JP4179937B2 - Digital watermarking device and application device using the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electronic watermarking apparatus that embeds information related to copyright protection in predetermined information such as video and audio, and an application apparatus using the electronic watermarking apparatus.
[0002]
[Prior art]
In recent years, DVDs (Digital Versatile Discs) have been widely used, and playback devices using DVDs have been introduced into aircraft and museums.
[0003]
Especially for in-flight applications, movies before the release may be shown on the ground, and the content of such movies before the release does not leak to the outside, or even if it leaks, where is the leaked content? There is a need for a system that realizes copyright protection so that it can be traced if it has been leaked from the network.
[0004]
Conventionally, as a copyright protection method, there is a technique called “digital watermark” in which specific information is embedded in content such as video and audio (see, for example, Patent Document 1).
[0005]
Information to be embedded as an electronic watermark (hereinafter referred to as “watermark information”) includes various information such as copy control information for limiting the number of copies of the content, content ID, and copyright holder ID.
[0006]
Most of the watermark information has the purpose of protecting the copyright of the content. For example, by embedding the copy control information in the content, the reproduction device can detect the copy control information from the content and operate the copy prevention function to limit the copy act. In addition, by embedding the ID of the content and the ID of the copyright holder, even if an illegal copy is made, the watermark information is detected from the content, and the copyright holder is proved from the detected numerical values and symbols. And claim content copyright.
[0007]
As described above, since the watermark information is information for protecting the copyright of the content, it is important that the watermark information itself has no error, that is, the numerical values and symbols embedded as the watermark information have no error.
[0008]
Also, in order to correctly detect watermark information from content, it is important that an apparatus for embedding watermark information embeds watermark information accurately in the content in accordance with a predetermined correct calculation method and processing procedure.
[0009]
As a technique for preventing falsification of watermark information embedded in content, there is a method in which watermark information is encrypted and then embedded in the content (see Patent Documents 2, 3, etc.).
[0010]
[Patent Document 1]
Japanese Patent No. 3106985
[Patent Document 2]
JP 2001-78013 A
[Patent Document 3]
Japanese Patent Laid-Open No. 2002-232424
[0011]
[Problems to be solved by the invention]
Once the watermark information is embedded in the content, it is difficult to alter or remove it. However, it is relatively easy to falsify the watermark information before it is embedded in the content. That is, the conventional digital watermark device has a problem that the watermark information itself is falsified before the watermark information is embedded in the content.
[0012]
When the tampered information is embedded in the content, for example, the copy control information of the content becomes a numerical value or a symbol indicating a copyable state any number of times, or the content ID or copyright holder ID is originally If it is different from the numerical value or symbol, the copyright holder's rights will be severely impaired, such as being unable to prove the copyright holder.
[0013]
In addition, the digital watermarking device, during the watermark embedding operation, sets setting values necessary for the embedding operation, such as a mode specification value for the embedding operation, various constants and variables used for the embedding operation, comparison values, table values, code data, and the like. Often used. The digital watermarking apparatus can embed watermark information into the content with a predetermined correct calculation method and processing procedure only when these setting values are set correctly.
[0014]
The setting value necessary for such an embedding operation may be altered when embedding watermark information in the content. If the setting value required for the watermark embedding operation is altered, a predetermined correct calculation result cannot be obtained. For example, the signal strength of the watermark information embedded in the content becomes weak, and the watermark information can be easily removed. In addition, embedding different from the method and procedure assumed by the device on the digital watermark detection side is performed, and there is an adverse effect such that watermark information cannot be detected from the content.
[0015]
In view of the problems of the conventional digital watermarking device, the present invention protects watermark information and setting values necessary for the operation of the digital watermarking device from tampering, thereby accurately embedding watermark information in content. Objective.
[0016]
[Means for Solving the Problems]
  In the present inventionAffectDigital watermarking deviceA device that inputs video information and embeds watermark information in the video information, and adds verification data to the encrypted setting value in which the setting value including the embedded signal strength required for the watermark information embedding process is encrypted Information verification means for inputting and verifying the set value information obtained, decryption means for decrypting the encrypted set value verified by the information verification means, and when the verification result by the information verification means indicates normal The watermark information is embedded in the input video information using the setting value decrypted by the decryption means, and the verification result does not indicate normality, the input video information is not output to the outside of the device, or Dummy video is output.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a digital watermarking device and an application device using the same according to the present invention will be described with reference to the accompanying drawings.
[0023]
(First embodiment)
FIG. 1 is a diagram showing an example of the configuration of a digital watermark apparatus according to the present invention. The digital watermark device 15 a is a device that embeds digital watermark information for copyright protection in video and audio data, and includes a watermark information embedding unit 102 and a decryption unit 105.
