JP6674401B2 - Detection system, detection method and detection program - Google Patents

Description

  The present invention relates to a system, method, and program for detecting illegally distributed data.

  2. Description of the Related Art In recent years, a system called a blockchain for decentralized management of transaction transactions has been developed, which has contributed to the realization of secure sales transactions whose validity has been verified (for example, see Non-Patent Documents 1 to 3).

Satoshi Nakamoto, “Bitcoin: A peer-to-peer electronic cash system,” 2008. Sompolynsky, Y .; , Zohar, A .; , "Accelerating bitcoin's transaction processing. Fast money growths on trees, not chains," IACR Cryptology ePrint Archive 2013 (2013) 881. Lewenberg, Y .; Sompolsky, Y .; , Zohar, A .; , "Inclusive Blockchain Protocols," Financing Cryptography and Data Security-19th International Conference, FC2015, San Juan, Puerto Rico, January 30, Ricoh, January 30, 2006. (2015) 528-547.

By the way, in a data distribution market, there is a case where illegally copied data is distributed, and it is required to control such a transaction of purchasing and selling illegal data.
However, it has been difficult for the platform operator to detect such illegal data from a huge transaction history, and a large cost has been required.

  An object of the present invention is to provide an unauthorized data detection system, a detection method, and a detection program that can realize a secure data distribution platform at low cost.

  A detection system according to the present invention includes: a database that stores a set of hash values of sales schedule data registered from a seller terminal; a transaction management unit that manages a block including a transaction history as a block chain; As a proof of work for closing, from the set of hash values, a verification terminal that detects a hash value that matches any of the transaction histories and stores the matching hash value in the block as an unauthorized hash list, The transaction management unit closes the block on condition that the unauthorized hash list is stored and provides a fee to the verification terminal storing the unauthorized hash list.

  The detection system may include an administrator terminal that mixes, in the database, a dummy hash value that duplicates any of the transaction histories and can be detected as the matching hash value.

  The administrator terminal may adjust the number of the dummy hash values to be mixed according to the size of the set of the hash values, and keep the dummy ratio constant.

  The administrator terminal may encrypt the dummy hash value and store it in the block before the block is closed.

  The transaction management unit may record the seller of the data corresponding to the hash value stored in the unauthorized hash list with reduced reliability regarding the transaction.

The hash value may be a result of performing a hash operation on each of one or a plurality of data after performing a predetermined operation on the data to be sold.

  The transaction management unit may be provided for each of a plurality of block chains corresponding to each hierarchical management unit.

  A detection method according to the present invention provides a system including: a database that stores a set of hash values of sales schedule data registered from a seller terminal; and a transaction management unit that manages a block including a transaction history as a blockchain. A verification terminal detects, as a proof of work for closing the block, a hash value that matches any of the transaction histories from the set of hash values, and sets the matching hash value as an unauthorized hash list to the block. The transaction management unit closes the block on condition that the unauthorized hash list is stored, and gives a price to the verification terminal storing the unauthorized hash list.

  A detection program according to the present invention causes a computer to function as the detection system.

  According to the present invention, a secure data distribution platform can be realized at low cost.

FIG. 1 is a schematic diagram illustrating a data distribution platform according to an embodiment. FIG. 1 is a diagram illustrating a configuration of a detection system according to an embodiment.

Hereinafter, an example of an embodiment of the present invention will be described.
FIG. 1 is a schematic diagram illustrating a data distribution platform according to the present embodiment.

In the data distribution platform, a seller registers sales data such as multimedia contents in a data distribution market (Data Trading Market), and a purchaser purchases data registered in the market.
Here, trading is the transfer of data, and a record of this transfer is accumulated as Verifiable Data Transfer Records (VDTR).

In such a data distribution market, an upper limit is set on the number of copies (sales) of data in order to stabilize the price of data. Therefore, a function for monitoring unauthorized duplication of data is required.
In the present embodiment, a block chain is used as the configuration of the VDTR, and the function of detecting data duplication is realized as a proof of work.

