JP2018022346A - Data transaction system and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transaction system which establishes data transaction over a network.SOLUTION: A transaction system includes: receiving means of receiving purchase information indicating a purchase request of sale data; management means of storing the purchase information received in a predetermined period by the receiving means into an open block, closing the open block at the end of the predetermined period, and creating a next open block; and fixing means of fixing transaction of the sale data indicated by the purchase information stored in the block when the open block is closed. In creating an open block, the management means stores a hash value of predetermined data in a previous block into the block to be created, and generates, in closing the open block, authentication information of the predetermined data in the block to be closed, with an encryption key, to be stored in the block to be closed.SELECTED DRAWING: Figure 3

Description

  The present disclosure relates to a data transaction system indicating content such as moving images, still images, and music.

  Non-Patent Document 1 discloses the creation of a so-called block chain in order to guarantee the validity of a transaction in a virtual currency system. First, the outline of the block chain will be described with reference to FIG. In FIG. 4, the immediately preceding block 51 has already been closed (closed), and the current block 52 is in an open state. In this example, for the sake of simplicity of explanation, it is assumed that the block chain of FIG. 4 is managed and created by a predetermined management server. When the management server closes the immediately preceding block 51, it creates the current block 52. At this time, the current block 52 stores the hash value of the predetermined data in the data of the immediately preceding block 51 as the hash value 521 of the block 51. Write to block 52. A plurality of terminals that perform virtual currency delivery constitute a peer-to-peer network, and when virtual currency delivery (hereinafter, individual virtual currency delivery is referred to as a transaction) is performed. Is sent to the management server. This information cannot be tampered with by authentication technology. The management server adds the hash value of the information indicating each transaction to the current block 52 as the transaction hash value 522.

  In addition, when the current block 52 is created, each terminal participating in the peer-to-peer network performs an operation of finding a nonce value 523 of the current block 52. The nonce value 523 is a condition in which the hash value of data obtained by concatenating the hash value 521, the hash value 522, and the nonce value 523 is a predetermined condition, for example, a condition that all of the initial predetermined number of bits are “0”. Is a value that satisfies Since the hash function is a one-way function, the task of finding the nonce value 523 is to obtain a hash value of data obtained by concatenating the appropriately generated value, the hash value 521, and the hash value 522 at that time. It is necessary to sequentially determine whether or not a predetermined condition is satisfied. However, since a large number of terminals participate in this work, a terminal that finds a nonce value 523 that satisfies the predetermined condition appears. The terminal writes the found nonce value 523 to the current block 52 via the management server, and further, with the secret key of the predetermined terminal, the hash value 521, the hash value 522 at that time, and the written nonce value 523 The authentication information is generated and this authentication information is also written in the current block 52 (not shown). As a result, the current block 52 is closed and the next block is created. In this next block, a hash value of data obtained by concatenating the hash value 521 of the immediately preceding block 51, the hash value 522 at the time of closing, and the written nonce value 523 is written.

  As described above, the operation of finding the nonce value 523 is performed by trial and error. However, since many terminals perform this work in parallel, a terminal that finds a nonce value in a time corresponding to a predetermined condition such as about 10 minutes appears. Note that the time until the nonce value 523 is found can be adjusted by changing a predetermined condition, for example, the number of conditions in which the hash value is the first consecutive “0”. Although the information itself indicating the transaction content is distributed and arranged in each terminal, the hash value of the transaction is stored in the block chain. Therefore, if the block chain is correct, the legitimacy of each transaction can be confirmed by comparing the contents of each block of the block chain with information indicating transactions distributed and arranged at each terminal.

  The operation of finding the nonce value 523 is completed within a certain amount of time because a large number of terminals perform in parallel. However, even if some malicious terminals attempt to rewrite the blockchain, The task of finding the value 523 is very time consuming, during which time the legally calculated blocks grow. That is, it is difficult for some malicious terminals to rewrite the block chain, and the validity of the block chain itself is ensured.

