JP2000287191A - Broadcast storage device - Google Patents

Abstract

(57) [Problem] To provide a broadcast storage device with high security strength. SOLUTION: In a broadcast storage device for storing and reproducing a scrambled broadcast program, a separating unit 201 separates ECM from video / audio data of the broadcast program, and the ECM is ECM.
The video / video data is stored in the ECM storage device via the storage device I / F 205.
The audio data is stored in the video / audio storage device via the storage device I / F 202. The storage capacity required for a recording medium for storing ECM is reduced, and a memory having high tamper properties can be used for storing ECM, and security strength can be increased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a broadcast storage device for storing a scrambled broadcast program, descrambling and reproducing the program, and more particularly, to preventing a decrease in security of a scramble key or the like.

[0002]

2. Description of the Related Art Conventionally, when a pay program is broadcast, a broadcasting station scrambles a broadcast program composed of video and audio with a scramble key Ks and transmits the scramble key Ks to the ECM (Entitlement Control Messages). : Common information), and this common information ECM is stored in the work key Kw.
And send it. This work key Kw is E
MM (Entitlement Management Messages: individual information)
And the individual information EMM is encrypted with the individual key Km and transmitted to each receiving side in advance.

On the other hand, when receiving the encrypted individual information EMM, the receiving side receives the individual key Km
To extract the work key Kw from the EMM. In addition, the EMM includes tier information indicating a program having a viewing right, etc.
Hold with w.

When a scrambled broadcast program and the encrypted common information ECM are received, the ECM is decrypted with the work key Kw to extract the scramble key Ks from the ECM. When it is confirmed from the information that the user has the viewing right, the scrambled broadcast program is descrambled using the extracted Ks.

A broadcast storage device for storing and playing back a scrambled broadcast program conventionally stores a scrambled broadcast program together with an ECM, and plays back the EC at the time of playback.
M is decoded to extract Ks, and the Ks is used to descramble the broadcast program to be reproduced.

FIG. 7 shows the configuration of the broadcast storage device. The apparatus includes a separating unit 101 for separating a multiplexed signal, an EMM decoding unit 109 for decoding the separated EMM using the Km held in a Km managing unit 112, and extracting the EMM from the decoded EMM. An individual information management unit 110 that manages the individual information that has been decrypted, and an E that is separated using the decrypted Kw.
An ECM decoding unit 107 for decoding a CM; a viewing right determination unit 111 for comparing program information extracted from the ECM with individual information to determine a viewing right; and outputting a Ks decoded from the ECM when the user has the viewing right. Ks output control unit 108 that performs
A descrambling unit 104 for descrambling video and audio data using Ks output from the output control unit 108, and a display control unit 105 for controlling display of video and audio on the display unit 106
And a storage control unit 10 for controlling storage of video, audio and ECM.
2 and a storage device I /
F103.

The Km management unit 112, the EMM decoding unit 109,
Individual information management unit 110, ECM decoding unit 107, viewing right determination unit 11
The 1 and Ks output control unit 108 is configured in a security module composed of an IC card or the like.

In this apparatus, multiplexed and broadcast data is input to a demultiplexing unit 101, and the demultiplexing unit 101 demultiplexes the multiplexed data. The separated EMM is used as an EMM decoding unit.
Ks decrypted at 109 and extracted from EMM is ECM
The individual information set in the decoding unit 107 and extracted from the EMM is stored in the individual information management unit 110.

When a broadcast program is viewed in real time, the components (video, audio, E
CM) separated by the separating unit 101 and encrypted.
M is input to the ECM decoding unit 107, and the scrambled video / audio is input to the descramble unit 104. EC
M decoding section 107 decodes the ECM using Kw,
The Ks extracted from M is output to the Ks output control unit 108,
Also, it outputs the program tier information extracted from the ECM to the viewing right determining unit 111. The viewing right determination unit 111 compares the program tier information with the individual information, and outputs the viewing right determination result to the Ks output control unit 108. The Ks output control unit 108 determines whether or not the viewing right is Is output to the descramble section 104. The descrambling unit 104 descrambles the video and audio using the Ks, and the descrambled video and audio are displayed on the display unit 106 under the control of the display control unit 105.

