KR20050096533A - System for providing high definition multimedia contents and preventing an infringing copies - Google Patents

Abstract

The present invention relates to a service system for providing digital multimedia contents, comprising: a main unit for digitizing multimedia contents and inserting copyright information into the digitized multimedia contents and transmitting the same; And a local unit displaying the digital multimedia contents transmitted from the main unit, and an information providing system for preventing illegal use of the digital contents and providing high quality multimedia contents.

Description

System for Providing High Definition Multimedia Contents and Preventing an Infringing Copies}

The present invention relates to a multimedia content service system, and more particularly, to a multimedia content service system capable of protecting and managing copyright of multimedia content when supplying or distributing multimedia content using the Internet.

On-demand digital movies are serviced as an example of a multimedia content service system. Video on Demand (VOD) is a method of providing a movie through the Internet in response to a user's request for a particular movie through the Internet, and a video and DVD title in the local area. Form. In the former case, high-quality multimedia contents of high definition (HD or higher) and high sound quality (5.1 or 7.1 channels) cannot be provided due to bandwidth or other limitations. As a result, image quality and sound quality are lower than video, and high value-added multimedia contents are provided at low price or free to members, which damages the economic value of multimedia contents. In the latter case, the copyright of the multimedia content is not considered. In other words, VIDEO and DVD are sold for personal use, not for business purpose, and are operated using these media, which infringes the copyright of the content author and distributor.

In addition, copyrights of content creators and distributors are violated by illegal rental of personal video or DVD titles in video or DVD rental shops.

The present invention has been made to solve such a problem, and aims to make the distribution system of multimedia contents transparent by protecting and managing copyright of the multimedia contents in a service providing high quality multimedia contents. In addition, it is an object of the user who uses a copyrighted work of multimedia contents to grasp the actual use of the copyrighted work to realize the protection of the use of the copyrighted work. Through this, the present invention aims to increase the economic value of the content in the multimedia content providing service.

In order to achieve the above object, the present invention provides a viewer with high-quality and high-quality multimedia content by including a main server providing multimedia content to a local server and a local server directly providing the viewer with the multimedia content downloaded from the main server. . The main server inserts copyright information such as content authors and distributors into the multimedia content, and the local server inserts usage information such as local server administrators and viewers into the multimedia content, thereby preventing illegal use of the multimedia content. To provide a service system.

Hereinafter, a high quality digital on demand service system (hereinafter referred to as a COD system), which is one of digital multimedia content service systems, will be described in detail with reference to the accompanying drawings.

1 is a block diagram of a COD system according to the present invention. As shown in FIG. 1, the COD system is divided into a main unit 100 that provides digital movie content through the Internet, and a local unit 200 that displays digital movie content from the main unit 100 to the viewer.

The main unit 100 corresponds to a copyright holder and a distributor who produces and provides digital movie contents, and includes a registration server 110, a main server 120, an authentication server 130, a billing server 140, and a main DB ( 150).

 The local unit 200 corresponds to a service provider that directly shows the viewers the digital movie contents downloaded from the main unit 100 to the viewers, and the local server 210 and the screener 220. , Local DB 230, and the like. The local unit 200 may be a space that provides a screening space and screens a movie, such as a movie theater of a certain size, or a provider that provides a high quality COD service to consumers in a region through the Internet, such as a video or DVD rental shop. . That is, the screening unit 220 of the local unit 200 may be installed in a consumer's home or movie theater.

2 is a configuration diagram of a registration server and a main DB constituting the main unit.

As shown in FIG. 2, the registration server 110 includes a register 111, a rule manager 112, a main watermarking 113, a key manager 114, a file packaging 115, and the like. Here, the registration server 110 may be configured as one, or may operate a separate server for each part (111 to 115).

The main DB 150 is provided with a plurality of DBs, that is, copyright information DB 151, rule DB 152, encryption key DB 153, multimedia content DB 154, and the like, related to the operation of the registration server 110. do.

The operation of the registration server having the configuration of FIG. 2 is as follows.

