JP2002203367A - Data recorder and data recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reliably make source data erase or read of source data impossible when the data recorded on an HDD are copied to other mediums. SOLUTION: When copying the data of title 1 recorded on the HDD to another medium, a controller 166 copies the system key of a first register 163 to a second register 167 beforehand, reads encrypted key data from the HDD, decodes the data with a first descrambler 168 by using the system key of the second register 167, extracts the title key corresponding to the title concerned from decoded data by referring to the title number, and stores the title key into the controller 166. Then the controller 166 reads the random number from a random number generator 162, sets a new value as a system key in the first register 163, and makes it impossible to use the key of the title which is remaining on the HDD and a copy of which is desired.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data recording device and a data recording method for recording digitized content data, and reproduces the recorded content data against the will of the copyright holder, and unlimitedly reproduces the content data. The present invention relates to a data recording apparatus and a data recording method having a function of preventing unauthorized duplication / reproduction for preventing the data recording from being performed.

[0002]

2. Description of the Related Art Currently, digital broadcasting is performed by digitizing video and audio, performing compression processing, and transmitting the digitalized video and audio. Since compressed video and audio content is a kind of digital data, a hard disk drive (HD) used for a personal computer or the like is used.
D) can be directly recorded as data.

When data of digital contents distributed by digital broadcasting is recorded on an HDD,
This data can be copied (copied) to a recording medium such as a memory card any number of times, and a duplicate can be created without limitation. This is convenient for the user. However, for copyright holders of contents such as movies, the copyrighted works can be copied and distributed without permission without any permission, resulting in great damage. Therefore, some conventional data recording devices employ a method of erasing the original data from the HDD, once the data is recorded on the HDD, when the data is copied to another recording medium therefrom. . Further, when the number of reproducible times is limited, there is a method of rewriting the reproducible number information for each reproduction.

However, in the above-mentioned method, the content data is backed up in advance from the HDD to another recording medium, and by returning the content data, the deleted content data is restored or the number of reproducible times is returned to the original. There is a problem that can be done.

[0005]

As described above, in the conventional data recording apparatus and data recording method, even when content data having a copyright is recorded, it is possible to copy or reproduce the content data without limitation. is there. In some cases, once data has been recorded, if the data is duplicated from there to another recording medium, the original data will be erased,
Some devices have an unauthorized duplication / reproduction prevention function that rewrites the number of reproducible times, but this method also backs up content data and reproducible number information in advance, The reproducible number-of-times information before rewriting can be restored.

[0006] The present invention solves the above-mentioned problem, and when recorded data is duplicated on another recording medium, the original data is reliably erased or unreadable, and cannot be restored by backup or the like. It is still another object of the present invention to provide a data recording device and a data recording method in which the number of reproducible times cannot be restored to the state before rewriting when the number of reproducible times is limited.

[0007]

In order to achieve the above-mentioned object, a data recording apparatus according to the present invention is arranged such that when recording content data for which unlimited copy protection is required on a recording medium, a title key is used for recording. The generating means generates a title key based on the given title number, the content data encrypting means encrypts the content data using the title key, and the title key encrypting means encrypts the title key using the system key. Encrypt and write the encrypted content data to the recording medium by the writing / reading means,
The encrypted data of the title key is written on the same or another recording medium as the recording medium, and at the time of reproduction, each encryption of the title key of the designated title and the content data from the recording medium or another recording medium is performed by the writing / reading means. The data is read out, the title key is decrypted by the title key decryption means using the system key, the content data is decrypted by the content data decryption means using the decrypted title key, and is output to the reproducing system. The reading means reads all the title key encrypted data from the recording medium, decrypts the data using the system key by the title key decrypting means, selects the title key of the designated title from all the decrypted title keys, and sets the title. Temporary storage by key temporary storage means After that, the system key is changed by the system key changing means, all the title keys decrypted using the changed system key are re-encrypted by the title key encrypting means, and written again on the recording medium by the writing / reading means. On the other hand, the content data of the specified title is read from the recording medium by the writing / reading means, and is output together with the temporarily stored title key.

