KR20140018612A - Method for preventing copylighted files from being distributed and copylight protection apparatus using the same - Google Patents

Abstract

If a copyrighted file is shared through a network, the present invention generates contamination file pieces corresponding to the size of a file piece in a copyrighted file service and manages the contamination file piece by storing the contamination file piece using a hash value as a key. If a file request is inputted, the present invention provides the contamination file piece corresponding to the hash value obtained by the corresponding request. [Reference numerals] (AA,CC) No; (BB,DD) Yes; (S300) Acts as a virtual peer; (S310) Standby the file request reception; (S320) Receiving the file request?; (S330) Obtain a hash value and a file piece size from the received file request; (S340) Search collision value database based on the hash value; (S350) Corresponding hash value exists?; (S360) Transmit the standby contaminated file piece; (S370) Response that no corresponding file piece exists

Description

Method for preventing copylighted files from being distributed and copylight protection apparatus using the same}

The present invention relates to a copyright protection device, and more particularly, to a method of blocking distribution of illegally shared copyright files and a copyright protection device using the same.

With the development of communication technology, various contents are digitized through a network, and content sharing is achieved.

Peer-to-peer (P2P) networks are networks in which individuals connect directly to each other to share files. Generally, peer-to-peer networks are used for sharing digital format files such as audio, video, and data. Real-time data, such as VoIP, can also be communicated with each other through P2P technology. In a pure P2P file transfer network, only peer nodes act as clients and servers at the same time, without the concept of a client or server. This network configuration model is distinct from the client-server model of communication, usually through a central server.

Protocols used in these P2P networks include Bittorent, Donkey (eDonkey), Gnutella, and Fasttrack. Among these, the BitTorrent protocol is widely used. BitTorrent is the name of the file transfer protocol and the name of the application software that uses it, allowing you to retrieve files from multiple locations simultaneously using multiple connections while the files are distributed and stored on the Internet.

As file sharing technologies such as BitTorrent are developed, illegal distribution of video and software is increasing, and in particular, illegal distribution of copyrighted files is increasing.

The problem to be solved by the present invention is to provide a method for suppressing and blocking the illegal distribution of copyright files.

Another object of the present invention is to provide a method for suppressing and blocking distribution of copyright files in a network environment using a P2P file transfer protocol and a copyright protection device using the same.

For the above technical problem, the method according to the features of the present invention is a method for blocking the distribution of the copyright file in a network environment using a peer-to-peer (P2P) file transfer protocol. The method includes the steps of a copyright protection device operating as a virtual peer using a meta information file associated with a copyright file; The copyright protection device receiving a file request from any peer; Analyzing the file request to obtain a hash value; Retrieving a collision value database in which contamination file fragments are stored based on the hash value; And providing the peer with a pollutant file piece corresponding to the hash value according to the search result.

The contamination file fragment is stored using the collision value database hash value as a key value, and the providing may include obtaining a pollution file fragment corresponding to the hash value when the hash value exists in the collision value database; If the contaminated file fragment is compressed, decompressing the contaminated file fragment and providing it to the peer; And notifying the peer that there is no corresponding file when the hash value does not exist in the collision value database.

Meanwhile, the meta information file may include hash values corresponding to a file fragment size and related polluted file fragments. In this case, obtaining the hash value may include analyzing the file request to identify a corresponding meta information file; And obtaining a hash value corresponding to the requested file from the meta information file. The searching may include searching the collision value database using the hash value as a key value.

In addition, the method may further include generating a contamination file fragment for the copyright file and storing the generated pollution file fragment in the collision value database.

The storing may include: copyright files are divided into pieces of a predetermined size, and generating a predetermined number of dirty file pieces for each file piece size supported by the file transfer protocol; Acquiring a hash value by applying a predetermined hash function to the generated contaminated file fragment for each file fragment size; And storing the contaminated file fragment in the collision value database for each file fragment size using a hash value as a key value.

