-prevented data registered on the blockchain to only specific viewers who have public keys. .

An information processing system according to a sixth aspect of the present invention is an information processing system according to the second aspect or a third aspect quoting the second aspect,
The registration device has a private key, the verification device has a public key corresponding to the private key,
The second specific information storage unit encodes the second specific information with the secret key and stores it in the property or file name of the file;
The alteration-prevented data acquisition unit decrypts and extracts the second specific information stored in the property or file name of the file with the public key.

According to this aspect, even when using a public blockchain, it is possible to limit the identification of the second transaction registered on the blockchain to only specific viewers who have the public key. Thus, viewing of the alteration-protected data stored in the second transaction can be restricted only to the specific viewer.

An information processing system according to a seventh aspect of the present invention is the information processing system according to any one of the first to third aspects,
The verification device has a private key, the registration device has a public key corresponding to the private key,
The image information transmission unit transmits a first transaction storing the image information encoded with the public key to a blockchain network;
The image information acquisition unit decrypts and acquires the image information stored in the first transaction on the blockchain with the private key.

According to this aspect, even when using a public blockchain, viewing of image information registered on the blockchain can be limited to specific viewers who have a private key.

An information processing system according to an eighth aspect of the present invention is the information processing system according to any one of the first to third aspects,
The verification device has a private key, the registration device has a public key corresponding to the private key,
The tamper-resistant data transmission unit transmits a second transaction containing the tamper-resistant data encoded with the public key to a blockchain network,
The alteration-prevented data acquisition unit decrypts and acquires the alteration-prevented data stored in the second transaction on the blockchain with the private key.

According to this aspect, even when using a public blockchain, it is possible to restrict viewing of alteration-prevented data registered on the blockchain to only specific viewers who have a private key. .

An information processing system according to a ninth aspect of the present invention is an information processing system according to the second aspect or the third aspect quoting the second aspect,
The verification device has a private key, the registration device has a public key corresponding to the private key,
The second specific information storage unit encodes the second specific information with the public key and stores the second specific information in the property or file name of the file;
The alteration-prevented data acquisition unit decrypts and extracts the second specific information stored in the property or file name of the file with the private key.

According to this aspect, even when using a public blockchain, it is possible to limit the identification of the second transaction registered on the blockchain to only specific viewers who have the private key. Thus, viewing of the alteration-protected data stored in the second transaction can be restricted only to the specific viewer.

A registration device according to a tenth aspect of the present invention,
A registration device for registering image data,
an image information transmission unit that transmits a first transaction in which image information is stored to a blockchain network;
a first specific information storage unit that embeds and stores in the image data a two-dimensional code in which first specific information for specifying the first transaction registered in the blockchain is encoded;
a tampering prevention data transmitting unit configured to transmit a second transaction storing tampering prevention data including a hash value of the image data in which the two-dimensional code is embedded and the first specific information to a blockchain network;
Prepare.

A registration device according to an eleventh aspect of the present invention includes:
an image information transmission unit that transmits a first transaction in which image information is stored to a blockchain network;
a first specific information storage unit that embeds and stores in the image data a two-dimensional code in which first specific information for specifying the first transaction registered in the blockchain is encoded;
a tampering prevention data transmission unit configured to transmit a second transaction storing tampering prevention data including a hash value of the image data embedded with the two-dimensional code to a blockchain network;
The second specification information for specifying the second transaction registered in the blockchain is stored in the property or file name of the file that does not affect the hash value of the image data in which the two-dimensional code is embedded. a storage unit;
Prepare.

A registration device according to a twelfth aspect of the present invention is the registration device according to the tenth or eleventh aspect,
further comprising an image data transmission unit that transmits a third transaction storing image data embedded with the two-dimensional code to a blockchain network;
The alteration prevention data transmission unit transmits to the blockchain network a second transaction storing alteration prevention data further including third identification information for identifying the third transaction registered in the blockchain.

A verification device according to a thirteenth aspect of the present invention comprises:
A verification device for verifying whether or not image data has been altered,
The first transaction on the blockchain is identified based on the first identification information extracted by decoding the two-dimensional code embedded in the image data to be verified, and the image information is obtained from the identified first transaction. an image information acquisition unit;
The second transaction on the blockchain is searched using the first specific information extracted by decoding the two-dimensional code embedded in the image data to be verified as a search key, and if there is no hit, the image to be verified an alteration-prevented data acquisition unit that determines that data has been altered, and acquires alteration-prevented data from the hit second transaction if there is a hit;
The hash value of the image data to be verified is compared with the hash value included in the alteration prevention data obtained from the second transaction on the blockchain to determine whether or not the image data to be verified has been altered. Department and
Prepare.

A verification device according to a fourteenth aspect of the present invention comprises:
A verification device for verifying whether or not image data has been altered,
The first transaction on the blockchain is identified based on the first identification information extracted by decoding the two-dimensional code embedded in the image data to be verified, and the image information is obtained from the identified first transaction. an image information acquisition unit;
Identify the second transaction on the blockchain based on the second identification information extracted from the file property or file name that does not affect the hash value of the image data to be verified, and extract the tamper-proof data from the identified second transaction a tampering prevention data acquisition unit that acquires
The hash value of the image data to be verified is compared with the hash value included in the alteration prevention data obtained from the second transaction on the blockchain to determine whether or not the image data to be verified has been altered. Department and
Prepare.

A verification device according to a fifteenth aspect of the present invention is the verification device according to the thirteenth or fourteenth aspect,
Image data acquisition for identifying a third transaction on the blockchain based on the third identification information included in the tamper-proof data obtained from the second transaction on the blockchain, and obtaining image data from the identified third transaction It further comprises a part.

An information processing method according to a sixteenth aspect of the present invention comprises:
A computer-executed information processing method comprising:
an image information transmission step of transmitting a first transaction in which image information is stored to a blockchain network;
a first specification information storing step of embedding and storing in the image data a two-dimensional code in which first specification information for specifying the first transaction registered in the blockchain is encoded;
a tampering prevention data transmission step of transmitting a second transaction in which tampering prevention data including a hash value of recorded data embedded with the two-dimensional code and the first specific information is stored to a blockchain network;
including.

An information processing method according to a seventeenth aspect of the present invention comprises:
A computer-executed information processing method comprising:
an image information transmission step of transmitting a first transaction in which image information is stored to a blockchain network;
a first specification information storing step of embedding and storing in the image data a two-dimensional code in which first specification information for specifying the first transaction registered in the blockchain is encoded;
a tampering prevention data transmission step of transmitting a second transaction in which tampering prevention data including a hash value of recorded data embedded with the two-dimensional code is stored to a blockchain network;
The second specification information for specifying the second transaction registered in the blockchain is stored in the property or file name of the file that does not affect the hash value of the image data in which the two-dimensional code is embedded. a storage step;
including.

An information processing method according to an eighteenth aspect of the present invention is the information processing method according to the sixteenth or seventeenth aspect,
further comprising an image data transmission step of transmitting a third transaction in which the image data embedded with the two-dimensional code is stored to a blockchain network;
In the alteration prevention data transmission step, a second transaction storing alteration prevention data further including third identification information for identifying the third transaction registered in the blockchain is transmitted to the blockchain network.

An information processing method according to a nineteenth aspect of the present invention comprises:
A computer-executed information processing method comprising:
The first transaction on the blockchain is identified based on the first identification information extracted by decoding the two-dimensional code embedded in the image data to be verified, and the image information is obtained from the identified first transaction. an image information acquisition step;
The second transaction on the blockchain is searched using the first specific information extracted by decoding the two-dimensional code embedded in the image data to be verified as a search key, and if there is no hit, the image to be verified a tamper-prevented data acquisition step of determining that data has been tampered with, and acquiring tamper-prevented data from the hit second transaction if there is a hit;
The hash value of the image data to be verified is compared with the hash value included in the alteration prevention data obtained from the second transaction on the blockchain to determine whether or not the image data to be verified has been altered. a step;
including.