[0024]
Here, an example of a system including a playback device using the digital watermark device described in the present embodiment and the embodiments described later will be described.
[0025]
FIG. 2A shows an example of the system configuration. The system includes a disk playback device 10 and a display device 50. The disc playback device 10 plays back the disc medium 1 and outputs video and audio. In particular, information recorded on the information recording medium 5 is required for playback to realize copyright protection.
[0026]
The information recording medium 5 is composed of, for example, an IC card, and stores key information necessary for reproducing the disk medium 1, information necessary for digital watermark embedding processing, and the like. These pieces of information are encrypted as necessary and stored with an electronic signature added. The information necessary for the digital watermark embedding process includes the encrypted watermark information or setting value, the watermark information or setting value with verification data, and the encrypted data with verification data in the embodiment of the present invention. It includes watermark information or setting values, or watermark information or setting values with encrypted verification data.
[0027]
The disk medium 1 stores video information and audio information. Since the disk reproducing apparatus 10 uses information recorded on the information recording medium 5 when reproducing the disk medium 1, the information recording medium 5 needs to be inserted. That is, the disc reproducing apparatus 10 can reproduce the disc medium 1 only when the information recording medium 5 is inserted.
[0028]
FIG. 2B is a diagram showing the configuration of the disc playback apparatus 10. The disc playback apparatus 10 includes a disc drive 11, a decryption unit 13, a digital watermark device 15, and a D / A conversion unit 17. The digital watermark device 15 may be any of the digital watermark devices 15a to 15h in the embodiment of the present specification.
[0029]
The disk drive 11 reads data recorded on the disk medium 1. The read signal is decoded by the decoding unit 13. The decoded signal is embedded with watermark information by the digital watermark device 15 and converted into an analog signal by the D / A converter 17 to be a video output.
[0030]
The digital watermark device 15 reads information necessary for embedding watermark information from the information recording medium 5, and performs processing for embedding watermark information in video and audio signals reproduced from the disk medium 1 using the information.
[0031]
Returning to FIG. 1, the details of the digital watermark device 15a of this embodiment will be described. The watermark information 111 that has been encrypted is input to the digital watermark device 15a. The input encrypted watermark information 111 is decrypted by the decryption unit 105. Here, the watermark information includes various information such as copy control information and ID related to the video / audio data, and the ID of the copyright holder. The watermark information is obtained by expressing these pieces of information with numerical values and symbols. The encryption key used by the decryption unit 105 to decrypt the cipher may be held in advance by the digital watermark device 15a or may be given from the outside of the device 15a.
[0032]
The watermark information decrypted by the decryption unit 105 is transmitted to the watermark information embedding unit 102. The watermark information embedding unit 102 inputs video / audio data, embeds the watermark information decrypted by the decryption unit 105 in the video / audio data, and outputs it. As a watermark embedding method used by the watermark information embedding unit 102, any of known digital watermark techniques may be used.
[0033]
As described above, in this embodiment, watermark information to be embedded in video / audio data is input to the apparatus in an encrypted state. The encrypted watermark information is a ciphertext whose meaning is not understood even when numerical values and symbols are shown, and it is difficult to alter the ciphertext so that the ciphertext is decrypted to an intended value. Therefore, it is possible to conceal the value of what kind of watermark information is embedded in video and audio from the outside of the apparatus, and it is possible to prevent the act of tampering with the watermark information to the intended value.
[0034]
In the first embodiment, the encrypted watermark information is decrypted by the decryption unit 105 and then embedded in the video / audio data. However, as another configuration, the encrypted watermark information can be decrypted. Instead, it may be embedded in video or audio data as it is. In this case, the decryption unit 105 is not required in FIG. 1, and the encrypted watermark information is directly input to the watermark information embedding unit 102. In this configuration, since the watermark information is embedded in the video or audio data in an encrypted state, the detected watermark information can be decrypted by providing a decryption means on the device that detects the watermark information. it can. Since the watermark information is embedded in the video and audio data in an encrypted state, the confidentiality of the watermark information is further enhanced.
[0035]
(Second Embodiment)
FIG. 3 is a diagram showing a second configuration example of the digital watermark apparatus according to the present invention. The digital watermark device 15 b includes a watermark information embedding unit 202 and a decryption unit 205.
[0036]
An encrypted setting value 211 is input to the digital watermark device 15b of this embodiment. The setting value is information necessary for watermark information embedding processing in the watermark information embedding unit 202. Examples of setting values necessary for the embedding operation include the following.