A method according to another aspect of the present invention is a method for blocking distribution of a copyright file in a network environment using a peer-to-peer file transfer protocol, wherein the copyright files are divided into pieces of a predetermined size, and in the file transfer protocol Generating a data structure listing the supported file fragment sizes: generating a predetermined number of dirty file fragments for each file fragment size; Acquiring a hash value by applying a predetermined hash function to the generated contaminated file fragment for each file fragment size; Storing the contaminated file fragment in the collision value database for each file fragment size using a hash value corresponding to the contaminated file fragment as a key value; And in response to a file request input through the network, providing a fragment of the dirty file stored in the collision value database.

A collision value database is formed for every file fragment size included in the data structure, and each collision value database may store a corresponding contamination file fragment using a hash value as a key value.

The providing of the contaminated file fragment may include analyzing the file request to obtain a hash result, the hash result including a hash value and a size of the requested file fragment; Searching for a collision value database corresponding to the size included in the hash result by using the hash value included in the hash result as a key value; And providing the peer with a polluted file fragment corresponding to the hash value according to the search result.

Here, the meta information file may include hash values corresponding to the file fragment size and the associated dirty file fragments. The acquiring the hash result may include analyzing the file request to identify a corresponding meta information file; And obtaining a hash result including a size and a hash value corresponding to the requested file from the meta information file.

In this method, the file transfer protocol may be a Bittorent protocol.

In addition, the device according to another aspect of the present invention is a copyright protection device that blocks the distribution of copyright files in a network environment using a peer-to-peer (P2P) file transfer protocol, hash value for each file fragment size supported by the file transfer protocol A collision value database in which the contaminated file fragment is stored using as a key value; A file request receiving unit that receives a file request from any peer while the copyright protection device operates as a virtual peer using a meta information file related to a copyright file; A hash analyzer for analyzing the file request to obtain a hash result, wherein the hash result includes a hash value and a size of a requested file fragment; A hash value search unit for searching the collision value database based on the hash result; And a polluted file fragment distributor configured to provide the peer with a polluted file fragment obtained from the collision value database according to the search result.

Herein, when the hash value included in the hash result exists in the collision value database, the pollution file fragment distribution unit provides the peer with a pollution file fragment corresponding to the hash value and includes the hash file fragment in the collision value database in the hash result. If the hash value does not exist, the peer may be notified that the file does not exist.

Meanwhile, the device generates a contaminated file fragment for each file fragment for each file fragment size supported by the file transfer protocol, and applies a preset hash function to the contaminated file fragment generated for each file fragment size. The method may further include a pollution file fragment generation unit configured to obtain a hash value and store the pollution file fragment in the collision value database using the hash value as a key value.

Herein, the file transfer protocol is a Bittorent protocol, copyright files are divided into pieces of a predetermined size, and the meta information file may include hash values corresponding to a file fragment size and associated dirty file fragments. have. In this case, the hash analyzer may acquire a hash value and a file fragment size corresponding to the requested file fragment from the meta information file identified by analyzing the file request.

In addition, the collision value database is formed for every file fragment size included in the data structure, and each collision value database stores a contaminated file fragment corresponding to each file fragment with a hash value as a key value, and the hash value search unit The collision value database corresponding to the file fragment size provided from the hash analyzer may be searched based on the hash value provided from the hash analyzer.

According to an embodiment of the present invention, by providing a portion of the copyrighted file distributed through the client in a network environment using the P2P file transfer protocol, it is possible to suppress the normal distribution of the file.

Also, users of the file sharing service cannot distinguish between files containing normal files and contaminated pieces. Illegal distribution can be kept under control.