An information processing method according to a twentieth aspect of the present invention comprises:
A computer-executed information processing method comprising:
The first transaction on the blockchain is identified based on the first identification information extracted by decoding the two-dimensional code embedded in the image data to be verified, and the image information is obtained from the identified first transaction. an image information acquisition step;
Identify the second transaction on the blockchain based on the second identification information extracted from the file property or file name that does not affect the hash value of the image data to be verified, and extract the tamper-proof data from the identified second transaction a tamper-resistant data acquisition step that acquires
The hash value of the image data to be verified is compared with the hash value included in the alteration prevention data obtained from the second transaction on the blockchain to determine whether or not the image data to be verified has been altered. a step;
including.

An information processing method according to a twenty-first aspect of the present invention is the information processing method according to the nineteenth or twentieth aspect,
Image data acquisition for identifying a third transaction on the blockchain based on the third identification information included in the tamper-proof data obtained from the second transaction on the blockchain, and obtaining image data from the identified third transaction Further including steps.

An information processing program according to a twenty-second aspect of the present invention comprises
to the computer,
an image information transmission step of transmitting a first transaction in which image information is stored to a blockchain network;
a first specification information storing step of embedding and storing in the image data a two-dimensional code in which first specification information for specifying the first transaction registered in the blockchain is encoded;
a tampering prevention data transmission step of transmitting a second transaction in which tampering prevention data including a hash value of recorded data embedded with the two-dimensional code and the first specific information is stored to a blockchain network;
to run.

An information processing program according to a twenty-third aspect of the present invention comprises
to the computer,
an image information transmission step of transmitting a first transaction in which image information is stored to a blockchain network;
a first specification information storing step of embedding and storing in the image data a two-dimensional code in which first specification information for specifying the first transaction registered in the blockchain is encoded;
a tampering prevention data transmission step of transmitting a second transaction in which tampering prevention data including a hash value of recorded data embedded with the two-dimensional code is stored to a blockchain network;
The second specification information for specifying the second transaction registered in the blockchain is stored in the property or file name of the file that does not affect the hash value of the image data in which the two-dimensional code is embedded. a storage step;
to run.

An information processing program according to a twenty-fourth aspect of the present invention is an information processing program according to the twenty-second or twenty-third aspect,
to the computer;
further executing an image data transmission step of transmitting a third transaction in which the image data embedded with the two-dimensional code is stored to a blockchain network;
In the tamper-prevented data transmission step, a second transaction storing tamper-prevented data further including third identification information for identifying the third transaction registered in the blockchain is transmitted to the blockchain network.

An information processing program according to a twenty-fifth aspect of the present invention comprises
to the computer,
The first transaction on the blockchain is identified based on the first identification information extracted by decoding the two-dimensional code embedded in the image data to be verified, and the image information is obtained from the identified first transaction. an image information acquisition step;
The second transaction on the blockchain is searched using the first specific information extracted by decoding the two-dimensional code embedded in the image data to be verified as a search key, and if there is no hit, the image to be verified a tamper-prevented data acquisition step of determining that data has been tampered with, and acquiring tamper-prevented data from the hit second transaction if there is a hit;
The hash value of the image data to be verified is compared with the hash value included in the alteration prevention data obtained from the second transaction on the blockchain to determine whether or not the image data to be verified has been altered. a step;
to run.

An information processing program according to a twenty-sixth aspect of the present invention comprises
to the computer,
The first transaction on the blockchain is identified based on the first identification information extracted by decoding the two-dimensional code embedded in the image data to be verified, and the image information is obtained from the identified first transaction. an image information acquisition step;
Identify the second transaction on the blockchain based on the second identification information extracted from the file property or file name that does not affect the hash value of the image data to be verified, and extract the tamper-proof data from the identified second transaction a tamper-resistant data acquisition step that acquires
The hash value of the image data to be verified is compared with the hash value included in the alteration prevention data obtained from the second transaction on the blockchain to determine whether or not the image data to be verified has been altered. a step;
to run.

An information processing program according to a twenty-seventh aspect of the present invention is the information processing program according to the twenty-fifth or twenty-sixth aspect,
to the computer;
Image data acquisition for identifying a third transaction on the blockchain based on the third identification information included in the tamper-proof data obtained from the second transaction on the blockchain, and obtaining image data from the identified third transaction Execute more steps.

A computer-readable recording medium according to the twenty-eighth aspect of the present invention comprises
to the computer,
an image information transmission step of transmitting a first transaction in which image information is stored to a blockchain network;
a first specification information storing step of embedding and storing in the image data a two-dimensional code in which first specification information for specifying the first transaction registered in the blockchain is encoded;
a tampering prevention data transmission step of transmitting a second transaction in which tampering prevention data including a hash value of recorded data embedded with the two-dimensional code and the first specific information is stored to a blockchain network;
An information processing program characterized by executing

A computer-readable recording medium according to a twenty-ninth aspect of the present invention comprises
to the computer,
an image information transmission step of transmitting a first transaction in which image information is stored to a blockchain network;
a first specification information storing step of embedding and storing in the image data a two-dimensional code in which first specification information for specifying the first transaction registered in the blockchain is encoded;
a tampering prevention data transmission step of transmitting a second transaction in which tampering prevention data including a hash value of recorded data embedded with the two-dimensional code is stored to a blockchain network;
The second specification information for specifying the second transaction registered in the blockchain is stored in the property or file name of the file that does not affect the hash value of the image data in which the two-dimensional code is embedded. a storage step;
An information processing program characterized by executing

A computer-readable recording medium according to a thirtieth aspect of the present invention is the computer-readable recording medium according to the twenty-eighth or twenty-ninth aspect,
to the computer;
further executing an image data transmission step of transmitting a third transaction in which the image data embedded with the two-dimensional code is stored to a blockchain network;
In the alteration-prevented data transmission step, a second transaction storing alteration-prevented data further including third identification information for identifying the third transaction registered in the blockchain is transmitted to the blockchain network;
An information processing program characterized by:

A computer-readable recording medium according to a thirty-first aspect of the present invention comprises
to the computer,
The first transaction on the blockchain is identified based on the first identification information extracted by decoding the two-dimensional code embedded in the image data to be verified, and the image information is obtained from the identified first transaction. an image information acquisition step;
The second transaction on the blockchain is searched using the first specific information extracted by decoding the two-dimensional code embedded in the image data to be verified as a search key, and if there is no hit, the image to be verified a tamper-prevented data acquisition step of determining that data has been tampered with, and acquiring tamper-prevented data from the hit second transaction if there is a hit;
The hash value of the image data to be verified is compared with the hash value included in the alteration prevention data obtained from the second transaction on the blockchain to determine whether or not the image data to be verified has been altered. a step;
An information processing program characterized by executing

A computer-readable recording medium according to a thirty-second aspect of the present invention comprises
to the computer,
The first transaction on the blockchain is identified based on the first identification information extracted by decoding the two-dimensional code embedded in the image data to be verified, and the image information is obtained from the identified first transaction. an image information acquisition step;
Identify the second transaction on the blockchain based on the second identification information extracted from the file property or file name that does not affect the hash value of the image data to be verified, and extract the tamper-proof data from the identified second transaction a tamper-resistant data acquisition step that acquires
The hash value of the image data to be verified is compared with the hash value included in the alteration prevention data obtained from the second transaction on the blockchain to determine whether or not the image data to be verified has been altered. a step;
An information processing program characterized by executing

A computer-readable recording medium according to a thirty-third aspect of the present invention is the computer-readable recording medium according to the thirty-first or thirty-second aspect,
to the computer;
Image data acquisition for identifying a third transaction on the blockchain based on the third identification information included in the tamper-proof data obtained from the second transaction on the blockchain, and obtaining image data from the identified third transaction An information processing program is recorded which is characterized by causing further steps to be executed.

According to the present invention, it is possible to provide a mechanism for ensuring that image data has not been altered.

FIG. 1 is a diagram showing a schematic configuration of an information processing system according to one embodiment. FIG. 2 is a diagram showing a schematic configuration of a registration device. FIG. 3 is a diagram showing a schematic configuration of a verification device. FIG. 4 is a flow chart showing an example of a registration method. FIG. 5 is a flow chart showing an example of a verification method. FIG. 6 is a diagram showing the flow of information in an example of the registration method. FIG. 7 is a diagram showing the flow of information in an example verification method. FIG. 8 is a diagram showing an example of image data in which a two-dimensional code is embedded. FIG. 9 is a diagram showing an example of image information. FIG. 10 is a flow chart showing a modification of the registration method. FIG. 11 is a flow chart showing a modification of the verification method. FIG. 12 is a diagram showing the flow of information in one modification of the registration method. FIG. 13 is a diagram showing the flow of information in one modification of the verification method.

