KR100635128B1 - Apparatus for generating encrypted motion-picture file with iso base media format and apparatus for reconstructing encrypted motion-picture, and method for reconstructing the same - Google Patents

Abstract

An apparatus for generating an encrypted moving picture file of an ISO(International Organization for Standardization) base media file format, an apparatus for recovering an encrypted moving picture, and a recovery method therefor are provided to protect contents from illegal copy in streaming or download service environment by allowing a server to apply encryption and decryption technique, encrypt moving picture contents of the ISO base media file format, and service the encrypted moving picture contents, and allowing a client to decrypt the encrypted moving picture in real time. An ISO base media file analyzing unit(12) receives an original moving picture file of an ISO base media file format, analyzes box information describing information about a media stream in an ISO base media file structure, and extracts positions of video and audio samples and a position of a hint sample of a hint track. A sample encrypting unit(13) confirms video and audio frame headers from video/audio sample position information extracted in the ISO base media file analyzing unit(12), and encrypts only video/audio data except for the video and audio frame headers in the video and audio samples according to an encryption option. A hint information generating unit(14) changes a streaming packet charged load size in the hint sample to a value which is times of a block size used in a block encryption method and is smaller than an MTU(Maximum Transport Unit) size, and newly generates hint information when a hint track does not exist. A meta data generating unit(11) receives meta data necessary for streaming or downloading an encrypted moving picture file, and generates meta data structured to be suitable for the ISO base media file format. An ISO base media file configuring unit(15) receives an encrypted video/audio sample from the sample encrypting unit(13), receives hint track information corrected or newly generated from the hint information generating unit(14), receives structured meta data information from the meta data generating unit(11), and replaces an original video/audio sample in the original moving picture file with the encrypted video/audio samples. The ISO base media file configuring unit(15) replaces the hint track with a corrected hint track or adds a hint track when the hint track does not exist, inserts the meta data into a user definition area of the ISO base media file, and configures a moving picture file encrypted to be suitable for the ISO base media file format.

Description

FIELD OF GENERATING ENCRYPTED MOTION-PICTURE FILE WITH ISO BASE MEDIA FORMAT AND APPARATUS FOR RECONSTRUCTING ENCRYPTED MOTION-PICTURE, AND METHOD FOR RECONSTRUCTING THE SAME}

1 is a view showing the structure of the ISO Base Media FIle used in the present invention,

2 is a block diagram showing the configuration of a video file protection system to which the present invention is applied;

3 is a block diagram showing the configuration of an apparatus for generating an encrypted video file according to an embodiment of the present invention.

4 is a block diagram showing the configuration of an apparatus for restoring an encrypted video according to an embodiment of the present invention.

5 is a flowchart illustrating a flow of a method for restoring an encrypted video according to an embodiment of the present invention when an encrypted video file is used for a streaming service.

6 is a flowchart illustrating a flow of an encrypted video restoration method according to an embodiment of the present invention when an encrypted video file is used for a download service.

<Explanation of symbols for the main parts of the drawings>

11: metadata generating unit 12: ISO Base Media file analysis unit

13 sample encryption unit 14 hint information generation unit

15: ISO Base Media file composition

The present invention relates to an encrypted video file generating apparatus and an encrypted video restoring apparatus in the form of ISO Base Media (hereinafter referred to as "ISO Base Media") file, and more particularly, Illegal storage and duplication of content through illegal storage and duplication of video in an environment where a movie in ISO Base Media File format, a standard file format specified by the Motion Picture Experts Group-4 (MPEG-4) system, is used for streaming or download services. The present invention relates to an encrypted video file generating apparatus and an encrypted video restoring apparatus capable of preventing the use and distribution of phosphorus, and a restoration method thereof.

The format of the ISO Base Media File is a standard file format defined by the MPEG-4 system, which is described in the MPEG standard document ISO / IEC 14496-12: ISO Base Media File Format. The format of the ISO Base Media File has been adopted by international standards bodies such as the Third Generation Partnership Project (3GPP) and the Internet Streaming Media Alliance (ISMA).