1 is a diagram illustrating the structure of a meta information file according to an embodiment of the present invention.
2 is a flowchart illustrating a process of generating a dirty file fragment according to an embodiment of the present invention.
3 is an exemplary view illustrating a process of generating a dirty file fragment according to an embodiment of the present invention.
4 is an exemplary diagram illustrating a network environment to which a distribution blocking method according to an exemplary embodiment of the present invention is applied.
5 is a flowchart illustrating a method for blocking distribution of illegally shared copyright files according to an embodiment of the present invention.
6 is an exemplary diagram illustrating a process of distributing a dirty file fragment for a copyright file according to an exemplary embodiment of the present invention.
7 is a diagram showing the structure of a copyright protection device according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Throughout the specification, when an element is referred to as "comprising ", it means that it can include other elements as well, without excluding other elements unless specifically stated otherwise.

Hereinafter, a method of blocking distribution of a copyright file and a copyright protection device using the same according to an embodiment of the present invention will be described with reference to the drawings.

In an embodiment of the present invention, a part of a file transmitted through a network is polluted and distributed. In other words, it contaminates and transfers a part of the copyrighted file so as to prevent normal distribution and use due to the contaminated file. Specifically, the copyright protection device according to an embodiment of the present invention obtains a meta information file of a copyrighted file (hereinafter referred to as a copyright file) and operates as a virtual peer to request file requests from other peers. Receives and responds to a file request in real time in response to a corrupted file, preventing some of the peers from receiving a normal file. Copyright protection is then achieved by allowing peers that receive the contaminated file to continue to distribute the contaminated file.

Files shared through a network according to an embodiment of the present invention (copyright files are included) are divided into a plurality of pieces having a preset size, and are shared while being supplied in pieces. The size of the file fragment is, for example, between 16KB and 16MB, and mainly uses 256KB to 1MB depending on the file size.

A hash function (eg, SHA-1 hash) is applied to each piece to obtain a hash value, and the obtained hash value is used to check the integrity of the pieces. For this purpose, the hash values obtained for each fragment are stored in the meta information file.

1 is a diagram illustrating the structure of a meta information file according to an embodiment of the present invention.

The meta information file for the file shared through the network may have a structure as shown in FIG. 1. The meta information file (also known as a torrent file) contains information required for file sharing, and as shown in FIG. 1, a first section (also called an announce section) TM1 and a second section (also called (Also known as an Info section) (TM2).

The first section TM1 contains uniform resource locator (URL) information for a central server (also called a tracker server).

The second section TM2 includes a name of a file, a length, a piece length of a file piece, and a hash code list TM3 of each file piece. The hash code list includes the hash values (piece1, ..., piece 25, ..., piece N) obtained for the piece of the file, and the hash values may be named hash codes. For example, if a SHA-1 hash function is used to obtain hash values, it may be named SHA-1 hash code.

In an embodiment of the present invention, in order to protect a copyright file among files shared through a network, a fragment of a dirty file is generated for the copyright file.

2 is a flowchart illustrating a process of generating a contamination file fragment according to an embodiment of the present invention, and FIG. 3 is an exemplary view illustrating a process of generating a contamination file fragment.

The copyright protection device 1 according to an embodiment of the present invention generates a data structure listing sizes of file fragment units supported by a protocol (eg, BitTorrent) used in a service for providing a file through a network. (S100). For example, if the file fragment size supported by the protocol is a first fragment size to an nth fragment size, a data structure listing these fragment sizes is created.

The copyright protection device 1 selects one file fragment size from the generated data structure (S110). In this case, the size of the selected file fragment can be excluded from the list of file fragment sizes included in the data structure so that it is not selected later.

The copyright protection device 1 generates a file including random data or data having a specific pattern, in response to the selected file fragment size (S120). For example, the protocol selects one of the first fragment size to the nth fragment size, and the order of the fragment size selected here is not fixed and may be set randomly according to circumstances.

The copyright protection device 1 generates a file having the selected file fragment size, for example, a file containing data with a hexah value 00. A file containing such arbitrary data or data with a specific pattern is used as a fragment of the dirty file.

The copyright protection device 1 obtains a hash value by applying a hash function (eg, SHA-1 hash function) to the generated pollution file fragment (S130). The copyright protection device 1 compresses the contaminated file to which the hash function is applied (S140), and stores the hash value corresponding to the compressed contaminated file fragment in a database (S150). Such a contaminated file fragment is stored in a database using a hash value as a key value, and information about the original file corresponding to the contaminated file fragment may be stored together in the database.

