JP2001333032A - Restricted reception system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a restricted reception system that realizes appropriate and efficient conditional access to a file to be broadcasted as an object. SOLUTION: A transmitting side 1 divides the data of a file to be transmitted into blocks of a fixed length, enciphers each block, includes information about an ECM for distributing an enciphering key in data configuration management information that regulates the relation between the file and the block and transmits the data configuration management information and the enciphered block in Carousel. A receiving side 2 acquires needed data from the information transmitted in Carousel on the basis of the received data configuration management information. Only a file can strictly be made an object for enciphering, and the receiving side can select only the needed data from the data transmitted in Carousel and store the data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conditional access system for charging a broadcasting service, and more particularly, to a system suitable for CA (conditional access) of a file transmitted by data broadcasting.

[0002]

2. Description of the Related Art A conventional standard conditional access system is set for a broadcasting service mainly for video and audio streams. In this method, a broadcasting station converts contents such as video and audio into a data format of a TS packet, scrambles the contents using a scramble key Ks, and transmits the scramble key Ks.
ent Control Messages: common information), the ECM is encrypted with the work key Kw, and transmitted. Further, the work key Kw is stored in advance in an EMM (Entitlement Manageme
nt Messages: individual information), encrypted with the individual key Km, and transmitted.

[0003] On the other hand, when receiving the encrypted EMM, the receiving side decrypts it with the previously held Km, extracts Kw from the EMM, and holds it. When receiving the video and audio of the scrambled program and the ECM including the scramble key Ks, the ECM is decrypted with Kw and the EC is decoded.
Ks is extracted from M, and the scrambled video / audio content is descrambled using the Ks.

FIG. 7 shows a simplified system for implementing a conventional conditional access system. The broadcasting station 1 includes a TS packetizing unit 11 for converting contents such as video and audio into TS packets, an ECM generating unit 13 for generating an ECM including Ks, and a scrambling process for scrambling and transmitting TS packets with Ks. Unit 12 and an ECM for sending the ECM
And a sending unit 14.

[0005] The receiving side is a receiver 2 for receiving a broadcast.
And an IC card (security module) 3 attached to the receiver 2. The receiver 2 includes a descramble processing unit 21 for descrambling scrambled contents such as video and audio. , ECM
And an ECM interpreting section 31 for interpreting and extracting Ks.

In this system, a TS packetizing unit 11 of the broadcasting station 1 converts contents such as video and audio into TS packets, and a scramble processing unit 12 converts a TS stream output from the TS packetizing unit 11 into a TS stream. ECM generation unit
Scramble with Ks obtained from 13. The scramble processing unit 12 manages the scramble for the stream by time, and changes Ks used for scramble every time a predetermined time elapses. The scrambled TS packet and ECM are multiplexed and transmitted from the broadcasting station 1.

[0007] The ECM received by the receiver 2 is sent to the ECM interpreting unit 31 of the IC card 3, and the ECM interpreting unit 31
It interprets the CM and outputs Ks. The descramble processing unit 21 of the receiver 2 sequentially obtains Ks used for scrambling from the IC card 3, and descrambles the content.

[0008]

However, in the conventional conditional access system, a broadcasting service for transmitting a file by data broadcasting (for example, downloading a music data file,
A broadcasting service that stores and plays this on the receiving side)
There are the following problems when applied to -In the conventional conditional access system, since the stream is assumed to be the subject of CA, only the time management can be performed for encryption.
The file cannot be identified and encrypted. For example, when a certain file is transmitted from the time “5 minutes 6 seconds 22” to the time “5 minutes 7 seconds 08”, in a system that performs time management in units of seconds, “5 minutes 6 seconds just” to “5 minutes 6 seconds 22”
Encryption is performed by designating up to “minutes 8 seconds”. Therefore, from "just 5 minutes 6 seconds" to "5 minutes 6 seconds 22"
In addition, the period from "5: 7: 08" to "5: 8: just" cannot be used effectively. -When transmitting a file or the like by data broadcasting, the same data is repeatedly transmitted by the carousel transmission method in order to surely transmit the data. On the receiving side, when data is missed, by taking in the missed data at the next transmission, all data can be aligned without omission. However, if all data transmitted by the carousel transmission method is stored as it is, the same data is stored in duplicate, which is very inefficient.