When a broadcast program is stored, the components (video, audio, ECM) of the broadcast program are output from the separation unit 101 to the storage control unit 102 while being scrambled or encrypted, and are stored in the storage device. Through the I / F 103, the data is stored in a storage device using a magnetic tape or the like as a recording medium.

FIG. 8 shows TS stored in a storage device of a system (first storage system) for storing a broadcast program and an ECM.
(Transport Stream) indicates a stream of packets. This stream is the audio of one stored program.
Partial TS composed of (audio) and Video (video)
The ECM is recorded and generated in the upper null packet (there is a null packet between TS packets) at the timing when the ECM is broadcast.

When the broadcast program stored in the storage device is reproduced and viewed, the TS stream of FIG. 8 is read from the storage device via the storage device I / F 103,
To enter. The separating unit 101 separates the ECM into an ECM and a video / audio signal,
The audio signal is output to descramble section 104. The subsequent operation is the same as in the case of real-time viewing, and the ECM decoding unit 107 decodes the ECM using Kw, outputs Ks to the Ks output control unit 108, and sends the program tier information to the viewing right determination unit 111. Output. The viewing right determining unit 111 compares the program tier information with the individual information and determines the viewing right determination result as Ks
The Ks output control unit 108 outputs Ks to the descrambling unit 104 when the viewing right is recognized. The descrambling unit 104 descrambles the video and audio using the Ks, and the descrambled video and audio are displayed on the display unit 106 under the control of the display control unit 105.

Also, components of a broadcast program (video,
When storing and recording audio and ECM, a method of storing encrypted EMMs together (second storage method) has also been developed. In this method, as shown in FIG. 9, an EMM is recorded prior to accumulation of a broadcast program, and thereafter,
The EMM is recorded in the null packet on the partial TS stored at an arbitrary time granularity.

When playing back and viewing the stored broadcast program,
Broadcast program (video / audio signal), ECM and E from storage device
The EMM is extracted by the EMM decoding unit 109 of the security module using the Km held in the Km management unit 112, and the KMM extracted from the EMM is extracted.
w is set in the ECM decoding unit 107, and the individual information extracted from the EMM is stored in the individual information management unit 110. Subsequent operations are the same as those of the first storage method described above.

The broadcast program stored in the second storage mode can be reproduced and viewed only by the receiving device storing the EMM.

[0016]

However, in the first storage method and the second storage method, the ECM and the EMM are recorded on the recording medium of the storage device together with the broadcast program. When a magnetic tape or the like having a low (tamper) property (hard to open or break when opened) is used, there is a possibility that the security of the ECM or EMM may be violated, and the so-called security strength is reduced. is there.

However, in order to store data using an IC card or the like having high tamper properties, there is a problem that the amount of data is large because the video and audio data are the same, and the capacity of the IC card cannot keep up. .

An object of the present invention is to solve such a conventional problem and to provide a broadcast storage device having high security strength.

[0019]

Therefore, in the broadcast storage device of the present invention, the ECM and the video / audio data of the broadcast program are separated and stored in separate recording media.

In addition, when the ECM is stored, control information for synchronizing with the video / audio data is added.

Therefore, the ECM can be stored in a memory having a small storage capacity but a high tamper property, and the security strength can be increased.

Although the ECM does not have synchronization information with the broadcast program, the addition of the synchronization information when the ECM is stored enables descrambling of video / audio data during reproduction.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is directed to a broadcast storage apparatus for storing and playing back a scrambled broadcast program, in which the ECM and the video / audio data of the broadcast program are separated and separated. The storage capacity required for the ECM storage medium is reduced, and a memory with high tamper properties can be used for ECM storage.

According to a second aspect of the present invention, the ECM is added with control information for synchronizing with the video / audio data, and is accumulated. -Playback is performed in synchronization with audio data, and video and audio data can be descrambled.

According to a third aspect of the present invention, when an ECM is stored, the ECM corresponding to a specific scene is invalidated to restrict the reproduction and viewing of the scene.
Is invalidated, the scene to which the scramble key is supplied by the ECM cannot be reproduced and viewed.

According to a fourth aspect of the present invention, the ECM is invalidated on the basis of an instruction included in the broadcasted information. Becomes possible.