In the case where the number-of-reproducible-times information is added to the content data, a title key is generated by a title-key generating means in a state where the reproducible-number information is connected by a connecting means during recording. The title key is encrypted by the title key encrypting means using the system key, and is written to the recording medium by the writing / reading means. At the time of reproduction, the encrypted data of the title key is read from the recording medium by the writing / reading means. After decrypting by the title key decrypting means, extracting the reproducible number information included in the decrypted title key, updating the reproducible number by the reproducible number updating means, reconnecting to the title number by the coupling means, Regenerate the title key by key generation means and change the system key. The title key regenerated using a system key which is changed by means and re-encrypted by the title key encryption means, and to re-write the recording medium by the write / read unit.

Further, the data recording method according to the present invention, when recording content data for which unlimited copy protection is required on a recording medium, at the time of recording, uses a title key based on a title number given by a title key generation procedure. Generating, encrypting content data using a title key according to a content data encryption procedure, encrypting a title key using a system key according to a title key encryption procedure, and writing / reading procedure. Writing the title key and the encrypted data of the content data to the recording medium, and reading the title key and the encrypted data of the content data of the designated title from the recording medium by a write / read procedure at the time of reproduction. Key decryption Decoding the title key using the system key in order, and decoding the content data using the decoding title key according to the content data decoding procedure, and outputting the data to the playback system. Reading all the title key encrypted data from the recording medium, decrypting using the system key by the title key decryption procedure, and selecting the title key of the designated title from all the decrypted title keys. Temporarily storing by a title key temporary storage procedure, changing a system key by a system key change procedure, and re-encrypting all title keys decrypted using the changed system key by a title key encryption procedure. Encrypting and writing / reading Writing the re-encrypted data of all the title keys to the recording medium again by the following procedure; reading the content data of the specified title from the recording medium by the writing / reading procedure; and temporarily storing the read content data. And outputting the title key together with the title key.

In the case where the number-of-reproductions information is added to the content data, at the time of recording, a title key is generated. A title key is generated, and at the time of reproduction, a step of extracting information on the number of reproducible times included in the title key read from the recording medium and decoded, and whether or not the number of reproducible times remains from the extracted reproducible number information Judgment is made, and if not remaining, the reproduction process is stopped. If remaining, the number of reproducible times is updated by the renewable number update procedure, and the renewable number is updated to the title number by the linking procedure. Re-linking the number of times information and regenerating the title key based on the link information by the title key generation procedure Re-encrypting the regenerated title key using the system key changed by the system key change procedure by the title key encryption procedure, and rewriting the title key re-encrypted data by the write / read procedure. Rewriting to a recording medium.

That is, in the data recording apparatus and method according to the above configuration, when the content data is duplicated, the system key for decrypting the title key of the recorded data after the duplication is changed. Even if the data is restored, the title key cannot be decrypted by the system key, so that the content data after the recovery cannot be decrypted.

In addition, since the system key of the reproducible number information is changed every time reproduction is performed, the title key including the reproducible number information can be decoded even if the recording data is returned to the state before the reproduction. Therefore, the content data cannot be decrypted.

[0013]

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

FIG. 1 is a block diagram showing an embodiment in which the data recording apparatus according to the present invention is applied to a digital broadcast receiver.

In FIG. 1, a tuner 11 is supplied with a digital broadcast reception signal from an antenna (not shown), and a tuning operation is performed here. The output is converted to a baseband digital signal by the demodulator 12, and one transport stream is output. The transport stream is a packet multiplex of content data such as a compressed video signal and audio signal, and data (service information (SI)) indicating the configuration thereof. The transport processor 13 extracts a necessary content signal from the packet multiplexed signal of the transport stream demodulated by the demodulator 12, decodes the video signal and the audio signal by the video / audio decoder 14, and Present it on a device or speaker.

The data recording device according to the present invention has a CPU 1
5, a protection unit 16, an HDD controller 17, an HDD 18, a descrambler 19, a memory card controller 20, and a memory card 21.

