JP2001331106A - Enciphered information signal, information recording medium, information signal reproducing device, and information signal recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it substantially impossible to reproduce an illegally made information signal from recording medium irrespective of the kind of the recording medium, and to make it possible to effectively and inexpensively prevent a copy from being produced. SOLUTION: The information signal is an enciphered information signal in which the information signal subjected to be controlled for reproduction is enciphered, and the information signal is a signal on which ID information for discriminating that the information signal is the one in an enciphered state is superimposed as a digital watermark information, and the enciphered information signal, an information recording medium on which the signal is recorded, an information signal reproducing device for reproducing the signal, and an information signal recording device for recording the signal are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for restricting illegal duplication when recording an information signal such as a digitized work, for example, video or music, on an information recording medium, and a technique for restricting illegal duplication. The present invention relates to a technique for restricting reproduction from an information recording medium.

[0002]

2. Description of the Related Art In recent years, with the spread of digital contents, copyright infringement due to unauthorized duplication of digital contents has become a serious problem. In order to prevent unauthorized duplication, information for duplication control (duplication control information) is added to the digital content, or the information signal is encrypted using encryption technology, and the device is not a licensed device. A technology for preventing decryption (decoding) is considered for such devices. There is also a technique for embedding copy control information as digital watermark information in an information signal. Since the digital watermark information is superimposed on the information signal as noise and cannot be easily rewritten, reproduction control and recording control can be performed even when the copy control information is illegally rewritten.

Information added to an information signal for duplication control includes "copy free (Copy Free)", "one copy possible (One Copy)", "no more copy prohibition (NoMore Copy)", and "absolute copy." Copy prohibited (Ne
ver Copy) ". These four states can represent a copy generation or a copy restriction state of the information signal.

[0004] Restriction of copying is performed as follows. That is, the recording apparatus checks the copy control information included in the information signal of the image, the sound, and the like, and restricts the recording if the copy control information indicates “no more copy prohibited” or “absolute copy prohibited”. Thereby, the copy generation restriction is realized. However, a recording device that does not check the copy control information can record an information signal in a state of “no more copy prohibited” on a recording medium, and this recording medium has the same information signal as the original information signal containing the copy control information. This is a recording medium on which an information signal is directly copied. This does not protect copyright.

As a technique for solving this problem, Japanese Patent Laid-Open No. 11-353796 discloses a technique in which digital watermark information is further superimposed on an information signal and the state indicated by the digital watermark information is rewritten when the information signal is reproduced. There is described a technique for substantially preventing reproduction from a recording medium on which an unauthorized recording has been made.

This will be described more specifically. In this description, corresponding to decryption processing or writing processing of digital watermark information is referred to as “compliant”, and non-compliant is referred to as “non-compliant”. FIG. 16 is a diagram illustrating the principle of the conventional copy control. In a RAM disk 1300 such as a DVD-RAM, copy control information (CGMS [11]) indicating “no more copy is prohibited” and digital watermark information (WM [No More]) indicating “no more copy is prohibited” Copy])
Are superimposed on the information signal. When reproducing this information signal, the compliant reproducing apparatus 1301
Rewrites the digital watermark information from “No More Copy” (no more copying prohibited) to “Never Copy” (absolute copying prohibited), superimposes it on the information signal, and sends out the information signal as a reproduction output signal. . In a DVD-RAM, "No More Copy" is normally used to prohibit copying, and "Neve
Therefore, when the digital watermark information superimposed on the information signal is detected as “Never Copy”, the compliant recording device 1302 does not record the information signal, thereby controlling the copy. .

On the other hand, the non-compliant recording device 13
No. 03 records an information signal on another RAM disk 1304 without recording restriction regardless of the content of the digital watermark information.
However, the illegally recorded RAM disk 130
The digital watermark information of No. 4 is “Never Copy”. Therefore, the compliant playback device 1305 reads the digital watermark information to read the digital
Is determined to be a recording medium on which illegal duplication has been performed, and reproduction is substantially disabled.

[0008]

As described above, the conventional compliant reproducing apparatus 1301 changes the contents of the digital watermark information from "No More Copy" (no more duplication is prohibited) to control duplication. Rewrite to “Never Copy”. For this reason, it is indispensable for the playback device to have means for rewriting digital watermark information, which leads to an increase in the cost of the playback device.

The above technique cannot be applied to a DVD-ROM. This is because in the DVD-ROM, digital watermark information “Never Copy” for determining whether or not the content is illegal is written to the disc in normal use.

In view of the above, it is an object of the present invention to effectively and inexpensively reduce the reproduction of information signals from an illegally created recording medium regardless of the type of the recording medium. The purpose is to prevent duplication.

[0011]

In order to solve the above-mentioned problems, a copy generation management according to the present invention provides at least an information recording medium for recording an information signal requiring copy control,
On the information signal, which is an information signal in a state of prohibiting further duplication and absolute duplication, scramble information indicating that the information signal is to be recorded in a scrambled state on an information recording medium is superimposed as digital watermark information, and the digital watermark information is superimposed. The information signal is a scrambled information signal.

According to the information recording / reproducing apparatus of the present invention, the information signal in which the further duplication is prohibited or the absolute duplication is prohibited includes scramble information indicating that the information signal is to be recorded on the information recording medium in a scrambled state. An information reproducing apparatus for reading an information recording medium recorded as an information signal obtained by scrambling an information signal on which the digital watermark information is superimposed, wherein the information reading means reads information from the information recording medium. Descrambler for descrambling the scramble applied to the information signal, digital watermark information detector for detecting scramble information superimposed on the descrambled information signal as digital watermark information, Examine the information and the descrambling behavior of the descrambling means, at least Scramble information child watermark information is in the scrambled state, if the descrambling unit is not in operation, and a reproduction control means for inhibiting normal reproduction of said information signal.

The information recording apparatus of the present invention can be copied once,
An information recording apparatus for writing the information signal having duplication control information in a state where duplication is prohibited or absolute duplication is prohibited to an information recording medium, comprising: means for detecting the duplication control information; When the information can be copied once, scramble information indicating that the information is recorded in a scrambled state on an information recording medium is superimposed on the information signal as electronic watermark information, and the electronic watermark information is superimposed. The information processing apparatus includes scrambling means for scrambling the information signal, and information writing means for writing the scrambled information signal on an information recording medium.

The information signal recording apparatus according to the present invention is an information recording apparatus for writing the information signal having duplication control information in a state where duplication is allowed once, no more duplication is prohibited, or absolute duplication is prohibited on an information recording medium, Copy control information detecting means for detecting the copy control information, digital watermark information detecting means for detecting digital watermark information superimposed on the information signal, and an information signal recorded in a scrambled state as the digital watermark information Recording control means for prohibiting recording when the scramble information indicating the fact is detected.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an encrypted information signal, an information recording medium, an information signal reproducing device, and an information signal recording device according to the present invention will be described with reference to the accompanying drawings. In the embodiment, the information recording medium is an optical disc represented by a DVD-RAM (ROM), and an information signal is recorded on the optical disc. The target of the copy control is an information signal representing an image, a sound, or the like, that is, image sound information.

In the following description, a recordable DVD is stored in a RAM.
Discs and read-only DVDs are referred to as ROM discs. Further, a recording device and a playback device that support the copy generation restriction process described later are called compliant devices, and a device that does not support the copy generation restriction process is called a non-compliant device.

(Embodiment 1) FIG. 1 is a schematic diagram for explaining a copy generation management method according to the present embodiment.
In the present embodiment, information signals such as video and audio are recorded on the ROM disk 100. However, a RAM disk may be used instead of a ROM disk.

First, an information signal according to the present embodiment will be described. The information signal includes digital watermark information WM (digital WaterMarmar) in the form of noise in addition to signals representing video and audio.
k) is embedded. The characteristics of digital watermark information are mainly that the digital watermark information does not disappear even if the copyrighted work (video or audio) is modified, compressed, or decompressed, and that the digital watermark information is hardly perceived by human eyes and ears. And that the quality of the original work is maintained even when the digital watermark information is embedded. With this feature, unauthorized rewriting can be prevented, and reproduction control and recording control can be performed.

The information signal further records copy control information (not shown). The copy control information is information that can express whether or not copying is possible. For example, CGMS (Copy Generation Management System) using 2-bit information
tem). According to the CGMS, “00” indicates “copy free”, “01” indicates “copy permitted once”, “10” indicates “absolute copy prohibited”, and “11” indicates “copy prohibited any more”.