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In addition, the same reference numerals are given to components having equivalent functions in each drawing, and detailed description of the components with the same reference numerals will not be repeated.

(Configuration of information processing system)
FIG. 1 is a diagram showing a schematic configuration of an information processing system 1 according to one embodiment.

As shown in FIG. 1, the information processing system 1 has a registration device 2 and a verification device 3 . At least part of the registration device 2 and the verification device 3 is implemented by a computer.

As shown in FIG. 1, the registration device 2 and the verification device 3 are each configured to function as a node that constitutes a blockchain network. P2P) method. The network between each node 2-6 may be either a wired line or a wireless line, regardless of the type or form of the line.

In the illustrated example, the node numbered 4 is a minor node that bundles unprocessed transactions to generate a new block (performs mining). Also, at least one of the nodes 2-6 is a full node and stores the entire block chain data. As the blockchain network, an existing blockchain network such as the Ethereum network can be used.

As shown in FIG. 1, a registrant terminal 7 such as a smartphone or a tablet terminal can be connected to the registration device 2 so as to be communicable via a network such as the Internet. The obtained image data (for example, image data captured by the camera function) and image information (text information associated with the image data) are transmitted to the registration device 2 via a network such as the Internet.

FIG. 9 is a diagram showing an example of image information. The image information includes information that can be automatically input at the registrant terminal 7, such as registrant name (registrant name, user ID, nickname, etc.), registration date, location information (for example, latitude and longitude information of shooting location). (Information that does not need to be input by the registrant) may be included, or a title (“Remarks” column shown in FIG. 9) or a comment (“Information” column shown in FIG. 9) linked to the image data may be included. ), etc., which requires input from the registrant. In addition, the image information includes information that can be used by the viewer to check the reliability of the image data (for example, when registering image data using a QR code (registered trademark) installed at a sightseeing spot). , a certificate proving that you have visited a tourist spot issued by the local government).

FIG. 2 is a diagram showing a schematic configuration of the registration device 2. As shown in FIG. As shown in FIG. 2 , the registration device 2 has a communication section 21 , a control section 22 and a storage section 23 . Each part is connected so as to be able to communicate with each other via a bus or a network.

Among these, the communication unit 21 is a communication interface between the registration device 2 and a network such as a blockchain network or the Internet. The communication unit 21 transmits and receives information between the registration device 2 and the other nodes 3 to 6 via the blockchain network. The communication unit 21 also transmits and receives information between the registration device 2 and the registrant terminal 7 via a network such as the Internet.

The storage unit 23 is non-volatile data storage such as flash memory. Various data handled by the control unit 22 are stored in the storage unit 23 . For example, the storage unit 23 stores image data 23a and image information 23b received from the registrant terminal 7, and a secret key 23c. The image data 23a may be still image data or moving image data. The private key 23c can be created by, for example, the RSA cryptosystem.

As shown in FIG. 2, the control unit 22 includes an image information transmission unit 22a, a first specific information storage unit 22b, an alteration prevention data transmission unit 22c, a second specific information storage unit 22d, and an image data transmission unit 22e. and Each of these units may be realized by the processor in the registration device 2 executing a predetermined program, or may be implemented by hardware.

The image information transmitter 22a generates a first transaction in which the image information 23b is stored. The image information transmitting unit 22a may encode the image information 23b with the secret key 23c and generate the first transaction storing the encoded image information 23b. The image information 23b is stored in the first transaction as non-rewritable (read-only) information.

The image information transmission unit 22a transmits the first transaction in which the image information 23b is stored to the blockchain network via the communication unit 21 . The first transaction sent to the blockchain network is registered in the blockchain by mining the block containing the transaction at the minor node 4, and the first transaction is registered on the blockchain to identify the first transaction. 1 specific information (eg, hash value or address value of the first transaction) is added. Since the first transaction in which the image information 23b is stored is registered in the blockchain, it is substantially impossible to alter the image information 23b after the fact.

The first specific information storage unit 22b acquires the specific information (first specific information) of the first transaction registered in the blockchain, and generates a two-dimensional code by encoding the first specific information. The two-dimensional code may be a QR code (registered trademark) or a color code. The first specific information storage unit 22b embeds the two-dimensional code in which the first specific information is encoded into the image data 23a and stores the same (see FIG. 8). Since the two-dimensional code in which the specific information (first specific information) of the first transaction is encoded is embedded in the image data 23a, the image data 23a and the specific information (first specific information) of the first transaction can be easily linked. can be managed The image data 23a embedded with the two-dimensional code is stored in the storage unit 23. FIG.

The image data transmission unit 22e generates a third transaction in which the image data 23a embedded with the two-dimensional code is stored. The image data transmission unit 22e may encode the image data 23a embedded with the two-dimensional code using the secret key 23c, and generate the third transaction storing the encoded image data 23a. The image data 23a embedded with the two-dimensional code is stored in the third transaction as non-rewritable (read-only) information.

The image data transmission unit 22e transmits the third transaction in which the image data 23a embedded with the two-dimensional code is stored to the blockchain network via the communication unit 21. FIG. The third transaction sent to the blockchain network is registered in the blockchain by mining the block containing the transaction at the minor node 4, and the third transaction is registered on the blockchain to identify the third transaction. 3 specific information (eg, hash value or address value of the third transaction) is added. Since the third transaction in which the image data 23a embedded with the two-dimensional code is stored is registered in the blockchain, it is substantially impossible to modify the image data 23a afterwards.

The alteration prevention data transmission unit 22c generates a hash value of the image data 23a in which the two-dimensional code is embedded. The alteration prevention data transmission unit 22c may acquire specific information (third specific information) of the third transaction registered in the blockchain.

The alteration prevention data transmission unit 22c generates a second transaction in which alteration prevention data including the hash value of the image data 23a embedded with the two-dimensional code, the first specification information, and the third specification information is stored. The alteration-prevented data transmitter 22c may encode the alteration-prevented data with the private key 23c and generate a second transaction containing the encoded alteration-prevented data. The alteration-protected data is stored in the second transaction as non-rewritable (read-only) information.

The tampering prevention data transmission unit 22c transmits the second transaction in which the tampering prevention data is stored to the blockchain network via the communication unit 21 . The second transaction sent to the blockchain network is registered in the blockchain by mining the block containing the transaction at the minor node 4, and the second transaction is registered on the blockchain to identify the second transaction on the blockchain. 2 specific information (eg, hash value or address value of the second transaction) is added. Since the second transaction in which the tamper-proof data is stored is registered in the blockchain, it is virtually impossible to tamper with the tamper-proof data afterwards.

The second specification information storage unit 22d stores the second specification information for specifying the second transaction registered in the block chain as a file property or a file property that does not affect the hash value of the image data 23a in which the two-dimensional code is embedded. stored in the name (for example, appended to the end of the file name). The second specific information storage unit 22d encodes the specific information (second specific information) of the second transaction with the secret key 23c, and stores the encoded second specific information in the image data 23a in which the two-dimensional code is embedded. May be stored in file properties or filename.

Referring to FIG. 1, image data 23a embedded with a two-dimensional code is transmitted to registrant terminal 7 via a network such as the Internet. The registrant terminal 7 may upload the image data 23a in which the two-dimensional code is embedded to an external server 9 (for example, a server that provides services such as SNS, auctions, and flea markets) via a network such as the Internet. . The external server 9 may generate a web page displaying the uploaded image data 23a. The viewer terminal 8 such as a smart phone or a tablet terminal accesses the external server 9 and downloads the image data 23a embedded with the two-dimensional code. can be viewed.

As shown in FIG. 1, a viewer terminal 8 such as a smartphone or a tablet terminal can be connected to the verification device 3 so as to be communicable via a network such as the Internet. For example, image data downloaded by the viewer terminal 8 from the external server 9) is transmitted to the verification device 3 via a network such as the Internet.

