JP2001333405A - Transmitter and authentication device and multimedia reproduction system and their control method, and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multimedia reproduction system that can protect the copyright of multimedia data in the unit of object configuring each scene. SOLUTION: A demultiplexer 102 extracts each bit stream (each medium, BIFS(binary format for scene), and IPMP(intellectual property management and protection)) from a received bit stream. The decoded BIFS is fed to a BIFS decoder 108. Simultaneously a secondary encryption key for each medium is fed to encryption decoders (105-107) for each medium. The encryption decoders (105-107) for each medium decode the encryption of each medium and the bit stream of each medium is fed to decoders (109-111) for each medium. As a result above, a renderer 112 arranges each medium and texture, video audio data attached thereto to the bit streams of each medium on the basis of tree information by the BIFS decoder and the result is displayed and reproduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a copyright protection system for multimedia data on a system having a scene synthesizing function.

[0002]

2. Description of the Related Art Currently, ISO / IEC19921 (MP
EG-4) has standardized multimedia encoding (compression format). In this standard, in addition to the conventional encoding of video and audio data, the spatial and temporal arrangement of each medium can be defined, and this is called a scene description. Each medium is called an object.

FIG. 6 shows an example of a scene description. In this example, as an object, a BOX (box) is attached to a graphic object and an image texture (T
exture1.jpg), Cylinder (cylinder) and the video texture (Texture2.mpg) attached to it, and the audio to be played simultaneously are defined.

[0004] The syntax of the scene description itself is as follows:
BIFS (BInary Folio) that has been extended and binarized based on VRML (Virtual Reality Modeling Language)
rmatfor Scene description). This example is also a source of BIFS, and binarizes (encodes) it according to a specific rule.

FIG. 7 shows an actual rendering result.

The BOX 701 has an image texture (Textur
e1.jpg) is affixed, and this object is displayed in VRML (Virtual Reality
Modeling Language).

A video texture (Texture2.mpg) is affixed to the cylinder 702, and the display of this object is based on the VRML node group on the 19th to 33rd lines in FIG.

At the same time, the audio 703 is reproduced by the VRML node group in the 36th to 39th rows in FIG.

FIG. 8 shows a multiplexed bit stream after encoding all objects.

Reference numeral 801 denotes a header, which is profile level information of a bit stream, setting information of a decoder,
The attribute information of each object is described.

Reference numeral 802 denotes a BIFS stream.

Reference numeral 803 denotes an image stream.

Reference numerals 804, 806, and 808 denote video streams, and reference numerals 805, 807, and 809 denote audio streams. In this way, media requiring real-time reproduction and synchronization, such as video and audio, are often superimposed alternately.

FIG. 9 shows an example of a conventional authentication device.

Reference numeral 901 denotes a bit stream receiving unit which receives bit stream data from a line. Further, the reception unit 901 is not necessarily limited to communication, and can be read from a recording medium or the like.

Reference numeral 902 denotes a demultiplexer, which extracts each bit stream from a single bit stream superimposed. Reference numeral 903 denotes a BIFS decoder (parser) that decodes scene information to be displayed and creates scene tree information 907. Here, the scene tree is, as can be seen from the VRML source code shown in FIG. 6, the arrangement information of each object, mutual dependency, and the like.

Reference numeral 904 denotes an image decoder, JP
This is a part for decoding compressed image code data such as an EG file. Reference numerals 905 and 906 denote video decoders and audio decoders, which decode coded data of each medium. Reference numeral 908 denotes a renderer which finally arranges each object, its associated texture, video and audio, and performs display and reproduction. Reference numeral 909 denotes a final output device, for example, an image is displayed on a TV monitor, and audio is reproduced from a speaker.

FIG. 12 shows another example of a conventional protected bit stream. Data such as texture images, video, and audio is protected in units of streams (media streams). 12
02 is IPMP (Intellectual Property Management)
and Protection), information for protection (scramble method, data for password verification, etc.) is superimposed. Streams such as video and audio (1205-
1210, shaded portions) are protected by the above-mentioned protection information, and display is started only when it is determined to be appropriate after descrambling and password collation are performed as appropriate. Further, the BIFS stream can be similarly protected as one media stream.