When the information signal is to be subjected to the duplication control, for example, when the duplication of the information signal is completely prohibited, the present invention is intended to prevent the information signal from being reproduced only by a properly licensed device. Then, the information signal is scrambled (encrypted) and recorded. The characteristic processing of the present invention is:
The purpose is to superimpose scrambled information “Scrambled” indicating that the information signal is scrambled information on the information signal as digital watermark information WM. Therefore, it can be said that the scramble information is encryption state identification information used to identify whether or not the information signal is encrypted. A detailed description of copy control using digital watermark information will be described later. According to the above-described feature of the digital watermark information, the scramble information “Scramble”
Since d ″ does not disappear regardless of the modification, compression or decompression processing of the signal information, it can be detected. The scrambling processing is performed by applying a specific scrambling method (encryption) to the information signal on which the digital watermark information is superimposed. Method).

On the other hand, when the information signal is not subjected to the duplication control, for example, when the free duplication of the information signal is permitted,
The information signal is not scrambled. In this case, the electronic watermark information may or may not be superimposed on the signal information. When the digital watermark information is superimposed, the digital watermark information is scramble information “Non-Scrambled” indicating that the signal information is not scrambled.
Becomes A recording device (not shown) records an unscrambled information signal as it is or an information signal on which digital watermark information is superimposed on a disc,
00 is manufactured.

Prior to describing the duplicate generation management method of the present invention, a procedure of a scrambling process when manufacturing the ROM disk 100 will be described first. The scrambling process described below is performed by the manufacturer of the ROM disk 100 using an authoring system and a disk cutting system. An example of the scramble process is DVD-RO
M copyright protection system CSS (Content Scramble Sys
tem). Information signals including video, audio, and the like are encrypted using three types of encryption keys in a hierarchical manner. The three types of encryption keys are a title key, a disk key, and a master key. Hereinafter, a description will be given along a content encryption procedure of the copyright protection system CSS. As used herein, the term “scramble” means “encrypted”. The encryption method for scrambling may be any algorithm that performs encryption using one key. Therefore, well-known algorithms are available. The description of the algorithm is omitted. Note that this algorithm is often kept secret from the viewpoint of security. On the other hand, returning scrambled information to unscrambled information is called "descrambling". This is synonymous with the words "decrypt" or "decrypt".

The procedure of the scrambling process is as follows. First, an information signal is MPEG-compressed and then scrambled using a title key. The title key is
This is a key freely selected by a copyright owner, for example, a movie director, for each title stored on the disc, that is, for each information signal unit. The scrambled signal information is stored in the data recording area of the disc.

Next, the title key is encrypted using the disk key. The disk key is a key that can be freely selected for each disk by a copyright manager, for example, a movie company. If the disc contains one or more encrypted titles,
The copyright manager is free to determine the disk key. The encrypted title key is stored in the sector header area of the disc, which is inaccessible to the user.

Finally, the disk key is encrypted using the master key and converted into an encrypted disk key set. The master key is a key assigned to each descrambler maker that decrypts the scrambled information signal, and is different for each maker. “Encrypted disk key set” means that one or more encrypted disk keys exist. This is because there are as many master keys as the number of licensed manufacturers, and one or more disk keys of the same number are generated.
The encrypted disk key set is stored in the lead-in area of the disk, which cannot be accessed by the user.

With the above processing, the ROM disk 100
Contains the scrambled signal information, the encrypted title key, and the encrypted disk key set.

ROM disk 10 subject to duplication control
In order to reproduce the information signal of 0, descrambling processing needs to be performed. In order to perform the descrambling process, a license for the above-mentioned predetermined encryption method is obtained,
Information about the decryption key (master key) and the decryption algorithm must be obtained. In a compliant playback device 101 having a decryption function as shown in FIG.
A scrambled information signal is read from the OM disc 100, descrambled, and an information signal that can be MPEG-decoded can be obtained.

The descrambling process performed by a playback device such as a DVD player will be described below.
The scrambling process performed by a recording device such as a drive will be described. FIG. 2 is a diagram showing a data flow when reading or writing scrambled signal information.

FIG. 2A is a conceptual diagram for descrambling a scrambled information signal recorded on the disk 210. The disk 210 is a disk corresponding to the ROM disk 100 (FIG. 1), in which a scrambled information signal 212, an encrypted title key 214, and an encrypted disk key set 216 are recorded. Here, the scrambled information signal 212 is MPEG-compressed video and audio information. The descrambling unit 220 of the playback device is a device that descrambles the information signal and performs MPEG decoding. The descrambling unit 220 includes a disk key decrypting unit 222, a title key decrypting unit 224, an information signal decrypting unit 226,
And an MPEG decoder 228.

The descrambling section 220 reads out the encrypted disk key set 216, the encrypted title key, and the scrambled information signal from the disk 210. The disk key decryption unit 222 first uses its master key stored in an internal storage area (not shown) or provided through another component of the playback device to read its own disk key set 216 from the disk key set 216. Decrypt the disk key. Next, the title key decryption unit 224 decrypts the title key 214 encrypted using the decrypted disc key.
Is decrypted. Then, the information signal decryption unit 226 decrypts the scrambled information signal 212 using the decrypted title key. Thus, the descrambling process is performed. The descrambled information signal is an MPE
Since the data is G-compressed, in the present embodiment, the MPEG decoder 228 performs a decoding process and outputs video and audio information. The processing of the descrambling unit 220 has been described above.

FIG. 2B is a conceptual diagram of scrambling the information signal for recording on the disk 230. This process is, for example, a process for recording an information signal that has been set to "one-time duplication possible". On the disk 230 used for writing, a disk key set 236 which has been encrypted in advance at the time of shipment from the manufacturer is recorded.

First, the MPEG encoder 248 of the scramble unit 240 performs an MPEG compression process on the input information signal, and converts the generated MPEG data into the information signal encryption unit 24.
Send to 6. Next, the information signal encryption unit 246 scrambles the MPEG data using the title key. The title key is a random number generated by the random number generator 250.
On the other hand, the title key encryption unit 244 encrypts the title key using the disk key. Encrypted title key 23
4 is recorded on the disk 230. Here, as the disk key, the disk key corresponding to the maker of the recording device is decrypted from the encrypted disk key set 236 recorded on the disk 230 using the master key held by the scramble unit 240. Is obtained by

Once the title key is generated and recorded on the disk 230 as the encrypted title key 234, when the information signal is scrambled and recorded thereafter, the recorded encrypted title key 234 is used. Used. That is, the scrambler 240 reads out the encrypted title key 234 of the disk, decrypts it with the disk key, and scrambles the information signal using the title key.

As described above, the scrambler 240
The title key can be obtained through two routes. That is, there are two cases, that is, the case where the random number generated by the random number generator 250 is obtained as the title key, and the case where the encrypted title key 234 recorded on the disk 230 is decrypted and obtained as the title key. When the program distribution increases in the future, it is considered that a title key is generated on the broadcaster (content creator) side, and the information signal scrambled by the title key is distributed as a digital broadcast by radio waves. In this case, the title key obtained from the broadcaster and the scrambled information signal are recorded on the disc.

As described above, the scrambling and descrambling of the information signal are performed.

Next, referring again to FIG. 1, the principle of copy generation management according to the present invention will be described. In the present embodiment, when signal information is to be subjected to copy control, scramble information “Scrambled” is superimposed on the signal information as digital watermark information. It is assumed that signal information on which scrambled information “Scrambled” is superimposed is recorded on the ROM disk 100 in a scrambled manner.

The main features of the copy generation management according to the present invention are that the signal information on the disc has a scrambled state (ie, whether or not it has been scrambled) and the state of the scrambled information (ie, the scrambled information is “
to determine whether to perform reproduction or recording or to limit them, according to the comparison result. Whether the signal information is scrambled depends on whether the signal information is scrambled or not. The determination is made based on whether a predetermined flag is set in the information or the information of the related attached file, or whether the descrambling unit operates normally.
Specifically, first, the playback device 101 first sets the RO
The scrambled signal information is read from the M disk 100 and descrambled. And the playback device 10
1 detects the scramble information from the descrambled signal information and compares whether the scramble states match. Here, the signal information is in a scrambled state, and the scramble information is “Sc
Therefore, it can be determined that the scrambled states match from each other, so that the compliant playback device 101 outputs the descrambled information signal. At this time, it should be noted that the output information signal includes the scramble information “ This is because the “Scrambled” is superimposed because the scramble information as the digital watermark information does not disappear by the descrambling process of the compliant playback device 101.