The register 111 converts the movie contents into a digital method (mpeg1, mpeg2, mpeg4, etc.) through the digitizer 160 by the copyright holder or the first service provider, and then converts the digital movie contents into the register 111 by using a dedicated line. When registered, the transmitted digital movie content and copyright information of the copyright holder or the first service provider stored in the copyright information DB 151 are transmitted to the main watermarking unit 113. In addition, the registration unit 111 receives the rules according to the screening of the digital movie content, that is, the information such as the screening period, price, rating, etc. from the rule management unit 112 and transmits the information to the file packaging unit 115. Here, the rule according to the screening of the movie content is the rule manager 112 retrieves the rule DB 152 and extracted. Meanwhile, the rule according to the screening of the movie content may be input when the copyright holder or the first service provider registers the content.

The rule managing unit 112 and the rule DB 152 store and manage the rules according to the screening of movie contents for each content. Here, the rule according to the screening means a period during which movie content can be screened, a screening price, a copyright validity period, a validity period of a high quality COD service provider, a distribution start time, and the like. Screening rules can manage content, copyright holders, distributors, providers of high-quality COD services, etc. by distinguishing or discriminating them, or they may manage all or part of them. Among the rules according to the screening, the rules according to the movie contents may be registered for each content when the copyright holder or the first service provider registers the movie contents, and may apply the rules which are set by default in the rule manager 112, and the rule manager ( In step 112, a rule according to movie content screening may be arbitrarily generated. Among the rules, the screening rules regarding copyright holders, distributors, and high-quality COD service providers may be applied differentially or equally at the time of initial registration, or may be applied by period or region. In addition, the rules according to the screening may be changed variably according to the situation.

The main watermarking unit 113 watermarks the copyright information transmitted from the registration unit 111 to the digital movie content. The watermark to be inserted is generated based on the copyright information. The watermark can be generated by various conventional watermark generation methods. The watermark can be used as a watermark by generating a pseudo random number using the copyright information as a key value, and use the image itself as a watermark by imaging the copyright information. It may be. Insert the generated watermark into the digital movie content. Through this, it is possible to eradicate the possibility of future copyright dispute and to prevent the illegal use of multimedia contents.

The key manager 114 randomly generates a key for encrypting the digital movie content into which the copyright information is inserted and transmits the key to the file packaging unit 115. At this time, the key manager 114 must have a unique key of the distributor to transmit the encryption key from the encryption key DB 153 to the file packaging unit. That is, the distributor's unique key is used to securely store and manage a randomly generated encryption key. In order to distribute a content encryption random key, the distributor's unique key is encrypted and stored and managed. In this case, the random key is a key to be used for encryption and decryption using a secret key encryption method, and the unique key of the distributor means a key to be used for encryption and decryption using a public key encryption method.

The file packaging unit 115 packages digital movie content into which copyright information is inserted. At this time. File packaging refers to an encryption process before storing a multimedia content file containing copyright information in a DB. It is not an encryption of a file but an encryption of a method of combining a predetermined rule or the like regarding the multimedia content transmitted from the registration unit 111. That is, the file packaging unit 115 that receives the digital movie content file into which the copyright information is inserted, the random key and the unique key of the distributor, and the service relating to the service of the multimedia content generates metadata according to a set of rules, Encrypts with a random key with embedded digital movie content. In addition, the random key is encrypted with the distributor's unique key and stored in the encryption key DB 153. The encrypted digital movie content is stored in the multimedia content DB 154. Thereafter, the registration server 110 transmits the registration of the digital movie content to the main server 120.

3 is a configuration diagram of a main server and a main DB constituting the main unit.

As shown in FIG. 3, the main server 120 includes a file synchronization unit 121, an authentication processing unit 122, and a charging processing unit 123. Here, the main server 120 may be configured as one server, or may operate a separate server for each part 121 to 123.

Main DB 150 is associated with the operation of the main server 120, a plurality of DB, that is, encryption key DB 153, multimedia content DB 154, service provider information DB 155, screening log DB 156, etc. It is provided.

The operation of the main server having the configuration of FIG. 3 is as follows.

When the file synchronizer 121 receives a notification from the registration server 110 that a new registration of digital movie content has occurred, the file synchronizer 121 passes through the authentication processing unit 122 to the local server 210 of each local unit 200 authenticated. The packaged movie content newly registered in the multimedia content DB 154 is uploaded. That is, the file synchronizer 121 matches the stored contents of the digital movie content DB 154 of the main unit 100 with the multimedia contents DB 231 of the local unit 200. The digital movie content stored in the multimedia content DB 231 and the digital movie content stored in the multimedia content DB 154 of the main unit 100 may not match. The rating of the local unit 200 is determined by the contract, and the type of digital image content uploaded to the local unit 200 by the main unit 100 is determined according to the grade of the local unit 200, and the main unit is also determined. This is because the time point at which the 100 removes the digital movie content from the multimedia content DB 231 of the local unit 200 may also be set differently by a contract with each local unit 200.