Next, the configuration of the verification device 3 will be described. FIG. 3 is a diagram showing a schematic configuration of the verification device 3. As shown in FIG. As shown in FIG. 3 , the verification device 3 has a communication section 31 , a control section 32 and a storage section 33 . Each part is connected so as to be able to communicate with each other via a bus or a network.

The communication unit 31 is a communication interface between the verification device 3 and a network such as a blockchain network or the Internet. The communication unit 31 transmits and receives information between the verification device 3 and the other nodes 2, 4 to 6 via the blockchain network. The communication unit 31 also transmits and receives information between the verification device 3 and the viewer terminal 8 via a network such as the Internet.

The storage unit 33 is non-volatile data storage such as flash memory. Various data handled by the control unit 32 are stored in the storage unit 33 . For example, the storage unit 33 stores image data 33 a to be verified received from the viewer terminal 8 and a public key 33 b corresponding to the private key 23 c stored in the registration device 2 . Public key 33b may be generated based on private key 23c, for example, in RSA cryptography.

As shown in FIG. 3, the control unit 32 has an image information acquisition unit 32a, an alteration prevention data acquisition unit 32b, an alteration determination unit 32c, and an image data acquisition unit 32d. Each of these units may be realized by the processor in the verification device 3 executing a predetermined program, or may be implemented by hardware.

The image information acquisition unit 32a decodes the two-dimensional code embedded in the image data 33a to be verified and extracts the first specific information. When the first specific information is not extracted from the two-dimensional code embedded in the image data 33a to be verified, the image information acquiring unit 32a determines that the image data 33a to be verified has been altered.

When the first specific information is extracted from the two-dimensional code embedded in the image data 33a to be verified, the image information acquisition unit 32a detects the first specific information on the blockchain based on the extracted first specific information. A transaction is identified, and image information 23b is obtained from the identified first transaction. When the image information 23b stored in the first transaction is encoded with the private key 23c, the image information acquisition unit 32a converts the encoded image information 23b into the public key stored in the storage unit 33. 33b decrypts and acquires.

The image information 23b acquired by the image information acquisition section 32a is transmitted to the viewer terminal 8 via a network such as the Internet. The viewer browses the image information 23b received from the verification device 3 at the viewer terminal 8 and visually confirms it. It is possible to directly verify that the image data 33a to be verified has not been altered.

The alteration prevention data acquisition unit 32b searches for the second transaction on the blockchain using the first specific information as a search key. If it does, it acquires the alteration prevention data from the hit second transaction. By searching for the second transaction on the blockchain using the first specific information as a search key, for example, when copying image data, the operating system (OS) operates to change the file properties and file name without permission. Even if it is lost, it is possible to identify the second transaction registered on the blockchain and obtain the tamper-proof data.

The alteration prevention data acquisition unit 32b identifies the second transaction on the blockchain based on the second identification information extracted from the file property or file name of the image data 33a to be verified, and retrieves the identified second transaction. You may obtain tamper-resistant data from

If the second transaction specific information (second specific information) stored in the file property or file name of the image data 33a to be verified is encoded with the private key 23c, the alteration prevention data acquisition unit 32b decodes the encoded second specific information with the public key 33b stored in the storage unit 33 and acquires it.

When the alteration-prevented data stored in the second transaction on the blockchain is encoded with the secret key 23c, the alteration-prevented data acquisition unit 32b stores the encoded alteration-prevented data in the storage unit 33. It is obtained by decrypting with the stored public key 33b.

The alteration determination unit 32c compares the hash value of the image data 33a to be verified with the hash value included in the alteration prevention data acquired from the second transaction on the blockchain to determine whether the image data to be verified has been altered. Determine presence/absence. More specifically, if the hash value of the image data 33a to be verified matches the hash value included in the alteration prevention data acquired from the second transaction on the blockchain, the alteration determination unit 32c It is determined that the image data to be verified has not been altered, and if they do not match, it is determined that the image data to be verified has been altered.

By confirming that the hash value of the image data 33a to be verified matches the hash value included in the alteration prevention data acquired from the second transaction registered on the blockchain, the image data to be verified is verified. has not been altered (for example, the two-dimensional code of correct image information has not been abused and embedded in other (fake) image data (the two-dimensional code portion has not been cut and pasted)) can be guaranteed.

The determination result of whether or not the image data 33a to be verified has been altered is transmitted to the viewer terminal 8 via a network such as the Internet, and notified to the viewer.

The image data acquisition unit 32d identifies the third transaction on the blockchain based on the third identification information included in the alteration prevention data obtained from the second transaction on the blockchain, and extracts two data from the identified third transaction. The image data 23a in which the dimension code is embedded is obtained. When the image data 23a stored in the third transaction on the blockchain is encoded with the private key 23c, the image data acquisition unit 32d stores the encoded image data 23a in the storage unit 33. It is obtained by decrypting with the public key 33b.

The image data 23a (stored in the third transaction) acquired by the image data acquisition unit 32d is transmitted to the viewer terminal 8 via a network such as the Internet. The viewer views both the image information 23b and the image data 23a received from the verification device 3 at the viewer terminal 8 and visually confirms the content of both the image information 23b and the image data 23a. Therefore, the viewer can directly verify with higher accuracy that the image data 33a to be verified has not been altered.

(Example of information processing method)
Next, an example of an information processing method by the information processing system 1 will be described with reference to FIGS. 4 to 7. FIG. FIG. 4 is a flow chart showing an example of the registration method by the registration device 2, and FIG. 5 is a flow chart showing an example of the verification method by the verification device 3. As shown in FIG. FIG. 6 is a diagram showing an information flow in an example of the registration method by the registration device 2, and FIG. 7 is a diagram showing an information flow in an example of the verification method by the verification device 3. As shown in FIG.

First, an example of a registration method by the registration device 2 will be described. As shown in FIG. 6, image data (for example, image data taken with a camera function) and image information (text information associated with the image data) generated by the registrant terminal 7 are transmitted via a network such as the Internet. It is sent to the registration device 2 . The image data 23 a and the image information 23 b received by the registration device 2 are stored in the storage section 23 .

As shown in FIGS. 4 and 6, the image information transmission unit 22a of the registration device 2 generates a first transaction in which the image information 23b is stored. The image information transmitting unit 22a may encode the image information 23b with the secret key 23c and generate the first transaction storing the encoded image information 23b.

Then, the image information transmission unit 22a transmits the first transaction in which the image information 23b is stored to the blockchain network via the communication unit 21 (step S11). The first transaction sent to the blockchain network is registered in the blockchain by mining the block containing the transaction at the minor node 4, and the first transaction is registered on the blockchain to identify the first transaction. 1 specific information is added.

After the first transaction is registered in the blockchain, the first specific information storage unit 22b acquires the specific information (first specific information) added to the first transaction, and encodes the first specific information into a two-dimensional Generate code. The two-dimensional code may be a QR code (registered trademark) or a color code. As shown in FIG. 8, the first specific information storage unit 22b embeds the two-dimensional code in which the first specific information is encoded into the image data 23a and stores the same (step S12). The image data 23a embedded with the two-dimensional code is stored in the storage unit 23. FIG.

Next, the alteration prevention data transmission unit 22c generates a second transaction in which alteration prevention data including the hash value of the image data 23a embedded with the two-dimensional code and the first specific information is stored. The alteration-prevented data transmitter 22c may encode the alteration-prevented data with the private key 23c and generate a second transaction containing the encoded alteration-prevented data.

Then, the alteration prevention data transmission unit 22c transmits the second transaction in which the alteration prevention data is stored to the blockchain network via the communication unit 21 (step S13). The second transaction sent to the blockchain network is registered in the blockchain by mining the block containing the transaction at the minor node 4, and the second transaction is registered on the blockchain to identify the second transaction on the blockchain. 2 Specific information is added.

After the second transaction is registered in the blockchain, the second specific information storage unit 22d acquires the specific information (second specific information) added to the second transaction, and stores the image data 23a embedded with the two-dimensional code. is stored in the file property or file name that does not affect the hash value of (step S14). The second specific information storage unit 22d encodes the specific information (second specific information) of the second transaction with the secret key 23c, and stores the encoded second specific information in the image data 23a in which the two-dimensional code is embedded. May be stored in file properties or filename.