FIG. 11 shows an authentication apparatus using such a bit stream when protection information is added.

Reference numeral 1103 denotes an IPMP manager;
Stream controller 1 according to the transmitted protection information
104 is controlled. More specifically, only when the above-mentioned authentication is successful, the stream controller 1104 transmits data to the subsequent media (image, video, audio) decoders (1106, 1107, 1108) and performs decoding. Finally, display and reproduction are performed.

[0021]

However, the prior art has the following problems.

Since protection is performed in units of individual media, the function of protection in units of objects constituting a scene is insufficient.

[0023]

In order to achieve the object of the present invention, for example, a transmitting apparatus of the present invention has the following arrangement. That is, first encryption means for encrypting scene description information using a primary encryption key, generation means for generating a secondary encryption key using the primary encryption key, and media using the secondary encryption key. A second encryption unit for encrypting the stream, a bit stream indicating the encryption method of the first encryption unit, and a bit stream resulting from the first and second encryption units are superimposed. A superimposing means for generating one bit stream and a transmitting means for transmitting the bit stream by the superimposing means to an external device are provided.

Further, in order to achieve the object of the present invention, for example, the authentication device of the present invention has the following configuration. That is,
A receiving unit that receives a bit stream transmitted from an external device, a detecting unit that detects a primary encryption key, and a primary encryption key that is included in the received bit stream using the primary encryption key detected by the detecting unit. First decryption means for decrypting the encrypted scene description information included in the received bitstream based on a decryption method, and generating a secondary encryption key using the primary encryption key Means, second decryption means for decrypting an encrypted media stream included in the bit stream using the secondary key, and the second decryption means based on scene description information by the first decryption means. Reproduction means for reproducing the media stream by the second decoding means.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

[First Embodiment] The transmitting apparatus according to the present embodiment has a scene description information B which describes the configuration of each medium of an image (still image), video (moving image), and audio.
The IFS is encrypted with a primary encryption key, and the above-described bit stream (media stream) of each medium is
Encrypt with the secondary encryption key and the secondary encryption key generated based on the BIFS checksum. The encrypted BIFS bit stream (BIFS bit stream), the bit stream of each medium (media stream), and the IPMP stream (BIFS bit stream)
Is transmitted to an authentication device described later.

On the other hand, the authentication device of the present embodiment reads the IC card in which the information of the primary encryption key is described into the authentication device, thereby decrypting the BIFS encrypted with the primary encryption key. A secondary encryption key is generated using the method described in the IPMP stream, and the encrypted bit stream of each medium is decrypted and played.

Hereinafter, the above-described transmitting device and authentication device will be described in detail.

FIG. 16 is a block diagram showing the internal configuration of the transmitting apparatus according to this embodiment.

Reference numeral 501 denotes a BIFS Encoder (BI
FS encoder), BI input from external device
FS Source (BIFS source) is encoded (compressed). At this time, BIFS checksum data is generated.

Reference numeral 502 denotes an Image Encoder (image decoder), which receives an Im input from an external device.
Encode (compress) the age Source (the source of the image).

Reference numeral 503 denotes a Video Encoder (video decoder), which is a Video Encoder input from an external device.
eo Source (video source) is encoded (compressed).

An audio encoder (audio encoder) 504 encodes (compresses) an audio source (audio source) input from an external device.

505 is a Key Generator (1)
The user operates the operation unit 1605 in the next encryption key generation unit).
A primary encryption key is generated based on the password input from.

Reference numeral 506 denotes BIFS Encryptor.
(Encryptor for BIFS), the encoder 50 for BIFS
The BIFS bit stream output from 1 is
Using the primary encryption key generated by the secondary encryption key generation unit 505, the primary encryption key and BIFS are encrypted.
A secondary encryption key for each medium is generated from the checksum of BIFS output from the encoder 501 for the medium.

Reference numerals 507, 508, and 509 denote Ima, respectively.
geoEncryptor (encryptor for image), V
video Encryptor (encryptor for video),
Audio Encoder (encryptor for audio), and encoders (502, 503,
The bit stream of each medium output from 504) is encrypted using the secondary encryption key for each medium.

