JP2001077806A - Data management card - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure a copyright protection function of contents recorded in a medium and to secure security required for it by using a card provided with an interface. SOLUTION: A card 102 has different encryption algorithm sets (encryption sections α, β), the encryption section α203 decodes contents that are encrypted and transmitted, the encryption section β 206 is used at recording, the contents that are encrypted by using a random number for a key and an identification code using the random number are recorded in a medium, the card has the identification code by each title of the contents and the decoding key, the identification code is used at reproduction of contents, key information not open to public is decoded at an outside of the card so as to attain copyright management such as output of contents to other recorder without recording the copyright protection information like the decoding key to the medium.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data management card used in a system for managing information required for reproducing content recorded on a medium using the card.

[0002]

2. Description of the Related Art In a cable television broadcast or the like, a broadcast is transmitted to a user who has become a contractor in accordance with the contents of a contract concluded between a broadcasting station as an information transmitting side and a receiving side. Specifically, the sender encrypts the content such as video and audio to protect the copyright, and gives the user who has signed the receiving contract
A conditional access system that issues a C card and enables decryption only to a contractor has been introduced.

[0003] In this conditional access system, the I
The receiving device equipped with the C card decrypts and distributes the content that has been encrypted and distributed from the broadcast station side.

[0004]

However, in the above-mentioned conventional configuration, when recording the content transmitted from the transmitting side on a medium, it is possible to record the content to be recorded in an encrypted state and to decrypt it at the time of reproduction. Although it is conceivable, when the transmission encryption method is decrypted, it is possible to freely decrypt the content recorded in the medium by encrypting it, which has a problem from the viewpoint of copyright protection.

[0005] Even if a key for decrypting a content is encrypted and placed on a medium, any device capable of reproducing the medium, such as a disk system or a tape system, can easily acquire recorded data. There was a problem in terms of the risk of decryption.

[0006] From the viewpoint of copyright protection, the following (1) to (4) are required as requests from content manufacturers.

(1) When the content recorded on the medium is output to another device (media), the number of times is limited.

(2) A playback charge for collecting a fee every time content recorded on a medium is played back.

(3) When recording content on a medium, information for identifying the source of the content is stored in order to prevent unauthorized distribution of the content.

(4) When contents recorded on a medium are output to another apparatus (media), conditions for viewing the contents are restricted.

As a method of fulfilling the above-mentioned demand, it is conceivable to perform the recording by recording each control information together with the content on a medium. Although there is a method for performing such operations, it is conceivable that the program for the CPU that controls the apparatus is tampered with and illegally operated.

[0012] Therefore, the existence of a third party who performs copyright protection having a security function that is neither a medium nor a device is desired.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and uses a removable card having a built-in interface and capable of adding a security function to a device capable of recording or reproducing on a medium. An object is to provide the functions of the above (1) to (4) and the following (5) and (6).

(5) The communication algorithm via the interface and the encryption algorithm used for the contents of the media function differently.

(6) When the encrypted content is recorded on the medium, the content can be decrypted without recording the key for decrypting the content on the medium.

[0016]

In order to achieve the above object, the present invention provides a data management card for managing contents by communicating with a device for recording or reproducing data on a medium. It has at least two or more types of encryption algorithms and an interface for communication with an external device, and has a function to convert the encryption algorithm used for data recorded on the medium and the encryption algorithm used for communication at the interface to be different. Having a configuration.

The data management card according to the second aspect of the present invention includes a random number generator for generating a random number when encrypting and recording the content on a medium, and encrypts the content in units of a name to be recorded using the random number generator. A unique identification code using a random number generator so as to differ for each data unit (name) to be recorded,
It has a configuration provided with storing the same identification code in the card and the medium.

A data management card according to a third aspect of the present invention stores information on a copy number restriction code for restricting output of a content recorded on a medium from an interface to an external device, and outputs content having the recording number restriction code. In this case, the copy number restriction code is updated for each content, and the output to the outside is disabled when the code reaches a predetermined value.