Then, as shown in FIG. 6, the image data 23a embedded with the two-dimensional code is transmitted to the registrant terminal 7 via a network such as the Internet. The registrant terminal 7 may upload the image data 23a in which the two-dimensional code is embedded to an external server 9 (for example, a server that provides services such as SNS, auctions, and flea markets) via a network such as the Internet. .

Next, an example of a verification method by the verification device 3 will be described. As shown in FIG. 7, a viewer terminal 8 such as a smart phone or a tablet terminal accesses an external server 9 and downloads image data embedded with a two-dimensional code. The downloaded image data is transmitted to the verification device 3 via a network such as the Internet as image data to be verified. The verification device 3 stores the received verification target image data 33 a in the storage unit 33 .

As shown in FIGS. 5 and 7, the image information acquisition unit 32a decodes the two-dimensional code embedded in the image data 33a to be verified and extracts the first specific information (step S21). If the first specific information is not extracted from the two-dimensional code embedded in the image data 33a to be verified (step S22: NO), the image information acquiring unit 32a determines whether the image data 33a to be verified has been modified. It is determined that there is (step S34).

When the first specific information is extracted from the two-dimensional code embedded in the image data 33a to be verified (step S22: YES), the image information acquisition unit 32a, based on the extracted first specific information, A first transaction on the blockchain is identified, and image information 23b is obtained from the identified first transaction (step S23). When the image information 23b stored in the first transaction is encoded with the private key 23c, the image information acquisition unit 32a converts the encoded image information 23b into the public key stored in the storage unit 33. 33b decrypts and acquires.

The image information 23b acquired by the image information acquisition section 32a is transmitted to the viewer terminal 8 via a network such as the Internet.

Next, the alteration prevention data acquisition unit 32b extracts the second specific information from the property or file name of the file of the image data 33a to be verified (step S24). When the second specific information stored in the file property or file name of the image data 33a to be verified is encoded with the secret key 23c, the alteration prevention data acquisition unit 32b retrieves the encoded second specific information. 2 The specific information is decrypted with the public key 33b stored in the storage unit 33 and acquired.

If the second specific information is extracted from the file property or file name of the image data 33a to be verified (step S25: YES), the alteration prevention data acquisition unit 32b obtains the second specific information based on the extracted second specific information. to identify the second transaction on the blockchain, and acquire the alteration prevention data from the identified second transaction (step S26). If the alteration-prevented data stored in the second transaction is encoded with the private key 23c, the alteration-prevented data acquisition unit 32b retrieves the encoded alteration-prevented data from the public key stored in the storage unit 33. It is obtained by decrypting with the key 33b.

On the other hand, if the second specific information is not extracted from the file property or file name of the image data 33a to be verified (step S25: NO), the alteration prevention data acquisition unit 32b uses the first specific information as a search key. Search for the second transaction on the blockchain (step S27).

If the second transaction does not hit (step S28: NO), the alteration prevention data acquisition unit 32b determines that the image data 33a to be verified has been altered (step S34).

If the second transaction is hit (step S28: YES), the alteration prevention data acquisition unit 32b acquires alteration prevention data from the hit second transaction (step S29). If the alteration-prevented data stored in the second transaction is encoded with the private key 23c, the alteration-prevented data acquisition unit 32b retrieves the encoded alteration-prevented data from the public key stored in the storage unit 33. It is obtained by decrypting with the key 33b.

After the alteration prevention data stored in the second transaction is acquired in step S26 or step S29, the alteration determination unit 32c acquires the hash value of the image data 33a to be verified from the second transaction on the blockchain. It is compared with the hash value contained in the alteration prevention data (step S31).

If the hash values match (step S32: YES), the modification determination unit 32c determines that the image data 33a to be verified has not been modified (step S33).

On the other hand, if the hash values do not match (step S32: NO), the alteration determination unit 32c determines that the image data 33a to be verified has been altered (step S34).

After the presence or absence of modification of the image data 33a to be verified is determined in step 33 or step S34, the determination result is transmitted to the viewer terminal 8 via a network such as the Internet and notified to the viewer. be.

According to the present embodiment as described above, since the first transaction in which the image information is stored is registered in the blockchain at the time of registration, it is substantially impossible to modify the image information after the fact. . In addition, since the two-dimensional code encoded with the specific information (first specific information) of the first transaction is embedded in the image data, the image data and the specific information (first specific information) of the first transaction can be easily linked. can be managed In addition, since the second transaction in which the alteration-prevented data including the hash value of the image data embedded with the two-dimensional code and the first specific information is stored in the block chain, the alteration-prevented data is subsequently altered. is also virtually impossible. Further, since the specific information (second specific information) of the second transaction is stored in the property or file name of the image data file, the image data and the specific information (second specific information) of the second transaction can be easily identified. Can be linked and managed. Then, at the time of verification, the first transaction registered on the blockchain is specified based on the first specifying information extracted by decoding the two-dimensional code embedded in the target image data, and from the first transaction By viewing and visually confirming the acquired image information, the viewer can directly verify that the image data has not been altered based on the contents of the image information. In addition, by confirming that the hash value of the target image data matches the hash value included in the alteration prevention data acquired from the second transaction registered on the blockchain, the target image data Must not be altered (for example, the two-dimensional code of correct image information must not be abused and embedded in other (fake) image data (the two-dimensional code must not be illegally cut and pasted) ) can be guaranteed.

Further, according to the present embodiment, even if the properties and file names of files are changed without permission due to the operation of the operating system (OS) when copying image data, for example, during verification, The second transaction registered on the blockchain by searching for the second transaction on the blockchain using the first specific information extracted by decoding the two-dimensional code embedded in the target image data as a search key. is specified, and based on the hash value included in the alteration prevention data acquired from the second transaction, it is possible to guarantee that the target image data has not been altered.

Further, according to the present embodiment, the image information transmission unit 22a transmits the first transaction storing the image information 23b encoded with the private key 23c to the blockchain network, and the image information acquisition unit 32a By decrypting the image information 23b stored in the first transaction on the blockchain with the public key 33b and obtaining it, even when using a public blockchain, the image information registered on the blockchain 23b can be restricted to only certain viewers with public key 33b.

Further, according to the present embodiment, the alteration-prevented data transmitting unit 22c transmits the second transaction containing the alteration-prevented data encoded with the secret key 23c to the blockchain network, and the alteration-prevented data acquisition unit 32b is registered on the blockchain even when using a public blockchain by decrypting and obtaining the tamper-prevented data stored in the second transaction on the blockchain with the public key 33b. It is possible to restrict viewing of the alteration-protected data to only specific viewers who have the public key 33b.

Further, according to the present embodiment, the second specific information storage unit 22d encodes the second specific information with the secret key 23c, stores it in the file property or file name of the image data 23a, and stores the second specific information in the file property or file name of the image data 23a. 32b decrypts and extracts the second specific information stored in the property or file name of the file of the image data 33a to be verified with the public key 33b, thereby using a public blockchain. Also, the identification of the second transaction registered on the blockchain can be limited to only a specific viewer who has the public key 33b, so that the alteration-protected data stored in the second transaction can be viewed. , may be limited to that particular viewer only.

In the above embodiment, the registration device 2 has the private key 23c and the verification device 3 has the public key 33b corresponding to the private key 23c, but the present invention is not limited to this. Instead, the verification device 3 may have the private key and the registration device 2 may have the public key corresponding to the private key.

In this case, the image information transmission unit 22a transmits the first transaction containing the image information 23b encoded with the public key to the blockchain network, and the image information acquisition unit 32a transmits the first transaction on the blockchain. The stored image information 23b may be obtained by decrypting it with a secret key. As a result, even when using a public blockchain, viewing of the image information 23b registered on the blockchain can be limited to only specific viewers who have a private key.

Further, the alteration-prevented data transmission unit 22c transmits a second transaction containing the alteration-prevented data encoded with the public key to the blockchain network, and the alteration-prevented data acquisition unit 32b transmits the second transaction on the blockchain. The tamper-protected data stored in can be obtained by decrypting it with a private key. As a result, even when using a public blockchain, it is possible to restrict access to alteration-prevented data registered on the blockchain to only specific viewers who have a private key.

