JP2000252977A - Method for scrambling and descrambling contents data, encoder, recording medium and user terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a scramble code from being recognized in the absence of audio data in a distribution system of contents data including the audio data. SOLUTION: In the presence of audio data, single scrambling is applied in response to a player ID and an output signal of an EX-OR circuit 2 is selected in an encoder 43A and in the absence of the audio data, double scrambling is applied and an output signal of an EX-OR circuit 2a is selected. Furthermore, a reproduction means in a user terminal applies descramble processing in response to the scrambling.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a content data scrambling and descrambling method, an encoding device, a recording medium, and a user terminal in a content data distribution system including audio data.

[0002]

2. Description of the Related Art Conventionally, a system for distributing music data and the like using a communication line (Japanese Patent Laid-Open No.
146820) and a system for distributing using a communication satellite (Japanese Patent Laid-Open Nos. 7-143081, 10-16399).
1) has been proposed.

[0003] The applicant of the present application has
A more specific proposal was made in Japanese Patent Application No. 10-288487, filed on 009. The main inventions in this proposal are:
"A user mobile terminal that transmits a mobile terminal ID and electronic money to a store-installed terminal and receives paid content data; a mobile terminal that receives the mobile terminal ID and the electronic money from the mobile terminal; And a store installation terminal that also transmits the installation terminal ID to the charging center, the content ID, and the mobile terminal I.
D, a billing center for receiving the installation terminal ID and the electronic money from the shop installation terminal,
D, receiving the mobile terminal ID and the installation terminal ID,
A content center that distributes the pay content data to the mobile terminal via the store-installed terminal, and a distribution system.

[0004] By the way, distribution in such a system is charged, and content data to be charged is scrambled by a predetermined method due to copyright management problems. As an example of the scrambling method, a DVD (digital video disc, digital
Versatile disk). In this method, video data is scrambled by a method called CSS (content scrambling system). In the CSS system, the original data is scrambled by exclusive-ORing the original data with a PN code as a scrambling code at the time of scrambling. Is exclusive-ORed and descrambled. As another example of the scrambling method, there is a scramble method in which a value obtained by a chaos function is added to original data at the time of scrambling, and a descrambling is performed by subtracting a chaos function value from the scrambled data at the time of descrambling.

[0005]

However, in the case of distributing content data including audio data, in particular, the audio signal has a silent section, and the audio data bits in the silent section become all zeros. For example, if this audio data is scrambled by taking an exclusive OR with the PN code, and if the exclusive OR of the scrambled data and the PN code is taken, the PN code is left as it is. There is a problem that the PN code is output and therefore the PN code is known.

In view of the above problems, the present invention takes an exclusive OR of audio data and a scramble code when scrambling in a system for distributing at least content data including audio data. Audio data scrambling and descrambling methods that can prevent the scrambling code and chaos function used when being known,
An object of the present invention is to provide a scrambling device, a recording medium, and a descrambling device.

[0007]

The present invention comprises the following means 1) to 4) in order to achieve the above object. That is,

[0008] 1) At least a content center that distributes content data including at least audio data, a management center that manages charging and the like when distributing the content data, and a user terminal that requests distribution of the content data In a content data distribution system for performing data distribution by connecting them by communication means, detecting at least a silent section of the audio data, and scrambling the audio data in a predetermined manner in a section other than the silent section, Performing multiplex scrambling based on the predetermined method in the silent section, transmitting the scrambled audio data and multiplex scrambled data to a user terminal that has requested the multiplex scrambling, and detecting a section that is not the silent section. You And scrambled content data in the user terminal, wherein the audio data is descrambled in a predetermined manner in the non-silent section and the multiplexed scrambled data is descrambled in the silent section. , How to descramble.