Since digital information is easy to produce and distribute, the production of digitized moving pictures is increasing. However, digital content is not only easy to copy, transform, and distribute, but also is distributed through the Internet, which is insecure from the viewpoint of security, so that security and copyright protection are emerging as important issues.

This problem has occurred mainly in the video stored in the user's PC and played back as needed. Conventionally, in order to protect a video file stored in a user's PC from illegal copying, after encrypting the entire video file, the encrypted content can be downloaded to the user's local system, and only the legitimate user can decrypt the encrypted video file. A method of providing information is used.

On the other hand, in order to prevent content from being stored in the local system, streaming technology is known that transmits data to the local system in real time and allows the content to be played on the local system. In general, in the case of large-capacity video content, a service for providing content through streaming in the same manner as video on demand has been realized.

In general, a video played through a streaming service is advantageous in solving the problem of illegal copying, compared to a video played back by being stored in the user's PC, and thus not being stored in the user's PC. Recently, however, a capture program capable of storing video serviced through streaming has emerged, and a copyright protection scheme for video serviced through streaming has also been required.

In the related art, in order to protect a streaming video from illegal copying, a security measure of a user authentication method using an ID and a password is mainly used. In addition, a method of encrypting the content to protect the content from illegal copying is also known, but this method is a method specific to a specific streaming format, which is difficult to use for general purposes.

Recently, for educational content, users tend to watch the content repeatedly, and instead of going online to the content delivery site each time the user plays the content, the user downloads the content to their system and, if necessary, There is a desire to play content.

Most Digital Rights Management (DRM) systems that support streaming content use Microsoft's Windows Media Rights Manager Software Development Kit (SDK) and Windows Media Format SDK to support Microsoft's streaming server, Windows Media Server, and WMV, a media format. , WMA, ASF, and other formats are supported, and there is a problem in that a streaming system that conforms to the general MPEG-4 streaming standard specification cannot be supported.

Therefore, there is a demand for a content protection method that supports MPEG-4 standard streaming in ISO Base Media File format and can be applied not only to a streaming method but also to a download service.

On the other hand, as a prior patent, "Information protection method and system for digital content" (Patent Application No. 2002-1916, filing date: January 12, 2002) is filed. The preceding patent applies the same encryption scheme to all contents and supports Microsoft's Windows Media Streaming System. However, the preceding patent provides a service for streaming and downloading video files in ISO Base Media File format, which is a standard of MPEG-4 system. Support is not considered.

As another prior patent, a "system and method for protecting digital data executed in a stream manner" (Patent Application 2001-50151, filed August 21, 2001) is filed. The preceding patent provides a method for securely decoding at a file system level contents provided by a client in a stream method, but support for a streaming and downloading service of a video file in ISO Base Media File format, which is a standard of MPEG-4 system, Not considering

As another prior patent, a "method and system for preventing illegal copying of digital video content" (Patent Application No. 2003-55796, filed August 12, 2003) is filed. The preceding patent is characterized in that the same encryption scheme is applied to all multimedia contents, stored in a recording medium, and distributed, but the streaming and downloading service of a video file in ISO Base Media File format, which is a standard of MPEG-4 system, Support is not considered.

Accordingly, the present invention has been made to solve the above-described technical problem, in order to protect the video from being illegally copied and distributed without legitimate authority, the server providing the video content applies an encryption and decryption technique to ISO. The video content of Base Media File format can be encrypted (encrypted video creation), and the client side that plays video content can decrypt the encrypted video in real time (recovery of encrypted video) at the time of video playback. Another object of the present invention is to provide an encrypted video file generating apparatus and an encrypted video restoring apparatus in ISO Base Media file format, which can be used in both a download service environment, and a method of restoring the encrypted video file.