-Setting value for selecting whether or not to embed
-When the watermark information embedding unit 202 has a plurality of embedding methods and modes, a setting value of a mode for selecting one of them
-Constants and variables used for embedding operations
-Comparison values and table values used for embedding operations
-Code data used for embedding processing
-Specified value of embedded signal strength
-Specifying the location and timing for embedding watermarks in video and audio
-Various other values necessary for the operation of the watermark information embedding unit 202
[0037]
The encrypted setting value 211 is input to the digital watermark device 15 b and is decrypted by the decryption unit 205. The setting value decrypted by the decryption unit 205 is transmitted to the watermark information embedding unit 202. The watermark information embedding unit 202 inputs video / audio data, embeds watermark information in the video / audio data, and outputs the data. At this time, the embedding process is performed using the setting value decrypted by the decryption unit 205 or according to the decrypted setting value.
[0038]
As described above, in the present embodiment, setting values necessary for the operation of the watermark information embedding unit 202 are input to the apparatus in an encrypted state. The encrypted set value is a ciphertext whose meaning is not understood even when the numerical values and symbols are shown, and it is difficult to alter the ciphertext so that the ciphertext is decrypted to the intended value. Therefore, the setting value used by the watermark information embedding unit 202 can be kept secret from the outside of the apparatus, and further, the act of altering the setting value of the watermark information embedding unit to the intended value can be prevented. it can.
[0039]
(Third embodiment)
FIG. 4 is a diagram showing a third configuration example of the digital watermark apparatus according to the present invention. The digital watermark device 15 c includes a watermark information embedding unit 302 and an information verification unit 305.
[0040]
The watermark information 311 with verification data is input to the digital watermark device 15c of this embodiment. The watermark information 311 with verification data is obtained by adding verification data for detecting an error in the information to the watermark information.
[0041]
Here, as means for detecting an information error, various error detection methods and error detection codes such as parity check and CRC (Cyclic Redundancy Check) are generally known. In order to prevent falsification of the watermark information, it is preferable that the method used for the error detection and the arithmetic expression are difficult to guess. Further, in order to enhance the security against tampering, an electronic signature using public key cryptography may be added as verification data added to the watermark information. In this case, the digital watermark device 15c may have a public key necessary for verifying the signature in advance, or may be given from outside the device. Further, other verification means may be used.
[0042]
The information verification unit 305 has a predetermined error detection function and verification function, and verifies the watermark information using the verification data in the input watermark information 311 with verification data. When the verification process is completed, the information verification unit 305 transmits the verification result (information indicating whether there is an error in the input watermark information) to the information embedding unit 302.
[0043]
The watermark information embedding unit 302 refers to the verification result transmitted from the information verification unit 305. If there is no error in the information, the watermark information embedding unit 302 acquires the verified watermark information from the information verification unit 305 and inputs the watermark information. It is embedded in audio data and output to the outside of the device 15c.
[0044]
On the other hand, when the verification result from the information verification unit 305 indicates an information error, the watermark information embedding unit 302 does not output the input video / audio data to the outside of the device 15c. At this time, instead of outputting the video / audio data to the outside of the apparatus, the watermark information embedding unit 302 may invalidate and output the video / audio data to the extent that viewing is difficult, or may output dummy data.
[0045]
As described above, in this embodiment, watermark information embedded in the video / audio data is input to the apparatus with the verification data added. Therefore, even if the input watermark information is falsified, the verification data is added, so that the information verification unit detects the falsification of the watermark information as an information error. When an information error is detected, the watermark information embedding unit 302 does not output the video / audio data to the outside of the apparatus, so that the video / audio data cannot be viewed. Therefore, the falsification of the watermark information can be prevented.
[0046]
(Fourth embodiment)
FIG. 5 is a diagram showing a fourth configuration example of the digital watermark apparatus according to the present invention. The digital watermark device 15d includes a watermark information embedding unit 402 and an information verification unit 405.
[0047]
The setting value 411 with verification data is input to the digital watermark device 15d of this embodiment. The setting value 411 with verification data is obtained by adding verification data for detecting an error in the setting value to the setting value that is a value necessary for the embedding operation of the watermark information embedding unit 402. The set value and the verification data are the same as those described in the second embodiment and the third embodiment.
[0048]
The information verification unit 405 verifies the setting value using the verification data in the setting value 411 with verification data, and transmits the result to the watermark information embedding unit 402.
[0049]
The watermark information embedding unit 402 refers to the verification result transmitted from the information verification unit 405, and acquires a verified setting value from the information verification unit 405 when there is no information error. Thereafter, the watermark information embedding unit 402 embeds watermark information in the input video / audio data. At this time, the watermark information embedding unit 402 performs an embedding operation using the verified setting value or according to the value of the verified setting value, and outputs the video / audio data in which the watermark information is embedded to the outside.