The data management card according to the fourth aspect of the present invention shows a class code information for identifying a fee for each content and a date when charging for playback for collecting a fee each time the content recorded on the medium is reproduced. It has date code information and information of a transfer code for selecting a grade code by the date code, stores the grade code and the date code for each content at the time of recording on the disc, and is selected from the grade code at the time of reproduction. Have a configuration for adding a fee.

The data management card according to the fifth aspect of the present invention has a configuration in which, when contents are recorded on a medium via an interface, information of a trace code capable of identifying a source of the contents is stored.

In the data management card according to the sixth aspect of the invention, when recording or reproducing a content to which information of a reproduction restriction code for restricting a condition of viewing the content is recorded or reproduced on a medium, the reproduction restriction code is stored at the time of recording and reproduced. The recording / reproducing apparatus is controlled so that the content is sometimes restricted according to the content restriction code.

[0022]

Embodiments of the present invention will be described below with reference to the drawings.

(Distribution of Content) A content transmitting / receiving system for distributing content via a public network will be described. FIG. 1 is a system diagram for transmitting and receiving contents.

In FIG. 1, reference numeral 100 denotes a broadcast transmitting station which is a content distribution side, and 101 denotes a broadcast transmitting station 1 by contract.
A receiving / recording / reproducing apparatus on the user side capable of receiving information from 00 and recording / reproducing on a medium, 102 is a card issued by contract, 103 is a public network, 104 is a television, and 105 is a card 102 This is a communication cable of an interface for transmitting and receiving data to and from another device.

The contents transmitted from the broadcast transmitting station 100 are video such as a movie, audio such as jazz, a game, character information such as a copyrighted work, etc., and the transmission contents are encrypted.

In this embodiment, the content is MPEG
2 (ISO 13818-2) will be described as a video transmitted using a transport stream which is a transmission format.

This content transmission and reception is performed by the broadcast transmitting station 10.
The content is encrypted from 0 and transmitted to the user's receiving / recording / reproducing apparatus 101 via the network 103, and is decrypted by the receiving / recording / reproducing apparatus 101 to be reproduced on the television 104.

As a method of encrypting the contents, a common key encryption method having the same key data is used. In this case, a common key (master key) is issued to the card 102 and the broadcast transmission station 100 issued by the user by contracting for reception. Is performed, as shown in FIG.

First, on the transmitting side, a content key 108 for encrypting the content to be distributed is generated, and the content key and the content key obtained by encrypting the content by the encryption unit 107 using the content key 108 are transferred to the master key 109. And transmits the content key information encrypted by the encryption unit 107 to the receiving side via the network 106.

On the receiving side, the encrypted content key information is decrypted by the decryption unit 110 using the master key 111 to obtain a content key 112, and the encrypted content information is decrypted using the content key 112. The content is encrypted and transmitted.

The content to be transmitted is divided into predetermined units for each title, and is performed as shown in FIG.
FIG. 3 is a diagram showing a format for transmitting content.

In FIG. 3, reference numeral 113 denotes a preamble indicating the beginning of the format, 114 denotes a transmission destination address indicating the transmission destination of the content, 115 denotes a transmission source address indicating the transmission source of the content, and 116 denotes a data section which is transmission data. Reference numeral 117 denotes a header information section in which data such as titles are arranged, 118 denotes a decryption key information section serving as a content key for decrypting the content, and 119 denotes a content information section composed of content information. Here, the header information section 117 has the same information in title units.

(Recording of Content on Media) Receiving, recording and reproducing apparatus 101 for receiving content from broadcast transmitting station 100
The recording operation to the data will be described. FIG. 4 is a configuration diagram of the card 102.

In FIG. 4, reference numeral 200 denotes a card I / O for transmitting / receiving data to / from the receiving / recording / reproducing apparatus 101;
01 is a CPU for controlling the card 102, 202 is a CPU
ROM that stores a program to be executed by 201, 2
03 is an encryption unit α having an encryption algorithm used for contents distributed from the broadcast transmission station 100, 204 is a random number generator that generates random numbers, and 205 is an interface that transmits and receives data to and from an external device of the reception recording / reproducing device 101. , 206 is an encryption unit β provided with an encryption algorithm used when recording the distributed content on a medium or the like, 207 is a master key which is a key for decrypting the encrypted content distributed from the broadcast transmitting station, Reference numeral 208 denotes a management information unit configured by a nonvolatile memory for storing information necessary for content reproduction, and reference numeral 209 denotes a reproduction charging table unit configured by a nonvolatile memory used for a reproduction charging process described later.