For example, as shown in FIG. 3, a pollution file (first in FIG. 3) having a file fragment size and including data consisting of hexa values is generated, and a hash function SHA- 1 hash) to obtain a hash value (H1). The polling file piece 'may be stored as a candidate key with the hash value H1 as the primary key, and the original piece file piece1 corresponding thereto may be stored in a database.

The copyright protection device 1 then changes the polluted file fragment created in step S120 above to create a new file. In more detail, it is determined whether generation of the pollution file fragments of a set number is completed (S160), and when generation of the pollution file fragments is not completed, new pollution file fragments are generated by changing the data of the pollution file fragments generated in step S120 ( S170). For example, if you want to create 2 ⁸⁰ set number of polluted file fragments, a new pollutant containing 1st data is added by adding +1 to the least significant bit for the polluted file fragment including the 0 th data in FIG. You can create file fragments. The hash function is also applied to a new pollutant file fragment to obtain a hash value, and the pollutant file fragment is compressed and stored in a database using the obtained hash value as a key value. As illustrated in FIG. 3, this process is repeatedly performed until data having only "FF" is generated to generate n (eg, 2 ⁸⁰ ) contaminated file pieces to correspond to a corresponding hash value. Can be stored in the database.

After performing the steps S130 to S170 as described above on the selected file fragment size to generate a set number of contaminated file fragments, the copyright protection device 1 contaminates all file fragment sizes included in the data structure. It is determined whether the file fragment generation is completed (S180). If no contaminated file fragment is generated for all file fragment sizes, the process returns to step S110 to select one of the sizes other than the selected size in the data structure, and to perform the steps as described above ( S120 ~ S180) is repeatedly performed.

The copyright protection device 1 performs a process of generating a contaminated file fragment as described above for every fragment file size included in the data structure.

The number of contaminated file fragments generated corresponding to the size of one file fragment may be set to be fluid, and the above contaminants may be generated until a predetermined number of contaminated file fragments required for contaminating a file distributed according to the copyright protection policy are generated. The number of times the process of creating a file fragment may be repeated.

Meanwhile, contaminated file fragments generated corresponding to one fragment file size are stored in a database based on the hash value, which may be referred to as a "collision database." A collision value database may be implemented in plurality for each file fragment size, and each collision value database may be implemented in a form including a contaminated file fragment having a corresponding fragment size and a hash value. Alternatively, the collision value database may be implemented in one form and include a contaminated file fragment and a hash value for every file fragment size.

On the other hand, when generating the contaminated file fragment as described above, in order to improve processing efficiency, simultaneously generating a plurality of contaminated file fragments for the plurality of file fragments corresponding to the file fragment size selected in step S120. For example, the hash value may be generated for each piece of the contaminated file and stored in the collision value database.

Next, a method of blocking the distribution of the illegally shared copyright file based on the collision value database thus generated will be described.

4 is an exemplary diagram illustrating a network environment to which a distribution blocking method according to an exemplary embodiment of the present invention is applied.

In a network environment where clients share files while transferring files in accordance with certain transport protocols, particularly the BitTorrent protocol, the client acts as a seedr or as a peer.

To share a file, each client installs client software that is compatible with the protocol. When a client wants to share a file, the client generates a meta information file of the file to be shared, transmits its own information, that is, client information to the central server 2, and shares a group (eg, swarm) from the central server 2. Information about the seeder or peer included in)), that is, peer information, is provided. Then, the generated meta information file is distributed to a network (for example, a web site) to prepare to start file sharing.

In this case, the client information includes an infohash having a hash value obtained by applying a hash function to a second section of the meta information file (for example, the Info section), the peer ID of the corresponding client, a port value, an IP address, and an uploaded file. Includes the amount of files downloaded, the amount of files downloaded, and the amount of files remaining. The peer information may include an info hash, a peer ID, an IP address, and a port value of the meta information file. In addition, the peer information may include an event value indicating an event such as starting, completing, or stopping the download of the file.