[0050]
On the other hand, if the verification result transmitted from the information verification unit 405 indicates that there is an information error, the watermark information embedding unit 402 prevents the input video / audio data from being output to the outside of the apparatus. The watermark information embedding unit 402 may output the audio / video data after invalidating the audio / video data to an extent that it is difficult to view, or output dummy data, instead of outputting the audio / video data to the outside of the apparatus.
[0051]
As described above, in this embodiment, the verification data is added to the setting value necessary for the operation of the watermark information embedding unit 402 and input to the apparatus. Thereby, even if the setting value is falsified, the verification data is added, so that the information verification unit detects the falsification of the setting value as an information error. When an information error is detected, the watermark information embedding unit does not output the video / audio data to the outside of the apparatus, so that the video / audio data cannot be viewed. Therefore, it is possible to prevent an act of tampering with a setting value necessary for the operation of the watermark information embedding unit.
[0052]
(Fifth embodiment)
FIG. 6 is a diagram showing a fifth configuration example of the digital watermark apparatus according to the present invention. The digital watermark device 15e includes a watermark information embedding unit 502, an information verification unit 505, and a decryption unit 508.
[0053]
The watermark information 511 with encryption verification data is input to the digital watermark device 15e of this embodiment. The watermark information 511 with encrypted verification data is data generated by adding verification data related to the watermark information to the watermark information and then encrypting all or part of the information including the verification data and the watermark information. Here, the verification data is data added to detect an error in the watermark information, and is the same as the verification data described in the third embodiment.
[0054]
The decryption unit 508 decrypts the watermark information 511 with encrypted verification data and transmits the watermark information with decrypted verification data to the information verification unit 505. Here, the watermark information with decrypted verification data is data in a state where the encryption of the watermark information with encrypted verification data 510 is decrypted, and includes watermark information and verification data.
[0055]
The information verification unit 505 verifies the watermark information with decrypted verification data and transmits the verification result to the watermark information embedding unit 502.
[0056]
The watermark information embedding unit 502 refers to the verification result transmitted from the information verification unit 505, and acquires verified watermark information from the information verification unit 505 when there is no information error. Thereafter, the watermark information embedding unit 502 embeds the acquired watermark information in the input video / audio data, and outputs the video / audio data in which the watermark information is embedded to the outside.
[0057]
On the other hand, when the verification result transmitted from the information verification unit 505 indicates that there is an information error, the watermark information embedding unit 502 does not output the input video / audio data to the outside of the device 15e. Note that the watermark information embedding unit 502 may invalidate the video / audio data to an extent that it is difficult to view or output the dummy data instead of outputting the video / audio data to the outside of the apparatus.
[0058]
As described above, in this embodiment, verification data is added to watermark information to be embedded in video / audio data, and at least a part thereof is encrypted and input to the apparatus. As a result, the meaning of the encrypted information cannot be understood even when looking at the notation of numerical values and symbols, so it is possible to conceal what values and symbols are embedded as watermark information from the outside of the device. become. It is also difficult to tamper with the ciphertext so that it is decrypted to the intended value. Even if the ciphertext is altered to an appropriate numerical value or symbol, the verification data is added, so that the information verification unit detects the alteration of the watermark information as an information error. When an information error is detected, the watermark information embedding unit does not output the video / audio data to the outside of the apparatus, so that the video / audio data cannot be viewed. From the above, it is possible to conceal the watermark information from the outside of the apparatus and further prevent the act of altering the watermark information to an appropriate numerical value by combining the information verification unit and the watermark information embedding unit.
[0059]
(Sixth embodiment)
FIG. 7 is a diagram showing a sixth configuration example of the digital watermarking apparatus according to the present invention. The digital watermark device 15 f includes a watermark information embedding unit 602, an information verification unit 605, and a decryption unit 608.
[0060]
A setting value 611 with encrypted verification data is input to the digital watermark device 15f of this embodiment. The setting value 611 with encrypted verification data is generated by first adding verification data to the setting value and encrypting all or part of the data including the setting value and the verification data. The verification data and the set value are as described in the third embodiment and the second embodiment, respectively.
[0061]
The decryption unit 608 decrypts the setting value 611 with encrypted verification data and transmits the set value with decrypted verification data obtained thereby to the information verification unit 605. The set value with decrypted verification data is data in a state where the cipher of the set value 611 with encrypted verification data is decrypted, and includes the set value after decryption and the verification data.
[0062]
The information verification unit 605 verifies the presence or absence of an error with respect to the set value after decoding using verification data, and transmits the verification result to the watermark information embedding unit 602.
[0063]
The watermark information embedding unit 602 refers to the verification result transmitted from the information verification unit 605, and acquires the verified setting value from the information verification unit 605 when there is no information error in the setting value. Thereafter, the watermark information embedding unit 602 embeds watermark information in the input video / audio data. At this time, the watermark information embedding unit 602 performs an embedding operation using the verified setting value or according to the value of the verified setting value, and outputs the video / audio data in which the watermark information is embedded to the outside of the apparatus.