Reference numeral 510 denotes a MUX (multiplexer).
The IFS encryptor 506 and the media encryptors (5
07, 508, 509), one superimposed bit stream is generated from each bit stream output. The generated bit stream is transmitted to the authentication device 1 described later.

Reference numeral 1600 denotes a transmission device main body.

Reference numeral 1601 denotes a CPU which executes a program code for controlling the entire transmitting device 1600 by reading the program code from a ROM 1602 in which the program code is stored.

Reference numeral 1602 denotes the above-described ROM, which stores character codes used when a primary encryption key is generated using the primary encryption key generation unit 506 and the operation unit 1605, in addition to the above-described program codes. .

Reference numeral 1603 denotes a RAM which is used as a work area when the CPU 1601 is executing the above-described program code.

Reference numeral 1604 denotes an external storage device which stores in advance some passwords used for generating a primary encryption key.

Reference numeral 1605 denotes the above-mentioned operation unit.

Reference numeral 1606 denotes a display unit which is constituted by a CRT, a liquid crystal screen, or the like, and displays some passwords stored in the external storage device 1604, and displays a system message of the transmitting device 1600.

Reference numeral 1607 denotes a bus connecting the above-described units.

Processing in transmitting apparatus 1600 of the present embodiment based on the above configuration will be described.

FIG. 5 shows a transmitting apparatus 160 according to this embodiment.
It is a block diagram which shows the process of 0.

As described above, B input from an external device
The IFS and the source of each medium are input to each encoder (501 to 504). A BIFS bit stream encoded by the BIFS encoder 501 is input to the BIFS encryptor 506 from the primary encryption key generation unit 505 by the user.
BIFS encrypted with the next encryption key
Are output to the multiplexer 510. At that time, the BIFS encryptor 506
BIFS generated by the IFS encoder 501
, And a secondary encryption key for each medium is generated using the above-mentioned primary encryption key.

On the other hand, each media encoder (50
2, 503, 504), the bit stream of each medium is encoded by the encryptor (507, 50) of each medium.
8, 509), the encrypted data is encrypted using the above-mentioned secondary encryption key and output to the multiplexer 510. Note that information on the method of generating the secondary encryption key for each medium and the BIFS encryption method using the primary encryption key is stored in the IPMP (stream) and output to the multiplexer 510.

The multiplexer 510 receives the input BIFS and the bit stream of each media,
In addition, all the IPMPs are superimposed to generate one bit stream having the structure shown in FIG. The generated bit stream is transmitted to an authentication device 1 described later. FIG. 1
2, the BIFS and video bit streams (120
5, 1207, 1209) and the audio bit stream (1206, 1208, 1210) are protected by being encrypted.

FIG. 17 shows a flowchart of the above-described processing, but the description is omitted because it is the same as that described above.

FIG. 14 is a block diagram showing the inside of the authentication apparatus 1 according to this embodiment.

Reference numeral 1 denotes an authentication device according to the present embodiment.

Reference numeral 101 denotes a bit stream receiving unit that receives the above-described bit stream transmitted from the transmitting device 1600. In addition, the bit stream receiving unit 101 does not always receive the data from the communication line, but stores the bit stream generated by the transmission device in a storage medium such as a floppy (registered trademark) disk or a CD-ROM. It may be read.

Reference numeral 102 denotes a DeMUX (demultiplexer).
Then, from the bit stream transmitted from the transmitting device 1600, the above-described media, BIFS, and IP
Extract MP bit stream.

Reference numeral 103 denotes an IPMP Manager (IP
MP Manager), Authentication S
When information indicating that the user who wants to play each of the above-described media is authenticated in the IPMP manager 103 in the
IFS Descriptor (BIFS Decryptor)
Operation permission is given to 104. Further, information on the BIFS encryption method stored in the IPMP from the demultiplexer 102 is read, and the BIFS Decri is read.
A decryption instruction is sent to the ptor (BIFS decryption device) 104.