An apparatus for generating encrypted video file of ISO Base Media file format of the present invention for achieving the above object,

ISO, which receives the original movie file in ISO Base Media file format, interprets the box information describing the media stream information in the ISO Base Media file structure, and extracts the location of the video and audio samples and the hint samples from the hint track. Base Media file analyzer;

A sample encryptor which checks frame headers of video and audio from the video / audio sample position information extracted by the ISO Base Media file interpreter 12, and performs encryption according to an encryption option;

A hint information generation unit configured to change the streaming packet payload size to a multiple of the block size used in the block encryption method in the hint sample, and newly generate the hint track if there is no hint track;

A metadata generator for receiving metadata necessary for streaming or downloading an encrypted video file and generating metadata structured according to an ISO Base Media file format; And

Accepts an encrypted video / audio sample from the sample encryptor, accepts a modified or newly generated hint track information from the hint information generator, accepts structured metadata information from the metadata generator, and receives an ISO Base Media file. And an ISO Base Media file composition unit constituting a video file encrypted according to a format.

In addition, the encrypted video restoration apparatus of the ISO Base Media file format of the present invention,

A content service information processing unit receiving content service information to request a streaming or download service, and generating license issuing request information to a license issuing server including encryption information and rights information necessary for decryption;

A license processor for requesting a license for the corresponding content from a license issuing server according to the license issuing request information, and extracting content encryption information and rights information from a license transferred from the license issuing server;

A video / audio sample configuration unit configured to read video and audio streaming packets or streaming downloaded ISO Base Media files to configure video and audio samples;

A sample decryption unit for decoding the video and audio samples configured in the video / audio sample configuration unit by using the content encryption information and right information; And

Extract the metadata inserted in the downloaded video file to check whether the encryption information and the rights information for the corresponding content are stored. If the information is not stored, the metadata required for the license issue request is extracted from the extracted metadata. And an encrypted video file processing unit for transmitting to the license processing unit and extracting encryption information and rights information for the corresponding content if the information is stored.

In addition, the encrypted video restoration method when the encrypted video file of the ISO Base Media file format of the present invention is a streaming service,

(a) receiving content service information necessary for receiving a streaming service or downloading video content;

(b) using the received content service information, checking whether encryption information and rights information for the corresponding content are stored;

(c) extracting the encrypted information and the right information if the encrypted information and the right information of the corresponding content are stored in the step (b);

(d) If the encryption information and the rights information of the corresponding content are not stored in the step (b), request a license from the license issuing server using the license issuing request information of the content service information, and receive the received license. Extracting and storing the content encryption information and the right information from the license;

(e) requesting a streaming service for the corresponding content by using the streaming request information among the content service information received in step (a) and receiving the content; And

(f) constructing the video and audio streaming packets received in step (e) into video and audio samples, and decrypting the video / audio samples thus constructed using encryption information and rights information. do.

In addition, the encrypted video restoration method when the encrypted video file of the ISO Base Media file format of the present invention is downloaded,

(a) reading the downloaded video file and extracting metadata inserted into the video file;

(b) using the extracted metadata, checking whether encryption information and right information of the corresponding content are stored;

(c) extracting the encrypted information and the right information if the encrypted information and the right information of the corresponding content are stored in the step (b);

(d) In step (b), if the encryption information and the right information of the corresponding content are not stored, request for issuance of a license using the content service information and receive it, and the content encryption information and the right information from the received license. Extracting and storing; And

(e) constructing video and audio samples from the encrypted video file, and decrypting the configured samples using the encryption information and the right information.

Other objects and advantages of the present invention will be understood from the following description, and will be apparent from the description of the preferred embodiments of the present invention. In addition, the objects and advantages of the present invention can be realized by the technical means or a combination thereof described in the claims below.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram illustrating the structure of an ISO Base Media FIle used in the present invention. As shown in Fig. 1, an ISO Base Media file is composed of objects called 'box', and all data is described in 'box'. The box object has type information and size information, and makes it easy to search the location of the box containing the desired information using the type information and the size information.