Satoshi Nakamoto "Bitcoin: A peer-to-peer electronic cash system", 2008

  Currently, contents such as moving images, still images, and music can be easily digitized, and data corresponding to these contents can be easily transmitted and received via a network. Therefore, for example, by using SNS or the like, a certain individual can make an unspecified number of people browse the created content. However, an SNS or the like allows content created by a certain individual to be viewed by others for free and is not sold. Here, in order to establish a transaction by matching what you want to sell the content you created and what you want to purchase content created by others, a transaction system that establishes a transaction for the content to be bought and sold Is required.

  The present invention provides a transaction system and a program for establishing a data transaction via a network.

  According to one aspect of the present invention, when a transaction system that establishes a transaction of data via a network receives sales data, the transaction system stores the sales data in the first storage unit, and the sales stored in the first storage unit Processing means for performing processing for publishing information indicating data on the network; receiving means for receiving purchase information indicating a purchase request for sales data stored in the first storage means; and the receiving means for a predetermined period Stores the purchase information received in the open block and, when the predetermined period ends, closes the open block and creates the next open block, and the open block is closed. Confirming means for confirming the transaction of the sales data indicated by the purchase information stored in the block when When creating the open block, the management means stores the hash value of the predetermined data of the previous block in the created block, and when closing the open block, The authentication information of the predetermined data is generated with an encryption key and stored in the block to be closed.

  According to the present invention, data can be traded via a network.

The block diagram of the transaction system by one Embodiment. The figure which shows the data stored in the mediation part by one Embodiment, and the data stored in a verification data holding part. The figure which shows the block chain managed with the transaction system by one Embodiment. Explanatory drawing of a block chain.

<First embodiment>
Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings. In the following drawings, components that are not necessary for describing the embodiment are omitted from the drawings. Moreover, the following embodiment is an illustration and does not limit this invention to the content of embodiment.

  FIG. 1 is a configuration diagram of a transaction system according to the present embodiment. The transaction system according to the present embodiment is configured such that a plurality of terminals participating in a transaction and the management server 1 can communicate with each other via a network. Here, the network is, for example, the Internet. Each terminal corresponds to a user, and the management server 1 has information about each user, and when communicating with each terminal, each terminal is authenticated in advance by a known authentication technique.

  A user who wants to sell content (hereinafter, a seller) transmits the content to be sold to the management server 1 using his / her terminal. When the mediation unit 11 of the management server 1 receives the content to be sold, it gives identification information of the content. Further, the mediation unit 11 encrypts the content with an encryption key, obtains a hash value of the content, uses the encryption key used for encrypting the content, the encrypted content encrypted with the encryption key, the content Are stored in the encrypted content holding unit 12 in association with information indicating the seller (seller information) and content identification information. The encryption key can be generated for each content. However, the encryption key is not different for each content, but a large number of encryption keys are prepared, and when the content is received, one encryption key is randomly selected from the prepared encryption keys. And may be configured to be encrypted. FIG. 2A shows data stored in the encrypted content holding unit 12.

  Further, when receiving the content to be sold, the mediation unit 11 cuts out a part of the content and stores it as verification data in the verification data storage unit 13 in association with the identification information of the content. In addition, when a content is a moving image or a music, a part of content is a part of a certain time range of a moving image or a music. Further, in the case of a still image such as a photograph, it is an area portion where the still image is present. Which part of the content is to be cut out may be determined by the mediation unit 11 or may be specified by the seller who has transmitted the content to the management server 1. A configuration may be adopted in which not all of the received content but the entire verification data is used. In this case, for example, an image or the like can be converted to a low resolution. Moreover, it can be set as the structure which converts into a low quality acoustic data about the music about the content of the original music which can be discriminate | determined. FIG. 2B shows data stored in the verification data storage unit 13.

  Further, the mediation unit 11 publishes the content being sold to each terminal together with attribute information indicating the content. The content attribute information is transmitted to the management server 1 together with the content by the content seller. Further, the mediation unit 11 publishes the verification data of the content as a content sample to each terminal. The verification data can be browsed or viewed, but cannot be downloaded and stored in each terminal.