According to a fifth aspect of the present invention, when a parental level is added to information defining a scene in a received program index, an ECM corresponding to the relevant scene is provided.
Is invalidated, and the broadcast station can specify a scene for which reproduction / viewing is restricted in a broadcast program index. According to the invention described in claim 6, the ECM is compressed and stored at the time of storing the ECM. For example, when the ECM having the same Ks is repeatedly broadcast, the ECM having the updated Ks is provided.
By accumulating only the data, the use of the storage capacity is made more efficient.

According to a seventh aspect of the present invention, the ECM is stored in a memory having a high tamper property, and the ECM is stored using a memory having a high security performance such as a memory card or a memory stick. Is done.

According to the eighth aspect of the present invention, the ECM is stored in a built-in security module, and the ECM can be stored in an IC card built in or inserted into the receiving device. .

According to a ninth aspect of the present invention, the ECM is stored on the home server. The ECM is stored on the home server separately from video and audio.・ Read the voice and ECM and play them back on the receiving device.

According to a tenth aspect of the present invention, the sending rate of the ECM from the storage device is controlled to suppress fast-forward and rewind during playback / viewing. Things can be restricted.

According to the eleventh aspect of the present invention, the output of the ECM from the storage device is stopped when the CM is not viewed, so that skipping of the CM during reproduction can be restricted.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First Embodiment) As shown in FIG. 1, a broadcast storage device according to a first embodiment includes a separating unit 201 for separating a multiplexed signal and a separated video / audio data. A descrambling unit 206 for descrambling, a display control unit 207 for controlling display of video and audio on the display unit 208, a storage control unit 203 for controlling storage of video and audio data, and a storage device for video and audio data A storage device I / F 202 that interfaces with the ECM and an E that generates a synchronization code for the ECM
The CM module includes a CM synchronization control unit 204, an ECM storage device I / F 205 that interfaces with a storage device that stores ECM, and a Km management unit in the security module.
214, an EMM decoding unit 211, an individual information management unit 213, an ECM decoding unit 209, a viewing right determination unit 212, and a Ks output control unit 210.

In this apparatus, when viewing a broadcast program in real time, the same operation as that described with reference to FIG. 7 is performed.

When storing a broadcast program, the separating unit 201
The video and audio data separated by
And the ECM separated by the separation unit 201
Is input to the ECM synchronization control unit 204. The video / audio data input to the storage control unit 203 is output through the storage device I / F 202 and stored in the video / audio storage device.

The ECM synchronization control unit 204 receives the input ECM
A synchronization code for synchronizing the ECM with video / audio data is generated, and the ECM provided with the synchronization code is stored in the ECM storage device I.
/ F205. This ECM is the ECM storage device I
/ F205 is output to and stored in the ECM storage device that stores the ECM.

FIG. 2 shows the ECM recorded in the ECM storage device.
CM is shown.

When viewing the stored broadcast program, the video / audio output from the storage device is stored in the storage device I.
The signal is input to the separation unit 201 via the / F 202, and is separated into video and audio signals by the separation unit 201 and input to the descramble unit 206.

On the other hand, the EC output from the ECM storage device
M is input to the ECM synchronization control unit 204 via the ECM storage device I / F 205. The ECM synchronization control unit 204 cooperates with the display control unit 207 and outputs the ECM to the ECM decoding unit 209 based on the synchronization code in accordance with the video / audio output state.

The ECM decoding unit 209 decodes the ECM using Kw set by the EMM decoding unit 211, outputs Ks extracted from the ECM to the Ks output control unit 210, and outputs the program extracted from the ECM. The tier information is output to viewing right determination section 212. The viewing right determining unit 212 compares the individual information managed by the individual information managing unit 213 with the program tier information, outputs a viewing right determination result to the Ks output control unit 210, and outputs the Ks output control unit 210. Outputs Ks to the descrambling unit 206 when the viewing right is recognized.
The descrambling unit 206 descrambles the video and audio using the Ks, and the descrambled video and audio are displayed on the display 208 under the control of the display control unit 207.