Next, the principle of restricting the recording when the information signal output from the reproducing apparatus is illegally recorded on the recording medium will be described. Compliant recording device 1
02 receives the descrambled information signal from the compliant playback device 101. The compliant recording device 102 recognizes that the received signal information is in a descrambling state and that the superimposed scramble information is “Scrambled”. As a result, since the state of the output information signal does not match the state indicated by the scramble information, the compliant recording device 10
2 does not perform recording on a recording medium such as a RAM disk.
This allows the compliant recording device 102 to restrict recording of signal information.

On the other hand, even when the information signal has not been scrambled, the scrambling state may be similarly compared. If digital watermark information is not detected, or if digital watermark information “Non-Scrambled” is detected, an information signal is output. The signal output in this manner can be freely copied, and the compliant recording device 102 permits the copying of the information signal to the RAM disk.

Next, the principle of restricting reproduction when an information signal is illegally copied to a RAM disk will be described.
The non-compliant recording device 103 receives the descrambled information signal output by the compliant playback device 101. This information signal is the scramble information.
Scrambled ", the copy control is performed. However, the non-compliant recording apparatus 103 transmits the information signal to the RAM disk 1 without detecting the digital watermark information.
Copy to 04. Then, the compliant playback device 1
When reproducing such a RAM disk 104 at 05, the compliant reproduction device 105 compares the scrambled state. In this case, the information signal is recorded in a descrambled state, while the information signal is superimposed with scramble information "Scrambled" indicating that the information signal is scrambled. Therefore, the compliant playback device 105 determines that the information signal of the RAM disk 104 is an information signal that has been illegally copied, since the comparison result indicates a mismatch. Thereby, the compliant reproduction device 105 prohibits reproduction of the information signal.

Note that the reproduction is restricted even when the recording target is not the RAM disk 104. For example, the target of recording may be a DVD-R that is writable but once written, becomes a read-only disc.

In order to more reliably prohibit unauthorized recording and reproduction, a technique of making the encryption algorithm used for scrambling different according to the type of recording medium is also used. For example, by making the encryption algorithm for DVD-ROM different from the encryption algorithm for DVD-RAM, the information signal scrambled by the algorithm for DVD-ROM is converted to DVD-ROM.
Even if illegally copied from DVD to DVD-RAM,
-Reproduction from RAM can be prohibited. In order to realize this operation, for example, a table may be provided for associating the type of the recording medium with the encryption algorithm used for each type. If the descrambling circuit fails to descramble by the decoding algorithm corresponding to the type of the recording medium, it is possible to prohibit reproduction of the signal information from the illegally duplicated recording medium. The type information indicating the type of the recording medium may be superimposed on the information signal as digital watermark information together with the scramble information. The type information indicates the type of the recording medium to be recorded. Therefore, DV
It is possible to distinguish between recording on the DR and recording on the DVD-RAM.

As described above, in the present invention, the scrambled (encrypted) information signal is provided with the encryption information (scrambled information “Scrambled”) indicating that the information signal is encrypted, as the digital watermark information. Are superimposed. Even if the signal information is decoded, the digital watermark information remains as it is without being altered. Since the signal information indicates a decrypted state (unencrypted state) and the digital watermark information indicates an encrypted state, by detecting the mismatch, any of the compliant recording apparatus and the reproducing apparatus can use other recording medium. Illegal recording on or reproduction from an unauthorized recording medium can be prohibited. Therefore, even if the digital watermark information rewriting means is not mounted on the compliant playback device, the unauthorized reproduction of the illegally copied disc performed by the non-compliant recording device 103 can be prohibited by the compliant playback device.

In the present embodiment, the scramble information (“S
crumbled "," Non-Scrambled "
Although d ") is superimposed on the information signal, other information may be used as long as the information indicates the scrambling state of the information signal. For example, in the case of a ROM disk, information indicating" absolute duplication prohibition "which is duplication control information When an information signal is scrambled and recorded on a signal, the same effect can be obtained by superimposing the copy control information on the information signal as digital watermark information.

[Recording Apparatus] Next, the configuration of the compliant recording apparatus 102 will be described with reference to FIG. FIG.
1 shows a configuration of a compliant recording device 102. The compliant recording device 102 has a digital input terminal 301.
And an analog input terminal 302. Each receives a digital signal such as encryption key information and an analog signal such as video and audio information from connected devices. Decryption unit 303
Decrypts the encrypted data based on the encryption key information sent from the device connected to the digital input terminal, and restores the compressed video data. At this time, copy control information indicating whether or not the input information signal can be copied is detected. The copy control information is also information superimposed on the information signal.

The video information input through the analog input terminal 302 is supplied to the encoding unit 304 through the analog input terminal 302 and is subjected to MPEG compression.
As a result, compressed video data is generated. At this time, copy control information indicating whether or not the input information signal can be copied is detected.

The selector 305 selects and outputs one of the data from the decryption unit 303 and the data from the encoding unit 304 according to a selector control signal corresponding to the user's input selection.

The data output from the selector 305 is supplied to the recording control unit 308 via the WM rewriting unit 306. The WM rewriting unit 306 adds scramble information “Scrambled (RA) to the information signal as digital watermark information.
M) ”is superimposed. However, this processing needs to be performed after determining the type of the recording medium described later. The processing of the WM rewriting unit 306 is, for example, a pseudo-noise code sequence. The spectrum spreading of the scramble information is performed by using the following code, and the spectrum spread scramble information is output.Since this is a well-known technique, detailed description is omitted.
It is also supplied to the WM decoding unit 307. The WM decoding unit 307 extracts the scramble information superimposed on the information signal as the digital watermark information, determines the description content,
The discrimination output is supplied to the control unit 309.

The control unit 309 determines whether or not recording (copying) of the input information is possible based on the copy control information detected from the input information and the discrimination output of the digital watermark information. If it is determined that it is possible, it is further determined whether or not the digital watermark information needs to be rewritten for copy control. When it is determined that the recording is prohibited, the control unit 309 controls the recording control unit 3
08 controls not to execute recording. When it is determined that recording is possible or that copying is possible once, the control unit 309 causes the recording control unit 308 to execute recording. At this time, the recording device 102 reads information about the type of the disk (type of a RAM disk, a type of disk that can be written only once, etc.) via the reading unit 313, and the disk type determining unit 314 determines the type of the disk. . As a result, the content of the scramble information as described above is determined, scramble information to be superimposed on the information signal is generated in the WM rewriting section 306, and is superimposed on the information signal in the recording control section 308. The information signal is subjected to a specific scramble according to the type of the disc by the scramble section 310 and the write section 31
1 is recorded on the RAM disk 312.

Next, with reference to FIG. 4, a process after the compliant recording apparatus 102 completes decryption will be described. FIG. 4 is a flowchart illustrating a recording processing flow of the recording apparatus 102.

First, the copy control information detected when the information signal is input is checked (step S101). Then, the copy control information is “Never Copy” (absolute copy prohibited)
Alternatively, it is determined whether or not “No More Copy” (no more copying is prohibited) (step S102). If it corresponds to any of them, the recording is prohibited and the recording process is stopped (step S103). Note that “Never Copy” (absolute copy prohibition) indicates that a restriction is imposed that copying of the information signal is completely prohibited. On the other hand, “No More Copy” (prohibition of further copying) imposes a restriction that if music data or image data that can be copied only once is copied, further copying of the information signal is prohibited. It represents that. If none of the above applies (“Never Copy” or “No M
If it is not “ore Copy”, the determination output of the digital watermark information (WM) superimposed on the input signal is checked (step S104), and the digital watermark information (WM) is set to “Scr”.
(step S105). In the case of the "Scrambled" state, since the information signal to be recorded is originally scrambled information, the information signal is the copy control information. Is determined to be information that has been tampered with and input, and the recording process is stopped (step S103).
If it is not in the “rambled” state, it can be determined that the information is recordable.

If it is determined that the information is recordable information, the copy control information is set to "copy once (One time)" in order to determine whether the information signal needs to be scrambled.
It is determined whether the information signal is in the “Copy” state (step S106). If the information signal is in the “one-time copy allowed” state, the digital watermark information is stored in “Scramble (RA)
M) "state (step S107), and performs a scrambling process in accordance with a specific scrambling method (step S108). The recording device 102 (FIG. 3) records the information thus generated on the RAM disk. (Step S109).