2) At least a content center that distributes content data including at least audio data, a management center that manages charging and the like when distributing the content data, and a user terminal that requests distribution of the content data An encoding apparatus used in a content data distribution system for performing data distribution by connecting them by a communication means, comprising: means for detecting at least a silent section of audio data; and encoding the audio data in accordance with a predetermined scramble key. A scrambler that scrambles in a predetermined manner and performs multiplex scrambling in the silent section based on the predetermined method; and a data structure including the scrambled audio data, multiplexed scrambled data, and the scramble key. And means for formatting to,
Content data encoding device.

3) At least a content center that distributes content data including at least audio data, a management center that manages charging and the like when distributing the content data, and a user terminal that requests distribution of the content data A recording medium used in a content data distribution system for distributing data by connecting them by a communication means, wherein at least a silent section of audio data is detected and a section other than the silent section is determined according to a predetermined scramble key. In the predetermined method, the audio data is scrambled, and in the silent section, multiplex scrambling is performed based on the scramble code, and the scrambled audio data, multiplex scrambled data, and the scramble key are used. Have de Recording medium content data data structure is recorded.

[0011] 4) At least a content center that distributes content data including at least audio data, a management center that manages billing and the like when distributing the content data, and a user terminal that requests distribution of the content data. It is used in a content data distribution system that performs data distribution by connecting these with communication means, detects at least a silent section of audio data, and uses a predetermined method in a section other than the silent section according to a predetermined scramble key. A data structure including scrambling the audio data, multiplexing and scrambling the audio data in the silence period in the predetermined manner, and including the scrambled audio data, the multiplexed scrambled data, and the scramble key. The death A user terminal for de-formatting as well as rumble, at the user terminal,
Means for descrambling the audio data in a predetermined manner in a section other than the silent section, and means for descrambling the multiplexed scrambled data in the predetermined manner in the silent section.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1A and 1B are general concept block diagrams of a system for distributing content data including at least audio data to which the present invention is applied. The system includes a user portable terminal (transmission side) 40,
Store installation terminal 41, charging center (management center) 4
2. It comprises a content center 43, a communication line 44, a communication satellite 45, and a user portable terminal (reception side) 46.

Each of the portable terminals 40 and 46 has a unique identification code (hereinafter, referred to as a player ID). Each content also has a unique identification code (hereinafter, referred to as a content ID). The mobile terminal 40 requests the store setting terminal 41 to transmit the content data. At that time, the mobile terminal 40 has the content ID
And the player ID.

Each store-installed terminal 41 also has a unique identification code (hereinafter, referred to as a company ID). The installation terminal 41 requested to transmit the content data notifies the accounting center 42 and the content center 43 that the transmission of the content data has been requested from the mobile terminal 40.

The billing center 42 is notified of the content ID, the player ID, and the company ID. The billing center 42 sends a request to send a content data fee corresponding to the content ID to the mobile terminal 40 via the communication line 44 and the installation terminal 41 with reference to a fee table created in advance.

The portable terminal 40 requested to send the content data fee sends the electronic money to the charging center 42 via the installation terminal 41 and the communication line 44 as the content fee. As electronic money, an IC that stores a monetary amount on an IC chip and makes payment through an IC card reader
Card type electronic money (for example, Mondex, VISA
A cash) or an electronic wallet (for example, an NTT flexible electronic ticket) can be used.

When the billing center 42 receives the predetermined electronic money, it notifies the content center 43 of the receipt. Upon receiving the electronic money receipt notification from the charging center 42, the content center 43 sends the content data to the portable terminal 40 via the communication satellite 45 and the installation terminal 41.

After the portable terminal 40 receives the content data via the installation terminal 41, the portable terminal 40 can be detached from the installation terminal 41 and freely carried, and the received content data (for example, music data ) Can be played and enjoyed.