Reference numeral 104 denotes a BIFS Descriptor.
(BIFS Decryptor), IPMP Manager 10
It operates only when the operation permission is given from 3. The contents of the operation are as follows. The encrypted BIFS input from the demultiplexer 102 is
IPMP manager 103 using the primary encryption key from
, And sends the decrypted BIFS to the BIFS Decoder (BIFS decoder) 108. At the same time, the decrypted B
The checksum of the IFS is taken, and the checksum and the primary encryption key from the authentication processing device 114 are used to generate a secondary encryption key for each medium stored in the IPMP from the demultiplexer 102 based on the method. A secondary encryption key is generated, and a decryption device (10
5, 106, 107).

Reference numeral 105 denotes an image descriptor
r (image decryptor) decrypts the bit stream of the image input from the demultiplexer 102 using the above-described secondary encryption key,
A bit stream of the decrypted image is output to a coder (image decoder) 109.

Reference numeral 106 denotes a Video Descriptor.
r (video decryptor) decrypts the video bit stream data input from the demultiplexer 102 using the above-mentioned secondary encryption key,
The decrypted video bit stream is output to an encoder (video decoder) 110.

Reference numeral 107 denotes Audio Descriptor
r (audio decryption device) decrypts the audio bit stream data input from the demultiplexer 102 using the above-described secondary encryption key,
ioDecoder (Audio Decoder) 111
To output the decrypted audio bit stream.

Numerals 108, 109, 110 and 111 are decoders for each of the above-mentioned media. BIFS
As a result of BIFS decoding, FIG.
The tree information of the scene shown in FIG. The tree information is, for example, arrangement information of each medium and mutual dependencies.

Reference numeral 112 denotes a Renderer.
In the end, each media and its accompanying texture,
This section arranges video / audio based on the above-described tree information and performs display / playback.

Reference numeral 113 denotes an output device (output device).
The audio is displayed on the monitor and the audio is played from the speakers.

Reference numeral 114 denotes the above-mentioned authentication processing apparatus, which can input the password of the user who wants to play each of the above-mentioned media to the above-mentioned primary encryption key. The password is input using an authentication IC card (not shown). Further, user information is described on the authentication IC card, and the authentication processing device 114 may read the user information. In the present embodiment, the authentication processing device 1
The internal structure of 14 is not particularly limited.

Reference numeral 115 denotes a CPU, which controls the above-described units based on the below-described program codes stored in the ROM 117.

Reference numeral 116 denotes a RAM, which is used as a work memory used by the CPU 115 while executing the program code. A TV monitor included in the output device 113 uses the VRAM as a VRAM. Also, bit stream data input from outside via the bit stream receiving unit 101 can be temporarily stored.

A ROM 117 stores various program codes to be executed by the CPU.

Reference numeral 118 denotes a bus connecting the above-described units.

FIG. 1 is a block diagram of the processing of the authentication device 1 having the above-described configuration.

The bit stream received from transmitting apparatus 1600 is input to authentication apparatus 1 via bit stream receiving section 101. Each bit stream (each media and BIFS and IPMP) is extracted from the input bit stream by the demultiplexer 102. The extracted IPMP is the IPMP manager 103
The BIFS is sent to the BIFS decoder 104, the image bit stream is sent to the image decoder 105,
The video bitstream is converted to a video decryptor 106.
Then, the audio bit stream is output to the audio decryption unit 107, respectively.

On the other hand, when the user who is trying to play each medium is authenticated in the above-described authentication processing, if the user is authenticated, the BIFS decryption device 104, which has been permitted to operate by the IPMP manager 103, as described above, As described above, BIFS is decrypted, and the decrypted BIFS stream is sent to the BIFS decoder 108. at the same time,
The secondary encryption key for each medium generated by the processing described above is sent to the decryptor (105 to 107) for each medium. Each media decryptor (105-107) decrypts each media, and sends the bit stream of each media to each media decoder (109-111).

As described above, as described above, based on the tree information by the BIFS decoder, in the renderer 112, each media, its associated texture, and video / audio are arranged, displayed and reproduced by the renderer 112. Are output to the output device 113.