When the main unit 100 uploads the digital movie content to the local unit 200, the random key encrypted with the distributor's unique key used when packaging the movie content is encrypted with the unique key (public key) of the local unit 200. To transmit. The unique key of the local unit 200 is received from the authentication server 130 through the authentication processing unit 122 when authenticating the local unit 200.

The file synchronizer 121 searches the multimedia contents DB 154 to display digital movie contents whose copyright has expired, and the multimedia contents DB 231 of the local unit 200 and the multimedia contents DB 154 of the main unit 100. Delete at the same time. The file synchronizer 121 deletes the encryption key of the digital movie content from the encryption key DB 153 of the main unit 100 and the decryption key DB 232 of the local unit 200. In this way, the file synchronization unit 121 serves to synchronize the synchronization between the main unit 100 DB and the local unit 200 DB in real time. However, content synchronization between the main unit 100 and the local unit 200 may have a slight time difference depending on the communication state of the Internet, the screening state of the local unit 200, and the working state of the main server 120. That is, since the Internet state between the main server 120 and the local server 210 are not all the same, the upload speed is adjusted according to each state. Since the local server 210 can screen a plurality of digital movie contents, the local server 210 is configured to adjust the speed of uploading and deleting according to the number of showings. In addition, it should be able to adjust the speed of the synchronous operation according to the amount of work of the main server 120.

The authentication processing unit 122, upon the request of the file synchronization unit 121, requests the authenticity of the local unit 200 to the authentication server 130, extracts the authentication information from the service provider information DB (155) The result is notified to the file synchronizer 121. In this case, in the case of the legitimate local unit 200, the unique key (public key) of the local unit 200 is received from the authentication server 130 and transmitted to the file synchronizer 121. In addition, the authentication processing unit 122 requests the authentication server 130 to authenticate the local unit 200 and the corresponding digital movie content when the local unit 200 displays the movie content, and the result of the charging processing unit ( 123).

The billing processing unit 123 determines whether or not screening is possible when the local unit 200 starts screening digital movie contents, and records a log generated during the screening in the screening log DB 156. Whether or not the screening is performed is performed using the result of the legality of the local unit 200 from the authentication server 130 through the authentication processing unit 122 and the result of the screening of the digital movie content through the file synchronizer 121. . When the recording of the log is determined that screening of the corresponding digital movie content is possible and the screening of the digital movie content starts, the event such as pausing, canceling the screening, ending the screening, and restarting the screening is stored in the screening log DB 156 in real time. By doing so. As such, the billing processing unit 123 records the screening state in real time for billing processing of the billing server 140.

In addition, the authentication server 130 shown in FIG. 3 determines the legality of the local unit 200 and whether the digital movie contents can be screened, and the charging server 140 processes the billing according to the screening.

4 is a configuration diagram of a local server and a related DB of the local unit. The local server 210 controls the reception, management, storage, and screening of digital movie contents, and includes a reception and processing unit 211, a decryption key management unit 212, a decryption unit 213, a local watermarking unit 214, The decoder 215, the screen 216, the multimedia content DB 231, the decryption key DB 232, the local and viewer information DB 233, the screen log DB 234 and the like.

The receiving and processing unit 211 receives digital movie content through the Internet and stores it in the multimedia content DB 231, and transfers a key necessary for decrypting the movie content to the decryption key manager 212 to decrypt the key DB 232. ).

Subsequently, when the local server 210 requests the screening by selecting a desired movie content for the viewer watching the digital movie content, the local server 210 receives the legality of the local part and the content in real time at the same time as the play signal. The movie content stored in the multimedia content DB 231 is played back through the decoder 213, the local watermarking unit 214, and the decoder 215.

When the person who wants to watch selects specific movie content, the decryption unit 213 extracts the corresponding movie content stored in the multimedia content DB 231, and then stores the key (the key that encrypted the file) stored in the decryption key DB 232. Decode the movie content using. Here, the key stored in the decryption key DB 232 is encrypted with the public key of the local unit 200. Decryption of the received key can be done only when the system ID is checked and matched through an application installed when the local unit 200 subscribes. When the key is decrypted, the digital movie content encrypted with the decrypted key is decrypted.