At the time of recording, the CPU 15 inputs the transport stream obtained by the demodulator 12 via the protection unit 16 and records the transport stream input to the HDD 18 through the HDD controller 17. During playback, the HDD controller 1
The transport stream is read out from the HDD 18 through 7 and added to the transport processor 13 via the protection unit 16 to reproduce the stream.

The CPU 15 includes a descrambler 19.
, The reading and writing of the memory card 21 can be performed through the memory card controller 20. That is,
The data recorded on the HDD 18 is copied to the memory card 21 via the descrambler 19,
Can be copied to the HDD 18.

The CPU 15 fetches the transport stream from the demodulator 12, determines the content information (title, copyright information, etc.), and causes the protection unit 16 to execute a protection process based on the determination result.

FIG. 2 shows a specific configuration of the protection unit 16 which is a feature of the present invention in the above configuration, and the functions performed by the unit 16 will be described.

(1) A case of recording content data of a title specified from a transport stream (hereinafter, referred to as a title) will be described.

The protection unit 16 includes a signal line L
Through 1, write data from the demodulator 12 is received. In the coupler 161, the CPU 1 is connected via the signal line L 2.
5, a data title number (TitleNo) identifying the title from 5 (the number is not limited to a numerical value, but may be a name, etc.), whether this title can be copied or not, the number of copies that can be made when copying is possible, Copyright information (Titl,
eNoCCI) and the random number from the random number generator 162 is bit-connected. The random number generated by the random number generator 162 has a different value for each title, and the concatenated data is used as a title key for encrypting and decrypting each title.

The first register 163 holds a preset system key. The first scrambler 164 encrypts the output of the coupler 161 with the output of the first register 163. The resulting encryption key data is recorded on the HDD 18 via the signal line L3.

On the other hand, the content data supplied from the signal line L1 is input to the second scrambler 165, encrypted with the title key generated by the random number generator 162, and recorded on the HDD 18 through the signal line L3. Here, the encrypted title key and content data are
It is not necessary to record the encrypted title key on the same HDD 18. For example, the encrypted title key may be recorded on an HDD (not shown) different from the HDD 18.

Here, a case will be described in which the content data of title 1 has already been recorded on the HDD 18 and additional content data of title 1 is further recorded there.

The CPU 15 sends the title 1 from the signal line L2.
And the copyright information about the title. The controller 166 has the first register 16
3 is copied to the second register 167.
The encryption key data corresponding to the title 1 is read from the HDD 18 and decrypted by the first descrambler 168 using the system key of the second register 167. The controller 166 gives the decrypted title key to the second scrambler 165, and scrambles the additional content data of the title 1 through the signal line L3.
Record in 8.

Next, the case where the content data of title 1 has already been recorded and the content data of title 2 is additionally recorded will be described.

In this case, it is necessary to generate a different title key. The CPU 15 sends the title 1 from the signal line L2.
And the copyright information about the title. The random number generator 162 generates a random number different from the title 1. The data obtained by concatenating these by the concatenator 161 is encrypted by the first scrambler 164 using the same system key as the title 1 obtained from the first register 163. The encryption key data thus obtained is additionally recorded on the HDD 18 via the signal line L3.

(2) A case where content data of a designated title is read will be described.

The CPU 15 gives the number of the title to be read from the signal line L2. Controller 166
Copies the system key of the first register 163 to the second register 167 in advance. Encrypted key data is stored in HDD 18
And decrypts it with the first descrambler 168 using the system key of the second register 167, and extracts the title key corresponding to the title by referring to the title number. The encrypted content data of the designated title read from the signal line L3 is decrypted by the second descrambler 169 using the title key from the first descrambler 168 and transmitted to the transport processor 13 through the signal line L1. Given and played.

(3) A case where the data of title 1 is moved to another recording medium, for example, a memory card 21 will be described.

The data movement described here refers to an HDD
18 means that the content data of the designated title recorded on the HDD 18 is copied to another recording medium, and the original data on the HDD 18 is deleted or cannot be read. Actually erasing the data takes time when the data size of the specified title is large. Therefore, the data cannot be read by erasing the descrambling key corresponding to the specified title.