FIG. 15 shows a flowchart of the above processing. The description is omitted because it is the same as the above-described processing.

In this embodiment, the primary encryption key and the BIFS checksum are used to generate the secondary encryption key.
In generating the secondary encryption key, the primary encryption key and the number of objects in the scene may be used.

By using the transmitting apparatus and the authenticating apparatus having the above-described configurations and their control methods, it is possible to protect the security of each medium included in the scene.

[Second Embodiment] In this embodiment, when a bit stream of a scene composed of protected scenes and unprotected scenes (hereinafter referred to as a mixed scene) is input, the input is performed. An authentication device that divides a bitstream of a protected scene into protected scenes and unprotected scenes will be shown and described.

Note that the transmission device for transmitting the bit stream to the authentication device in this embodiment uses the same transmission device as that used in the first embodiment.

FIG. 2 is a block diagram showing the inside of the authentication apparatus according to this embodiment.

Reference numeral 201 denotes Unprotected Sce
Ne Bit Stream (bit stream of an unprotected scene) is a bit stream obtained as a result of the demultiplexer 102 dividing the bit stream of the mixed scene input from the transmitting device 1600 via the bit stream receiving unit 101.

Reference numeral 202 denotes a protected scene.
In the bit stream (bit stream of a protected scene), a bit stream of a mixed scene input from the transmitting apparatus 1600 via the bit stream receiving unit 101 is a bit stream obtained as a result of division by the demultiplexer 102.

Note that the mixed scene in this embodiment is
As shown in FIG. 3, BOX and Ima attached to the BOX
The geoTexture is not protected, indicating that only the Cylinder, VideoTexture, and Audio are protected. Therefore, when this mixed scene is output to the output device 113, the result shown in FIG. 13 is obtained.

FIG. 4 shows the structure of a bit stream of the above-mentioned mixed scene in which protected and unprotected scenes are superimposed.

The shaded portion is a protected bit stream. For example, 403 is the portion of the unprotected BIFS bit stream, and 405 is the protected BIFS bit stream.
This is the part of the FS bit stream. Thus BI
It can be seen that the FS bit stream is divided.

The bit stream 201 of the unprotected scene is directly used as the BIFS decoder 108b.
To generate the tree information of the scene shown in FIG. On the other hand, the bit stream 202 of the protected scene is decrypted by the BIFS decryptor 104. Thereafter, as described in the first embodiment, the secondary encryption key for each medium is generated in the BIFS decryption device 104, and the video decryption device 106
The secondary encryption key is output to the audio decryptor 107. Hereinafter, the same processing as in the first embodiment is performed.

By using the authentication apparatus having the above-described configuration and the control method thereof, a mixed scene including a protected scene and an unprotected scene is included in the mixed scene. Security could be protected for each individual media.

[Other Embodiments] The above-described embodiment is applied to a system including a plurality of devices (for example, a host computer, an interface device, a reader, a printer, etc.), but is constituted by one device. The present invention may be applied to an apparatus (for example, a copying machine, a facsimile machine, etc.).

Further, an object of the above-described embodiment is to supply a storage medium (or a recording medium) storing a program code of software for realizing the functions of the above-described embodiment to a system or an apparatus, and to provide the system or apparatus with the storage medium. It is needless to say that the present invention is also achieved when a computer (or a CPU or an MPU) reads and executes a program code stored in a storage medium. In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiment, and the storage medium storing the program code constitutes the above-described embodiment. By executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also an operating system (OS) running on the computer based on the instruction of the program code. It goes without saying that a case where some or all of the actual processing is performed and the functions of the above-described embodiments are realized by the processing is also included.

Further, after the program code read from the storage medium is written into the memory provided in the function expansion card inserted into the computer or the function expansion unit connected to the computer, the program code is read based on the instruction of the program code. Needless to say, the CPU included in the function expansion card or the function expansion unit performs part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.

When the above-described embodiment is applied to the storage medium, the storage medium stores program codes corresponding to the above-described flowcharts (shown in FIG. 15 or FIG. 17).