On the other hand, in the case of downloading the file shared in the network, each client downloads the meta information file from the central server 2. In addition, a hash function is applied to the second section of the downloaded meta information file to obtain an info hash, and the file is requested while transmitting the obtained info hash to the central server 2. The central server 2 transmits the peer information including the infohash provided from the client to the client so that the client can download the file from other peers based on the peer information.

Through the above process, for example, as shown in the accompanying FIG. 4, peer 1, which is downloading a predetermined file consisting of four pieces from the seeder, downloads the remaining pieces while receiving pieces 1 and 4 already. Should receive In this case, fragment 2 is provided from the seeder, fragment 3 is provided from another peer 2, and the fragment 4 that it has can be uploaded to peer 2. Peer 2 uploads Piece 3 to Peer 1, where Piece 1 and Piece 2 can be downloaded from Cedar, and Piece 4 can be downloaded from Peer 1. In this way, the peer can upload the file fragments it has for other peers like the role of a cedar, and can download the file fragments from peers that have the file fragments to be downloaded in addition to the seeder.

As such, in an environment where clients share files through a network while operating as peers or seeders, a copyright protection device according to an embodiment of the present invention operates as follows in order to prevent illegal copyright files from being shared.

5 is a flowchart illustrating a method of blocking distribution of illegally shared copyright files according to an embodiment of the present invention, and FIG. 6 is an exemplary view illustrating a process of distributing a dirty file fragment for a copyright file according to an embodiment of the present invention. .

Assume that the copyright file is File 1 and its associated meta-information file, File1.torrent. The meta information file includes a file size, a name, hash information about file fragments, a URL of a central server, and the like, and may have a structure as shown in FIG. 1. The hash information included in the meta information file may include hash values corresponding to the contaminated file fragments generated corresponding to the corresponding file fragment size.

The copyright protection device 1 is a central server 2 that acts as an intermediary for client information including infohash which is a result obtained by applying a hash function to the second section (info section) of the meta information file of the copyright file. There is a URL (for example, http://opentracker.bittorent.com: 80 / announce) to deliver, and begins to operate as a virtual peer (S300).

After passing the client the information to the central server 2, the copyright protection device 1 enters a reception waiting state for receiving file requests from other peers (S310). Then, when a file request from other peers is received (S320), the copyright protection device 1 provides a file corresponding to the file request to the corresponding peer.

The copyright protection device 1 obtains relevant information from the received file request. For example, any peer that wants to download copyright file File 1 may request piece 25, which is a piece of copyright file File 1. The copyright protection device 1 obtains the hash value of the file fragment from the request, and checks the size of the file fragment in addition (S330).

The copyright protection device 1 searches the collision value database based on the obtained hash value and determines whether there is a corresponding hash value (S340 to S350). At this time, if the collision value database is implemented for each file fragment size, the copyright protection device 1 selects a collision value database corresponding to the file fragment size obtained from the received file request, searches the selected collision value database, and searches for a file. Determines if the hash value obtained from the request exists.

As a result of the search, if there is a hash value obtained from the file request by searching the collision value database, the copyright protection device 1 provides the peer with the contaminated file fragment corresponding to the hash value of the collision value database (S360). In this case, when the polluted file fragment corresponding to the retrieved hash value is compressed, the file may be decompressed and provided to the requesting peer.