[0064]
On the other hand, when the verification result transmitted from the information verification unit 605 indicates that there is an information error, the watermark information embedding unit 602 does not output the input video / audio data to the outside of the apparatus. The watermark information embedding unit 602 may invalidate and output the video / audio data to the extent that it is difficult to view or output dummy data instead of outputting the video / audio data to the outside of the apparatus.
[0065]
As described above, in this embodiment, verification data is added to a setting value necessary for the operation of the watermark information embedding unit 602, and a part or all of the verification data is input to the apparatus in an encrypted state. As a result, the meaning of the encrypted information cannot be understood even when looking at the notation of numerical values and symbols. Therefore, it is concealed from the outside of the apparatus what setting value is used to operate the watermark information embedding unit. It becomes possible. Furthermore, since it is difficult to alter the ciphertext so that it is decrypted to the intended value, it is possible to prevent the setting value from being altered to the intended value. Even if the ciphertext is altered to an appropriate numerical value or symbol, the verification data is added, so the information verification unit detects the setting value alteration as an information error. When an information error is detected, the watermark information embedding unit does not output the video / audio data to the outside of the apparatus, so that the video / audio data cannot be viewed. From the above, it is possible to conceal the set value from the outside of the apparatus and to prevent the setting value from being altered to an appropriate value by combining the information verification unit and the watermark information embedding unit.
[0066]
(Seventh embodiment)
FIG. 8 is a diagram showing a seventh configuration example of the digital watermark apparatus according to the present invention. The digital watermark device 15g includes a watermark information embedding unit 702, an information verification unit 705, and a decryption unit 708.
[0067]
The encrypted watermark information 711 with verification data is input to the digital watermark device 15g of this embodiment. The encrypted watermark information with verification data 711 is generated by adding verification data to the encrypted watermark information. The verification data is data added to detect an error in the encrypted watermark information, and is the same as the verification data described in the third embodiment.
[0068]
The information verification unit 705 verifies the encrypted watermark information using the verification data included in the encrypted watermark information 711 with verification data, and transmits the verification result to the watermark information embedding unit 702.
The information verification unit 705 also transmits the encrypted watermark information to the decryption unit 708. The decryption unit 708 decrypts the encrypted watermark information from the information verification unit 705.
[0069]
The watermark information embedding unit 702 refers to the verification result transmitted from the information verification unit 705, and acquires the decoded watermark information from the decryption unit 708 when there is no error in the watermark information.
[0070]
As described above, the watermark information embedding unit 702 acquires the decrypted watermark information through the processing in the decryption unit 708 only when the verification result indicates that there is no information error, This is preferable because unnecessary processing is reduced. The reason is that if the verification result indicates that there is an information error, there may be an information error in the verified encrypted watermark information or decrypted watermark information, and it is used as watermark information. This is because the decryption processing in the decryption unit 708 is wasted. Regardless of the verification result, the watermark information embedding unit 702 may always acquire the decrypted watermark information through the processing of the decryption unit 708.
[0071]
The watermark information embedding unit 702 refers to the verification result transmitted from the information verification unit 705, and if there is no information error, the watermark information is embedded by embedding the decoded watermark information in the input video / audio data. Video / audio data is output to the outside of the device.
[0072]
On the other hand, when the verification result transmitted from the information verification unit 705 indicates that there is an information error, the watermark information embedding unit 702 does not output the input video / audio data to the outside of the apparatus. Note that the watermark information embedding unit 702 may invalidate the video / audio data to an extent that it is difficult to view or output dummy data instead of outputting the video / audio data to the outside of the apparatus.
[0073]
As described above, in the present embodiment, watermark information to be embedded in video / audio data is encrypted, and further input to the apparatus with verification data added. As a result, the meaning of the encrypted information cannot be understood even when looking at the notation of numerical values and symbols, so it is possible to conceal what values and symbols are embedded as watermark information from the outside of the device. become. It is also difficult to tamper with the ciphertext so that it is decrypted to the intended value. Even if the ciphertext is altered to an appropriate numerical value or symbol, the verification data is added, so that the information verification unit detects the alteration of the watermark information as an information error. When an information error is detected, the watermark information embedding unit does not output the video / audio data to the outside of the apparatus, so that the video / audio data cannot be viewed. Further, by performing the processing of the information verification unit prior to the decryption unit, it is possible to quickly detect falsification of the watermark information.
[0074]
From the above, the watermark information is concealed from the outside of the device, and further, the combination of the information verification unit and the watermark information embedding unit prevents the act of altering the watermark information to an appropriate numerical value, and Detection in a short time is possible.