As shown in FIG. 1B, after receiving the content data, the portable terminal (transmitting side) 40 can be detached from the installation terminal 41, can be carried freely, and stored in the portable terminal (transmitting side) 40. The content data can be copied (transferred) to the portable terminal (reception side) 46. The installation terminal 41 does not participate in such copying. In other words, where there is no installation terminal 41, the mobile terminal (transmission side) 40
Content data can be copied between the portable terminal (receiving side) 46 and the portable terminal (receiving side) 46. A fee is also charged for copying the content data between the portable terminals, and electronic money corresponding to the content data fee is sent from the portable terminal (receiving side) 46 to the portable terminal (transmitting side) 40. When the content data is copied between the portable terminals, the portable terminal ID of the portable terminal (receiving side) 46 and the content ID of the copied content data are stored in the portable terminal (transmitting side) 40 as a transfer history. You. This transfer history is stored in the store installation terminal 4 together with the electronic money when the portable terminal (transmission side) 40 is connected to the store installation terminal 41 at a later date.
1 and transferred to the charging center 42. As a result, information as to which portable terminal has acquired which content and electronic money are collected at the charging center 42.

The portable terminal (transmitting side) 40 and the portable terminal (receiving side) 46 are distinguished as a “transmitting side” and a “receiving side” for the sake of convenience, but both have both transmitting and receiving functions. The same thing. The term “sending side” means that the data is transferred between the portable terminals, and the term “transmitting side” is used. The term “receiving side” is used when the data is transferred between the portable terminals. ”.

FIG. 2 is a block diagram showing the configuration of the transmitting-side encoding device. The encoding device 43A is installed in the content center 43 (FIG. 1) and is used to encode transmission data into a predetermined format.

In FIG. 2, for example, the input stereo two-channel L and R audio signals are converted into M-bit digital data for each channel by an A / D converter 1, and then the M-bit data of each channel is converted into parallel data. Is applied to one input terminal of one of the M EX-OR circuits 2. The PN code generator 3 generates a PN code of M bits in one word by the scramble key determined by the scramble key determination unit 9 in accordance with the player ID, and the other input terminals of the EX-OR circuits 2 and 2a in parallel. Therefore, the audio data is exclusive-ORed with the PN code and scrambled. The scrambled audio data is applied to one input terminal a of the switch 4. The switch 4 is switched by the scramble change flag Fsc, and the data selected by the switch 4 is applied to the DVD audio formatting circuit 8. Also, the player ID
And the scramble key data encrypted by the encryption unit 10 using this player ID are also applied to the DVD audio formatting circuit 8.

Further, the audio signals of the two channels L and R converted by the A / D converter 1 are applied to silence section detectors 6L and 6R, respectively, and based on the reference data shown in detail in FIG. A section close to silence is detected. As shown in FIG. 3, the reference data includes N consecutive M bits of “+0” or “−”.
A code for determining whether or not the number is "0". N is, for example, the number of words of a scramble serial code = 6.
Half of four. The detection signal is ORed by the OR gate 7 to detect a silent section or a section close to silent section of one of the channels, and is applied to the control terminal of the switch 4 as a scramble change flag Fsc. The switch 4 selects the output signal of the EX-OR circuit 2 in a section with sound, and the output signal of the EX-OR circuit 2a in a section with no sound or a section close to no sound, and performs double scrambling. The selected output signal is selected.

DVD audio formatting circuit 8
Is a compressed P that records the scrambled audio data on a DVD audio disc as shown in FIG.
Format into a CM audio pack (A-pack). The A-pack of the compressed PCM is composed of 2048 bytes or less, and the breakdown is composed of a 14-byte pack header and an A packet. The A packet is composed of a packet header of 17, 9, or 14 bytes, a private header, and 1 to 2011 bytes of audio data (scrambled or unscrambled compressed PCM data).

The private header includes: an 8-bit substream ID; a 4-bit reserved area in the ISRC; a 4-bit ISRC number in the ISRC; an 8-bit ISRC data in the ISRC; It is composed of an 8-bit private header length, 16-bit first access unit pointer, 6-byte audio data information (ADI), and 0 to 7 stuffing bytes.