An object of the present invention is to solve such a conventional problem, and an object of the present invention is to provide a conditional access system which realizes appropriate and efficient conditional access for broadcasted files. .

[0010]

Therefore, according to the present invention, in a conditional access system for performing conditional access on a file to be broadcast, a transmitting side divides data of a file to be transmitted into fixed-length blocks. Then, each block is encrypted, and in the data configuration management information that defines the relationship between the file and the block, information on the ECM that distributes the encryption key is included. The carousel transmits the converted block and the carousel, and the receiving side acquires necessary data from information transmitted by the carousel based on the received data configuration management information.

[0011] Therefore, only the file can be strictly targeted for encryption, and the receiving side can select and store only necessary data from the data transmitted by the carousel.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a conditional access system according to an embodiment of the present invention, when a unit of accounting is a file, one ECM information for distributing an encryption key Ks is set for the file, and In the case of charging for content composed of a set of a plurality of files, one ECM information is set for the content. That is,
One ECM information is set for a charging unit.

In order to transmit data of a file by a carousel, the file data is divided into fixed-length blocks, encrypted for each block, and transmitted by the carousel. When a set of blocks obtained by dividing data of one file is referred to as a “content block”, when charging is performed on a file-by-file basis, all blocks included in the content block corresponding to the file in question are set to Ks set on a file-by-file basis. Will be encrypted. In the case of charging for each content, all blocks included in the content blocks of a plurality of files constituting the content are encrypted using the same Ks set for each content.

[0014] Further, with the transmission of the file data in the carousel, "data configuration management information" indicating the relationship between the file and the block is created for each content, and this is transmitted to the receiving side together with the content. In the data configuration management information, which file is composed of which block is defined as content management information, and detailed information on the files constituting the content such as the type of each file (text, graphic) is defined as file management information. I do. Only one piece of content management information is included in the data configuration management information of one piece of content. The file management information includes the number of files constituting the content in the data configuration management information of one content.
In addition, information for designating the ECM and the ECM itself are embedded in the data configuration management information and transmitted to the receiving side.

FIG. 1 shows a configuration of a conditional access system according to an embodiment. The broadcast station 1 includes a carousel processing unit 15 that creates content blocks and data configuration management information from data content, and an EC that generates an ECM in charge units.
An M generation unit 13 and a content encryption unit that encrypts content blocks and embeds ECM information in data configuration management information
16, a TS packetizing section 17 for TS-packaging data transmitted by the carousel in accordance with a broadcast standard, a TS packet sending section 18 for sending TS packets output from the TS packetizing section 17, and sending an ECM. An ECM sending unit 14 is provided.

An IC card 3 mounted on the receiver 2
Includes an ECM interpreting unit 31 that interprets the ECM and outputs Ks, and the receiver 2 includes a content decoding unit 22 that decodes the content using Ks acquired from the IC card 3.

The ECM generated by the ECM generator 13 is distributed to the receiving side in two ways. One is multiplexed with other data and transmitted as usual. In this case, the data configuration management information includes ECM instruction information for pointing the ECM to be used for decoding the block by the receiving side.

FIG. 2 specifically shows a part of a broadcast station when multiplexing and transmitting ECM. The broadcast station includes an ECM information embedding unit 41 for embedding the ECM pointing information output from the ECM generation unit 13 in the data configuration management information output from the carousel processing unit 15;
An encryption unit 42 for encrypting the content block with the encryption key Ks, a transmission unit 43 for transmitting the content block and the configuration management information, and multiplexing the output of the transmission unit 43 and the ECM output from the ECM transmission unit 14 And a multiplexing unit 44.

In this broadcasting station, the ECM information embedding section 41
Embeds the ECM pointing information output from the ECM generation unit 13 in the data configuration management information output from the carousel processing unit 15. Further, the encryption unit 42 encrypts the content block output from the carousel processing unit 15 with the encryption key Ks acquired from the ECM generation unit 13. The encrypted content block and the data configuration management information in which the ECM instruction information is embedded are transmitted through the transmission unit 43, and the multiplexing unit 44 determines whether the output of the transmission unit 43
The ECM multiplexed with the ECM output from the CM sending unit 14 is output.