[0075]
In the present embodiment, the encrypted watermark information verified from the information verification unit 705 is decrypted by the decryption unit 708 and then embedded in the video / audio data. Alternatively, the watermark information may be embedded as it is in video or audio without being decoded. In this case, in FIG. 8, the decryption unit 708 is not required, and the verified encrypted watermark information from the information verification unit 705 is input to the watermark information embedding unit 702 as it is. In this configuration, since the watermark information is embedded in the video and audio in an encrypted state, the detected watermark information can be decrypted by providing a decryption means on the device that detects the watermark information. . Since the watermark information is embedded in the video and audio in an encrypted state, the confidentiality of the watermark information can be further improved.
[0076]
(Eighth embodiment)
FIG. 9 is a diagram showing an eighth configuration example of the digital watermark apparatus according to the present invention. The digital watermark device 15h includes a watermark information embedding unit 802, an information verification unit 805, and a decryption unit 808.
[0077]
The encryption setting value 811 with verification data is input to the digital watermark device 15h of this embodiment. The encryption setting value 811 with verification data is obtained by encrypting the setting value and adding the verification data to the encrypted setting value. Here, the verification data and the set value are the same as those described in the third embodiment and the second embodiment, respectively.
[0078]
The information verification unit 805 verifies the encrypted setting value using the verification data included in the encrypted setting value 811 with verification data, and transmits the verification result to the watermark information embedding unit 802. The information verification unit 805 transmits the verified encrypted setting value to the decryption unit 808. The decryption unit 808 decrypts the encrypted set value.
[0079]
The watermark information embedding unit 802 refers to the verification result from the information verification unit 805, and obtains a decrypted set value from the decryption unit 808 when there is no information error.
[0080]
As described above, the watermark information embedding unit 802 is useless by performing the process of acquiring the set value that has been decrypted through the process of the decryption unit 808 only when there is no information error based on the verification result. Less processing is preferable.
[0081]
The reason is that if there is an information error in the verification result, there may be an information error in the verified encrypted setting value or decrypted setting value, and it cannot be used as a setting value. This is because the decryption processing in the decryption unit 808 is wasted. It should be noted that the watermark information embedding unit 802 may acquire the set value that has been decrypted through the processing in the decryption unit 808 regardless of the verification result.
[0082]
When the verification result transmitted from the information verification unit 805 indicates that there is no information error, the watermark information embedding unit 802 embeds watermark information in the input video / audio data. At this time, the watermark information embedding unit 802 performs an embedding operation using the decoded setting value or according to the value of the decoded setting value, and outputs the video / audio data in which the watermark information is embedded to the outside of the apparatus. To do.
[0083]
On the other hand, when the verification result transmitted from the information verification unit 805 indicates that there is an error in the information, the watermark information embedding unit 802 prohibits the output of the video / audio data input to the watermark information embedding unit 802 to the outside of the apparatus. The watermark information embedding unit 802 may output the audio / video data after invalidating the audio / video data to an extent that it is difficult to view, or output dummy data, instead of outputting the audio / video data to the outside of the apparatus.
[0084]
As described above, in the present embodiment, the setting value necessary for the operation of the watermark information embedding unit is encrypted, and further input to the apparatus with verification data added. As a result, the meaning of the encrypted information cannot be understood even when looking at the notation of numerical values and symbols. Therefore, it is concealed from the outside of the apparatus what setting value is used to operate the watermark information embedding unit. It becomes possible. Furthermore, since it is difficult to alter the ciphertext so that it is decrypted to the intended value, it is possible to prevent the setting value from being altered to the intended value. Even if the ciphertext is altered to an appropriate numerical value or symbol, the verification data is added, so the information verification unit detects the setting value alteration as an information error. When an information error is detected, the watermark information embedding unit does not output the video / audio data to the outside of the apparatus, so that the video / audio data cannot be viewed. Further, by performing the processing of the information verification unit prior to the decryption unit, it is possible to quickly detect falsification of the set value.
[0085]
From the above, the setting value is concealed from the outside of the device, and further, the combination of the information verification unit and the watermark information embedding unit prevents the setting value from being altered to an appropriate value, and the setting value is not altered. It becomes possible to detect in a short time.
[0086]
(Ninth embodiment)
FIG. 10 shows a configuration of an information reproducing apparatus which is one of application devices using the above-described digital watermarking apparatus. The information reproducing apparatus 10a includes a data reproducing apparatus 909 and a digital watermark apparatus 901. The digital watermarking device 901 has basically the same configuration as the digital watermarking device 15c described in the third embodiment, except that the verification result from the information verification unit 905 is output to the outside of the device. . That is, the verification result from the information verification unit 905 is transmitted to the data reproduction device 909.