The CPU 15 gives the number of the title to be moved from the signal line L2. Controller 166
Copies the system key of the first register 163 to the second register 167 in advance. Encrypted key data is stored in HDD 18
And decrypts it with the first descrambler 168 using the system key of the second register 167, and extracts the title key corresponding to the title by referring to the title number. This title key is stored in the controller 166 as Kt.

The key of the title to be copied to the memory card 21 remains in the HDD 18. A mechanism for disabling this will be described.

To disable reading the title data stored in the HDD 18, the registers 163 and 167
It becomes possible by deleting or changing the system key stored in the. Therefore, the controller 166 reads a random number from the random number generator 162 and sets a new value in the first register 163 as a system key.

However, if the value of the second register 167 is immediately changed here, for example, the content data of the title 1 to be moved can be made unreadable, but the content data of the title 2 not to be moved cannot be read. turn into. Therefore, before updating the value of the second register 167, the title key other than title 1, that is, the title key of title 2 (the title key combined with the copyright information) is set to H.
The data is read from the DD 18, decrypted by the first descrambler 168 using the system key of the second register 167, encrypted by the first scrambler 164 using the system key of the first register 163, and written again to the HDD 18. return.

At this time, the data of the title key encrypted with the previous system key may be overwritten. This saves storage capacity. At this point, the title keys of all recorded titles have been encrypted with the new system key, and the title key of the title 1 to be read is stored in the controller 166. not exist.

The CPU 15 reads the content data of the title 1 read from the HDD 18 without descrambling through the signal line L2, and writes the data into the memory card 21 through the descrambler 19 and the memory card controller 20.

The controller 166 transmits the stored title key Kt to the descrambler 19 via the signal line L4.
Pass to. When writing to the memory card 21, the received title key may be descrambled and recorded by the descrambler 19, and the passed title key may be stored in a register in the descrambler 19, and may be stored in the memory card 21. When the title is read from 21, the key may be used for descrambling.

(4) Next, a description will be given of a processing operation when the number of reproducible times of the title is described in the copyright information.

The case where the number of reproductions of the already recorded title 2 is two will be described as an example. In this example, when the number of times the title has been played reaches the number of times that the title can be played, the title is made unreadable thereafter.

First, the first reproduction will be described. When there is a reproduction request for title 2, the CPU 15 sends the signal line L2
The controller 166 instructs the controller 166 to reproduce the title 2 through. The controller 166 copies the system key of the first register 163 to the second register 167, and
And reads the encrypted title key from the first descrambler 1 using the system key of the second register 167.
At 68, the title key is decrypted. Controller 166
Extracts the linked copyright information from the decrypted title key and determines the number of reproducible times. At this time, the number of reproducible times is determined to be “two times”, which indicates that reproducibility is still possible.

The controller 166 calculates 1
Is subtracted to obtain a “one time” calculation result. The number of reproducible times of the copyright information is rewritten to “one time”, and the copyright information is re-synthesized with the title key. The controller 166 reads a random number from the random number generator 162 and
Set a new value for 3. The title key combined with the copyright information of all other recorded titles is stored in the HDD 18.
, And decrypted by the first descrambler 168 using the system key of the second register 167, and the first scrambler 164 using the system key of the first register 163 And write it back to the HDD 18 again. Since it is known that reproduction is still possible, the content data of title 2 read from the HDD 18 is descrambled by the second descrambler 169 using the previously decrypted title key, output to the signal line L1, and reproduced. I do.

Next, the second reproduction will be described. When there is a reproduction request for title 2, the CPU 15 instructs the controller 166 to reproduce title 2 via the signal line L2. The controller 166 copies the system key of the first register 163 to the second register 167, and
18, the encrypted title key is read out, and the title key is decrypted by the first descrambler 168 using the system key of the second register 167. Controller 1
Reference numeral 66 extracts copyright information from the decrypted title key, and determines the number of reproducible times. At this time, the reproducible number of times is “one time”, and it can be seen that the reproduction is still possible.