The ADI is: an 8-bit forward access unit search pointer (an address one second ahead can be read during compression)
An 8-bit backward access unit search pointer (used to read the address one second later); an audio sampling frequency fs1 of a 4-bit group "1"; and a 4-bit group "2". Audio sampling frequency fs2, 4 bit reserved area, 4 bit multi-channel type, 3 bit reserved area, 5 bit channel allocation information, 8 bit dynamic range control It consists of information. When text data accompanying the audio data is recorded together, the text data is formatted into a text data pack (not shown) by the DVD audio formatting circuit 8 without being scrambled. The compression PCM recorded on the DVD audio disk employs a lossless compression method. However, the compression method may be a lossy compression method employed in MPEG, or may be another compression method, and is not limited thereto. Absent.

Next, the processing of the DVD audio formatting circuit 8 will be described with reference to FIG. First, each time data is input, it is determined whether or not it is the audio pack start time (step S1). If it is the start time, the data counter DC is set to start counting (step S1).
2) Then, the management data of the scramble method change flag Fsc is reset (Step S3), and then Step S3
Proceed to 4. On the other hand, if it is not the start time in step S1, the process proceeds to step S4, and the scramble method change flag Fsc is determined.

In step S4, if "the scramble method has been changed", it is determined whether or not the count value of the data counter DC is N or more (step S5). Sets the management data of the scramble method change flag Fsc (step S6), and then proceeds to step S7. Here, as an example, if the audio data in one channel is 2800, M = 24 bits, and one pack is 1800 bytes, the count value of the data counter DC is 300 at the maximum, but N =
32. On the other hand, if it is determined in step S4 that "there is no change in the scramble method" and if the count value of the data counter DC is not equal to or more than N in step S5, the process proceeds to step S7. In step S7, it is determined whether or not the audio pack has ended. If not, the process returns to step S1. On the other hand, if the audio pack has ended, this process ends. Then, the scramble method change flag Fsc is set to ADI based on the management data of the scramble method change flag Fsc. The data formatted by the DVD audio formatting circuit 8 in this way is supplied to an output terminal and transmitted by a satellite broadcast transmitter (not shown) or the Internet. In data distribution, output data is further subjected to a specific encryption (distribution encryption).

FIG. 6 shows a data structure at the time of transmission. As shown in FIG. 3A, the data is composed of a common header area and each content area. The common header area includes a player ID area, a distribution encryption key area, a content set number area, a use area information area, a transfer prepaid area, and a transfer history area.

The player ID area is an area for storing a player ID used as a public key in the encryption processing. The player ID is first sent from the data transfer destination to the data transfer source. That is, the mobile terminal 40
Receives data from the installation terminal 41, the player ID of the mobile terminal 40 is
Sent to When the portable terminal 46 receives data from the portable terminal 40, the player ID of the portable terminal 46
Is sent from the portable terminal 46 to the portable terminal 40.

The distribution encryption key area is an area for storing an encryption key used as a secret key in the distribution encryption processing. In the content number area, the total number of contents stored in the content area is stored.
The use area information area in this area stores an area name obtained by dividing the whole country into a plurality. In the case of Japan, it is Kanto, Kansai, Kyushu, Hokkaido, etc.In the case of the world,
Use the country name. The transfer prepaid area stores content sales information (value).

The transfer history area contains a content ID.
(Hereinafter, referred to as CID) area, a transfer count area, and a transfer date and time area. The number of transfers refers to the number of times data has been transferred from the portable terminal 40 on the transmitting side to the portable terminal 46 on the receiving side, and the transfer date and time refers to the date and time at which the transfer was performed.

FIG. 6B shows a detailed data structure of each content area. As shown in the figure, the content area includes a content header area and a content data area following the content header area. The content header area includes a content ID area, a company ID area, a title information area, a player ID area, a transfer level flag area, and an additional information area.

The company ID area stores a company ID, which is an identification code assigned to each installation terminal that receives distribution data. The title information area stores title information, which is a copyright identification code (ISRC) of the song title. The transfer level flag area stores a transfer level flag which is a type of transfer rate. The additional information area includes TOC (Total Of Content).
Additional information such as s) is stored. The TOC is a table of contents in which address information for so-called song heading and performance time are recorded. The TOC may be stored in the common header or in both the common header and the content header.