The ISO Base Media file has one box of 'moov' type that contains description information about the media stream, and one box of 'mdat' type that contains actual media data. The 'moov' type box has a video description track and an audio description track that contains technical information about video and audio, and the 'mdat' box contains a video sample track and an audio sample track that contain the actual video and audio streams. Have The hint track contained in the 'moov' type box contains information for packetizing video and audio samples when ISO Base Media files are streamed through the streaming protocol.

Next, a video file protection system to which an encrypted video file generating apparatus and an encrypted video restoring apparatus of the ISO Base Media file format of the present invention are applied will be described with reference to FIG. 2. Figure 2 shows the overall configuration of a video file protection system that provides a streaming service or a download service while protecting a video file in the ISO Base Media file format from illegal copying and use.

The existing system for providing a content streaming service may include a streaming server, a content service server, and a streaming client and a decoder of a user terminal. A system that provides an existing content download service may be similarly configured.

In order to apply the protection method of the video content to the system for the existing streaming service and download service, the encrypted video by encrypting the original video file of the ISO Base Media file format in advance using the encrypted video file generating device of the present invention It is required to register the file with the streaming server and to stream or download the encrypted video file. Encrypted video files also follow the ISO Base Media File format, so streaming servers can stream in the same way as unencrypted files.

As shown in FIG. 2, the video file protection system to which the encrypted video file generating apparatus and the encrypted video restoring apparatus of the present invention are applied include an encrypted video file generating apparatus 10, a license issuing server 20, and a content. The service server 30, the streaming server 40, the encrypted video restoration device 50, the video player 60 is composed of.

The encrypted video file generating apparatus 10 receives the original video file and the metadata, encrypts the original video in the ISO Base Media file format in advance, and inserts the metadata to generate an encrypted video file. The video file and the metadata are transmitted to the corresponding server, that is, the streaming server 40, to be registered in the streaming server 40. In addition, the encrypted video file generating apparatus 10 transmits the encryption information (the encryption key used when encrypting the original video, the encryption option) and the content information (content ID of the corresponding content, authorization information) to the license issuing server 20. Then, the content service information (streaming or download service address, content ID, license issue address, content related information) is provided to the content service server 30.

The streaming server 40 provides the encrypted video file in the ISO Base Media file format to the user through a streaming service or a download service according to the user's request.

The license issuing server 20 manages the encryption information and the content information transmitted from the encrypted video file generating device 10, which encryption information and encryption option information necessary for the user to decrypt and watch the encrypted video. to be. When a license issuance request is made from a legitimate user, the license issuing server 20 generates a license including encryption information and right information necessary for decrypting the encrypted video and issues it to the corresponding user.

The content service server 30 receives the content service information from the encrypted video file generating apparatus 10, provides the user with content information such as a preview, and when the user requests this content, streams the content or Provide the necessary information to receive via download.

The encrypted video restoring apparatus 50 decrypts an encrypted video transmitted from the streaming server 40 by using encryption information and right information included in a license issued from the license issuing server 20, and decrypts the decrypted video. The streaming is sent to the video player 60. The video player 60 plays the decoded video stream so that the user can watch the content.

Next, the encrypted video file generating apparatus 10 shown in FIG. 2 will be described in more detail with reference to FIG. 3.

3 is a block diagram showing the configuration of an encrypted video file generating apparatus 10 according to an embodiment of the present invention. As shown in FIG. 3, the encrypted video file generating apparatus 10 according to the embodiment of the present invention includes a metadata generating unit 11, an ISO Base Media file analyzing unit 12, and a sample encrypting unit 13. ), A hint information generation unit 14, and an ISO Base Media file construction unit 15.

Basically, the encrypted video file generating apparatus 10 receives the original video file and the metadata to generate the encrypted video file and the structured metadata.

The original moving picture file input to the ISO Base Media file analyzing unit 12 has an ISO Base Media file format. The ISO Base Media file analysis unit 12 receives the original video file in the ISO Base Media file format, and analyzes the 'moov' type box information describing the information about the media stream in the ISO Base Media file structure to analyze the video and audio. The offset of the sample (frame) and the offset of the hint sample of the video / audio hint track are extracted. The ISO Base Media file analyzer 12 transmits the extracted video / audio sample position information to the sample encryptor 13 and transmits the hint sample position information to the hint information generator 14.