The local watermarking unit 214 is for preventing illegal use of the digital movie content. The local watermarking unit 214 inserts the information of the local part to be screened and the viewer's information to the digital movie content. Digital movie contents are high quality data with high definition and high sound quality. If digital movie contents are illegally stored and leaked using a storage device such as a video recorder or a camcorder when the digital movie contents are being screened, the leaked contents may also have commercial value as high quality movie contents. Have In order to prevent such content leakage, watermark information generated based on the information of the local part and the viewer is inserted into the digital movie content in real time. Watermark can use various watermark generation methods, including inserting local part information on the screen so that it can be directly identified (Visible watermark) and hiding the generated watermark in the content (Invisible watermark). You can choose either or both. Also, the screening date and time can be inserted into the content.

In FIG. 4, the local watermarker 214 is located between the decoder 213 and the decoder 215, while the local watermarker 214 is located between the decoder 215 and the screen 216. Can be.

The decoding unit 215 decodes the digital movie content into analog movie content.

The screening unit 216 transmits the movie contents to the screening unit 220. At this time, all the information is stored in the screening log DB 234 in real time, and the screening log is transmitted to the main unit 100.

According to the present invention, there is one watermarking part in the main part 100 and the local part 200, and they use a strong watermarking method. That is, information such as copyright information, local information (service provider information), viewer information, and show date and time information are inserted into digital movie contents, and the inserted information is extracted even when recorded and edited by a recording device such as a video recorder or a digital camcorder. It can be inserted robustly without degrading the picture quality and sound quality. However, the watermarking unit 113 of the main unit 100 inserts and stores / manages the digital movie contents in advance when registering the digital movie contents, and the watermarking unit 214 of the local unit 200 displays the digital movie contents. The difference is that it is inserted in real time. In addition, the watermarking unit 214 of the local unit 200, like the watermarking unit 113 of the main unit 100, inserts information into the digital movie contents invisibly, and in order to cause visual alertness. It is preferable to use two methods in parallel: inserting information at the top and bottom.

5 shows a method and process for embedding a watermark invisibly into digital movie content. The digital movie contents for the high quality COD service of the present invention have a large amount because they are high quality and high quality contents. That is, for an hour of digital movie content, the file is at least 4 gigabytes in size. Therefore, since a considerable amount of calculation is required to decode and encode all contents for watermarking, a method of inserting a watermark in only part of the content is used.

As shown in FIG. 5, the insertion position determiner 320 determines a position at which the watermark information is to be inserted using the first PN sequence generated by the PN sequence generator 310, and only a part of the decoder decodes the watermark information. Decode at 330. In this case, the position determined by the insertion position determiner 320 corresponds to a block obtained by dividing the digital movie content of one screen into blocks. The size of the block can vary depending on the computational power of the CPU. Since the insertion position of the watermark information is changed by the insertion position determiner 320, a security effect of not knowing in which part the watermark information is inserted can be obtained. The insertion amount determiner 340 determines the amount (size) to insert the watermark information in consideration of the mathematical characteristics of the digital movie content decoded by the decoding unit 330. Meanwhile, the watermark generator 350 generates a watermark to be inserted using the size determined by the insertion amount determiner 340 and the information to be inserted, and the PN sequence generator 310 to secure the watermark information to be inserted. The watermark generated by using the second PN sequence received from the) is encrypted or scattered. The first and second PN sequences are generated to have a constant rule for convenience in watermark detection. However, for security purposes, the relationship between two PN sequences can be flexibly changed. The watermark inserting unit 360 inserts the generated watermark information into the digital movie content decoded by the decoding unit 330. Some encoder 370 encodes the decoded some digital movie content with the watermark embedded therein. Thereafter, the content synthesizing unit 380 replaces and inserts the encoded digital movie content with the original digital movie content. Here, the file size of the original digital movie content input to the watermarking unit and the digital movie content into which the watermark is inserted may be different, so that a buffer overflow does not occur in the screening unit 216 when the digital movie content is displayed. Should be. Since the watermark embedding method of the present invention uses two PN sequences, it is highly stable against the leakage of the inserted information. However, the watermark embedding method encrypts the information to be inserted to the watermark generator 350 to prevent the information leakage more strongly. The watermark generated by the watermark generator 350 may be encrypted and sent to the watermark inserter 360. It is also possible to use both methods.