FIG. 5 is a block diagram of the receiving / recording / reproducing apparatus 101. In FIG. 5, reference numeral 210 denotes a network interface for transmitting and receiving data to and from the broadcast transmitting station 100 via the public network 103; A decompression processing unit for decoding video and audio data, a card I / O 212 for transmitting and receiving data to and from the card 102, a signal processing unit 213 for creating a recording format, a laser driving unit 214, and an optical head 215 Reference numeral 216 denotes a disk. Reference numeral 217 denotes a control unit for controlling the receiving / recording / reproducing apparatus 101. Reference numeral 218 denotes a setting unit 218 for the user to set the operation of the receiving / recording / reproducing apparatus 101.

Here, the card 102 is a card I / O 20
0 is arranged in the receiving apparatus 101 so as to be able to communicate with the card I / O 211 of the receiving / recording / reproducing apparatus 101.

Table 1 shows the format of data stored in the management information section 208, where 300 is the title of the content,
301 is an identification code for identifying each content, 302
Is the key for encrypting and recording the content, 3
03 is a copy number limiting code for limiting the number of times the content is output to the outside, 304 is a class code for identifying a fee for charging for reproduction when recorded on a medium for each content, and 305 is a recorded code for each content. A date code indicating a date at the time; 306, a playback constraint code that limits the quality of output of the content recorded on the medium to the outside of the playback device; 307, a trace code that records a distribution source for each content when recording the content; Reference numeral 308 denotes a charging fee when the reproduction is charged.

[0038]

[Table 1]

The operation of recording the content of the title X on the receiving / recording / reproducing apparatus 101 will be described. First, a content transmitted from the broadcast transmitting station 100 in an encrypted form via the network 103 is transmitted to the receiving / recording / reproducing apparatus 10.
1 and is transmitted to the card 102 from the card I / O 212.

In the card 102, the CPU 201 executes the control program of the ROM 202, thereby generating a first random number in the random number unit 204 in step S11 and setting it as a key A in step S11. Is generated as a random number A. In step S13, the random number A is compared with information registered as an identification code in the management information unit 208. If they match (no), step S12 is executed, and if they do not match (yes). ) Sets the random number A as the identification code B in step S14. Thereby, a key for encrypting the content at the time of recording, which will be described later, and a card 102 necessary for decrypting the content at the time of reproduction.
Create a pair of identification codes that can identify the key stored in.

Then, the content input via the card I / O 200 is decrypted in a predetermined unit by the encryption unit α203 using the master key 207, and the content is encrypted by the encryption unit β206 using the key A, and is identified. The code B and the encrypted content are transmitted from the card I / O 200 to the receiving / recording / reproducing apparatus 101, and the key A and the identification code B and the information included in the header information section 117, which will be described later in detail, are transmitted to the management information section 208. It is stored as shown in Table 1 for each title. Here, if there is no setting, it will be described below as 0.

The receiving / recording / reproducing apparatus 101 has a card I / O2
The identification code and the content received by the signal processing unit 2
In step 13, an error correction code for correcting an error is added to convert the recording information into a recording format, and the recorded information is converted in a laser drive unit 214 into an electric signal into an optical signal.
Record at 16.

By making the encryption algorithm used for distributing the contents via the network different from the encryption algorithm used for the device capable of recording or reproducing data on the medium by the above operation, even if the encryption algorithm used for the network is decrypted. It is impossible to decrypt the content that has been encrypted and recorded on the medium, and the security of copyright protection for the content is enhanced.

Further, by converting the encryption of the contents in the card, the encryption can be converted while the security of the contents is maintained without disclosing the plaintext of the conversion process to the outside.

(Reproduction of Content from Media) The reproduction of the content of the title X recorded in the receiving / recording / reproducing apparatus 101 will be described. First, the reception recording / reproducing device 1
01 converts information obtained by optically reading the content of the title X and the identification code B from the disk 216 from the optical head unit 215 into an electric signal in the laser driving unit 214,
Error correction is performed in the signal processing unit 213, and the card I
ID code B and contents from card / 10 from / O212
Send to 2.