In the second method of distributing the ECM, the ECM or data conforming to the ECM is embedded in the data configuration management information. FIG. 3 shows a specific configuration of a broadcast station that embeds an ECM in data configuration management information and transmits the data. In this broadcast station, an ECM generation unit is included in the data configuration management information output from the carousel processing unit 15. An ECM embedding unit 45 for embedding the ECM output from 13 is provided, and the multiplexing unit 44 multiplexes the content block output from the transmission unit 43 and the data configuration management information.

FIGS. 4 and 5 schematically show data configuration management information in which an ECM is embedded and encrypted content blocks. FIG. 4 and FIG. 5 show data configuration management information of content composed of two files and content blocks of each file.
FIG. 4 shows a case where the charge unit is content, and FIG. 5 shows a case where the charge unit is file unit.

In any case, the content management information of the data configuration management information describes the configuration information of the file corresponding to each file constituting the content, and the file management information of each file includes Detailed information of the file such as the type of each file is described.

In the case where the content is set as a charging unit (FIG. 4)
The ECM including the key 1 is embedded in the content management information, and the content block of each file constituting the content is encrypted by the key 1. When a file is used as a charging unit (FIG. 5), an ECM is embedded in file information of each file, and a content block of each file is encrypted with a key included in each ECM.

When ECM instruction information is embedded in the data configuration management information, ECM instruction information is embedded instead of the ECM information shown in FIGS.

As described above, billing by content and billing by file are possible. For example, when music content is composed of 15 music files, 1
When all five songs are collectively used as a sales unit, data configuration management information as shown in FIG. 4 is created. When one song is used as a sales unit, the data configuration management information as shown in FIG. 5 is used. Generated.

When ECM or ECM instruction information is embedded in both the content information and the file information, the file information is given priority.

The data thus encrypted and multiplexed are formed into TS packets by a TS packetizing unit 17 in accordance with a broadcasting standard, and transmitted from a TS packet transmitting unit 18.

With such a configuration, the broadcasting station can strictly encrypt only the file specified by the data configuration management information.

On the other hand, as shown in FIG.
Upon receiving the S packet, the carousel restoring unit 23 restores the carousel and extracts the data configuration management information and the encrypted content block. When the data configuration management information includes ECM instruction information, an ECM is acquired according to the ECM instruction information.

The receiver 2 can know from the data configuration management information which content block of the file that constitutes the content, and based on this, the data configuration management information, the content block, and E
CMs are stored in the storage unit 24 without duplication.

When the user selects (purchases) the content stored in the storage unit 24, the ECM (or the ECM) embedded in the data configuration management information of the content is used.
The ECM stored in the storage unit 24 is read out and the IC
The data is output to the ECM interpretation unit 31 of the card 3. The storage unit
The encrypted content block of the content stored in 24 is output to the content decryption unit 22.

The ECM interpreting section 31 decodes the ECM, and if necessary billing processing is established, outputs the extracted encryption key to the content decoding section 22. The content decoding section 22 uses this encryption key. Decrypt the content block.

As described above, this receiver can efficiently store the data of the content transmitted by the carousel without duplication.

The storage unit is a hard disk built in the receiver, a hard disk connected to the receiver, or the like. Further, the storage unit may be a removable medium such as a memory card that can be inserted into and removed from the receiver. A system for reproducing music by attaching a memory card storing content-encrypted data to a dedicated player can also be constructed.

Further, the receiver can quickly acquire only necessary data even when reproducing received data without storing it.

[0036]

As is apparent from the above description, in the conditional access system of the present invention, in conditional access for a file, only the file can be strictly targeted for encryption, and efficient access can be achieved. Encryption can be implemented.