The controller 166 subtracts 1 from the remaining number of reproducible times, and obtains the remaining "0" calculation result. The number of reproducible times of the copyright information is rewritten to “0”, and the copyright information is synthesized again with the title key. If the key of the title 1 is not rewritten in the recording process of the title key, which will be described later, the composition need not be performed. At this point, since it is determined that the reproduction of this title cannot be performed thereafter, the title key of this title is erased, or the copyright information whose reproducible number has become “0” is written back. The controller 166 reads a random number from the random number generator 162 and sets a new value in the first register 163.

When erasing the key of title 1, a title key other than title 1, that is, a title key of title 2 (a key combined with copyright information) is read from HDD 18, and the first desk is read using the system key of second register 167. The data is decrypted by the rambler 168, encrypted by the first scrambler 164 using the system key of the first register 163, and written back to the HDD 18 again. Thus, the title key of title 1 is deleted.

When the key of the title 1 is not deleted, the title key of the title 2 (the key combined with the copyright information) is read from the HDD 18 and the second register 167 is read.
Using the system key of the first descrambler 168, and combining this with the title key of title 1 obtained by combining them first by the first scrambler 164 using the system key of the first register 163. Encrypted and HDD1 again
Write back to 8.

At this time, the title key data encrypted with the previous system key may be overwritten. This saves storage capacity.

Since it is known that reproduction is still possible, the content data of title 2 read from the HDD 18 is descrambled by the descrambler 169 using the previously decrypted title key and output to the signal line L1, Reproduce.

(5) In the above description, the controller 166 decrypts the encrypted title key with the system key, and then uses the random number generator 162 to generate a new system key used for encryption. However, it is also possible to generate a new system key by another method. One example will be described with reference to FIG.

In FIG. 3, a counter 1610 is set to a predetermined value. The constant generator 1611 generates a predetermined constant. The initial value of the counter 1610 and the constant generated by the constant generator 1611 are set differently for each data recording device. DES (Data Encyption S
Tandard) The encryptor 1612 performs DES encryption of the output of the constant generator 1611 using the output value of the counter 1610. This value is used as a system key. When a new system key is required, the counter 1610 is instructed and its value is incremented by one. As a result, a completely different value is D
Appears as the output of ES encryptor 1612, which can be used as a new system key. A system key having a different value is generated each time the counter value increases.

In the above description, the protection processing is performed by the protection unit 2. However, the same effect can be obtained even if this processing operation is performed by software in the CPU 15.
Hereinafter, the flow of the processing will be schematically described with reference to FIGS.

In the processing, a system key generation procedure for generating a system key as a program
A title key generation procedure for generating a different title key for each content by concatenating a title number, copyright information, and random number data attached to the content data to be recorded, and a title key for encrypting the title key using a system key An encryption procedure, a content data encryption procedure for encrypting content data using a title key, a write / read procedure for writing the title key and encrypted data of the content data to the HDD 18 and reading and outputting the HDD 18 in response to a request; A title key decryption procedure for decrypting the read title key encrypted data using the system key; and a content data decryption procedure for decrypting the read content data encrypted data using the decrypted title key. Tie to temporarily store decrypted title keys To the temporary storage procedure Ruki, the system key change procedure for changing the system key generated by the system key generation procedure, intended to comprise a procedure reproducible count update to update every play reproducible number information.

FIG. 4 shows a processing flow at the time of recording.
When a recording instruction for content data is input (step S11), it is first determined whether or not the recording mode is a new recording (step S12). In the case of a new recording, the title number and the title given by the title key generation procedure are determined. Generates a title key based on copyright information (step S1)
3) Encrypt the input content data using the title key according to the content data encryption procedure (step S14), and encrypt the title key using the system key according to the title key encryption procedure (step S1).
5) Write the title key and the encrypted data of the content data into the HDD 18 according to the write / read procedure (step S16).

In step S12, in the case of additional recording, it is determined whether or not the title is the same as the already recorded title (step S17). In the case of the same title, the encrypted title key and the content data of the same title are read from the HDD 18 by the write / read procedure (step S18), and the title key is decrypted by the title key decryption procedure using the system key (step S18). S19) Encrypt the input content data using the decryption title key according to the content data encryption procedure (step S20), and encrypt the content data using the HDD1 according to the write / read procedure.
8 is additionally recorded (step S21).