The sample encryptor 13 checks the frame header of the video and audio from the video / audio sample position information transmitted from the ISO Base Media file interpreter 12, and the video and audio sample excludes the video and audio frame header. Encrypts only audio data according to the encryption option to generate an encrypted video / audio sample.

The hint information generation unit 14 has a hint sample of the video / audio hint track transmitted from the ISO Base Media file analysis unit 12 (with payload size information of the packetized packet when the video file is transmitted through streaming). Using the location information, change the effective size of the streaming packet in the hint sample to be smaller than the MTU (Maximum Transport Unit) size, which is a multiple of the block size of the block encryption method used when encrypting the video / audio sample. If it does not exist, create one.

The metadata generator 11 receives metadata necessary for streaming or downloading an encrypted video file and generates metadata structured according to the ISO Base Media file format. Here, the metadata is information about a content title, genre, plot, production year, content ID, license issuing server address, streaming service address, and the like.

The ISO Base Media file construction unit 15 receives the encrypted video / audio sample from the sample encryption unit 13, receives the modified or newly generated hint track information from the hint information generation unit 14, and receives the metadata generation unit ( 11) accepts structured metadata information from the original video file, replacing the original video / audio sample with an encrypted video / audio sample in the original movie file, replacing the hint track with a modified hint track, or if there is no hint track. Add metadata and insert metadata into the custom area of the ISO Base Media file to compose an encrypted video file for the ISO Base Media file format.

In the present invention, the video and audio in the original video file in the ISO Base Media file format, so that the encrypted video file can be streamed in the same way as the original unencrypted video file without additional work in the existing streaming system By extracting the sample and encrypting only the data except the video and audio frame headers in the video and audio samples, the video and audio streams are encrypted without modifying the ISO Base Media file format.

In addition, when encrypting the entire media data in order to protect the video file, performance degradation may occur due to the decryption process when restoring the encrypted video according to the terminal environment of the client side. In order to solve this problem, the present invention selectively encrypts only I-frames among video streams, which occupy a much larger capacity than audio streams in a video file, and in particular, encrypts only the video data portion without encrypting the video frame header. As a result, the encrypted video reconstruction device 50 can identify the I-frame to be decrypted using the frame header.

In the hint information generation unit 14 of the encrypted video file generating apparatus 10, when the video and audio samples encrypted using the block encryption method are packetized into streaming packets, the payload size of the streaming packets is generally used. Since the size of the video sample is much larger than that of one video sample, it is divided into several streaming packets. In this case, when a packet loss occurs during streaming transmission when splitting within one encryption block unit, another streaming splitted from the same video sample due to a packet lost during decryption in the video file recovery apparatus 50 It also affects the decoding of packets. In order to make the impact of such packet loss at the time of decryption independent from one packet to another streaming packet, in the present invention, the payload size of the streaming packet is a multiple of the encryption block size of the block encryption method and is smaller than the MTU size. Change it to a value.

Next, the encrypted video restoration apparatus 50 shown in FIG. 2 will be described in more detail with reference to FIG. 4.

4 is a block diagram showing the configuration of an encrypted video decompression device 50 according to an embodiment of the present invention.

As shown in FIG. 4, the encrypted video restoration apparatus 50 according to the embodiment of the present invention includes a content service information processing unit 51, a video / audio sample configuration unit 52, and an encrypted video file processing unit 53. ), A license processing unit 54, a sample decoding unit 55 and a storage 56. The download file storage 57 is installed outside the encrypted video restoring apparatus 50 so that the video file can be transmitted to the encrypted video file processing unit 53.

The content service information processor 51 obtains content service information (content ID, streaming or download service address, address of a license issuing server) necessary for a streaming service or a download service of video content from the content service server 30 of FIG. 2. Receives, requests a streaming or download service, generates license request information for requesting a license issuance to the license server, and transmits the license request information to the license processing unit 54.