FIG. 2 is a diagram illustrating a configuration of the detection system 1 according to the present embodiment.
The detection system 1 includes a seller terminal 10, a purchaser terminal 20, a market manager terminal 30, and a verifier terminal 40. Further, the detection system 1 includes a database 50 and a transaction management unit 60, which may be distributed on a network (Internet).

The seller terminal 10 encrypts the sales data and transmits it to the buyer terminal 20.
Upon confirming the validity of the data based on the transaction history of the blockchain, the buyer terminal 20 decrypts the purchased data using a key separately received from the seller.

  Further, the seller terminal 10 registers the hash value of the sales schedule data in the database 50. The database 50 stores a set of hash values of the sales schedule data, which may include data obtained by illegally copying data sold in the past.

  The terminal 30 of the market manager mixes, into a set of hash values stored in the database 50, a dummy hash value obtained by copying any of the hash values included in the transaction history managed by the blockchain. This dummy hash value can be detected at the verifier's terminal 40 as a hash value that matches the transaction history.

  At this time, the terminal 30 of the market manager adjusts the number of dummy hash values to be mixed according to the size of the set of hash values and keeps the ratio of the dummy constant, thereby reducing the processing load of the proof of work. Properly.

  Further, the terminal 30 of the market manager encrypts the dummy hash value mixed in the database 50 by public key encryption, and stores the encrypted hash value in the block before the block is closed. The encrypted hash value is decrypted and provided by the market manager for verification of the unauthorized hash list stored in the next block by the verifier's terminal 40.

  The verifier's terminal 40 uses a hash value selected from a set of hash values stored in the database 50 as a proof of work for closing the block of the block chain and a hash value stored in the transaction history of the block chain. And. Upon detecting a hash value that matches any of the transaction histories from the set of hash values, the verifier terminal 40 stores the matching hash value as an unauthorized hash list in the block.

As described above, the database 50 stores the hash value of the sales schedule data and the dummy hash value.
In the present embodiment, the format of the hash value is not limited, but it may be generated for each appropriately set data unit in order to detect illegally copied data.
Specifically, the hash value may be a value obtained by performing a hash operation on each of one or a plurality of data after a predetermined operation has been performed on the data to be sold.

For example, in the case of moving image content, the original data may be divided into a plurality of parts, such as dividing the moving image content for a predetermined time or for each scene, and a hash value may be generated for each division unit. The size of the division may be set in a tree-like hierarchy.
Further, after calculating the feature amount of each data, a hash value for this feature amount may be calculated.

  The transaction management unit 60 manages a block including the transaction history as a block chain. The transaction management unit 60 may be provided for each of a plurality of block chains corresponding to each hierarchical management unit. The management unit is provided, for example, for each country or region, or for each field.

For example, the following elements are stored in each block managed by the block chain.
・ Transaction history including the hash value of data ・ Illegal hash list ・ Commitment for the next block which encrypted the dummy hash value ・ Hash value of the entire previous block ・ Electronic signature of the verifier who performed the audit

The transaction management unit 60 closes the block in accordance with the verifier's or market manager's instruction on condition that the fraudulent hash list is stored by the verifier's terminal 40, and also verifies the verifier's terminal 40 that stores this fraudulent hash list. Give consideration to
Note that the transaction management unit 60 may close the block on condition that all of the mixed dummy hash values are detected in addition to the fact that the illegal hash list is stored.

  Further, when the detected hash value includes a hash value of fraudulent data that is not a dummy, the transaction management unit 60 records the seller of the fraudulent data corresponding to the hash value with reduced reliability regarding the transaction. .

According to the present embodiment, the detection system 1 uses a block chain as a configuration of a VDTR that records a sales transaction of data. The proof-of-work performed by the verifier to close each block is defined as a process of searching for a hash value of fraudulent data that matches the transaction history.
Therefore, usually, a calculation problem only for closing a block is prepared as a proof-of-work, but the detection system 1 can detect illegal data by the proof-of-work and efficiently change the motivation of the verifier without changing the motivation. Can utilize computing resources.

The detection system 1 mixes a dummy hash value that matches the past transaction history into the set of hash values of the sales plan data.
Therefore, the detection system 1 can expect that a hash value that matches the transaction history is detected within a predetermined time period regardless of the presence or absence and the number of fraudulent data. Can be verified and closed.