If it is determined in step S17 that the title is different, the title key is generated by changing the random number data in the title key generation procedure (step S22), and is input by the content data encryption procedure using the changed title key. The encrypted content data is encrypted (step S23), and the title key is encrypted using the system key according to the title key encryption procedure (step S2).
4) Write the title key and the encrypted data of the content data into the HDD 18 according to the write / read procedure (step S25).

FIG. 5 shows a processing flow at the time of reproduction.
When there is a designation input of a title number to be reproduced (step S31), the HDD 18 is read / written by a write / read procedure.
Then, the title key of the designated title and the respective encrypted data of the content data are read out (step S32), the title key is decrypted using the system key by the title key decryption procedure (step S33), and the title key is used by the content data decryption procedure. The content data is decrypted and output to the playback system (step S34).

FIG. 6 shows a processing flow at the time of copying.
When there is a designation input of the title to be copied (step S4
1) Read all title key encrypted data from the HDD 18 by a write / read procedure (step S)
42), the title key is decrypted using the system key by the title key decryption procedure (step S43), and the title key of the designated title is selected from all the decrypted title keys (step S44), and the selected title key is selected. The title key is temporarily stored according to the title key temporary storage procedure (step S45). Then, the system key is changed according to the system key changing procedure (step S46).
All title keys decrypted using the changed system key are re-encrypted by a title key encryption procedure (step S47), and re-encrypted data of all title keys are written again to the HDD 18 by a write / read procedure (step S47). S48). Thereafter, the content data of the specified title is read from the HDD 18 by a write / read procedure (step S49), and the read content data is output together with the temporarily stored title key, and the writing process to the memory card 21 is performed. (Step S50).

FIG. 7 shows a processing flow at the time of reproduction when the number of reproducible times is set. When the designation of the title number to be reproduced is inputted (step S51), the designated title is read from the HDD 18 by the writing / reading procedure. Then, each encrypted data of the title key and the content data is read out (step S52). Here, the title key is decrypted using the system key according to the title key decryption procedure (step S53), and information on the number of reproducible times in the copyright information included in the decrypted title key is extracted (step S54). It is determined whether or not the number of times remains (step S55). If not, the reproduction process is not performed.

If the number of reproducible times remains in step S55, the number of reproducible times is updated by the reproducible number of times updating procedure (step S56), and a new copyright information including the updated reproducible number information is used. (S57), re-encrypt the regenerated title key using the system key changed in the system key change procedure by the title key encryption procedure (step S58), and perform the write / read procedure. The re-encrypted data of the title key is rewritten to the HDD 18 (step S59).

According to the above configuration, when the content data of the title 1 is moved, the data of the title key is backed up before the movement, and even if the data is restored after the movement, the title key is already decrypted. Since the system key to be deleted has been deleted, the title key of the content data that should have been deleted cannot be decrypted, and it can be reliably read out.

According to this method, in the event that unauthorized use is considered, the title key Kt of the title to be read is transferred to the memory card 21 first, and then the system key is changed to re-encrypt the title key. 21
After the title key Kt is sent to the system, the power is forcibly turned off or the system key change processing is interrupted, so that even after the key is copied, it appears that the title key of the title remains.

However, since the title key Kt is output from the controller 166 after the system key is changed, the controller 166 can control whether the power is turned off before the system key is changed or the power is turned off immediately after the system key is changed. Is not read out. Therefore, it is possible to reliably prevent the title from being copied without being erased.

According to this method, the system key, which is the encryption key of the title key, is changed, the copyright information whose number of reproducible times has been reduced by the changed key is stored, and then the content data of the title is reproduced. Therefore, even if the system key change is prevented immediately before or after the system key change by turning off the power, the data cannot be restored before the number of reproducible times decreases. It is possible to prevent endless reproduction of a given title.

[0065]

As described above, according to the present invention, when recorded data is copied to another recording medium, the original data can be reliably erased or unreadable, and can also be restored by backup or the like. It is possible to provide a data recording device and a data recording method that cannot perform the data recording.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment when a data recording device according to the present invention is applied to a digital broadcast receiver.