If it is not "one-time duplication possible" (any number of "duplication possible"), the scramble processing is not performed and R
The data is recorded on the AM disk (step S109).

The compliant recording device 1 as described above
In the RAM disk recorded by No. 02, scramble information as digital watermark information and scramble for the information signal are recorded as a pair with respect to an information signal which can be copied once and which requires copy control.

Further, based on the predetermined information read by the reading unit 213 (FIG. 2), the disc type discriminating unit 21
4 may determine the type of the loaded disk and record the type of the disk in the digital watermark information. The disk type is
Whether it is a ROM disk (playback only), a RAM disk (writable), a disk that can be written only once, a disk that can be written about 1000 times, or a disk that can be written about 100,000 times Is a good disk. The disc is determined based on, for example, physical characteristics (focus characteristics, tracking characteristics, and reproduction characteristics) of the disk, information on a control area in which the disk type is recorded, and the like.

In the scrambling process, only a part of information (such as I-frame data of MPEG compressed data) may be subjected to scrambling in consideration of a load at the time of reproducing information. In this case, the electronic watermark information needs to be superimposed on all of the partial information.

When producing a ROM disk in which the information signal is scrambled as described above, for example, the information recording apparatus is configured as an authoring system and a disk cutting system. The authoring system compresses the information signal according to the information signal and superimposes scramble information as digital watermark information. The disc cutting system performs a scramble process according to the information signal to create a master disc. By using these, it is possible to produce a ROM disk capable of performing the above-described duplication control.

[Reproducing Apparatus] Next, the configuration of the compliant reproducing apparatus 105 will be described with reference to FIG. The compliant playback device 105 and the compliant playback device 101 have the same configuration. FIG. 5 is a block diagram showing a configuration of the compliant playback device 105. Information recorded on the disc loaded in the playback device 105 is read by the reading unit 401 and supplied to the descrambling unit 402, the scramble state detecting unit 403, and the disc type determining unit 404.

The scramble state detection unit 403 extracts a scramble flag recorded on the disc as additional information, detects whether or not the record information is scrambled, and outputs the detection result to the control unit 405. . Note that a copy prohibition ROM disk has a specific encryption method (for example, CSS: Contents Scr).
It is assumed that the encryption is performed by the use of an encryption system or the like.

The disc type discriminating unit 404 discriminates the type of the loaded disc, and supplies the discrimination result to the control unit 405. The disk type is a ROM disk (playback only), a RAM disk (writable), a disk that can be written only once, a disk that can be written about 1000 times,
It is a disc that can be written to about 100,000 times.
The disc is determined based on, for example, physical characteristics (focus characteristics, tracking characteristics, and reproduction characteristics) of the disk, information on a control area in which the disk type is recorded, and the like.

In the case of a ROM disk, the descrambling unit 402 converts the scramble performed by the manufacturer into a RAM.
In the case of a disc, the scrambling unit 240 of the recording device
The scramble performed in ((b) of FIG. 2) is decoded.
The descrambling unit 402 performs the processing of the descrambling unit 220 described with reference to FIG.

The descrambling unit 402 supplies the output data to the WM decoding unit 406 and the reproduction control unit 407. The WM decoding unit 406 decodes scramble information superimposed on the information signal as digital watermark information. "Decoding" means to extract scramble information and determine its contents. This is because the electronic watermark information is superimposed on the information signal as noise and is considered to be encoded. The WM decoding unit 406
The determination result is output to the control unit 405.

The control unit 405 determines whether to permit or prohibit the reproduction based on the discrimination result of the disc type, the scramble flag, and the discrimination output of the digital watermark information. Compliant recording device 102
In the disk recorded by FIG. 1 (FIG. 1), the scramble for the information signal and the contents represented by the scramble information are recorded in pairs.

Therefore, when a disc that violates this is loaded, the descramble section 402 supplies the control information of the reproduction inhibition to the reproduction control section 407 and inhibits the processing after the reproduction control section 407. I do. In the case of an information signal from a legitimate disk, the processing after the reproduction control unit 407 becomes effective. The reproduction control unit 407 supplies the video / audio information to the decoding unit 408, and the decoding unit 408 expands (decodes) the MPEG-compressed data. The analog I / F 409 performs D / A conversion on the decompressed (decoded) data and supplies the data to an external device. In addition, digital I / F4
In the case where there is a device connected to the H.11, the encryption unit 410 encrypts the MPEG-compressed data,
411.

Next, the reproduction process of the compliant reproduction device 105 (FIG. 5) will be described with reference to FIG. FIG.
It is a flowchart which shows a reproduction | regeneration processing flow. The playback device 105 (FIG. 5) first determines whether or not the information signal recorded on the loaded disc is scrambled (step S201). The scrambling includes a scrambling method for a RAM disk applied by the scrambling unit 240 (FIG. 2) of the recording device 102 and a scrambling method for a ROM disk (for example, CSS).
Method). Since the scrambling method differs depending on the type of the disk, the disk type determining unit 404 (FIG. 5)
Checks the disk type (step S202).

As a result of the disc type check, if the disc is a ROM disc, the descrambling processing unit 4
02 (FIG. 5) performs a descrambling process for the ROM (step S203). Next, the WM decoding unit 406 (FIG. 5) checks whether digital watermark information (WM) indicating a scramble state is described in the descrambled information signal (step S204), and the control unit 405 (FIG. 5). ) Indicates that the digital watermark information is “Scramble
It is determined whether the status is “led (ROM)” (step S205). “Scrambled (RO)
M) ", the control unit 405
(FIG. 5) permits reproduction (step S211), and prohibits reproduction when not in that state (step S212).

As a result of the disk type check in step S202, if the disk is a RAM disk, the descramble processing unit 402 (FIG. 5) similarly
Perform descrambling processing for M (step S20)
6). Then, the WM decoding unit 406 (FIG. 5) detects digital watermark information (WM) indicating a scrambled state from the descrambled information signal (step S207).
The control unit 405 (FIG. 5) determines whether the digital watermark information is in a “Scrambled (RAM)” state (step S208). “Scrambl
ed (RAM) ", the control unit 405 (FIG. 5) permits reproduction (step S21).
1) When it is not in that state, reproduction is prohibited (step S212).

If it is determined in step S201 that scrambling has not been performed, descrambling section 402 (FIG. 5) transmits signal information to WM decoding section 406 (FIG. 5) without performing descrambling processing. Send. The WM decoding unit 406 (FIG. 5) detects the digital watermark information (WM) (step S209), and the control unit 405 (FIG. 5) determines that the digital watermark information is “Scramble”.
ed "is determined (step S2).
10). When in the “Scrambled” state,
The control unit 405 (FIG. 5) prohibits reproduction (step S212), and if not, permits reproduction (step S211). Here, “when not in that state” means that the digital watermark information is not detected or that the detected digital watermark information is “Non-Scram”.
bled ".

That is, the compliant recording device 10
2 (FIG. 1), the information signal in which the digital watermark information WM is recorded as "Scrambled" has been scrambled. However, the fact that the information signal is not scrambled even though “Scrambled” is recorded in the digital watermark information WM means that the information signal has been illegally copied. For example, when the output of the compliant playback device 101 (FIG. 1) is recorded on the disc by the non-compliant recording device 103 (FIG. 1), or the scramble applied to the information signal is illegally descrambled, This is the case when recorded in.

On the other hand, the recording apparatus 102 (FIGS. 1 and 3) and the reproducing apparatuses 101 and 105 according to the present invention as described above.
By using (FIGS. 1 and 5), reproduction in such a case can be prohibited. Thereby, even if the rewriting device for rewriting the digital watermark information is not mounted on the playback device,
Unauthorized duplication can be prevented, and the cost of the reproducing apparatus can be easily reduced.

When only a part of the information signal is scrambled, it is necessary to check not only the scramble flag of the information signal but also whether or not the descrambling process is normally performed in the descrambling unit 402. is necessary. Thus, it is possible to prohibit reproduction even if the scramble flag of the illegally copied information signal is rewritten to the scramble state. Although the information signal is encrypted by scrambling here, the same effect can be obtained when encryption is performed using another method.

Although the first embodiment has described the case where the optical disk is used as the information recording medium, the same applies to other semiconductor memories and magnetic recording media (such as hard disks).