FIG. 3 shows the relationship among the receiving device 41, the video / audio storage device 43, and the ECM storage device 43 for storing the ECM. When receiving a broadcast and storing a broadcast program, the receiving device 41 including the security module 42 outputs video and audio to the storage device 43 and converts the ECM into an EC.
Output to the M storage device 43. The storage device 43 for video and audio includes, for example, a normal VT using a magnetic tape as a recording medium.
A storage device having high tamper properties using a memory card or a memory stick as a recording medium is used as the ECM storage device 43 using R.

As shown in FIG. 4, video and audio are stored in a video and audio storage device 43, and the ECM is stored in a receiving device.
The information may be recorded in a security module 42 provided in 41.

As shown in FIG. 5, the home server 44
Is installed so that the video / audio and ECM of the broadcast program are separately stored in the home server 44, and the video / audio and ECM are transmitted from the home server 44 to the receiving device 41 during playback and viewing. Is also good.

As described above, in this broadcast storage device, since the video and audio of the broadcast program and the ECM are stored separately,
The storage device of the CM may have a small storage capacity.
Therefore, it is possible to use a storage device having a high tamper property as the ECM storage device, thereby increasing the security strength.

In this broadcast storage device, in order to reproduce and view video and audio, the separately stored video and audio data and the ECM must be synchronized and reproduced, and this is utilized. ECM from the ECM storage device
, It is possible to suppress the fast-forward and rewind. By suppressing the fast-forward and rewind, C
It is possible to reject partial viewing for skipping M and reproducing.

Further, by stopping the output of the ECM from the ECM storage device when the CM is not viewed, the skipping of the CM can be avoided.

At present, Ks is updated at an interval of one second, but the ECM for updating Ks is broadcast at an interval shorter than that. Therefore, an ECM having the same Ks is repeatedly broadcasted. When storing the ECM, the ECM is compressed and stored by a method such as storing only the ECM having the updated new Ks. By doing so, the amount of accumulation can be reduced.

(Second Embodiment) In the broadcast storage device according to the second embodiment, a specific scene can be made invisible during reproduction by invalidating the ECM for a certain period of time.

As shown in FIG. 6, the apparatus includes a program index storage management unit 317 for storing and managing broadcasted program indexes, and an ECM invalidation control unit 316 for invalidating the ECM in a period designated by the program index. And Other configurations are the same as those of the first embodiment (FIG. 1).

In this broadcast storage device, separation section 301 separates video / audio data from a broadcast reception signal and outputs the separated data to descrambling section 306 and storage control section 303, and separates ECM to ECM decoding section 309. The program index is output to the ECM invalidation control unit 316 and the program index is separated and output to the program index accumulation management unit 317. The program index includes information that defines a scene, and the program index accumulation management unit 317 accumulates the program index, and when the viewing restriction information for the scene is added to the program index, the program index accumulation management unit 317 specifies the scene index. EC to invalidate ECM of scene
It instructs the M invalidation control unit 316.

In response to this, the ECM invalidation control unit 316 invalidates the input ECM and sets the ECM synchronization control unit 304
Output to

The ECM synchronization control unit 304 receives the input ECM
To the ECM storage device I / F 305, and outputs the ECM to the ECM storage device I / F 305.
It is output to the M storage device and stored. Thus ECM
The storage device has an EC in a state where a specific ECM is invalidated.
M is accumulated.

When viewing the stored broadcast program, the video / audio data output from the storage device is stored in the storage device I.
/ F 302 and the separating unit 301, the descrambling unit 306
To enter.

Also, the EC output from the ECM storage device is
M is input to the ECM synchronization control unit 304 via the ECM storage device I / F 305, and the ECM synchronization control unit 304 outputs the ECM to the ECM decoding unit 309 in synchronization with video and audio.

The ECM decoding unit 309 uses the Kw to calculate the ECM
, And outputs the Ks extracted from the ECM to the Ks output control unit 310, and outputs the program tier information extracted from the ECM to the viewing right determination unit 312. Viewing rights judgment unit 312
Determines the viewing right based on this, outputs the determination result to the Ks output control unit 310, and when the viewing right is recognized, the Ks output control unit 310 outputs Ks to the descrambling unit 306,
The descrambling unit 306 descrambles the video and audio using the Ks. The descrambled video and audio are displayed on the display 308 under the control of the display control unit 307.

However, when the ECM is invalidated, the video / audio to be descrambled by Ks included in the ECM is not descrambled, and the scene cannot be viewed.