[0090]

According to the above description, there is an effect that protection is performed for each object constituting a scene.

[Brief description of the drawings]

FIG. 1 is a block diagram of processing of an authentication device.

FIG. 2 is a block diagram of the inside of the authentication device.

FIG. 3 is a diagram showing tree information of protected scenes and tree information of unprotected scenes.

FIG. 4 is a diagram illustrating a structure of a bit stream of a mixed scene.

FIG. 5 is a block diagram illustrating processing of a transmission device.

FIG. 6 is a diagram illustrating an example of a scene description.

FIG. 7 is a diagram showing a rendering result.

FIG. 8 is a diagram showing a multiplexed bit stream.

FIG. 9 is a diagram showing a conventional authentication device.

FIG. 10 is a diagram showing tree information of a scene.

FIG. 11 shows a conventional authentication device.

FIG. 12 is a diagram illustrating an example of a protected bit stream.

FIG. 13 shows a rendering result in the second embodiment.

FIG. 14 is a block diagram showing the inside of the authentication device.

FIG. 15 is a flowchart of the authentication device.

FIG. 16 is a block diagram illustrating an internal configuration of a transmission device.

FIG. 17 is a flowchart of the transmission device.

Claims (15)

[Claims] A first encryption unit that encrypts scene description information using a primary encryption key; a generation unit that generates a secondary encryption key using the primary encryption key; A second encryption unit for encrypting the media stream using the first encryption unit, a bit stream indicating an encryption method of the first encryption unit, and a bit stream resulting from the first and second encryption units. A transmission apparatus comprising: superimposition means for generating one bit stream by superimposition; and transmission means for transmitting the bit stream by the superimposition means to an external device. 2. The transmitting apparatus according to claim 1, wherein the generating unit further generates the secondary encryption key using the scene description information. 3. A receiving means for receiving a bit stream transmitted from an external device; a detecting means for detecting a primary encryption key; and a receiving means for receiving the bit stream using the primary encryption key detected by the detecting means. First decryption means for decrypting the encrypted scene description information included in the received bitstream based on a decryption method included in the bitstream; and secondary encryption using the primary encryption key. Generating means for generating a key; and a second means for decrypting an encrypted media stream included in the bit stream using the secondary key.
Based on the scene description information by the first decoding means,
An authentication device comprising: a reproducing unit that reproduces a media stream by the second decryption unit. 4. The authentication apparatus according to claim 3, wherein said detecting means detects said primary encryption key from a storage medium storing said primary encryption key. 5. The authentication apparatus according to claim 3, wherein the generation unit generates the secondary encryption key using the scene description information. 6. A multimedia playback system comprising a transmission device and an authentication device, wherein the transmission device encrypts scene description information using a primary encryption key.
Encryption means; generating means for generating a secondary encryption key using the primary encryption key; second encryption means for encrypting a media stream using the secondary encryption key; A superimposing unit that generates one bit stream by superimposing a bit stream indicating an encryption method of an encryption unit and a bit stream resulting from the first and second encryption units; Transmitting means for transmitting a bit stream to the authentication device, the authentication device receiving means for receiving the bit stream transmitted from the transmitting device, detecting means for detecting a primary encryption key, and detecting means Using the primary encryption key detected in the above, included in the received bit stream based on the decryption method included in the received bit stream First decryption means for decrypting the encoded scene description information; generating means for generating a secondary encryption key using the primary encryption key; and a generation means for using the secondary key to be included in the bit stream. To decrypt the encrypted media stream to be encrypted
Based on the scene description information by the first decoding means,
A reproducing unit for reproducing a media stream by the second decoding unit. 7. A first encryption step for encrypting scene description information using a primary encryption key; a generation step for generating a secondary encryption key using the primary encryption key; A second encryption step of encrypting the media stream using the first encryption step, a bit stream indicating an encryption method in the first encryption step, and a bit stream resulting from the first and second encryption steps. A control method for a transmitting apparatus, comprising: a superimposing step of generating one bit stream by superimposing; and a transmitting step of transmitting the bit stream in the superimposing step to an external device. 8. The control method according to claim 7, wherein the generating step further generates the secondary encryption key using the scene description information. 9. A receiving step of receiving a bit stream transmitted from an external device; a detecting step of detecting a primary encryption key; and a receiving step using the primary encryption key detected in the detecting step. A first decryption step of decrypting the encrypted scene description information included in the received bitstream based on a decryption method included in the bitstream; and a secondary encryption using the primary encryption key. Generating a key, and decrypting an encrypted media stream included in the bit stream using the secondary key.