(Embodiment 2) In Embodiment 1, the recording device 102 (FIGS. 1 and 3) and the reproducing devices 101, 10
Blocks 5 (FIGS. 1 and 5) record information signals on a disk or reproduce information signals from a disk (a writing unit 311 (FIG. 3) and a reading unit 401 (FIG. 5)), a digital watermark. A block for detecting information (the WM decoding units 307 (FIG. 3) and 406 (FIG. 5)) and a block for expanding / compressing the information signal (the encoding unit 304 (FIG. 3) and the decoding unit 408 (FIG. 5)) The description has been made assuming that the apparatus is configured to be entirely included in the apparatus.

However, when the functions of the recording device and the reproducing device are realized by the PC, the drive unit for recording / reading the information signal and the encoder / decoder unit are generally configured as separate devices. It is a target.

If the apparatus is configured as a separate device, since the decoder controls the reproduction based on the disk type detected by the drive unit, the disk type is improperly replaced and the illegally duplicated disk can be reproduced. More specifically, when an information signal recorded on a ROM disk is recorded on a RAM disk by a non-compliant recording device and then reproduced, illegal software intervenes between the drive unit and the decoder unit. The disk type detected by the drive can be replaced with “ROM”. As a result, the ROM disk is
When illegally copied to the M disk, reproduction cannot be prevented as in the compliant reproduction apparatuses 101 and 105 (FIG. 1). In the present embodiment, a configuration for preventing reproduction even in such a case will be described.

[Recording Device by PC] FIG. 7 is a diagram showing an example in which a compliant recording device is realized by a personal computer (PC) recording system 600. As shown in FIG. 7, such a compliant PC recording system 600 mainly includes a PC encoder 600-1 and a PC recording device (drive) 600-2. Digital I / F that can prevent duplication (SCSI, ATAPI, IEEE1394, etc.)
Connected by The PC encoder 600-1 includes an I / F 301 of the compliant recording device 102 (FIG. 3),
It corresponds to the configuration from 302 (FIG. 3) to the scrambler 310 (FIG. 3), and performs the same operation as the operation. Therefore, description of the common operation is omitted. On the other hand, the PC recording device (drive) 600-2 corresponds to the configuration of the writing unit 311 (FIG. 3).

Hereinafter, the operation of the PC encoder 600-1 is determined by the I / F of the compliant recording device 102 (FIG. 3).
Points different from the operations realized by the configuration from 301, 302 (FIG. 3) to the scrambler 310 (FIG. 3) will be described. When an information signal that can be duplicated once is recorded on the RAM disk, the scrambling unit 610 of the PC encoder 600-1 performs a specific scrambling on the information signal. At this time, in order to safely share the key information serving as the basis for scrambling between the PC recording drive and the PC encoder,
Authentication unit 613 via digital I / F 615, 616,
617 performs mutual authentication. If the authentication is successful, it can be confirmed that the authentication unit 613 and the authentication unit 617 in the PC recording drive are devices that have received a proper license, that is, compliant devices. If the authentication is successful, a bus key for encrypting data to be transmitted on the digital I / F is shared. In this way, the PC encoder uses the shared bus key to encrypt data (key information, information signal, and the like) that needs to be protected in the encryption unit 614, and the digital I / F 615
Data encrypted via the PC recording drive 600
-2.

The decryption unit 618 of the PC recording drive 600-2 decrypts the received data based on the shared bus key. The writing unit 611 includes the PC encoder 60
The information signal received from 0-1 is recorded on the RAM disk 612. At this time, the recording control unit 619 performs recording control so that data that needs to be recorded in a specific protected area, such as key information, is not written to the RAM disk 612 unless the authentication for the PC encoder is established.

In a compliant device, a mutual authentication method and a processing method for key information and an information signal are changed according to a disc type and a recorded information signal. Disc type discriminating section 62 of PC drive 600-2
1 determines the physical characteristics (focus characteristics, tracking characteristics, and reproduction characteristics) of the disk 612 and the type of the disk recorded in the control area of the disk 612 based on the signal reproduced from the reading unit 620. The determination result is output to the control unit 622. It is to be noted that the information indicating the disk type may be falsified during transfer. However, according to the method described later, such tampering during transfer can be prevented. The control unit 622 switches an authentication method, a data transmission method, and the like according to the disk type, and performs data transmission with the PC encoder 600-1.

Next, the processing flow of the PC encoder 600-1 and the PC drive 600-2 of the PC recording system 600 will be described. FIG. 8 shows the PC encoder 600-1.
8 is a flowchart showing a processing flow in a control unit 609 (FIG. 7). First, when recording an information signal that can be copied once, the control unit 609 (FIG. 7)
Are the authentication unit 613 and the authentication unit 6 of the PC drive 600-2.
17 (FIG. 7) (step S301). As a result of the authentication by the authentication unit 613 (FIG. 7),
The control unit 609 (FIG. 7) determines whether both are compliant devices (step S30).
2). Thus, it is possible to confirm whether or not the device is a properly licensed device before recording the information signal.

If the authentication is successful, the PC encoder 6
A common bus key is generated between 00-1 and the PC drive 600-2 (FIG. 7) (step S303). And P
The C encoder 600-1 (FIG. 7)
The key information used for scrambling generated in 0-2 (FIG. 7) (hereinafter, referred to as “scramble key information”) is obtained from the PC drive 600-2 (step S304).
The scramble key information is stored on the PC based on the shared bus key.
This is information transferred by the drive 600-2 after performing encryption and / or tampering prevention processing.

The control unit 609 (FIG. 7) of the PC encoder 600-1 records an information signal according to the same recording flow as in FIG. 4 (steps after step S305). Since this recording flow has already been described with reference to FIG. 4, its description is omitted.

The difference from the flow of FIG.
Step S31 of checking whether or not mutual authentication has been established after discrimination of “one-time copying is possible” in step 06 (FIG. 4).
1 is inserted. If mutual authentication has not been established in step S311, recording is prohibited.

Next, the processing of the PC drive 600-2 (FIG. 7) will be described. FIG. 9 shows a PC recording drive 600-2.
8 is a flowchart showing a processing flow in the control unit 622 (FIG. 7). The previous PC encoder 600
As in the case of -1, when recording an information signal that can be duplicated once,
The control unit 622 (FIG. 7) is the authentication unit 617 (FIG. 7).
And the authentication unit 613 (FIG. 7) of the PC encoder 600-1 to perform mutual authentication (step S401). Then, as a result of the authentication by the authentication unit 617 (FIG. 7), the control unit 622 (FIG. 7) determines whether or not the mutual authentication has been established (step S402).

If the authentication is successful, the control unit 6
22 (FIG. 7) generates a common bus key. Then, the control unit 622 (FIG. 7) performs encryption and / or tampering prevention processing on the scramble key information based on the shared bus key, and transmits the P-key from the PC recording drive 600-2 (FIG. 7).
Transfer to the C encoder 600-1 (FIG. 7) (S40)
4). Then, access (recording and reproduction) to the scrambled information signal, scramble key information, scramble control information, and the like is permitted, and recording is performed (step S405). On the other hand, if mutual authentication is not established in step S402, recording of only the information signal is permitted,
Recording of scramble key information, scramble control information, and the like in a specific area of a part of the disc is prohibited. (Step S
406).

Therefore, when the compliant PC encoder 600-1 and the PC drive 600-2 (FIG. 7) are not the same, access to the scramble key information and the scramble control information can be prevented. As a result, in the recording of an information signal that can be duplicated once and requires duplication control, both are compliant with the PC encoder 60.
In the compliant PC system 600 (FIG. 7) in which the PC drive 0-1 and the PC drive 600-2 are combined, the digital watermark information “Scrambled” and the scrambled state of the information signal are detected, and copying is enabled. On the other hand, in a PC system in which either the PC encoder or the PC drive is non-compliant, it is not possible to access a specific area on the disc and correct scrambling cannot be performed. [Playback Device by PC] FIG. 10 is a diagram showing an example in which a compliant playback device is realized by a personal computer (PC) playback system 900. As shown in FIG. 10, such a compliant PC playback system 900 mainly includes a PC decoder 900-1 and a PC playback device (drive device) 900-2.
Digital I / F between them can prevent unauthorized duplication
(SCSI, ATAPI, IEEE1394, etc.). The PC decoder 900-1 corresponds to a configuration from the descrambler 402 (FIG. 5) to the I / F 409 and 411 (FIG. 5) of the compliant playback devices 101 and 105 (FIG. 5), and performs the same operation as the operation. Do. Therefore, description of the common operation is omitted. On the other hand, the PC playback device (drive) 900-2 includes a reading unit 401.
This corresponds to the configuration shown in FIG. The reading unit 901 reads the recorded information from the disk 950 loaded in the PC playback device (drive) 900-2, and reads a scrambled state detection unit 904 and a disk type determination unit 903.
To supply. The scramble state detection unit 904 and the disc type determination unit 903
As in the case of 1, 105 (FIG. 5), the scramble flag and the disc type are obtained.