Meanwhile, in FIG. 5, the amount of calculation required to insert the watermark information depends on the size of the block to be used for insertion. For example, if you use only one sixteenth of the full screen size, the computation is reduced to one sixteenth. However, in the present invention, since the information included in the stream header of the digital movie content is extracted and stored by some decoding unit 330 and encoded by the some encoding unit 370 based on the information, the required amount of calculation is Less than 1/16 In particular, the watermarking unit of the local unit 200 should insert the watermark information in real time. Using the watermark information insertion procedure of FIG. 5, the watermark information may be inserted in real time.

FIG. 6 illustrates a method and process of extracting watermark information inserted invisibly in FIG. As shown in FIG. 6, the watermark information extraction unit 400 includes a block size inference unit 410, an insertion position inference unit 420, a PN sequence inference unit 430, a PN sequence generation unit 440, and information. The extractor 450 and the like.

The movie content to extract the watermark information may be illegally copied or distributed content or legitimate content. In addition, illegally copied or distributed content may be digital or analog. For example, the recording may be performed again with a device such as a digital camcorder, or may be content distributed by recording with a recording device such as a video. Therefore, illegal multimedia content may have a different screen size, file size, image quality, and sound quality from the original digital multimedia content.

The block size inference unit 410 divides the screen into a predetermined portion to extract the inserted watermark information. Based on the IF ~ THEN rule, the block size inference unit 410 divides the size of the block into which the watermark information is inserted into the original multimedia content as accurately as possible. Uses fuzzy inference.

The insertion position inference unit 420 divides the screen based on the size of the block transferred from the block size inference unit 410, and infers whether watermark information is inserted into each block. At this time, inference is made using the IF ~ THEN fuzzy inference method. The insertion position inference unit 420 finds all blocks in which the watermark information may have been inserted, and passes the information to the PN sequence inference unit 430.

The PN sequence inference unit 430 determines a sequence used when the watermarking information insertion unit determines the position to insert the information. At this time, since the number of the first PN sequences used for the insertion position is quite large, it takes a lot of time and effort to find the PN sequence used for the insertion position by calculation accurately. Therefore, in the present invention, the IF to THEN fuzzy inference method is also used to find the first PN sequence as in the case of the previous case. However, the rules for fuzzy reasoning used in each reasoning unit may be different or the same. In addition, in order to increase accuracy, the movie content may be summed and used according to the length of the first PN sequence. When summing up the average, be careful when the screen size and the center of the screen are off by using a camcorder or a multimedia editor. When the PN sequence inference unit 430 infers the first PN sequence, the error of block size and insertion position inference can be corrected and corrected, and the block size inference unit 410 and the insertion position inference unit 420 can be corrected. Communicate appropriately with At this time, it is possible to adaptively supplement and modify the fuzzy inference rule used in each inference unit.

The PN sequence generator 440 generates a second PN sequence using the first PN sequence inferred by the PN sequence inference unit, and transmits the extracted first and second PN sequences to the information extractor 450.

The information extracting unit 450 extracts information such as a copyright holder, a distributor, a service provider, a viewer, and a date and time which are initially inserted using the first and second PN sequences.

Although the above has described the movie content which is one of the digital multimedia contents, it can be applied to various fields such as music contents and educational contents other than the movie contents.

According to the high quality COD service system described above, the copyright of the digital multimedia contents can be managed transparently, and since the usage history is directly collected from the high quality COD service provider (local part), the billing can be made transparent, and through the billing system Can automate royalty collection. Digital rights management (DRM) and watermarking technologies can prevent illegal copying and distribution of content.

The ripple effects of each sector are as follows.

First, in terms of economics, the original value of the multimedia contents is recognized through the prevention of illegal screening or illegal rental, thereby creating a new profit for the copyright holder. Existing movie rooms can be transformed into high-quality COD service providers, ensuring the right to screen multimedia content legally, thereby boosting sales. In addition, it is advantageous to secure a new movie, and can overcome concerns about inventory caused by the purchase of video and DVD titles, such as an existing movie room or rental shop. In addition, installation and maintenance cost can be reduced by server system of screening equipment.

Second, in terms of culture, it is possible to provide high quality and high sound quality services by securing high quality multimedia contents and to provide the latest multimedia contents, thereby increasing user's service satisfaction. By resolving the copyright problem of the multimedia content, which has become a conventional problem, the profits of the multimedia content producers are guaranteed, and the producers can be actively engaged in cultural activities such as being able to pay attention only to the creation of high quality content. In addition, as illegal copying and distribution are prevented, a healthy multimedia content usage culture can be established.