  Each user can browse / view the contents being sold published by the mediation unit 11 with his / her terminal, and if he / she wants to purchase the contents, he / she sends a purchase request including information specifying the contents to be purchased to the management server 1. Send. The mediation unit 11 transfers the purchase request to the block chain management unit 14 together with information indicating a user who purchases (hereinafter, a purchaser).

  FIG. 3 shows a block chain managed by the block chain management unit 14 in this embodiment. In FIG. 3, the block 21 is closed and the block 22 is in an open state. When a block is closed, the block chain management unit 14 creates a block on the downstream side of the closed block in an open state. At this time, the block chain management unit 14 records the hash value of the predetermined data of the closed block in the newly created block. In FIG. 3, the hash value 221 of the predetermined data stored in the block 21 is stored in the open block 22.

  Further, when receiving a purchase request from the mediation unit 11, the block chain management unit 14 adds the received purchase request as purchase information 222 to the block 22 that is open at that time. That is, the purchase information 222 of the block 22 is a list of purchase requests for each content received after the block 21 is closed. Each purchase request includes content to be purchased and information indicating a purchaser of the content.

  Further, as described above, each user can freely browse and view the verification data of the content being sold, which is stored in the verification data storage unit 12 via each terminal. Here, when each user browses / views the verification data, for example, if they are not clearly created by an individual, such as a TV program or a song on a CD being sold, The content is notified to the management server 1 as illegal content. When the illegal content is notified, the mediation unit 11 of the management server 1 notifies the block chain management unit 14 of information indicating the illegal content. The block chain management unit 14 adds information indicating the notified unauthorized content to the unauthorized content information 223 of the block that is open at that time. In the example of FIG. 3, since the block 22 is in an open state, information indicating the newly notified unauthorized content is added to the unauthorized content information 223 of the block 22.

  Note that, unlike the purchase information 222, information indicating the illegal content included in the illegal content information 223 is taken over to the next block when a new block is generated. In other words, the illegal content information indicates all illegal contents discovered in the past.

  The block chain management unit 14 adds the electronic signature 224 to the open block 22 at a predetermined timing, closes the block 22, and generates the next block in the open state. Here, the predetermined timing can be, for example, when a predetermined period has elapsed since the block 22 was generated. In the present embodiment, the electronic signature 224 is obtained by a public key encryption method using a data obtained by concatenating the hash value 221, the purchase information 222, and the illegal content information 223, and a secret key used by the management server 1. Generated. Further, the block chain management unit 14 stores the hash value of the data of the block 22 and the illegal content information of the block 22 in the block next to the block 22. In the present embodiment, the hash value of the data of the block 22 is a hash value of data obtained by concatenating the hash value 221 of the block 22, the purchase information 222, the unauthorized content 223, and the electronic signature 224. However, the electronic signature 224 can be excluded from the calculation target. While the next block is in an open state, the block chain management unit 22 adds the newly received purchase request to the purchase information to the next block, and adds the found illegal content to the illegal content information. To do.

  Assume that the broker 11 confirms the transaction for each purchase request indicated by the closed purchase information 222 when the open block is closed. At this time, if the content indicated by the purchase request is included in the illegal content information, the purchase request is invalidated. Then, the mediation unit 11 notifies the purchaser terminal of the purchase request that has been invalidated that the purchase request has become invalid. On the other hand, the intermediary unit 11 confirms that the transaction has been established, the encrypted content of the purchased content, its hash value, and the decryption key of the encrypted content at the terminal of the purchase requester who has not become invalid. Send. At the same time, the mediation unit 11 collects the purchase price from the purchaser. The purchase price can be collected by acquiring credit card information from each user in advance.

  The purchaser's terminal that has received the encrypted content decrypts the encrypted content with the received decryption key, and determines whether the hash value of the decrypted content is the same as the received hash value. This determines that the content has not been altered.

  Further, the mediation unit 11 performs a payment process in which a predetermined percentage of the collected purchase price is paid to the content sold. The remaining amount is for the operation of the trading system. At this time, it is possible to adopt a configuration in which a predetermined amount is paid to the terminal that has notified the illegal content.