FIG. 2 is a block diagram showing a specific configuration of a protection unit which is a feature of the present invention in the embodiment.

FIG. 3 is an exemplary block diagram for explaining another method of the system key generating means in the embodiment.

FIG. 4 is an exemplary flowchart showing a processing flow at the time of recording when the embodiment is realized by software.

FIG. 5 is an exemplary flowchart showing a processing flow at the time of reproduction when the embodiment is realized by software;

FIG. 6 is an exemplary flowchart showing the processing flow at the time of copying when the embodiment is realized by software.

FIG. 7 is an exemplary flowchart showing a processing flow at the time of reproduction when the number of reproducible times is set when the embodiment is realized by software;

[Explanation of symbols]

11: Tuner, 12: Demodulator, 13: Transport processor, 14: Video / audio decoder, 15: CPU, 16
... Protection unit, 17 ... HDD controller, 18 ... HDD, 19 ... Descrambler, 20 ... Memory card controller, 21 ... Memory card, 161 ...
Coupling device, 162: random number generator, 163: first register,
164: first scrambler, 165: second scrambler, 166: controller, 167: second register, 1
68 first descrambler, 169 second descrambler, 1610 counter, 1611 constant generator, 16
12 ... DES encryption device.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) H04N 5/781 H04N 5/781 510F 5/91 5/91 P 5/92 5/92 H

Claims (10)