When the scrambled information signal is output from the digital I / F 916, the authentication unit 915 of the PC playback device (drive) 900-2 exchanges information with the authentication unit 919 of the PC decoder 900-1. Perform authentication. If the authentication has not been established, the reproduction control unit 913 sets the PC
Reading of information signals from the playback drive is prohibited. If the authentication is successful, the descrambling unit 902 in the PC decoder reads the information signal and performs a specific descrambling process on the scrambled copy-prohibited information signal.

At this time, in order to securely share the key information serving as the basis of the scramble between the PC reproduction drive and the PC decoder, the authentication section 9 is transmitted via the digital I / Fs 916 and 917.
15, 919 perform mutual authentication. If the authentication is successful, it is possible to confirm between the authentication unit 915 and the authentication unit 919 that the devices are properly licensed. Specifically, when the authentication is successfully established, a bus key for encrypting data to be transmitted on the digital I / F is further shared. Using the shared bus key, the PC playback device (drive) 900-2 encrypts the data (key information, information signal, and the like) that needs to be protected by the encryption unit 914, and performs digital I / O. The encrypted data is transmitted to the PC decoder 900-1 via / F916.

In a compliant device, a mutual authentication method and a processing method for key information and an information signal are changed depending on a disc type and a recorded information signal. The disc type discrimination unit 903 discriminates a discrimination from physical characteristics (focus characteristics, tracking characteristics, and reproduction characteristics), a control area where a disc type is recorded, and the like, based on a reproduction signal of the reading unit 901. The determination result is output to the control unit 912. Control unit 91
In 2, the authentication system, the data transmission system, and the like are switched according to the disk type, and data transmission with the PC decoder 900-1 is performed. Similarly, in the PC decoder 900-1,
The authentication method and the data transmission method are switched according to the type of the disc on which the information signal to be reproduced is recorded and the information signal scrambling method.

Decryption section 91 of PC decoder 900-1
8 decrypts the received data based on the shared bus key. A descrambling unit 902 to an I / F unit 909,
The processing up to 911 is performed by the compliant playback device 10.
1 and 105 (FIG. 5), and a description thereof will be omitted.

The control unit 905 of the PC decoder 900-1 uses not only the information signal scrambling (scramble presence / absence and scrambling method) and the reproduction control based on the scramble information as digital watermark information, but also the authentication method and data transmission method. To perform playback control.

Next, the PC decoder 900-1 and the PC playback device (drive) 900 of the PC recording system 900
-2 will be described. FIG. 11 is a flowchart showing a processing flow in the control unit 912 (FIG. 10) of the PC drive 900-2. First, when reproducing the information signal scrambled and recorded on the disc, the control unit 912 (FIG. 10) includes the authentication unit 915 and the authentication unit 919 of the PC encoder 600-1.
Authentication with each other (step S50).
1). As a result of the authentication by the authentication unit 915, the control unit 912 (FIG. 10) determines whether or not both are compliant devices (step S502). Thus, it is possible to confirm whether or not the device is a properly licensed device before recording the information signal.

If the authentication is successful, the PC decoder 90
A common bus key is generated between 0-1 and the PC drive 900-2 (FIG. 10) (step S503). Then, the control unit 912 (FIG. 10) performs encryption and / or tampering prevention processing on the scramble key information based on the shared bus key, and transmits the PC drive 900-2 (FIG. 10) to the PC decoder 900-1 (FIG. 10). ) (S
504). Then, access to the scrambled information signal, scramble key information, scramble control information, and the like is permitted, and reproduction is performed (step S50).
5). On the other hand, if mutual authentication is not established in step S502, reproduction of only the information signal is permitted, and reproduction of information in a specific area of a part of the disc is prohibited. (Step S506).

FIG. 12 is a flowchart showing a processing flow of control section 905 (FIG. 10) of PC decoder 900-1. As with the previous PC drive 900-2,
When reproducing the information signal scrambled and recorded on the disc, the control unit 905 (FIG. 10)
Causes the authentication unit 919 and the authentication unit 915 to perform mutual authentication (step S601). Then, as a result of the authentication by the authentication unit 919, the control unit 905 (FIG. 10)
It is determined whether or not mutual authentication has been established (step S50).
2).

If the authentication is successful, the PC decoder 90
A common bus key is generated between 0-1 and the PC drive 900-2 (FIG. 10) (step S603). And P
The C decoder 900-1 (FIG. 10)
The scramble key information generated in 0-2 (FIG. 10) is represented by P
Acquired from the C drive 900-2 (step S60)
4).

The control section 905 (FIG. 10) of the PC decoder 900-1 reproduces the information signal according to the reproduction flow shown in FIG. 6 (step S605).
Subsequent steps). Since this reproduction flow has already been described with reference to FIG. 6, its description will be omitted.

The difference from the flow of FIG.
In other words, after discrimination of the disk type 02 (FIG. 6), a check is made to determine whether or not mutual authentication has been established for each disk (steps S609 and S612). When the mutual authentication for the ROM or the RAM is not established, the reproduction of such an information signal is prohibited.

Therefore, the compliant PC decoder 900-1 and PC drive 900-2 (FIG. 1)
0) When they are not the same, access to scramble key information, scramble control information, and the like can be prevented. As a result, when reproducing an information signal that cannot be duplicated that requires duplication control, both are compliant with the PC decoder 900-.
1 and the PC drive 900-2 (FIG. 10) combined with the PC drive 900-2 (FIG. 10), the descrambling state for the information signal and the digital watermark information “Sc
In a non-compliant PC system, key information cannot be reproduced from a specific area on a disc, and regular descrambling can be prevented.

[Disk Type Transfer Method] Next, with reference to FIG. 13, a method of transferring the disk type from the PC drive unit to the encoder or the decoder without tampering will be described in detail. FIG. 13 is a diagram showing a data flow when transferring the information of the disk type. PC drive part is P
C drive 600-2 (FIG. 7) or PC drive 90
0-2 (FIG. 10).

In a PC encoder or a PC decoder,
Recording and reproduction of information signals are permitted using the disc type. For this reason, it is necessary to transfer the information indicating the disk type from the drive unit to the encoder unit or the decoder unit without tampering. PC encoder or P
The C decoder is, for example, PC encoder 600-1 (FIG. 7) or PC decoder 900-1 (FIG. 10).

The disc 1250 in FIG. 13 records authentication key information 1201 used for mutual authentication between the drive unit and the encoder / decoder. Authentication key information 1201
Are one or more encrypted authentication keys (EAK1, EAK
2,...). The encrypted authentication key is a key in which a common key (authentication key) used for mutual authentication and a type of a disc on which authentication key information is recorded are encrypted with a device key. The device key is a key assigned to each device.

The following is an example of the encrypted authentication key.

EAK1 = ENC (device key (DK
1), {authentication key (AK), disk type (DT)} EAK2 = ENC (device key (DK2), {authentication key (AK), disk type (DT)}) An encryption authentication key (EAK1) assigned to the device is extracted from the authentication key information read from 1250, and decrypted with the device key DK1 held by itself. As a result, the authentication key and (A
K) The disc type (DT) is obtained. The PC drive uses physical characteristics (focus characteristics,
The disc type (DT ′) is determined from the tracking area, the reproduction property), the control area in which the disc type is recorded, and the like. Mutual authentication uses a disk authentication key (DAK ') obtained by performing a specific operation (for example, adding in the figure) on the authentication key (AK) and the disk type (DT') from the disk type determination unit 1202.

On the other hand, the PC encoder / PC decoder extracts the encrypted authentication key (EAK2) assigned to the device from the authentication key information read from the disk 1250, and decrypts it with the device key DK2 held by itself.
As a result, the authentication key and the (AK) disk type (DT) are obtained. For mutual authentication, a disk authentication key (DAK) obtained by performing a specific operation (for example, adding in the figure) on the authentication key (AK) and the disk type (DT) is used.