In the content data area, a physical information part according to the DVD audio standard, audio management information (AMG), a scrambled A pack of the compressed PCM shown in FIG. A content set including an audio title in which the text data having the data structure of is combined is stored.

Next, the reproducing means 40A and 46A in the user terminal device will be described with reference to FIG. The input data stream reproduced from the storage unit 23 in the device is:
The data is decrypted by the data changing unit 24 and is deformatted by the DVD audio formatting circuit 11.
Scrambled audio data and player I
D and the scrambling method change flag Fsc. Further, the encryption key data is read from the physical information section and decrypted by the decryption section 11a of the encryption key data using the player ID read from the player ID 22. Therefore, if the terminal is not a legitimate user terminal, the encryption key data cannot be decrypted and the scramble cannot be decrypted. The scramble method change flag Fsc is EX-O
The signal is applied to the enable terminal ENB of the R circuit 13, the clear terminal CLR of the PN code generator 12, and the control terminal of the switch 15. The PN code generator 12 generates a P based on the key data.
The N-code is generated, and the scrambled audio data is exclusive-ORed with the PN code by the EX-OR circuit 13 and descrambled. The descrambled audio data is applied to one input terminal a of the switch 15.

A descrambled signal of data that has been double scrambled in a silent section or a section near a silent section is applied to the input terminal b. Audio data L,
R is applied to the silent section detectors 14L and 14R, and a silent section or a section close to silent is detected based on the reference data 10 shown in FIG. This detection signal is logically ORed by the OR gate 14A to detect a silent section or a section close to silent on either channel, and outputs it as a scramble change flag Fsc. Then, based on the detected scramble change flag Fsc, the switch 15 selects the output signal of the EX-OR circuit 13 in a section having a sound, and on the other hand, in a section having no sound or a section close to no sound, a signal E is output.
The output signal of the X-OR circuit 13a is selected and is converted by the D / A converter 16 into an analog audio signal. Also,
Although not shown, the text data pack is DVD
It is separated by the audio deformatting circuit 11 and output as character information via the text data generator 17.

Electronic money corresponding to the content fee of the received content data is paid from the electronic wallet 19. If the TOC is recorded in the TOC memory 18, a high-speed content search stored in the storage unit 23 can be performed. When the user designates the first content set, the second content set,..., The Nth content set from the operation hand unit 21, the TOC refers to the corresponding location of the TOC via the system control unit 20. , The address, the reproduction time, and the like, to start the access and to display the reproduction time. Since there is no need to scan the header of the content, there is no so-called waiting time, and access is easy, so that it can be effectively used for high-speed scanning (intro scan). When the terminal shown in FIG. 7 is used for transfer (transmission), the content stored in the storage unit 23 is decrypted by the data change unit 24 and transmitted from the data transfer interface 25. When the terminal in FIG. 7 receives a content from another terminal, the content is encrypted by the data changing unit 24 before being stored in the storage unit 23.

In the above embodiment, the scrambling system based on the CSS system has been described. However, another scrambling system such as a chaos function system may be used. Further, in the above embodiment, the data structure has been described using DVD audio. However, this is an example of the data structure, for example, a data broadcasting transmission protocol (the MHEG standard is used as a representative) used for multimedia services. However, the present invention is not limited to this. In the above embodiment, double scrambling is performed in a silent section or a section close to silent. However, multiple scrambling may be applied more than that.

[0040]

As described above, according to the present invention, even when pay content data including at least audio data is transmitted, at least a silent section is detected, and audio data is multiplex-scrambled in a silent section. Since the scrambling code is used, it is possible to prevent the scrambling code from being known when the exclusive OR of the audio data and the scrambling code is obtained, and to prevent the chaos function from being used when the chaotic function is used.

[Brief description of the drawings]

FIG. 1 is a block diagram conceptually showing an entire system for performing transmission and reception to which the present invention is applied.

FIG. 2 is a block diagram showing an embodiment of a transmitting-side encoding device according to the present invention.