For example, as shown in FIG. 6, when a request for file fragment "piece 25" for copyright file File 1 is received from any peer, copyright protection device 1 obtains an info hash from the received request, The obtained info hash is analyzed to find the corresponding meta information file. When the meta information file has the structure as shown in FIG. 1, the file fragment size "16384" is obtained from the meta information file, and the hash value "841ae846b05b6d7bd6e9aa3dd9e551559082ab01" for the requested file fragment "piece 25" is obtained. Based on the obtained hash value, the collision value database D1 is searched as shown in FIG. 6. If the search result confirms that there is data corresponding to the hash value "841ae846b05b6d7bd6e9aa3dd9e551559082ab01" from the collision value database D1, the copyright protection device 1 sends the polluted file piece "piece 25 '" corresponding to the hash value to the peer. to provide. Thus, a piece of the contaminated file can be distributed and provided to other peers, thereby preventing the copyright file from being illegally shared on the network.

Meanwhile, in FIG. 5, when the hash value obtained from the file request does not exist in the search result collision value database, the copyright protection device 1 responds to the corresponding peer that there is no file fragment corresponding to the file request (S370). .

7 is a diagram showing the structure of a copyright protection device according to an embodiment of the present invention. As shown in FIG. 7, the copyright protection device 1 according to an embodiment of the present invention includes a collision value database D1, a polluted file fragment generator 10, a file request receiver 20, and a hash analyzer 30. ), A hash search unit 40, and the contamination file fragment distribution unit 50.

The collision value database D1 stores the dirty file fragments for the file fragments. In particular, the dirty file fragments are stored with the hash value as a key, and the dirty file fragments can be compressed and stored. A plurality of dirty file fragments may be stored for each file fragment size.

The pollution file fragment generation unit 10 generates a pollution file fragment for each file fragment size.

The file request receiving unit 20 receives a request for a predetermined file from other peers. It also provides the central server with client information to act as a virtual peer to receive file requests. The client information may be generated based on the meta information file of the copyright file to be protected, and the meta information file may include hash values for the contaminated file fragments generated corresponding to the corresponding file fragment size.

The hash analyzer 30 performs a hash analysis on the received file request to obtain a hash value. The corresponding meta information file is identified from the file request, and a hash value corresponding to the requested file fragment is obtained from the checked meta information file. In addition, the file size is obtained from the checked meta information file.

The hash search unit 40 searches the collision value database D1 based on the hash value provided from the hash analysis unit 30. At this time, the collision value database corresponding to the file size may be searched to determine whether the hash value exists.

The contamination file fragment distribution unit 50 provides the file with a file fragment corresponding to the retrieved hash value to the peer when the hash value exists in the collision value database. On the other hand, if there is no hash value corresponding to the collision value database, then the requested file fragment is notified.

The embodiments of the present invention are not limited to the above-described apparatuses and / or methods, but may be implemented through a program for realizing functions corresponding to the configuration of the embodiment of the present invention, a recording medium on which the program is recorded And such an embodiment can be easily implemented by those skilled in the art from the description of the embodiments described above.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, It belongs to the scope of right.

Claims (16)