Mutual authentication is performed using the disk authentication key shared in this way. That is, DAK = DAK '
In the case of, mutual authentication is established, and in the case of DAK ≠ DAK ', mutual authentication is not established. That is, the authentication units 915 and 9
Reference numeral 19 denotes the DT of the authentication key information and the DT 'detected by the drive.
If does not match, authentication can be failed. As a result, the information signal and the key information obtained from the ROM
Even if the disc is illegally copied to the AM disc, the disc type (DT) in the authentication key information does not match the disc type (DT ') detected by the drive. Therefore, mutual authentication is not established, and reproduction of the information signal can be prevented. Further, even if the authentication key information is improperly exchanged, the authentication key and the disc type do not match, and the mutual authentication fails.

The case where the authentication key and the disc type are encrypted and recorded in the authentication key information has been described. However, even in a method in which the disk type is not included in the authentication key information, the disk type detected by the drive is encrypted, transmitted to a PC encoder or a decoder, and decrypted to obtain the disk type, the disk type is safely transferred. be able to. Therefore, it is possible to reproduce a substantially normal information signal. If the disk type is not included in the authentication key information, the mutual authentication is common regardless of the disk type, and the mutual authentication is established regardless of the disk type. However, even if the mutual authentication is established, if the information signal is reproduced with the wrong disc type (scramble method), the video and audio may not be displayed correctly.

According to the recording apparatus or the reproducing apparatus as described above, even if the WM detecting section and the WM rewriting section are not mounted on the PC drive section, the illegal reproduction of the duplicated disc can be prevented.

Next, a description will be given of a process of changing the authentication method and the data transmission method (data and key information transmission procedure) depending on the disk type. If this property is used in reverse, it is also possible to perform processing for discriminating the disk type from the processing procedure in which authentication was performed. The following description is of a system that can be used as a PC drive and a PC decoder (FIG. 10).

FIG. 14 shows that the playback system 1400 is a DVD
An authentication procedure and a data transfer procedure when reproducing the ROM disk 1450 are shown. First, the bus authentication step will be described. The MPEG decoder module 1428 generates a random number c1 and sets it as challenge data (drv_chal (c1)) in the DVD drive 1400-1. DVD drive 14
00-1 generates f (c1) using a function f which is secret information, and generates MPEG (f) as response data (drv_res (f (c1)).
Return to decoder module 1400-2. The MPEG decoder module 1400-2 generates f (c1) using a function f which is secret information owned by the MPEG decoder module 1400-2. And MPEG
The decoder module 1400-2 checks whether or not f (c1) matches the response data returned from the DVD drive 1400-1.
428 confirms that the DVD drive 1400-1 is a compliant device.

Next, the DVD drive 1400-1 stores a random number
c2 is generated and set as challenge data in the MPEG decoder module 1400-2 (dec_chal (c2)).
The MPEG decoder module 1400-2 generates f (c2) using the function f which is the secret information, and returns it to the DVD drive 1400-1 as response data (dec_res (f (c
2)). The DVD drive 1400-1 generates f (c2) using a function f that is secret information owned by the DVD drive. And D
The VD drive 1400-1 checks whether f (c2) matches the response data returned from the MPEG decoder module 1400-2, and the DVD drive checks that the MPEG decoder is a compliant device. . As a result, a secret time-varying key is shared between the DVD drive 1400-1 and the MPEG decoder module 1400-2.

Next, a secret transmission step of key information using a time-varying key will be described. The DVD drive 1400-1 uses a shared time-varying key to store the DVD-ROM disc 1450.
The encrypted disc key set and the encrypted title key recorded in the MPEG decoder module 140
Transfer to 0-2. MPEG decoder module 140
In step 0-2, the received bus-encrypted disk key set and encrypted title key are bus-decrypted using the shared time-varying key.

For decoding the scrambled information signal, the MPEG decoder module 1400-12 uses the bus-decrypted encrypted disk key set and the encrypted title key as shown in FIG. The information signal as content can be obtained by decoding the scrambled information signal.

FIG. 15 shows that the reproduction system 1500 is a DVD.
An authentication procedure and a data transfer procedure when reproducing the R disk 1550 will be described. First, the bus authentication step is the above-mentioned D
This is the same as the bus authentication step when reproducing a VD-ROM 1450 (FIG. 14) disc. Therefore, the description is omitted. Next, a secret transmission step of key information using a time-varying key will be described. The DVD drive 1500-1 performs bus encryption on the encrypted disk key set using the shared time-varying key, and adds a falsification check code to the media ID. Then, the DVD drive 1500-1 transfers the encrypted disk key set and the media ID to the MPEG decoder module 1500-2. The MPEG decoder module 1500-2 decrypts the received bus-encrypted disk key set using the shared time-varying key. MPEG decoder module 1500
In -2, the tampering check code assigned to the media ID is checked using the shared time-varying key.

Lastly, decoding of the scrambled information signal (content) will be described. The MPEG decoder module 1500-2 reads the encrypted title key and the scrambled information signal (AV data) from the user area of the DVD-R disc 1550. Then, the MPEG decoder module 1500-2 decrypts the disk key with the decrypted encrypted disk key set, and decrypts the disk unique key with the decrypted disk key. Further, the title key is decrypted with the disc unique key, and the information signal scrambled with the title key is descrambled.

As described above, information such as a key necessary for decoding a scrambled information signal is stored in a playback type DVD (D
VD-ROM discs and recordable DVDs (DVD-R discs) are different, so that data to be transferred and transfer procedures are different. According to the present invention, a disc type is identified in a DVD drive, and control is performed so as to follow a transfer procedure corresponding to the disc type. The MPEG decoder module can limit the reproduction by identifying the disc type from the difference in the data transfer procedure and comparing the disc type with the disc type superimposed on the digital watermark information. 14 and 15, the same authentication method is used for the reproduction type DVD and the recording type DVD. However, by using different authentication methods for the playback DVD and the recordable DVD, the MPEG decoder module can identify the disc type in the same manner as described above due to the difference between the authentication methods. Examples of different authentication methods include an authentication method using a different algorithm (the above function f), and using different parameters in the same even algorithm. In the description so far, the information signal is encrypted by scrambling. However, the same effect can be obtained when the encryption is performed using another method.

In this embodiment, the case where the optical disk is used as the information recording medium has been described. However, the description can be applied to other semiconductor memories and magnetic recording media (such as hard disks) in the same manner. Further, the encrypted information signal of the present invention may be transmitted by radio waves as a network line (transmission medium) such as the Internet or a program such as a digital broadcast. At this time, by performing authentication on the receiving side and the transmitting side by the above-described authentication procedure, illegal duplication can be prevented.

[0117]

As described above, according to the present invention,
For an information signal to be subjected to predetermined duplication control (for example, an information signal for which duplication is prohibited or absolute duplication is prohibited), scramble information indicating that the information signal is scrambled is used as digital watermark information. The recording on the information recording medium is performed by superimposing and scrambling according to the type of the information recording medium. As a result, it is possible to restrict unauthorized recording on the information recording medium after decrypting the scramble, and reproduction from another type of information recording medium that has been illegally copied. More specifically, the latter reproduces the state indicated by the digital watermark information (scramble information) superimposed on the read information signal and the scramble state (whether or not scrambled) of the read information signal. Compare. Accordingly, when the comparison result does not match, it is determined that the reproduction is from the information recording medium created by the illegal duplication, and the reproduction can be prevented. According to the present invention, since the digital watermark information is not rewritten in the information reproducing apparatus, there is no need to implement a digital watermark information rewriting means, so that an inexpensive configuration can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic diagram for explaining a replication generation management method according to a first embodiment.

FIG. 2 is a diagram showing a data flow when reading or writing scrambled signal information.

FIG. 3 is a diagram illustrating a configuration of a compliant recording device.

FIG. 4 is a flowchart illustrating a recording processing flow of the recording apparatus.

FIG. 5 is a block diagram illustrating a configuration of a compliant playback device.

FIG. 6 is a flowchart showing a reproduction processing flow.

FIG. 7 is a diagram illustrating an example in which a compliant recording device is realized by a personal computer (PC) recording system.

FIG. 8 is a flowchart showing a processing flow in a control unit of the PC encoder.

FIG. 9 is a flowchart showing a processing flow in a control unit of the PC recording drive.

FIG. 10 is a diagram illustrating an example in which a compliant playback device is realized by a personal computer (PC) playback system.