The second specific information storage unit 22d encodes the second specific information with a public key and stores it in the file property or file name of the image data 23a. The second specific information stored in the file properties or file name of 33a may be decrypted with the private key and extracted. As a result, even when using a public blockchain, it is possible to limit the identification of the second transaction registered on the blockchain to only specific viewers who have the private key. Viewing of the tamper-resistant data stored in the second transaction can be restricted to only those specific viewers.

(Modified example of information processing method)
Next, a modified example of the information processing method by the information processing system 1 will be described with reference to FIGS. 10 to 13. FIG. FIG. 10 is a flow chart showing a modified example of the registration method by the registration device 2, and FIG. 11 is a flow chart showing a modified example of the verification method by the verification device 3. As shown in FIG. FIG. 12 is a diagram showing the flow of information in a modified example of the registration method by the registration device 2, and FIG. 13 is a diagram showing the flow of information in an example of the verification method by the verification device 3. As shown in FIG.

First, a modified example of the registration method by the registration device 2 will be described. As shown in FIGS. 10 and 12, in one modification of the registration method, the first specific information is encoded from the step (step S11) in which the first transaction in which the image information 23b is stored is transmitted to the blockchain network. Up to the step (step S12) where the two-dimensional code thus obtained is embedded in the image data 23a and stored is the same as the example of the registration method described above (see FIGS. 4 and 6), and a description thereof will be omitted.

As shown in FIGS. 10 and 12, in one modification of the registration method, after the two-dimensional code in which the first specific information is encoded is embedded in the image data 23a and stored (after step S12), the image The data transmission unit 22e generates a third transaction in which the image data 23a embedded with the two-dimensional code is stored. The image data transmission unit 22e may encode the image data 23a embedded with the two-dimensional code using the secret key 23c, and generate the third transaction storing the encoded image data 23a.

Then, the image data transmission unit 22e transmits the third transaction storing the image data 23a embedded with the two-dimensional code to the blockchain network via the communication unit 21 (step S112). The third transaction sent to the blockchain network is registered in the blockchain by mining the block containing the transaction at the minor node 4, and the third transaction is registered on the blockchain to identify the third transaction. 3 Specific information is added.

After the third transaction is registered in the blockchain, the alteration prevention data transmission unit 22c acquires the specific information (third specific information) added to the third transaction, and converts the image data 23a in which the two-dimensional code is embedded. A second transaction is generated in which alteration prevention data including the hash value, the first identification information, and the third identification information is stored. The alteration-prevented data transmitter 22c may encode the alteration-prevented data with the private key 23c and generate a second transaction containing the encoded alteration-prevented data.

Then, the alteration prevention data transmission unit 22c transmits the second transaction in which the alteration prevention data is stored to the blockchain network via the communication unit 21 (step S113). The second transaction sent to the blockchain network is registered in the blockchain by mining the block containing the transaction at the minor node 4, and the second transaction is registered on the blockchain to identify the second transaction on the blockchain. 2 Specific information is added.

After the second transaction is registered in the blockchain, the second specific information storage unit 22d stores the specific information (the second 2 specific information) is acquired and stored in the file property or file name that does not affect the hash value of the image data 23a in which the two-dimensional code is embedded (step S14). The second specific information storage unit 22d encodes the specific information (second specific information) of the second transaction with the secret key 23c, and stores the encoded second specific information in the image data 23a in which the two-dimensional code is embedded. May be stored in file properties or filename.

Then, as shown in FIG. 12, the image data 23a embedded with the two-dimensional code is transmitted to the registrant terminal 7 via a network such as the Internet. The registrant terminal 7 may upload the image data 23a in which the two-dimensional code is embedded to an external server 9 (for example, a server that provides services such as SNS, auctions, and flea markets) via a network such as the Internet. .

Next, a modified example of the verification method by the verification device 3 will be described. As shown in FIGS. 11 and 13, in a modification of the verification method, a step of decoding the two-dimensional code embedded in the image data 33a to be verified and extracting the first specific information (step S21). to the step of obtaining the alteration-protected data stored in the second transaction (step S26 or step S29) are the same as the example of the verification method described above (see FIGS. 5 and 7), and the description thereof will be omitted.

As shown in FIGS. 11 and 13, in one modification of the verification method, after the alteration prevention data stored in the second transaction is obtained (after step S26 or step S29), the image data obtaining unit 32d A third transaction on the blockchain is identified based on the third identification information included in the alteration prevention data stored in the second transaction, and the image data 23a embedded with the two-dimensional code is obtained from the identified third transaction. (step S30). When the image data 23a stored in the third transaction is encoded with the private key 23c, the image data acquiring unit 32d converts the encoded image data 23a into the public key stored in the storage unit 33. 33b decrypts and acquires.

The image data 23a (stored in the third transaction) acquired by the image data acquisition unit 32d is transmitted to the viewer terminal 8 via a network such as the Internet.

After that, as in the example of the registration method described above (see FIGS. 4 and 6), the alteration determination unit 32c includes the hash value of the image data 33a to be verified in the alteration prevention data stored in the second transaction. It is compared with the hash value obtained (step S31).

If the hash values match (step S32: YES), the modification determination unit 32c determines that the image data 33a to be verified has not been modified (step S33). On the other hand, if the hash values do not match (step S32: NO), the alteration determination unit 32c determines that the image data 33a to be verified has been altered (step S34).

After the presence or absence of modification of the image data 33a to be verified is determined in step 33 or step S34, the determination result is transmitted to the viewer terminal 8 via a network such as the Internet and notified to the viewer. be.

According to the aspect of the modified example as described above, at the time of registration, the third transaction in which the image data embedded with the two-dimensional code is stored is registered in the blockchain. becomes virtually impossible. Then, at the time of verification, the first transaction registered on the blockchain is specified based on the first specifying information extracted by decoding the two-dimensional code embedded in the target image data, and from the first transaction By browsing and visually confirming the acquired image information, and by browsing and visually confirming the image data acquired from the third transaction registered on the blockchain, the content of the image information and image data Based on this, it is possible for the viewer to directly verify that the image data has not been altered with a higher degree of certainty.

It should be noted that the description of the above-described embodiment and individual modifications and the disclosure of the drawings are only examples for explaining the invention described in the claims, and the above-described embodiment and individual modifications are merely examples. The disclosure of the description or drawings does not limit the claimed invention. The constituent elements of the above-described embodiments and individual modifications can be arbitrarily combined without departing from the gist of the invention.

In addition, although the recording device and the determination device according to the above-described embodiments can be configured by a computer system, a program for realizing the recording device and the determination device in the computer system and the program are non-transitory Recorded computer-readable media are also subject to protection in this case.

1 information processing system 2 registration device 21 communication unit 22 control unit 22a image information transmission unit 22b first specific information storage unit 22c alteration prevention data transmission unit 22d second specific information storage unit 22e image data transmission unit 23 storage unit 23a image data 23b Image information 23c Private key 3 Verification device 31 Communication unit 32 Control unit 32a Image information acquisition unit 32b Alteration prevention data acquisition unit 32c Alteration determination unit 32d Image data acquisition unit 33 Storage unit 33a Verification target image data 33b Public keys 4-6 Nodes 7 Registrant terminal 8 Viewer terminal 9 External server