In the card 102, the CPU 201 executes the control program in the ROM 202, and the card I / O 2
00, the content and the identification code B are input, and the identification code B is compared with the identification code recorded in the management information unit 208. If they match, the encryption unit β206 is used by using the key (A) of the matching identification code. And decrypts the content from the card I / O 200 to record and playback
Send to 1.

In the receiving / recording / reproducing apparatus 101, the card I / O
The content received from 212 is expanded by
Performs PEG processing and outputs video or audio.

When the content is encrypted and recorded on the medium by the above operation, a unique (identification code) code is recorded on the content without recording the key information on the medium,
By identifying and reproducing the key, the key can be decrypted without disclosing it outside the card, and the copyright can be strengthened.

Hereinafter, the operation of the card 102 in the reproducing operation will be described.

(Restriction on the Number of Digital Outputs to Other Media) The contents reproduced from the disk 216 of the receiving / recording / reproducing apparatus 101 are connected to the external via the communication cable 105 from the interface 205 of the card 102 as shown in FIG. The limitation on digital output of content to the recording device 106 as a device will be described.

Here, the number-of-times-of-copying restriction code shown in Table 1 is set to 0 when no data is set, and when set, counts down every time a digital output is made and when it becomes 1, digital output is not permitted. For example, when digital output is permitted only once, 2 is set, and the operation of the card 102 when the copy operation to the recording device 106 as an external device is set by the setting unit 218 of the receiving / recording / reproducing device 101 Will be described.

In step S21, the copy number restriction code is compared with 0. If they match (no), step S24 is executed. If they do not match (yes), the copy number restriction code is compared with 1 in step S22. If (no), the process is terminated without outputting the content from the interface 205, and if they do not match (yes), the copy number restriction code -1 is performed in step S23, and the content is output from the interface 205 in step S24.

For example, in the case of title X, since the number-of-times-of-copies restriction code is 2, output to the outside is possible only once.

As described above, by providing information that can limit the number of times of output such as copying of contents from the interface and the interface to the outside within the card for each title, the information can be easily output from the interface without leaking to the outside of the card. Since the output of the content information can be stopped, the copyright protection of the recorded content is strengthened.

(Playback Billing) A playback billing for collecting a fee every time content recorded on a medium is played back will be described.

Table 2 shows a format of data stored in the reproduction / charging table unit 209.

[0057]

[Table 2]

In Table 2, reference numeral 400 denotes a class part which is a code for identifying the charge of the content; 401, a date part indicating the date of each information of the class part 400; 402, a transfer part indicating the address in the charge search; Is a charge section indicating a charge for reproduction, 404 is a main table area indicating a basic charge in reproduction charge, and 405 is a transfer table area indicating a charge other than the basic charge.

Here, the date code 305 and the date part 4
The date information at 01 is displayed in (AD. Month), and the search operation moves from the transfer table area 405 to the main table area 404 when the code of the class section 400 indicated by the transfer section 402 is determined when the charge for the reproduction charge is determined. In this case, the charge of the charge unit 403 in the code of the class unit 400 is unconditionally charged.

In step S31, the grade code 304 of the content to be reproduced is compared with the code of the grade section 400 in the main table 404. If they do not match (no), the reproduction is terminated, and if they match (yes), the corresponding code is matched. The step S32 is executed with reference to the information of.

In step S32, the date information of the date code 401 of the matching class code 400 and the date information of the date code 305 of the content are compared.
In the case of ≧ date part 401 (yes), the charge of the content in charge part 403 is added to charging charge 308 in step S35 as charge fixed, and date code 305 is set.
<If the date part 401, that is, the date code 305 is old (n
o) is a transfer table area 404 indicated by the transfer unit 402 in the code of the class unit 400 in step S33.
Is compared with the date part 401 in the code of the class part 400 in the above.

In step 33, the date code 305
In the case of ≧ date part 401 (yes), the charge of the content in charge part 403 is added to charging charge 308 in step S35 as charge fixed, and date code 305 <
When the date part 401, that is, the date code 305 is old (n
o) executes step S34.