As described above, in the broadcast storage device of this embodiment, the broadcast side invalidates the ECM of the corresponding scene by adding the viewing restriction information to the information of the program index defining the scene, and reproduces the broadcast program. Viewing can be partially restricted. Here, the case where the broadcasting side specifies the disabling of the ECM has been described. However, the present invention is not limited to this. For example, a viewer who is recording a program for a child may receive an EC of a scene that is considered inappropriate for the child.
Manually disable M
It is also possible to specify the invalidation of M.

[0059]

As is clear from the above description, the broadcast storage device of the present invention can maintain the security of ECM and EMM, and can maintain high security strength.

In viewing the stored program, the CM
Skipping can be restricted.

Further, by disabling the ECM, it is possible to easily restrict reproduction and viewing of a specific scene.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a broadcast storage device according to a first embodiment of the present invention;

FIG. 2 is a diagram showing an ECM recording format in the ECM storage device according to the first embodiment;

FIG. 3 is a diagram showing a video / audio storage device and an ECM storage device in the broadcast storage device of the first embodiment;

FIG. 4 is a diagram showing an example of a broadcast storage device according to the first embodiment;
Configuration diagram when M is stored in a security module,

FIG. 5 is a diagram showing a form in which ECM is stored using a home server in the broadcast storage device of the first embodiment;

FIG. 6 is a block diagram illustrating a configuration of a broadcast storage device according to a second embodiment of the present invention;

FIG. 7 is a block diagram showing a configuration of a conventional broadcast storage device;

FIG. 8 is a diagram showing a TS stream stored in a conventional broadcast storage device of a first storage method;

FIG. 9 is a diagram showing a TS stream stored in a conventional broadcast storage device of the second storage system.

[Explanation of symbols]

 101, 201, 301 Separation units 102, 203, 303 Storage control units 103, 202, 302 Storage device I / Fs 104, 206, 306 Descramble units 105, 207, 307 Display control units 106, 208, 308 Display units 107, 209, 309 ECM decoding unit 108, 210, 310 Ks output control unit 109, 211, 311 EMM decoding unit 110, 213, 313 Individual information management unit 111, 212, 312 Viewing right determination unit 112, 214, 314 Km management unit 204 , 304 ECM synchronization control unit 205, 305 ECM storage device I / F 316 ECM invalidation control unit 317 Program index storage management unit

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Mitsuru Kataoka 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. F-term (reference) 5C053 FA20 FA22 FA23 FA27 GB06 GB10 GB11 GB40 HA40 JA21 JA30 5C064 CA14 CA16 CB01 CB08 5D110 DA04 DA11 DB05 DE04 DE06 5J104 AA16 AA44 AA46 EA04 JA03 NA02 NA27 NA42 PA05

Claims (11)

[Claims] 1. A broadcast storage device for storing and reproducing a scrambled broadcast program, wherein the ECM and the video / audio data of the broadcast program are separated and stored in separate recording media. . 2. The broadcast storage device according to claim 1, wherein the ECM is added with control information for synchronizing with the video / audio data and stored. 3. The broadcast storage device according to claim 1, wherein at the time of storing the ECM, an ECM corresponding to a specific scene is invalidated to restrict reproduction and viewing of the scene. 4. The method according to claim 3, wherein the ECM is invalidated based on an instruction included in the broadcast information.
A broadcast storage device according to claim 1. 5. The method according to claim 4, wherein when a parental level is added to the information defining the scene in the received program index, the ECM corresponding to the relevant scene is invalidated. Broadcast storage device. 6. The broadcast storage device according to claim 1, wherein when storing the ECM, the ECM is compressed and stored. 7. The broadcast storage device according to claim 1, wherein the ECM is stored in a memory having a high tamper property. 8. The broadcast storage device according to claim 1, wherein the ECM is stored on a built-in security module. 9. The broadcast storage device according to claim 1, wherein the ECM is stored on a home server. 10. The broadcast storage device according to claim 1, wherein a transmission rate of the ECM from the storage device is controlled to suppress fast-forward or rewind during reproduction / viewing. 11. An output from the storage device of the ECM,
The broadcast storage device according to claim 1, wherein the broadcast storage device stops when the CM is not viewed.