[0087]
The data reproduction device 909 is a device that reproduces and outputs a recording medium 1a on which video and audio such as a tape, a disk, and a memory card are recorded. The video / audio data output from the data reproduction device 909 is transmitted to the digital watermark device 901. The information verification unit 905 receives watermark information with verification data. Here, the verification data is as described in the third embodiment. The information verification unit 905 verifies the input watermark information with verification data and transmits the verification result to the data reproduction device 909.
[0088]
The data reproduction device 909 refers to the verification result transmitted from the digital watermark device 901, and executes the reproduction operation of the recording medium 1a when there is no information error. As a result, video / audio data is output from the data reproduction device 909 and transmitted to the watermark information embedding unit 902 of the digital watermark device 901. The watermark information embedding unit 902 embeds the verified watermark information acquired from the information verification unit 905 in the video / audio data, and outputs the video / audio data in which the watermark information is embedded to the outside of the apparatus.
[0089]
On the other hand, the data reproducing device 909 refers to the verification result from the digital watermark device 901, and does not execute the reproducing operation from the recording medium 1a when there is an information error. Note that the data reproducing device 909 may invalidate and output the video / audio data to an extent that it is difficult to view or output dummy data instead of executing the reproducing operation of the recording medium 1a. In this case, the watermark information embedding unit 902 does not need to perform the watermark information embedding process because normal video / audio data cannot be obtained. As a result, video / audio data is not output or invalid video / audio data is output from the information reproducing apparatus 10a.
[0090]
In the above description, an example in which the digital watermark apparatus described in the third embodiment is modified as the digital watermark apparatus 901 has been described. However, the configuration of the digital watermark apparatus 901 is not limited to this. That is, in the digital watermarking apparatus having the information verification unit shown in the fourth to eighth embodiments, the configuration is changed so that the verification result by the information verification unit can be output to the outside of the digital watermarking apparatus 901. It can be used as the digital watermark device 901 of the embodiment. This makes it possible to verify not only the watermark information but also the set value.
[0091]
As described above, in this embodiment, the information verification unit included in the digital watermark apparatus detects the alteration of the information by verifying the watermark information and the set value, and further transmits the verification result to the reproduction apparatus. Thus, the playback device does not play back the video / audio data. As a result, not only the video and audio cannot be viewed when the tampering is performed, but the video / audio data does not exist as a signal by stopping the output source of the video / audio data. A safe and reliable protection means can be realized by preventing the interception. From the above, it is possible to prevent falsification of watermark information and setting values and provide a safe system configuration.
[0092]
(Tenth embodiment)
FIG. 11 shows a configuration of an information recording apparatus which is one of application devices using the above-described digital watermarking apparatus. The information recording device 30 includes a digital watermark device A01 and a data recording device A09.
[0093]
The digital watermarking device A01 has the same basic configuration as the digital watermarking device 15c described in the third embodiment, but is different in that the verification result from the information verification unit A05 can be output to the outside of the device. . The data recording device A09 is a device that records video and audio on a recording medium such as a tape, a disk, or a memory card.
[0094]
The verification result from the information verification unit A05 is transmitted to the data recording device A09. Also, the video / audio data in which the watermark information is embedded is transmitted to the recording apparatus A09. The watermark information with verification data is input to the information verification unit A05. Here, the verification data is data added to detect an error in the watermark information, and is the same as the verification data described in the third embodiment.
[0095]
The watermark information embedding unit A02 acquires verified watermark information from the information verification unit A05, and embeds the watermark information in the video / audio data input to the information recording device 30.
[0096]
The information verification unit A05 verifies the watermark information and transmits the verification result to the recording device A09.
[0097]
The data recording device A09 refers to the verification result transmitted from the digital watermark device A01, and executes the recording operation when there is no information error. As a result, the video / audio data in which the watermark information is embedded is recorded by the data recording device A09.
[0098]
On the other hand, if there is an information error, the data recording device A09 does not execute the recording operation. The data recording device A09 does not execute the recording operation, but records the audio / video data transmitted from the digital watermark device A01 after invalidating it to an extent that viewing is difficult, or records dummy data. Also good. At this time, since the normal video / audio data is not recorded, the watermark information embedding unit A02 may or may not perform the watermark information embedding process.
[0099]
In the above description, an example in which the digital watermark apparatus described in the third embodiment is modified and used as the digital watermark apparatus A01 has been described. However, the configuration of the digital watermark apparatus A01 is not limited to this. That is, in the digital watermark apparatus having the information verification unit shown in the fourth to eighth embodiments, the configuration is changed so that the verification result by the information verification unit can be output to the outside of the digital watermark apparatus A01. It can be used as the digital watermark apparatus A01 of the embodiment. This makes it possible to verify not only the watermark information but also the set value.