In step S34, the transfer section 402
Is compared with the final code (T9) in the main table area 404, and if the code is within the main table area 404, in step S35, the charge of the content in the charge section 403 is added to the charge charge 308 in the charge section 403 in step S35. If the code is other than the above, step S33 is executed in the transfer table area 405.

For example, when the title X is reproduced, since the class code 304 is T1 in step S31, the information in the class unit 400 at T1 is referred to, and step S3 is performed.
2, the date code 305 of the title X and the class part 40
The date information of the date part 401 at T1 of 0 is compared. Since the date code 305 is old, the date part 401 of the class part 400 and the date code of the title X of the class part 400 in the transfer table area 405 indicated by the transfer part 402 in step S33. The date information in 305 is compared, and since the date code 305 is old, the transfer unit 4
It is checked whether or not the code of the class part 300 indicated by No. 02 indicates the main table area 404. Since the transfer part 402 is the main table area 404 because it is T3, step S3
At 5, the charge unit 403 at T3 of the class unit 400 is added to the charging fee 308, and the reproduction of the title X is charged.

Then, the receiving / recording / reproducing apparatus periodically transmits the charging fee 308 to the broadcasting transmitting station 100, and the broadcasting transmitting station 100 later withdraws the charging fee from a bank account or the like based on the charging fee 308.

A class code indicating the rank of the fee and a date code indicating the date when the content is recorded on the medium are stored in the card, and the charging table information periodically distributed from the broadcast transmitting station 100 is reproduced and charged. Since the content has a social value (market value) as time progresses by having the table unit 209 perform the above-described operation at the time of playback and performing the above operation at the time of playback, the content recorded on the media is changed. Reproduction can be charged at the market price at the time of reproduction.

(Operation of Restriction on Reproduction) When the content recorded on the medium is output to another device (media), restrictions on the viewing conditions of the content will be described.

Table 3 shows content constraint information, and the content of this information is assumed to be stored in the ROM 202.

[0069]

[Table 3]

In step S41, the reproduction constraint code 306 of the content to be reproduced is compared with 0, and if they match (n
o) indicates that there is no restriction on the content to be reproduced, and if they do not match (yes), it is determined that there is restriction information and the ROM 2 is determined in step S42 according to the reproduction restriction code 306.
02 is executed.

For example, in the case of title X, since the reproduction constraint code 306 is 011, the CPU 201 operates (decreases) the number of scanning lines of high-definition high-definition (HD) video data to the level of the current television broadcasting (NTSC). From the interface 205 to the communication cable 10
Output via 5.

A playback constraint code indicating the condition of the playback constraint of the content recorded on the medium is stored in the card,
By performing the above operation when outputting content to an external device via the interface, even if copied, it is possible to differentiate in quality from the original,
The original value can be prevented from declining.

(Trace operation) By recording the transmission source address 115 of the transmission source of the content recorded on the medium on the card, when the content copied illegally via the network 103 is recorded, the transmission source is specified. it can.

[0074]

As described above, according to the present invention, by using a card having the following features, the copyright protection of contents stored in media or the like is strengthened.

(1) By making the encryption algorithm used for distributing contents via a network different from the encryption algorithm used for a device capable of recording or reproducing data on a medium, even if the encryption algorithm used for the network is decrypted, It is impossible to decrypt the content that has been encrypted and recorded on the medium, and the security of copyright protection for the content is enhanced.

Further, by converting the encryption of the content in the card, the encryption can be performed while the security of the content is maintained without disclosing the plaintext of the conversion process to the outside.

(2) Since the social value (market value) of the content changes as time progresses, it is possible to charge for reproduction at the market value at the time of reproducing the content recorded on the medium.

(3) When the content is encrypted and recorded on the medium, the key information is not recorded on the medium, but a unique code is recorded and identified so that the content can be reproduced. Decryption is possible without public disclosure, and copyright can be strengthened.

(4) By holding the interface and information for limiting the number of outputs for each content in the card, the card itself can detect and prevent unauthorized copying.