The license processing unit 54 requests the license issuing server 20 of FIG. 2 to issue a license for the corresponding content according to the license request information, and in response thereto, encrypts the content from the license securely delivered from the license issuing server 20 and The rights information is extracted and stored in the storage 56.

On the other hand, the video / audio sample configuration unit 52 reads the video and audio streaming packets or locally downloaded files that are streamed from the streaming server 40 and configures the video and audio samples to decode the video / audio samples. 55).

The sample decryption unit 55 decrypts the video / audio sample transmitted from the video / audio sample configuration unit 52 using the encryption information and the right information stored in the storage 56 to output the decrypted sample.

The storage 56 stores the content encryption information and the right information transmitted from the license processing unit 54. In addition, the symmetric key of the public key-based certificate or the secret key method, and the encrypted video restoration device 50 are stored. Unique identification information and the like.

The file downloaded by the download service is stored in the storage 57. When a file downloaded from the storage 57 is read and transmitted to the encrypted video file processing unit 53 for reproduction of the encrypted video file, the encrypted video file processing unit 53 sends the metadata inserted into the encrypted video file. Extract. At this time, it is checked whether the encryption information and the rights information of the corresponding content are stored in the storage 56 by using the content ID among the metadata, and if the information does not exist in the storage 56, the license is extracted from the extracted metadata. The license request information necessary for the issuance request is transmitted to the license processing unit 54. If the encrypted information and the right information of the corresponding content exist in the storage 56, the encrypted video file processing unit 53 extracts the encrypted information and the right information from the storage 56 and the sample decryption unit 55. To transmit.

Next, referring to the flowchart of FIG. 5, when an encrypted video file is used for a streaming service, an encrypted video restoration method according to an embodiment of the present invention will be described.

When the operation starts, it receives the content service information (content ID, streaming service address, address of the license issuing server, etc.) necessary for using the video content for the streaming service (S11).

Next, using the content ID of the content service information received in step S11, it is checked whether encryption information and rights information for the corresponding content are stored in the storage (S12).

In step S12, if the encryption information and the right information for the content is stored in the storage, the encryption information and the right information is extracted from the storage (S13). If, in step S12, the encryption information and the right information for the content is not stored in the storage, the license issuance request is made to the license issuing server using the content service information and received (S14). Next, the content encryption information and rights information is extracted from the license received from the license issuing server and stored in the storage (S15).

Next, by using the streaming service address of the content service information received in step S11, a streaming service for the corresponding content is requested and the corresponding content is received through the streaming service (S16).

In step S16, the video and audio streaming packets received through the streaming service are composed of video and audio samples (S17). Next, the configured video / audio sample is decrypted using the encryption information and the right information extracted in the above step S13 or S15 (S18).

Next, with reference to the flow chart of Figure 6, when the encrypted video file is used in the download service, the encrypted video restoration method according to an embodiment of the present invention will be described.

When the operation starts, the downloaded video file is read (S21). Next, the metadata inserted into the read video file is extracted (S22). When the metadata is extracted, it is checked whether the encryption information and the right information of the corresponding content are stored in the storage using the content ID (S23).

In step S23, if it is confirmed that the encryption information and the right information for the content is stored in the storage, the encryption information and the right information is extracted from the storage (S24).

If it is determined in step S23 that the encryption information and the right information for the corresponding content are not stored in the storage, the license issuing server address and the content ID are extracted from the metadata extracted in the step S22 to the license issuing server. Request a license issuance and receive it (S25).

Next, the content encryption information and rights information is extracted from the license received from the license issuing server in step S25 and stored in the storage (S26). Meanwhile, video and audio samples are constructed from the encrypted video file (S27). Next, the sample configured as described above in step S27 is decrypted using the encryption information and the right information stored in step S26 (S28).

Although the present invention has been described in more detail with reference to some embodiments, the present invention is not necessarily limited to these embodiments, and various modifications can be made without departing from the spirit of the present invention.