  Further, since the detection system 1 can adjust the number of dummy hash values to be mixed and make the ratio of the dummy in the set of hash values constant, the processing load of the proof of work can be made uniform. Further, the processing load of the proof of work can be easily adjusted.

  Since the detection system 1 encrypts the dummy hash value and stores it in the block, the detection system 1 can appropriately collate the hash value with the unauthorized hash list, and can easily verify the accuracy of the proof of work and specify the unauthorized data. .

  The detection system 1 gives a penalty to the seller of the data that matches the transaction history and is determined to be an illegal copy. For example, by lowering the reliability of the seller's transactions and recording the information, In addition, fraudulent receipt of consideration due to collusion with the verifier can be suppressed.

The detection system 1 generates a hash value for each of one or a plurality of data after performing a predetermined operation, for example, dividing the data or calculating a feature amount, on the sales schedule data.
Therefore, the detection system 1 can cope with a part of the data or an unauthorized copy after the modification, and can improve the detection accuracy.

  The detection system 1 can divide the data distribution market into a plurality of management units by hierarchizing the block chains. In addition, in the higher hierarchy, by confirming with a more reliable organization, the reliability of the entire system is improved.

  The embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments. Further, the effects described in the present embodiment merely enumerate the most preferable effects resulting from the present invention, and the effects according to the present invention are not limited to those described in the present embodiment.

  In the present embodiment, the sales schedule data and the past transaction history are compared by the hash value. However, the present invention is not limited to this, and a function other than the hash calculation may be used.

  The detection method by the detection system 1 is realized by software. When realized by software, a program constituting the software is installed in an information processing device (computer). Further, these programs may be recorded on a removable medium such as a CD-ROM and distributed to the user, or may be distributed by being downloaded to the user's computer via a network.

DESCRIPTION OF SYMBOLS 1 Detection system 10 Seller's terminal 20 Buyer's terminal 30 Market manager's terminal (manager's terminal)
40 Verifier's terminal (verification terminal)
50 database 60 transaction management department

Claims (9)

A database for storing a set of hash values of sales schedule data registered from the seller's terminal,
A transaction management unit that manages a block including a transaction history as a blockchain,
Verification, as a proof of work for closing the block, detecting a hash value that matches any of the transaction histories from the set of hash values, and storing the matching hash value in the block as an unauthorized hash list And a terminal,
The detection system, wherein the transaction management unit closes the block on condition that the unauthorized hash list is stored and provides a fee to the verification terminal storing the unauthorized hash list.   2. The detection system according to claim 1, further comprising: an administrator terminal that mixes a dummy hash value that can be detected as the matching hash value, in which one of the transaction histories is duplicated in the database. 3.   3. The detection system according to claim 2, wherein the administrator terminal adjusts the number of the dummy hash values to be mixed according to the size of the set of hash values to make the ratio of the dummy constant. 4.   4. The detection system according to claim 2, wherein the administrator terminal encrypts the dummy hash value and stores the encrypted hash value in the block before the block is closed. 5.   5. The detection system according to claim 1, wherein the transaction management unit records a seller of data corresponding to the hash value stored in the unauthorized hash list with reduced reliability regarding the transaction. 6. The hash value according to claim 1, wherein the hash value is obtained by performing a hash operation on each of one or a plurality of data after performing a predetermined operation on the sales schedule data. 7. Detection system.   The detection system according to any one of claims 1 to 6, wherein the transaction management unit is provided for each of a plurality of block chains corresponding to each of the hierarchized management units. In a system including a database that stores a set of hash values of sales schedule data registered from a seller terminal and a transaction management unit that manages a block including a transaction history as a blockchain,
A verification terminal detects a hash value that matches any of the transaction histories from the set of hash values as a proof of work for closing the block, and detects the matching hash value as an unauthorized hash list in the block. Stored in
A detection method in which the transaction management unit closes the block on the condition that the fraudulent hash list is stored and gives a price to the verification terminal storing the fraudulent hash list.   A detection program for causing a computer to function as the detection system according to any one of claims 1 to 7.

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