FIG. 3 is an explanatory diagram showing reference data of FIG. 2 in detail;

FIG. 4 is an explanatory diagram showing a format of an audio pack of a DVD audio disc.

FIG. 5 is a flowchart showing processing of a DVD audio formatting circuit in the encoding device.

FIG. 6 is a diagram showing a data structure at the time of transmission.

FIG. 7 is a block diagram showing an embodiment of a reproducing unit in the user terminal according to the present invention.

[Explanation of symbols]

2, 2a EX-OR circuit (along with the PN code generator 3,
A scramble means based on exclusive OR is constructed. 3, 12 PN code generator 5, 14 Inverter (other scrambling means) 6L, 6R Silent section detector (constitutes silent section detecting means together with OR gate 7) 7 OR gate 8 DVD audio formatting circuit ( Formatting means) 13, 13a EX-OR circuit (constitutes a descrambling means by exclusive OR together with PN code generator 12.) 19 Electronic wallet 40, 46 User portable terminal 40A, 46A Reproducing means 41 Store establishment Terminal 43 Content center 43A Encoding device 45 Communication satellite

 ────────────────────────────────────────────────── ─── Continued on the front page F term (reference) 5C064 CA14 CA16 CB01 CC04 5D044 AB05 AB07 BC03 CC04 GK12 GK17 GL01 GL02 GL18 HH15 5J104 AA35 AA43 BA03 FA08 JA04 PA04 PA05

Claims (4)

[Claims] At least a content center that distributes content data including at least audio data, a management center that manages billing and the like when distributing the content data, and a user terminal that requests distribution of the content data are provided. In a content data distribution system for performing data distribution by connecting them by a communication means, detecting at least a silent section of the audio data, and scrambling the audio data in a predetermined method in a section other than the silent section, Performing a multiplex scramble based on the predetermined method in the silent section; transmitting the scrambled audio data and the multiplex scrambled data to a user terminal that has requested the multiplex scrambling; detecting a section that is not the silent section Do And, at the user terminal, descrambling the audio data in a predetermined manner in a section other than the silent section, and descrambling the multiplexed scrambled data in the silent section. , How to descramble. 2. A content center for distributing content data including at least audio data, a management center for managing charging and the like when distributing the content data, and a user terminal for requesting the distribution of the content data. An encoding device used in a content data distribution system for performing data distribution by connecting them by a communication means, comprising: means for detecting at least a silent section of audio data; and encoding the audio data in accordance with a predetermined scramble key. A scrambler that scrambles in a predetermined manner and performs multiplex scrambling in the silent section based on the predetermined method; and a data structure including the scrambled audio data, multiplexed scrambled data, and the scramble key. And means for formatting, encoding device of content data having. 3. A content center for distributing content data including at least audio data, a management center for managing charging and the like when distributing the content data, and a user terminal for requesting distribution of the content data. A recording medium for use in a content data distribution system for distributing data by connecting them by a communication means, wherein at least a silent section of audio data is detected, and a section other than the silent section is determined according to a predetermined scramble key. In the predetermined method, the audio data is scrambled, and in the silent section, multiplex scrambling is performed based on the scramble code, and the scrambled audio data, multiplex scrambled data, and the scramble key are used. Data to have A recording medium for content data in which the structure is recorded. 4. A content center for distributing content data including at least audio data, a management center for managing charging and the like when distributing the content data, and a user terminal for requesting distribution of the content data. It is used in a content data distribution system that distributes data by connecting them by communication means, detects at least a silent section of audio data, and uses a predetermined method in a section other than the silent section according to a predetermined scramble key. A data structure including scrambling the audio data, multiplexing and scrambling the audio data in the silence period in the predetermined manner, and including the scrambled audio data, the multiplexed scrambled data, and the scramble key. The deskra A user terminal that descrambles and deformats the audio data, wherein the user terminal descrambles the audio data in a predetermined manner in a section other than the silent section, and converts the multiplexed scrambled data into the predetermined section in the silent section. Means to descramble in the method of
User terminal having.