[Claims] 1. A data recording apparatus for recording content data for which unrestricted copy protection is required on a recording medium, wherein a system key generating means for generating a system key and a title number different for each title number attached to the content data to be recorded are provided. Title key generating means for generating a title key; title key encrypting means for encrypting the title key using the system key; and content data encrypting means for encrypting the content data using the title key. Writing / reading means for writing the encrypted data of the content data on the recording medium, writing the encrypted data of the title key on the same or another recording medium as the recording medium, and reading and outputting each of them as required. And encrypting the read title key Data, title key decryption means for decrypting using the system key, and encrypted data of the read content data,
Content data decrypting means for decrypting using the decrypted title key, title key temporary storing means for temporarily storing the decrypted title key, and a system key for changing a system key generated by the system key generating means And a title key generating means for generating a title key based on a given title number during recording,
The content data encrypting means encrypts the content data using the title key, the title key encrypting means encrypts the title key using the system key, and the writing / reading means encrypts the title key. And writing the encrypted data of the content data on the recording medium, and at the time of reproduction, reading and writing the title key of the designated title and the encrypted data of the content data from the recording medium by the writing / reading means, The title key is decrypted using the system key, the content data is decrypted by the content data decrypting means using the decrypted title key, and the content data is decrypted and output. Read the title key encrypted data encrypted with the system key, decrypt the data using the system key by the title key decrypting means, and select the title key of the designated title from all the decrypted title keys. After temporarily storing by the title key temporary storage means, the system key is changed by the system key change means, and all the decrypted title keys are decrypted by using the changed system key. Re-encrypted by the writing / reading means, and re-written on the recording medium by the writing / reading means. On the other hand, the writing / reading means reads out the content data of the designated title from the recording medium, together with the temporarily stored title key. A data recording device for outputting. 2. An associating means for associating the title number with the reproducible number information when the reproducible number information is added to the content data, and a reproducible unit for updating the reproducible number information every reproduction. Means for updating the number of times, at the time of recording, a title key is generated by the title key generating means in a state where the reproducible number information is connected by the connecting means, and the title key is transmitted to the system key by the title key encrypting means. Then, the data is encrypted by using the writing / reading means, and is written to the recording medium by the writing / reading means. At the time of reproduction, the encrypted data of the title key is read from the recording medium by the writing / reading means and decrypted by the title key decrypting means. Extracts the number of reproducible times contained in the decrypted title key After updating the reproducible number by the reproducible number updating means,
The title key is regenerated by the title key generating means by reconnecting to the title number by the connecting means, and the regenerated title key is changed to the title using the system key changed by the system key changing means. 2. The data recording apparatus according to claim 1, wherein the data is re-encrypted by a key encrypting means and rewritten on the recording medium by the writing / reading means. 3. The data recording apparatus according to claim 1, wherein a random number generator is used as the system key generating means, and random number data generated by the random number generator is used as a system key. 4. The system key generating means includes a counter for setting an initial value arbitrarily and counting the number of operations, a constant generator for generating a constant, a constant generated by the constant generator and a counter for the counter. 2. An arithmetic unit for performing a predetermined operation using the count value, wherein an operation result of the arithmetic unit is used as a system key.
The data recording device according to the above. 5. The data recording apparatus according to claim 4, wherein the constant generator generates a different constant for each data recording apparatus. 6. A data recording method for recording content data for which unlimited copy protection is required on a recording medium, wherein a system key generation procedure for generating a system key and a title number attached to the content data to be recorded are different. A title key generating procedure for generating a title key, a title key encrypting procedure for encrypting the title key using the system key, and a content data encrypting procedure for encrypting the content data using the title key. A writing / reading procedure of writing the encrypted data of the content data on the recording medium, writing the encrypted data of the title key on the recording medium or another recording medium, and reading and outputting each of them as required; Encrypted data of the read title key A title key decryption procedure for decrypting using the system key, and encrypting the read content data.
A content data decrypting procedure for decrypting using the decrypted title key; a title key temporary storing procedure for temporarily storing the decrypted title key; and a system key for changing a system key generated in the system key generating procedure. Generating a title key based on the title number given by the title key generation procedure during recording, and encrypting the content data using the title key by the content data encryption procedure. Encrypting the title key using the system key according to the title key encryption procedure, and writing the title key and content data encrypted data to the recording medium according to the write / read procedure. Be prepared, Reading the title key of the designated title and each encrypted data of the content data from the recording medium by the writing / reading procedure; decrypting the title key by using the system key by the title key decrypting procedure; Decrypting the content data using a decryption title key according to a content data decryption procedure, and outputting the decrypted content data. At the time of duplication, a title key encryption encrypted from the recording medium with at least the system key according to the write / read procedure Reading the encrypted data;
Decrypting using the system key according to the title key decrypting procedure, and selecting a title key of a designated title from all decrypted title keys and temporarily storing the title key according to the title key temporary storing procedure Changing the system key by the system key change procedure; re-encrypting the decrypted all title keys by the title key encryption procedure using the changed system key; and Writing the re-encrypted data of all title keys to the recording medium again by a read / read procedure;
Data comprising a step of reading content data of a designated title from the recording medium by the write / read procedure, and a step of outputting the read content data together with the temporarily stored title key. Recording method. 7. An associating procedure for associating the title number with the reproducible number information when the reproducible number information is added to the content data, and a reproducible unit for updating the reproducible number information for each reproduction. And a step of generating the title key during recording.
A title key is generated by the title key generation procedure in a state where the number of times of reproduction is linked by the linking procedure, and at the time of reproduction, the number of times of reproduction which is read from the recording medium and included in the decrypted title key is reproduced. Extracting and judging whether or not the number of reproducible times remains from the extracted information on the number of reproducible times. If not, the reproducing process is stopped. Updating the reproducible count, reconnecting the reproducible count information updated to the title number by the concatenating procedure, and regenerating a title key based on the concatenated information by the title key generating procedure. The title key regenerated using the system key changed in the system key change procedure. 2. The data recording method according to claim 1, further comprising the steps of: re-encrypting data by a torque key encryption procedure; and rewriting re-encrypted data of a title key to the recording medium by the writing / reading procedure. . 8. The data recording method according to claim 6, wherein said system key generating step uses random number data as a system key. 9. The system key generating procedure includes a counting procedure in which an initial value is arbitrarily set and counting the number of operations, a constant generating procedure for generating a constant, a constant generated in the constant generating procedure, and the count. 7. The data recording method according to claim 6, further comprising an operation procedure for performing a predetermined operation using the count value of the operation procedure, and using an operation result of the operation procedure as a system key. 10. The data recording method according to claim 9, wherein said constant generating step generates a different constant for each data recording device.