In a method of blocking distribution of copyright files in a network environment using a peer-to-peer file transfer protocol,
Operating by the copyright protection device as a virtual peer using the meta information file associated with the copyright file;
The copyright protection device receiving a file request from any peer;
Analyzing the file request to obtain a hash value;
Retrieving a collision value database in which contamination file fragments are stored based on the hash value; And
Providing the peer with a polluted file fragment corresponding to the hash value according to the search result
≪ / RTI > The method of claim 1, wherein
Contamination file fragments are stored using the collision value database hash value as a key value.
The providing step
If the hash value exists in the collision value database, obtaining a dirty file fragment corresponding to the hash value;
If the contaminated file fragment is compressed, decompressing the contaminated file fragment and providing it to the peer; And
Notifying the peer that the file does not exist if the hash value does not exist in the collision value database.
Methods of inclusion. The method of claim 1, wherein
And wherein the meta information file includes hash values corresponding to file fragment size and associated polling file fragments. The method of claim 3, wherein
Acquiring the hash value
Analyzing the file request to identify a corresponding meta information file; And
Obtaining a hash value corresponding to the requested file from the meta information file
Lt; / RTI >
The searching step
Retrieving the conflict value database using the hash value as a key value. The method according to any one of claims 1 to 4, wherein
Generating a pollution file fragment for the copyright file and storing the generated pollution file fragment in the collision value database. The method of claim 5, wherein
Wherein the storing step comprises:
Copyright files are divided into pieces of a predetermined size, and generating a predetermined number of dirty file pieces for each file piece size supported by the file transfer protocol;
Acquiring a hash value by applying a predetermined hash function to the generated contaminated file fragment for each file fragment size; And
Storing the contaminated file fragment in the collision value database for each file fragment size using a hash value as a key value
≪ / RTI > In a method of blocking distribution of copyright files in a network environment using a peer-to-peer file transfer protocol,
Copyright files are divided into pieces of a predetermined size, and creating a data structure listing the file fragment sizes supported by the file transfer protocol:
Generating a predetermined number of dirty file fragments for each file fragment size;
Acquiring a hash value by applying a predetermined hash function to the generated contaminated file fragment for each file fragment size;
Storing the contaminated file fragment in the collision value database for each file fragment size using a hash value corresponding to the contaminated file fragment as a key value; And
In response to a file request input through the network, providing a fragment of the polluted file stored in the collision value database.
≪ / RTI > The method of claim 7, wherein
And a collision value database is formed for every file fragment size included in the data structure, and each collision value database stores a corresponding polluted file fragment with a hash value as a key value. The method of claim 8, wherein
Providing the contamination file fragments,
Analyzing the file request to obtain a hash result, the hash result including a hash value and the size of the requested file fragment;
Searching for a collision value database corresponding to the size included in the hash result by using the hash value included in the hash result as a key value; And
Providing the peer with a polluted file fragment corresponding to the hash value according to the search result
≪ / RTI > The method of claim 9, wherein
The meta-information file includes hash values corresponding to file fragment size and associated dirty file fragments,
Acquiring the hash result is
Analyzing the file request to identify a corresponding meta information file; And
Obtaining a hash result including a size and a hash value corresponding to the requested file from the meta information file
≪ / RTI > The method according to claim 1 or 7,
And the file transfer protocol is a Bittorent protocol. In a copyright protection device that blocks the distribution of copyright files in a network environment using a peer-to-peer file transfer protocol,
A collision value database in which a contaminated file fragment is stored using a hash value as a key value for each file fragment size supported by the file transfer protocol;
A file request receiving unit that receives a file request from any peer while the copyright protection device operates as a virtual peer using a meta information file related to a copyright file;
A hash analyzer for analyzing the file request to obtain a hash result, wherein the hash result includes a hash value and a size of a requested file fragment;
A hash value search unit for searching the collision value database based on the hash result; And
The contamination file fragment distribution unit for providing the peer with the pollution file fragment obtained from the collision value database according to the search result.
Including, copyright protection device. The method of claim 12, wherein
The pollution file fragment distribution unit
If there is a hash value included in the hash result in the collision value database, provide the peer with a contaminated file fragment corresponding to the hash value,
And notifying the peer that there is no corresponding file when the hash value included in the hash result does not exist in the collision value database. The method of claim 12, wherein
Contaminated file fragments are generated for each file fragment for each file fragment size supported by the file transfer protocol, and a hash value is obtained by applying a predetermined hash function to the polluted file fragments generated for each file fragment size. And a polluted file fragment generator for storing a polluted file fragment in the collision value database using the hash value as a key value. The method of claim 12, wherein
The file transfer protocol is a Bittorent protocol, copyright files are divided into pieces of a predetermined size, the meta information file includes hash values corresponding to the file fragment size and associated dirty file fragments,
The hash analysis unit
And analyzing the file request to obtain a hash value and a file fragment size corresponding to the requested file fragment from the meta information file identified. The method of claim 15, wherein
The collision value database is formed for every file fragment size included in the data structure, and each collision value database stores a dirty file fragment corresponding to each file fragment using a hash value as a key value,
And the hash value search unit searches for a collision value database corresponding to a file fragment size provided from the hash analyzer, based on the hash value provided from the hash analyzer.

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