FIG. 11 is a flowchart showing a processing flow in a control unit of the PC drive.

FIG. 12 is a flowchart showing a processing flow of a control unit of the PC decoder.

FIG. 13 is a diagram showing a data flow when transferring information of a disk type.

FIG. 14 shows an authentication procedure and a data transfer procedure when the playback system plays a DVD-ROM disc.

FIG. 15 shows an authentication procedure and a data transfer procedure when the playback system plays a DVD-R disc.

FIG. 16 is a diagram showing the principle of conventional copy control.

[Explanation of symbols]

 101 Compliant playback device 102 Compliant recording device 105 Compliant playback device 301 Digital I / F 302 Analog I / F 303 Decryption unit 304 Encoding unit 306 WM rewriting unit 307 WM decoding unit 308 Recording control unit 309 Control unit 310 Scramble unit 311 Writing unit 313 Reading unit 314 Disk type discriminating unit 401 Reading unit 402 Descrambling unit 403 Scramble state detecting unit 404 Disk type discriminating unit 405 Control unit 406 WM decoding unit 407 Reproduction control unit 408 Decoding unit 409 Analog I / F 410 Encryption Part 411 Digital I / F

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 1/387 H04L 9/00 601A 1/40 H04N 1/40 Z 5/91 5/91 P

Claims (20)

[Claims] An encrypted information signal obtained by encrypting an information signal to be subjected to duplication control, wherein the information signal is identification information for identifying that the information signal is a signal in an encrypted state. Is an encrypted information signal, which is a signal superimposed as digital watermark information. 2. The information signal according to claim 1, further comprising:
2. The encrypted information signal according to claim 1, wherein the information signal is an information signal to which at least one restriction of absolute copy prohibition is imposed. 3. The encrypted information signal according to claim 1, wherein the digital watermark information further includes type information indicating a type of an information recording medium on which the encrypted information signal is recorded. 4. An information recording medium on which the encrypted information signal according to claim 1 is recorded. 5. An information recording medium on which an encrypted first key and an encrypted second key are further recorded, wherein the first key has electronic watermark information superimposed thereon. The information recording medium according to claim 4, wherein the key is used to encrypt the information signal, and wherein the second key is a key used to encrypt the first key. . 6. A reading unit for reading an encrypted information signal from the information recording medium according to claim 4, and an encryption unit for determining that the encrypted information signal read by the reading unit is in an encrypted state. A state determination unit, a decryption unit that decrypts the encrypted information signal to extract an information signal on which digital watermark information is superimposed, and extracts the digital watermark information from the information signal decrypted by the decryption unit, and extracts the identification information. A digital watermark information decoding unit for determining the contents indicated by the above, and comparing the state determined by the encryption state determining unit with the state indicated by the identification information determined by the digital watermark information decoding unit. An information signal reproducing device, comprising: a reproduction control unit that prohibits reproduction of an information signal. 7. The information signal according to claim 6, wherein the encryption state determination unit determines that the encrypted information signal is in an encrypted state when the decryption unit extracts the information signal. Playback device. 8. The digital watermark information further includes type information indicating a type of an information recording medium on which the encrypted information signal is recorded, wherein the information signal reproducing device determines a type of the information recording medium. A reproduction control unit that permits reproduction of the information signal when the type of the information recording medium represented by the type information matches the type of the information recording medium determined by the type determination unit. An information signal reproducing apparatus according to claim 6. 9. The information recording medium further records an encrypted first key and an encrypted second key, and the first key is a digital watermark information superimposed on the first key. The second signal is a key used to encrypt the first key, and the decryption unit is a key used to encrypt the first key. Used to encrypt the key of
Holding a third key uniquely assigned to the information signal reproducing apparatus, and decrypting the second key encrypted with the third key to obtain the second key; The first key encrypted by the second key is decrypted to obtain the first key, and the encrypted information signal is decrypted by the obtained first key to superimpose the digital watermark information. Extracting information signals,
The information signal reproducing device according to claim 6. 10. An information signal reproducing apparatus comprising: a read unit, an encryption state discriminating unit, and a type discriminating unit; a drive device further including a first authentication unit; a decoding unit; A decoding device that includes a playback control unit and further includes a second authentication unit; and an interface that connects the drive device and the decoding device. The first authentication unit and the second authentication unit Communicates via the interface, the first authentication unit authenticates whether the decoding device is a compliant device, and the second authentication unit is a device whose drive device is compliant. 9. The device according to claim 8, wherein whether or not authentication is established, if the authentication is established between the first authentication unit and the second authentication unit, the reproduction control unit permits reproduction of the information signal. 10. information No. reproducing apparatus. 11. The information recording medium according to claim 1, wherein said first authentication unit and said second authentication unit each use for authentication.
A first authentication key and a second authentication key are further recorded, and the first authentication unit has a first device key uniquely assigned to the drive device, and the first authentication key; A first medium authentication key is generated based on the first device key and the type of the information recording medium determined by the type determination unit, and the second authentication unit is uniquely assigned to the decoding device. A second device key, said second authentication key;
Generating a second medium authentication key based on the second device key; the first authentication unit and the second authentication unit comprising a first medium authentication key and a second medium authentication key The information signal reproducing device according to claim 10, wherein authentication is performed by comparing the information signal with the information signal. 12. The second authentication unit detects an information recording medium type by using at least one of an authentication procedure different for each information recording medium and an information signal transfer procedure.
The information signal reproducing device according to claim 11. 13. An information signal recording apparatus for recording an information signal to be subjected to duplication control on an information recording medium, comprising: identification information for identifying that the information signal is a signal in an encrypted state; A digital watermark information processing unit for superimposing the digital watermark information on the information signal as digital watermark information; an encryption unit for encrypting the information signal on which the digital watermark information is superimposed by the digital watermark information unit to generate an encrypted information signal; An information signal recording device, comprising: a writing unit that writes an encrypted information signal generated by a unit on an information recording medium. 14. A digital still camera further comprising: a type determining unit configured to determine a type of the information recording medium;
14. The information signal recording device according to claim 13, further comprising type information indicating a type of an information recording medium on which the encrypted information signal is recorded. 15. An electronic watermark information decoding unit for extracting electronic watermark information superimposed on an information signal to determine the content indicated by the identification information, and based on the identification information determined by the electronic watermark information decoding unit. 15. The information signal recording apparatus according to claim 14, further comprising: a recording control unit that permits recording. 16. An information signal recording device, comprising: a drive unit including a writing unit and a type determining unit, and further including a first authentication unit; an encryption unit, a digital watermark information processing unit, a digital watermark information decoding unit, An encoding device that includes a recording control unit and further includes a second authentication unit; and an interface that connects the drive device and the encoding device. The first authentication unit and the second authentication unit Communicating via the interface, the first authentication unit authenticates whether the encoding device is a compliant device, and the second authentication unit determines whether the drive device is a compliant device. 16. The authentication device according to claim 15, wherein if the authentication is established between the first authentication unit and the second authentication unit, the recording control unit permits the recording of the information signal. The information signal recording apparatus. 17. The information recording medium, wherein the first authentication unit and the second authentication unit respectively use for authentication.
A first authentication key and a second authentication key are further recorded, and the first authentication unit has a first device key uniquely assigned to the drive device, and the first authentication key; A first medium authentication key is generated based on the first device key and the type of the information recording medium determined by the type determination unit, and the second authentication unit is uniquely assigned to the encoding device. Generating a second medium authentication key based on the second authentication key and the second device key, the first authentication unit and the second 17. The information signal recording device according to claim 16, wherein the authentication unit performs authentication by comparing the first medium authentication key with the second medium authentication key. 18. The information processing apparatus according to claim 18, wherein the second authentication unit detects an information recording medium type using at least one of an authentication procedure different for each information recording medium and an information signal transfer procedure.
The information signal recording device according to claim 17. 19. The information recording medium has recorded therein a second key encrypted with a third key uniquely assigned to the information signal reproducing device. Acquiring the first key based on any of a internally generated random number, first key information recorded on the information recording medium, and first key information superimposed on radio waves, Encrypting the information signal on which the digital watermark information is superimposed with a first key, encrypting the first key with a second key, and encrypting the third key with an encrypted third key recorded on an information recording medium. 14. The information signal reproducing apparatus according to claim 13, wherein a second key is obtained based on the second key. 20. The writing unit further writes the first key encrypted with the second key on an information recording medium.
10. The information signal recording device according to item 9.