(5) When recording content via a network, by holding the address that is the source of the content, the source of the illegal copy can be specified when it is distributed.

(6) By retaining information that restricts the viewing conditions of digitally output content and restricting the quality of digitally output content in accordance with the restriction information, discrimination in quality from the original even if copied, It is possible to reduce the value of the original.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a transmission system according to an embodiment of the present invention.

FIG. 2 is a block diagram showing an encrypted transmission configuration of content in the transmission system.

FIG. 3 is a configuration diagram of a transmission format of the transmission system.

FIG. 4 is a configuration diagram of a card used in the transmission system.

FIG. 5 is a configuration diagram of a reception recording / reproducing device of the transmission system.

FIG. 6 is a flowchart of the identification code generation.

FIG. 7 is a configuration diagram of another transmission system in the present embodiment.

FIG. 8 is a flowchart for restricting the output of recorded content according to the embodiment;

FIG. 9 is a flowchart in the reproduction charging according to the present embodiment.

FIG. 10 is a flowchart for detecting a restriction on output of recorded content according to the embodiment;

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 broadcast transmitting station 101 reception recording / reproducing device 102 card 103 network 104 television 105 communication cable 106 recording device 200 card I / O 201 CPU 202 ROM 203 encryption unit α 204 random number unit 205 interface 206 encryption unit β 207 master key 208 management information unit 209 Playback billing table section 210 Network interface 211 Decompression processing section 212 Card I / O 213 Signal processing section 214 Laser drive section 215 Optical head section 216 Disk 217 CPU 218 Setting section 300 Title 301 Identification code 302 Key 303 Copy count restriction code 304 Grade Code 305 Date code 306 Reproduction restriction code 307 Trace code 308 Billing fee 400 Grade part 401 Date part 402 Transfer part 403 Gold 404 main table area 405 forwarding table area

Continued on the front page F term (reference)

Claims (9)

[Claims] At least two or more types of encryption algorithms for managing contents by communicating with a device having a function of recording or reproducing data on a medium and an interface for communicating with an external device are provided. And a cryptographic algorithm used for data recorded on the medium and a cryptographic algorithm used for communication in the interface are different. 2. The apparatus further comprises a random number generator for generating a random number,
When encrypting and recording content on the media,
Content unit (name) to be recorded using the random number generator
A unique identification code information is created by using the random number generator so as to be different for each data unit (name) to be recorded, and the same identification code is assigned to the card and the medium. The data management card according to claim 1, wherein the data management card is stored. 3. A copy number limiting code information for limiting an output of a content recorded on a medium from an interface to an external device is stored, and when the content having the copy number limiting code is output, the copy number is set for each content. 2. The data management card according to claim 1, wherein output to the outside is disabled by updating the restriction code to a predetermined value. 4. A class code for identifying a fee for each content, a date code indicating a date, and a date code indicating a date, for performing a playback charge for collecting a fee each time the content recorded on the medium is reproduced. Having the transfer code information for selecting the grade code by the date code, storing the grade code and the date code for each content at the time of recording on the disc, and selecting from the grade code at the time of reproduction. 2. The data management card according to claim 1, wherein a charge is added. 5. The data management card according to claim 1, wherein, when the content is recorded on the medium via the interface, information of a trace code capable of identifying a source of the content is stored. 6. When recording or reproducing a content added with information of a reproduction restriction code for restricting a condition of viewing the content on a medium, the reproduction restriction code is stored at the time of recording, and the reproduction restriction code according to the content is restricted at the time of reproduction. 2. The data management card according to claim 1, wherein recording or reproduction control is performed so as to be restricted. 7. A method of using a card having a first encryption unit and a second encryption unit which are different encryption algorithms, decoding information transmitted by being encrypted by the first encryption unit, and recording the information on a medium. Is a data management method, wherein the data is encrypted using a second encryption unit. 8. The data management method according to claim 7, wherein a content encrypted with the random number as a key and a unique identification code using the random number are recorded on a medium. 9. A method in which a card is provided with an identification code and a decryption key for each title of a content, and when the content is reproduced, the key information is decrypted without disclosing the key information to the outside of the card using the identification code. The data management method according to claim 7, wherein