On the receiving side, only necessary data can be selected and stored from the data transmitted by the carousel, and the efficiency of the storage can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a conditional access system according to an embodiment of the present invention;

FIG. 2 is a block diagram showing a configuration of a transmission side (when transmitting ECM instruction information) in the conditional access system of the embodiment;

FIG. 3 is a block diagram showing a configuration on the transmission side (when ECM information is embedded in data configuration management information) in the conditional access system according to the embodiment;

FIG. 4 is a diagram showing data configuration management information and content blocks in the conditional access system according to the embodiment (when charging is performed in units of content);

FIG. 5 is a diagram showing data configuration management information and content blocks in the conditional access system according to the embodiment (when charging is performed in file units);

FIG. 6 is a configuration diagram showing storage processing on the receiving side in the conditional access system of the embodiment;

FIG. 7 is a block diagram showing a configuration of a conventional conditional access system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Broadcasting station 2 Receiver 3 IC card 11 TS packetization processing part 12 Scramble processing part 13 ECM generation part 14 ECM transmission part 15 Carousel processing part 16 Content encryption part 17 TS packetization processing part 18 TS packet transmission part 21 Descramble Processing unit 22 Content decryption unit 31 ECM interpretation unit 41 ECM information embedding unit 42 Encryption unit 43 Transmission unit 44 Multiplexing unit 45 ECM embedding unit

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) H04N 7/167 H04N 7/167 Z (72) Inventor Hironori Murakami 1006 Kazuma, Kazuma, Kazuma, Osaka Matsushita Electric Industrial Co., Ltd. (72) Inventor Satoshi Niwano 1006 Kadoma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (72) Inventor Akio Higashi 1006 Odaka Kadoma, Kadoma City Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (72) Toru Nakahara Inventor Matsushita Electric Industrial Co., Ltd. (72) Inventor Yukiyasu Fukami 2-6-1, Sakae, Naka-ku, Nagoya-shi, Aichi Prefecture Shirokawa Building Annex Building 5th Floor Matsushita Electric Information System Nagoya Research Laboratory Co., Ltd. F-term (reference) 5C064 BA01 BB01 BC01 BC06 BC17 BC22 BD02 BD04 BD08 BD09 BD14 CA14 CB01 CB08 CC01 CC04 5J104 AA01 AA16 EA04 EA22 JA03 NA02 NA35 NA37 PA05 PA11 9A001 BB03 BB04 BB06 CC05 DZ15 EE03 HKK15 KK

Claims (13)

[Claims] In a conditional access system for performing conditional access on a file to be broadcast, a transmitting side divides data of a file to be transmitted into fixed-length blocks, and encrypts each block. An ECM (Entitl) that distributes the encryption key is included in the data configuration management information that defines the relationship between the file and the block.
ement Control Messages), the data configuration management information and the encrypted block are transmitted, and the receiving side determines the necessary information from the transmitted information based on the received data configuration management information. A conditional access system for acquiring data. 2. The conditional access system according to claim 1, wherein the encrypted block and the data configuration management information are transmitted by a carousel. 3. The conditional access system according to claim 1, wherein an ECM is embedded in the data configuration management information as the information on the ECM. 4. An ECM which points an ECM in the data configuration management information as the information on the ECM.
The conditional access system according to claim 1, wherein CM instruction information is embedded, and the ECM is multiplexed with the data configuration management information and the encrypted block and transmitted. 5. The method according to claim 1, wherein the data configuration management information includes file management information for each of a plurality of files constituting the content, and content management information for defining a relationship between each of the files and the block. The conditional access system according to claim 1, wherein: 6. When charging for content as a unit,
The conditional access system according to claim 5, wherein each block of the plurality of files constituting the content is encrypted with the same key. 7. The conditional access system according to claim 6, wherein information on the ECM is included in the content management information. 8. The conditional access system according to claim 5, wherein when charging for each file, each block of a plurality of files constituting the content is encrypted with a different key for each file. 9. The conditional access system according to claim 8, wherein the information on the ECM is included in each file management information of a plurality of files constituting the content. 10. The conditional access system according to claim 1, wherein the receiving side includes a storage unit, and stores the acquired data configuration management information and the encrypted block in the storage unit. 11. The data configuration management information according to claim 1, wherein
11. The conditional access system according to claim 10, wherein when CM instruction information is embedded, an ECM is acquired based on the ECM instruction information and stored in the storage unit. 12. The conditional access system according to claim 10, wherein said storage means is a hard disk. 13. The storage device according to claim 1, wherein said storage means is a removable medium that can be attached to and detached from a receiver.
0. The conditional access system according to 0.