As described above, the apparatus for generating and restoring an encrypted video file in the ISO Base Media file format according to the present invention encrypts the video content in the ISO Base Media File format by applying encryption and decryption techniques on the server side providing the video content. In addition, the client side playing the video content can decrypt the encrypted video at the time of playing the video in real time, and the content can be protected from illegal copying in a streaming service or a download service environment.

Claims (6)

ISO, which receives the original movie file in ISO Base Media file format, interprets the box information describing the media stream information in the ISO Base Media file structure, and extracts the location of the video and audio samples and the hint samples from the hint track. Base Media file analyzer; Check the frame header of the video and audio from the video / audio sample position information extracted by the ISO Base Media file analysis unit 12, and encrypt only the video / audio data except the video and audio frame header in the video and audio sample. A sample encryption unit for performing encryption according to the; A hint information generation unit configured to change the streaming packet payload size from the hint sample to a value smaller than the MTU size while being a multiple of the block size used in the block encryption method, and newly generating the hint track if there is no hint track; A metadata generator for receiving metadata necessary for streaming or downloading an encrypted video file and generating metadata structured according to an ISO Base Media file format; And Accept the encrypted video / audio sample from the sample encryptor, accept the modified or newly generated hint track information from the hint information generator, accept the structured metadata information from the metadata generator, and Replace the original video / audio sample with an encrypted video / audio sample, replace the hint track with a modified hint track, add a hint track if there is no hint track, and add metadata to the custom area of the ISO Base Media file. And an ISO Base Media file configuration unit inserted into and forming an encrypted video file in accordance with the ISO Base Media file format. The method of claim 1, And the hint information generator is configured to perform the change by using the positions of the hint samples of the video and audio hint tracks extracted by the ISO Base Media file analyzer. The method of claim 1, The metadata generated by the metadata generator is information including a content title, genre, plot, production year, content ID, license issuing server address, and streaming service address. A content service information processing unit which receives content service information and requests a streaming or download service, generates license request information including encryption information and rights information necessary for decryption, and transmits the license request information to a license issuing server; A license processing unit which requests a license for the corresponding content from a license issuing server according to the license request information, and extracts content encryption information and right information from a license transferred from the license issuing server correspondingly; A video / audio sample configuration unit configured to read video and audio streaming packets or streaming downloaded ISO Base Media files to configure video and audio samples; A sample decryption unit for decoding the video and audio samples configured in the video / audio sample configuration unit by using the content encryption information and right information; And Extract the metadata inserted in the downloaded video file to check whether the encryption information and the rights information for the corresponding content are stored. If the information is not stored, the metadata required for the license issue request is extracted from the extracted metadata. And an encrypted video file processing unit for transmitting the license information to the license processing unit, and extracting the encryption information and the right information of the corresponding content if the information is stored. (a) receiving content service information necessary for using the video content in a streaming service; (b) using the received content service information, checking whether encryption information and rights information for the corresponding content are stored; (c) extracting the encrypted information and the right information if the encrypted information and the right information of the corresponding content are stored in the step (b); (d) If the encryption information and the right information of the content is not stored in the step (b), by using the content service information, request a license having the encryption information and the right information necessary for decryption, and receive it, Extracting and storing content encryption information and right information from the received license; (e) using the encryption information and the right information extracted in the step (c) or (d), requesting a streaming service for the content and receiving the content; And (f) constructing the video and audio streaming packets received in step (e) into video and audio samples, and decrypting the video / audio samples thus constructed using encryption information and rights information. To restore encrypted video streaming (a) reading the downloaded video file and extracting metadata inserted into the video file; (b) checking whether encrypted information and rights information of the corresponding content are stored using the extracted content ID of the metadata; (c) extracting the encrypted information and the right information if the encrypted information and the right information of the corresponding content are stored in the step (b); (d) In step (b), if the encryption information and the rights information of the corresponding content are not stored, the license is requested and received using the content ID of the metadata and the license issuing server address, and the received license Extracting and storing content encryption information and right information; And (e) constructing a video and audio sample from an encrypted video file, and decrypting the configured sample using the encryption information and the right information.

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