  In this way, the block chain management unit 14 manages a block chain including purchase information and unauthorized content information. In this embodiment, since the operator of the transaction system manages the block chain and confirms the identity of each user who participates in the transaction in advance, the work of finding a nonce value as in Non-Patent Document 1 is Not performed. On the other hand, the validity of the connection between the blocks is ensured by storing the hash value of the data of the previous block in the newly generated block, and the validity of the data of each block is ensured by the electronic signature 224. Is done. Therefore, the transaction content is secured by the block chain managed by the block chain management unit 14, and tampering of the block chain is difficult.

  Furthermore, there is a possibility that fraudulent content is sold in content transactions via a network. In the present embodiment, it is possible to efficiently acquire information on illegal content by generating and publishing verification data and allowing each user participating in the transaction to browse. Furthermore, when a transaction is established, information regarding illegal content can be acquired more efficiently by adopting a configuration in which a predetermined amount is paid to the user who has notified the illegal content. When unauthorized content is notified, for example, the operator of the transaction system confirms whether the notified content is really unauthorized, and confirms that the operator is unauthorized. The configuration may be such that the unauthorized content information 223 is stored only when an acknowledgment is sent to the management server 1. This is because there is a possibility that non-illegal content is notified as illegal content. In any case, it is possible to efficiently collect information about illegal contents by disclosing the verification data, and thus the reliability of transactions can be improved.

  The management system 1 according to the present invention can be realized by a program that causes one or more computers to operate as the management system 1 in cooperation. Note that one or more computers can be distributed, and in this case, they are connected to each other via a network. These computer programs can be stored in a computer-readable storage medium or distributed via a network.

Claims (7)

A transaction system for establishing data transactions via a network,
Processing means for receiving the sales data, storing the sales data in the first storage means, and performing processing for publishing information indicating the sales data stored in the first storage means on the network;
Receiving means for receiving purchase information indicating a purchase request for sales data stored in the first storage means;
Management information for storing purchase information received by the receiving means in a predetermined period in an open block, and closing the open block and creating a next open block when the predetermined period ends;
Confirming means for confirming the transaction of the sales data indicated by the purchase information stored in the block when the open block is closed;
With
When creating the open block, the management means stores the hash value of the predetermined data of the previous block in the created block, and when closing the open block, A system characterized in that authentication information of predetermined data is generated by an encryption key and stored in the block to be closed. When the processing means receives the sales data, it generates verification data of the sales data and stores it in the second storage means,
The system according to claim 1, wherein the processing unit publishes verification data stored in the second storage unit on the network. The sales data is a video or music,
The system according to claim 2, wherein the verification data is data of a time range of a part of the moving image or the music piece. When the management unit receives a notification from the terminal that has received the verification data stored in the second storage unit via the network that the verification data is data corresponding to illegal content, the management data When the information indicating the original sales data is added to the open block as invalid information and the open block is closed to create the next open block, the illegal stored in the closed block Store the information in the created block,
The confirmation means is configured to store sales data other than the sales data included in the fraudulent information of the closed block among the sales data indicated by the purchase information stored in the block when the open block is closed. 4. The system according to claim 2, wherein the transaction is finalized. When the open block is closed, the confirming means stores the sales data indicated by the purchase information in the sales data stored in the first storage means at the terminal of the confirmed transaction purchase information transmission source. Send
The system according to claim 4, wherein a terminal that is a source of purchase information indicating sales data included in the fraud information is notified that the transaction has not been confirmed.   When the management unit receives a notification from the terminal that has received the verification data stored in the second storage unit via the network that the verification data is data corresponding to unauthorized content, the management unit When the content indicated by the original sales data of the verification data is displayed to the operator and the confirmation input from the operator is received, the information indicating the original sales data of the verification data is added to the open block as illegal information The system according to claim 4 or 5, characterized in that:   A program that causes a computer to function as the system according to any one of claims 1 to 6.

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