Claims (33)

a registration device for registering image data;
a verification device that verifies whether or not the image data has been altered;
with
The registration device
an image information transmission unit that transmits a first transaction in which image information is stored to a blockchain network;
a first specific information storage unit that embeds and stores in the image data a two-dimensional code in which first specific information for specifying the first transaction registered in the blockchain is encoded;
a tampering prevention data transmitting unit configured to transmit a second transaction storing tampering prevention data including a hash value of the image data in which the two-dimensional code is embedded and the first specific information to a blockchain network;
has
The verification device is
The first transaction on the blockchain is identified based on the first identification information extracted by decoding the two-dimensional code embedded in the image data to be verified, and the image information is obtained from the identified first transaction. an image information acquisition unit;
The second transaction on the blockchain is searched using the first specific information extracted by decoding the two-dimensional code embedded in the image data to be verified as a search key, and if there is no hit, the image to be verified an alteration-prevented data acquisition unit that determines that data has been altered, and acquires alteration-prevented data from the hit second transaction if there is a hit;
The hash value of the image data to be verified is compared with the hash value included in the alteration prevention data obtained from the second transaction on the blockchain to determine whether or not the image data to be verified has been altered. Department and
having
An information processing system characterized by: a registration device for registering image data;
a verification device that verifies whether or not the image data has been altered;
with
The registration device
an image information transmission unit that transmits a first transaction in which image information is stored to a blockchain network;
a first specific information storage unit that embeds and stores in the image data a two-dimensional code in which first specific information for specifying the first transaction registered in the blockchain is encoded;
a tampering prevention data transmission unit configured to transmit a second transaction storing tampering prevention data including a hash value of the image data embedded with the two-dimensional code to a blockchain network;
The second specification information for specifying the second transaction registered in the blockchain is stored in the property or file name of the file that does not affect the hash value of the image data in which the two-dimensional code is embedded. a storage unit;
has
The verification device is
The first transaction on the blockchain is identified based on the first identification information extracted by decoding the two-dimensional code embedded in the image data to be verified, and the image information is obtained from the identified first transaction. an image information acquisition unit;
Modification to identify the second transaction on the blockchain based on the second identification information extracted from the property or file name of the file of the image data to be verified, and to acquire the alteration prevention data from the identified second transaction a prevention data acquisition unit;
The hash value of the image data to be verified is compared with the hash value included in the alteration prevention data obtained from the second transaction on the blockchain to determine whether or not the image data to be verified has been altered. Department and
having
An information processing system characterized by: The registration device
further comprising an image data transmission unit that transmits a third transaction in which the image data embedded with the two-dimensional code is stored to a blockchain network;
The alteration-prevented data transmission unit transmits to the blockchain network a second transaction in which alteration-prevented data is stored, further including third identification information for identifying the third transaction registered in the blockchain;
The verification device is
Image data acquisition for identifying a third transaction on the blockchain based on the third identification information included in the tamper-proof data obtained from the second transaction on the blockchain, and obtaining image data from the identified third transaction 3. The information processing system according to claim 1, further comprising a unit. The registration device has a private key, the verification device has a public key corresponding to the private key,
The image information transmission unit transmits a first transaction storing the image information encoded with the private key to a blockchain network,
The image information acquisition unit decrypts and acquires the image information stored in the first transaction on the blockchain with the public key.
4. The information processing system according to any one of claims 1 to 3, characterized by: The registration device has a private key, the verification device has a public key corresponding to the private key,
The alteration-prevented data transmission unit transmits a second transaction storing the alteration-prevented data encoded with the private key to a blockchain network,
The alteration-prevented data acquisition unit decrypts and acquires the alteration-prevented data stored in the second transaction on the blockchain with the public key,
4. The information processing system according to any one of claims 1 to 3, characterized by: The registration device has a private key, the verification device has a public key corresponding to the private key,
The second specific information storage unit encodes the second specific information with the secret key and stores it in the property or file name of the file;
The alteration prevention data acquisition unit decrypts and extracts the second specific information stored in the property or file name of the file with the public key.
The information processing system according to claim 2 or claim 3 quoting claim 2, characterized in that: The verification device has a private key, the registration device has a public key corresponding to the private key,
The image information transmission unit transmits a first transaction storing the image information encoded with the public key to a blockchain network;
The image information acquisition unit decrypts and acquires the image information stored in the first transaction on the blockchain with the private key.
4. The information processing system according to any one of claims 1 to 3, characterized by: The verification device has a private key, the registration device has a public key corresponding to the private key,
The tamper-resistant data transmission unit transmits a second transaction containing the tamper-resistant data encoded with the public key to a blockchain network,
The alteration-prevented data acquisition unit decrypts and acquires the alteration-prevented data stored in the second transaction on the blockchain with the private key,
4. The information processing system according to any one of claims 1 to 3, characterized by: The verification device has a private key, the registration device has a public key corresponding to the private key,
The second specific information storage unit encodes the second specific information with the public key and stores the second specific information in the property or file name of the file;
The alteration-prevented data acquisition unit decrypts and extracts the second specific information stored in the property or file name of the file with the private key,
The information processing system according to claim 2 or claim 3 quoting claim 2, characterized in that: A registration device for registering image data,
an image information transmission unit that transmits a first transaction in which image information is stored to a blockchain network;
a first specific information storage unit that embeds and stores in the image data a two-dimensional code in which first specific information for specifying the first transaction registered in the blockchain is encoded;
a tampering prevention data transmitting unit configured to transmit a second transaction storing tampering prevention data including a hash value of the image data in which the two-dimensional code is embedded and the first specific information to a blockchain network;
A registration device comprising: an image information transmission unit that transmits a first transaction in which image information is stored to a blockchain network;
a first specific information storage unit that embeds and stores in the image data a two-dimensional code in which first specific information for specifying the first transaction registered in the blockchain is encoded;
a tampering prevention data transmission unit configured to transmit a second transaction storing tampering prevention data including a hash value of the image data embedded with the two-dimensional code to a blockchain network;
The second specification information for specifying the second transaction registered in the blockchain is stored in the property or file name of the file that does not affect the hash value of the image data in which the two-dimensional code is embedded. a storage unit;
A registration device comprising: further comprising an image data transmission unit that transmits a third transaction storing image data embedded with the two-dimensional code to a blockchain network;
The alteration-prevented data transmission unit transmits to the blockchain network a second transaction in which alteration-prevented data is stored, further including third identification information for identifying the third transaction registered in the blockchain.
12. The registration device according to claim 10 or 11, characterized by: A verification device for verifying whether or not image data has been altered,
The first transaction on the blockchain is identified based on the first identification information extracted by decoding the two-dimensional code embedded in the image data to be verified, and the image information is obtained from the identified first transaction. an image information acquisition unit;
The second transaction on the blockchain is searched using the first specific information extracted by decoding the two-dimensional code embedded in the image data to be verified as a search key, and if there is no hit, the image to be verified an alteration-prevented data acquisition unit that determines that data has been altered, and acquires alteration-prevented data from the hit second transaction if there is a hit;
The hash value of the image data to be verified is compared with the hash value included in the alteration prevention data obtained from the second transaction on the blockchain to determine whether or not the image data to be verified has been altered. Department and
A verification device comprising: A verification device for verifying whether or not image data has been altered,
The first transaction on the blockchain is identified based on the first identification information extracted by decoding the two-dimensional code embedded in the image data to be verified, and the image information is obtained from the identified first transaction. an image information acquisition unit;
Identify the second transaction on the blockchain based on the second identification information extracted from the file property or file name that does not affect the hash value of the image data to be verified, and extract the tamper-proof data from the identified second transaction a tampering prevention data acquisition unit that acquires
The hash value of the image data to be verified is compared with the hash value included in the alteration prevention data obtained from the second transaction on the blockchain to determine whether or not the image data to be verified has been altered. Department and
A verification device comprising: Image data acquisition for identifying a third transaction on the blockchain based on the third identification information included in the tamper-proof data obtained from the second transaction on the blockchain, and obtaining image data from the identified third transaction 15. A verification device according to claim 13 or 14, further comprising a unit. A computer-executed information processing method comprising:
an image information transmission step of transmitting a first transaction in which image information is stored to a blockchain network;
a first specification information storing step of embedding and storing in the image data a two-dimensional code in which first specification information for specifying the first transaction registered in the blockchain is encoded;
a tampering prevention data transmission step of transmitting a second transaction in which tampering prevention data including a hash value of recorded data embedded with the two-dimensional code and the first specific information is stored to a blockchain network;
An information processing method comprising: A computer-executed information processing method comprising:
an image information transmission step of transmitting a first transaction in which image information is stored to a blockchain network;
a first specification information storing step of embedding and storing in the image data a two-dimensional code in which first specification information for specifying the first transaction registered in the blockchain is encoded;
a tampering prevention data transmission step of transmitting a second transaction in which tampering prevention data including a hash value of recorded data embedded with the two-dimensional code is stored to a blockchain network;
The second specification information for specifying the second transaction registered in the blockchain is stored in the property or file name of the file that does not affect the hash value of the image data in which the two-dimensional code is embedded. a storage step;
An information processing method comprising: further comprising an image data transmission step of transmitting a third transaction in which the image data embedded with the two-dimensional code is stored to a blockchain network;
In the alteration-prevented data transmission step, a second transaction storing alteration-prevented data further including third identification information for identifying the third transaction registered in the blockchain is transmitted to the blockchain network.
18. The information processing method according to claim 16 or 17, characterized by: A computer-executed information processing method comprising:
The first transaction on the blockchain is identified based on the first identification information extracted by decoding the two-dimensional code embedded in the image data to be verified, and the image information is obtained from the identified first transaction. an image information acquisition step;
The second transaction on the blockchain is searched using the first specific information extracted by decoding the two-dimensional code embedded in the image data to be verified as a search key, and if there is no hit, the image to be verified a tamper-prevented data acquisition step of determining that data has been tampered with, and acquiring tamper-prevented data from the hit second transaction if there is a hit;
The hash value of the image data to be verified is compared with the hash value included in the alteration prevention data obtained from the second transaction on the blockchain to determine whether or not the image data to be verified has been altered. a step;
An information processing method comprising: A computer-executed information processing method comprising:
The first transaction on the blockchain is identified based on the first identification information extracted by decoding the two-dimensional code embedded in the image data to be verified, and the image information is obtained from the identified first transaction. an image information acquisition step;
Identify the second transaction on the blockchain based on the second identification information extracted from the file property or file name that does not affect the hash value of the image data to be verified, and extract the tamper-proof data from the identified second transaction a tamper-resistant data acquisition step that acquires
The hash value of the image data to be verified is compared with the hash value included in the alteration prevention data obtained from the second transaction on the blockchain to determine whether or not the image data to be verified has been altered. a step;
An information processing method comprising: Image data acquisition for identifying a third transaction on the blockchain based on the third identification information included in the tamper-proof data obtained from the second transaction on the blockchain, and obtaining image data from the identified third transaction 21. The information processing method according to claim 19 or 20, further comprising steps. to the computer,
an image information transmission step of transmitting a first transaction in which image information is stored to a blockchain network;
a first specification information storing step of embedding and storing in the image data a two-dimensional code in which first specification information for specifying the first transaction registered in the blockchain is encoded;
a tampering prevention data transmission step of transmitting a second transaction in which tampering prevention data including a hash value of recorded data embedded with the two-dimensional code and the first specific information is stored to a blockchain network;
An information processing program characterized by executing to the computer,
an image information transmission step of transmitting a first transaction in which image information is stored to a blockchain network;
a first specification information storing step of embedding and storing in the image data a two-dimensional code in which first specification information for specifying the first transaction registered in the blockchain is encoded;
a tampering prevention data transmission step of transmitting a second transaction in which tampering prevention data including a hash value of recorded data embedded with the two-dimensional code is stored to a blockchain network;
The second specification information for specifying the second transaction registered in the blockchain is stored in the property or file name of the file that does not affect the hash value of the image data in which the two-dimensional code is embedded. a storage step;
An information processing program characterized by executing to the computer;
further executing an image data transmission step of transmitting a third transaction in which the image data embedded with the two-dimensional code is stored to a blockchain network;
In the alteration-prevented data transmission step, a second transaction storing alteration-prevented data further including third identification information for identifying the third transaction registered in the blockchain is transmitted to the blockchain network;
24. The information processing program according to claim 22 or 23, characterized by: to the computer,
The first transaction on the blockchain is identified based on the first identification information extracted by decoding the two-dimensional code embedded in the image data to be verified, and the image information is obtained from the identified first transaction. an image information acquisition step;
The second transaction on the blockchain is searched using the first specific information extracted by decoding the two-dimensional code embedded in the image data to be verified as a search key, and if there is no hit, the image to be verified a tamper-prevented data acquisition step of determining that data has been tampered with, and acquiring tamper-prevented data from the hit second transaction if there is a hit;
The hash value of the image data to be verified is compared with the hash value included in the alteration prevention data obtained from the second transaction on the blockchain to determine whether or not the image data to be verified has been altered. a step;
An information processing program characterized by executing to the computer,
The first transaction on the blockchain is identified based on the first identification information extracted by decoding the two-dimensional code embedded in the image data to be verified, and the image information is obtained from the identified first transaction. an image information acquisition step;
Identify the second transaction on the blockchain based on the second identification information extracted from the file property or file name that does not affect the hash value of the image data to be verified, and extract the tamper-proof data from the identified second transaction a tamper-resistant data acquisition step that acquires
The hash value of the image data to be verified is compared with the hash value included in the alteration prevention data obtained from the second transaction on the blockchain to determine whether or not the image data to be verified has been altered. a step;
An information processing program characterized by executing to the computer;
Image data acquisition for identifying a third transaction on the blockchain based on the third identification information included in the tamper-proof data obtained from the second transaction on the blockchain, and obtaining image data from the identified third transaction 27. The information processing program according to claim 25 or 26, further causing steps to be executed. to the computer,
an image information transmission step of transmitting a first transaction in which image information is stored to a blockchain network;
a first specification information storing step of embedding and storing in the image data a two-dimensional code in which first specification information for specifying the first transaction registered in the blockchain is encoded;
a tampering prevention data transmission step of transmitting a second transaction in which tampering prevention data including a hash value of recorded data embedded with the two-dimensional code and the first specific information is stored to a blockchain network;
A computer-readable recording medium recording an information processing program characterized by executing to the computer,
an image information transmission step of transmitting a first transaction in which image information is stored to a blockchain network;
a first specification information storing step of embedding and storing in the image data a two-dimensional code in which first specification information for specifying the first transaction registered in the blockchain is encoded;
a tampering prevention data transmission step of transmitting a second transaction in which tampering prevention data including a hash value of recorded data embedded with the two-dimensional code is stored to a blockchain network;
The second specification information for specifying the second transaction registered in the blockchain is stored in the property or file name of the file that does not affect the hash value of the image data in which the two-dimensional code is embedded. a storage step;
A computer-readable recording medium recording an information processing program characterized by executing to the computer;
further executing an image data transmission step of transmitting a third transaction in which the image data embedded with the two-dimensional code is stored to a blockchain network;
In the alteration-prevented data transmission step, a second transaction storing alteration-prevented data further including third identification information for identifying the third transaction registered in the blockchain is transmitted to the blockchain network;
30. The computer-readable recording medium according to claim 28 or 29, which records an information processing program characterized by: to the computer,
The first transaction on the blockchain is identified based on the first identification information extracted by decoding the two-dimensional code embedded in the image data to be verified, and the image information is obtained from the identified first transaction. an image information acquisition step;
The second transaction on the blockchain is searched using the first specific information extracted by decoding the two-dimensional code embedded in the image data to be verified as a search key, and if there is no hit, the image to be verified a tamper-prevented data acquisition step of determining that data has been tampered with, and acquiring tamper-prevented data from the hit second transaction if there is a hit;
The hash value of the image data to be verified is compared with the hash value included in the alteration prevention data obtained from the second transaction on the blockchain to determine whether or not the image data to be verified has been altered. a step;
A computer-readable recording medium recording an information processing program characterized by executing to the computer,
The first transaction on the blockchain is identified based on the first identification information extracted by decoding the two-dimensional code embedded in the image data to be verified, and the image information is obtained from the identified first transaction. an image information acquisition step;
Identify the second transaction on the blockchain based on the second identification information extracted from the file property or file name that does not affect the hash value of the image data to be verified, and extract the tamper-proof data from the identified second transaction a tamper-resistant data acquisition step that acquires
The hash value of the image data to be verified is compared with the hash value included in the alteration prevention data obtained from the second transaction on the blockchain to determine whether or not the image data to be verified has been altered. a step;
A computer-readable recording medium recording an information processing program characterized by executing to the computer;
Image data acquisition for identifying a third transaction on the blockchain based on the third identification information included in the tamper-proof data obtained from the second transaction on the blockchain, and obtaining image data from the identified third transaction 33. The computer-readable recording medium according to claim 31 or 32, recording an information processing program characterized by further executing steps.

Images