Third, from the social side, new royalty is secured, and the profits from multimedia contents are increased, thereby making it possible to invest a lot in content creation, which can bring vitality to society as a whole. In addition, the transparency of the billing settlement system can be secured, thereby making taxation easier.

Fourth, in the industrial aspect, technology companies can increase sales according to the formation of new markets, and can be accompanied by efforts to improve related technologies to meet user demands.

In addition, it can contribute to the rationalization of management by providing various statistical information functions through the screening log database. Since one local server can display one or a plurality of multimedia contents through several theaters, the initial investment is inexpensive. Therefore, small businesses in small capital can participate in the multimedia contents service industry, thereby enabling the multimedia contents service industry to be activated. have.

1 is a configuration diagram of a COD system according to the present invention;

2 is a configuration diagram of a registration server and a main DB constituting the main unit;

3 is a configuration diagram of a main server and a main DB constituting the main unit;

4 is a configuration diagram of a local server and a related DB of the local unit;

5 is a configuration diagram of a process of inserting a watermark into digital movie contents, and

FIG. 6 illustrates a method and process of extracting watermark information inserted invisibly in FIG.

-Explanation of symbols for the main parts of the drawing-

100: main unit 110: registration server

113: main water marking section 115: packaging section

120: main server 121: file synchronization

130: authentication server 140: billing server

150: main DB 156: show log DB

200: local part 210: local server

214: local watermarking unit 220: screening machine

230: local DB

Claims (9)

In the service system for providing digital multimedia content, A main unit for digitizing the multimedia contents and inserting copyright information into the digitized multimedia contents and transmitting the copyright information; And And a local unit for displaying the digital multimedia contents transmitted from the main unit. The method of claim 1, wherein the local portion And the digital multimedia contents are displayed after storing the information of the local unit in the transmitted digital multimedia contents. The method of claim 2, wherein the local portion And storing the user's information and a display date and time of the digital multimedia content in the transmitted digital multimedia content, and displaying the digital multimedia content. The method according to any one of claims 1 to 3, The main unit includes a main content database for storing the digital multimedia content, and the local unit includes a local content database for storing digital multimedia content transmitted from the main unit, the content stored in the main content database and the local unit. A system for preventing illegal use and providing high quality multimedia contents, wherein the contents are stored in the local contents database. The method of claim 4, wherein The main unit further includes an encryption unit that encrypts the digital multimedia contents, and the local unit further includes a decryption unit that decrypts the digital multimedia contents encrypted by the main unit. system. The method of claim 5, When the display of the digital multimedia contents starts, the local unit transmits display related events such as pause, display cancellation, display termination, and display restart in real time to the main unit in real time. . The method of claim 6, wherein the main portion and the local portion And a watermarking unit for inserting copyright information, local information, and user information into digital multimedia contents using a watermark generation method. The method of claim 7, wherein the watermarking unit A PN sequence generator for generating first and second PN sequences; A positioning unit to determine a position at which a watermark is to be inserted using the first PN sequence; A partial decoding unit for decoding only a portion of the digital multimedia contents into which the watermark is to be inserted; An insertion amount determination unit for determining an amount of watermark information to be inserted using the digital multimedia content decoded by the decoding unit; A watermark generator for generating a watermark using the insertion amount and the insertion information determined by the insertion amount determiner, and encrypting the watermark using a second PN sequence received from the PN sequence generator; A watermark inserting unit for inserting the generated watermark information into digital movie contents decoded by the decoding unit; A partial encoder which encodes the decoded partial digital movie content having the watermark embedded therein; And And a content synthesizing unit for replacing and inserting some encoded digital movie contents into original digital movie contents. The method of claim 8, A block size inference unit for dividing the screen into predetermined portions to extract the inserted watermark information; An insertion position inference unit for inferring which of the blocks passed from the block size inference unit is inserted with watermark information; A PN sequence inference unit for inferring a sequence used to determine a position to insert information in the watermarking unit; A PN sequence generator configured to generate a second PN sequence using the first PN sequence inferred by the PN sequence inference unit; And It further includes a watermark information extraction unit including an information extraction unit for extracting the copyright information, the local unit and the viewer, the date and time information inserted using the first and second PN sequences. Multimedia content providing service system.