Based on the scene description information in the first decoding step,
And a reproducing step of reproducing the media stream in the second decrypting step. 10. The method according to claim 9, wherein in the detecting step, the primary encryption key is detected from a storage medium storing the primary encryption key. 11. The control method according to claim 9, wherein the generating step further generates the secondary encryption key using the scene description information. 12. A method of controlling a multimedia playback system including a transmitting device and an authentication device, wherein the controlling method of the transmitting device comprises: a first method of encrypting scene description information using a primary encryption key.
An encryption step; a generation step of generating a secondary encryption key using the primary encryption key; a second encryption step of encrypting a media stream using the secondary encryption key; A superimposing step of generating one bit stream by superimposing a bit stream indicating an encryption method in the encryption step of the above and a bit stream resulting from the first and second encryption steps; and A transmitting step of transmitting a bit stream to the authentication device according to the above, wherein the control method of the authentication device comprises: Using the primary encryption key detected in the detection step, based on a decryption method included in the received bit stream, and receiving the received bit stream A first decryption step of decrypting the encrypted scene description information included in the first step, a generation step of generating a secondary encryption key using the primary encryption key, and the bit processing using the secondary key. Second decryption of the encrypted media stream contained in the stream
Based on the scene description information in the first decoding step,
A playback step of playing back a media stream in the second decryption step. 13. A program code for a first encryption step for encrypting scene description information using a primary encryption key, a program code for a generation step for generating a secondary encryption key using the primary encryption key, A program code of a second encryption step for encrypting a media stream using the secondary encryption key, a bit stream indicating an encryption method in the first encryption step, the first and the second A program code of a superimposition step of generating one bit stream by superimposing a bit stream resulting from the encryption step, and a program code of a transmission step of transmitting the bit stream obtained by the superimposition step to an external device. A storage medium characterized by the above-mentioned. 14. A program code for a receiving step for receiving a bit stream transmitted from an external device, a program code for a detecting step for detecting a primary encryption key, and a primary encryption key detected in the detecting step. And a program code for a first decryption step for decrypting encrypted scene description information included in the received bit stream based on a decryption method included in the received bit stream. A program code for generating a secondary encryption key using a secondary encryption key; and a second code for decrypting an encrypted media stream included in the bit stream using the secondary key.
Based on the program code of the decoding step of the above, and the scene description information by the first decoding step,
A program code for a reproduction step of reproducing the media stream in the second decryption step. 15. A storage medium that stores a program code that functions as a multimedia playback system including a transmission device and an authentication device, wherein the storage medium that stores the program code that functions as the transmission device is a primary medium. First to encrypt scene description information with an encryption key
A program code for generating a secondary encryption key using the primary encryption key, and a second encryption for encrypting a media stream using the secondary encryption key. One bit stream by superimposing a program code of a step, a bit stream indicating an encryption method in the first encryption step, and a bit stream resulting from the first and second encryption steps A program code of a transmission step of transmitting a bit stream from the superposition step to the authentication device, the storage medium storing a program code functioning as the authentication device, And a detection code for detecting a primary encryption key in a receiving step for receiving a bit stream transmitted from Using the program code of the step and the primary encryption key detected in the detecting step, based on the decryption method included in the received bit stream, an encrypted scene description included in the received bit stream A program code for a first decryption step for decrypting information; a program code for a generation step for generating a secondary encryption key using the primary encryption key; and a program code included in the bit stream using the secondary key. To decrypt the encrypted media stream to be encrypted
Based on the program code of the decoding step of the above, and the scene description information by the first decoding step,
A program code for a reproducing step of reproducing the media stream in the second decrypting step.