[0100]
As described above, in this embodiment, the information verification unit included in the digital watermark device detects the alteration of the information by verifying the watermark information and the set value, and further transmits the verification result to the recording device. Thus, the recording apparatus itself does not record the audio / video data, which can prevent falsification of watermark information and setting values.
[0101]
(Eleventh embodiment)
In the ninth embodiment, the application example of the digital watermarking apparatus to the information reproducing apparatus has been described. In this embodiment, an application example of the digital watermarking apparatus to the information receiving apparatus will be described. As shown in FIG. 12, the information receiving device 35 includes a receiving / decoding device B09 that receives, decodes, and outputs encoded video and audio via radio waves and lines, and a digital watermark device 901. The configuration and operation of the digital watermark device 901 are the same as those described in the tenth embodiment.
[0102]
That is, the reception decoding device B09 refers to the verification result from the digital watermark device 901, and when there is an error in the watermark information or the setting value information, the reception operation and / or the decoding operation is not executed, and there is no error. Only, the receiving operation and the decoding operation are executed, and the digital watermark apparatus 901 receives and decodes the decoded video and audio information. The digital watermark device 901 embeds a digital watermark in the output information from the reception decoding device B09 and outputs the information.
[0103]
Note that the receiving / decoding device B09 may invalidate and output the video / audio data to the extent that viewing is difficult, or may output dummy data, instead of performing the receiving operation and / or the decoding operation. Further, as described in the tenth embodiment, as the digital watermark device 901, another digital watermark device having an information verification unit can be used.
[0104]
As described above, according to the information receiving apparatus, it is possible to detect falsification of watermark information and setting values, and when the falsification is detected, the received information is not transmitted correctly, so that fraud can be prevented.
[0105]
(Twelfth embodiment)
In the tenth embodiment, the application example of the digital watermarking apparatus to the information recording apparatus has been described. In this embodiment, an application example of the digital watermarking apparatus to the information transmitting apparatus will be described. As shown in FIG. 13, the information transmission device 40 includes a digital watermark device A01 and an encoding transmission device C09. The encoded transmission device C09 is a device that encodes video or audio and transmits it via radio waves or lines. The configuration and operation of the digital watermark apparatus A01 are the same as those described in the eleventh embodiment.
[0106]
The encoding / transmission device C09 refers to the verification result from the digital watermarking device A01, and when there is an error in the watermark information or setting value information, the encoding operation and / or transmission operation is not executed and there is no error. Only the encoding operation and the transmission operation are executed.
[0107]
Instead of executing the encoding operation and / or the transmission operation, the encoding / transmission apparatus C09 invalidates the video / audio data to an extent that it is difficult to view, encodes it, or transmits it after invalidating it, Data may be encoded or dummy data may be transmitted. Further, as described in the eleventh embodiment, as the digital watermark apparatus A01, another digital watermark apparatus having an information verification unit can be used.
[0108]
As described above, according to the present information transmission apparatus, it is possible to detect falsification of watermark information and setting values, and when the falsification is detected, correct information is not transmitted, so that fraud can be prevented.
[0109]
In each of the embodiments of the present invention described above, the watermark information has been described using an example of using information stored in advance on a medium different from the content storage medium, such as an IC card. May use various information stored in a content storage medium (for example, a tape, a disk, or a memory card medium), or various information included in the apparatus. Examples of information stored in the content storage medium include a medium ID of the medium, a content ID, and a copyright holder ID. Examples of information that the device has include device ID, date information that the device timer has, and user ID of the device. By embedding these pieces of information as watermark information while protecting them with the methods shown in the embodiments of the present invention, for example, the above information is detected as watermark information from illegally copied video and audio. A clue to track the source.
[0110]
In each embodiment of the present invention, the example in which watermark information and setting values are read from a medium such as an IC card has been described. However, the present invention is not limited to this, and the apparatus is connected to a network and used as watermark information. Various IDs and setting values necessary for watermark embedding processing may be downloaded from a server via a network and used. Even when such information is downloaded and used via a network, the same effect can be obtained by using the method shown in each embodiment of the present invention while protecting watermark information and setting values.
[0111]
Although the apparatus of each embodiment of the present invention described above may be realized by hardware, part or all of the processing may be performed by software of a computer. In each of the above embodiments, video or audio information is used as information to add watermark information, but other types of information may be used.
[0112]
【The invention's effect】
According to the present invention, in the digital watermark device or an application device using the digital watermark device, the watermark information and the setting value necessary for the watermark information embedding operation are kept secret from the outside of the device. Tampering can be prevented. Further, it is possible to detect falsification of watermark information and setting values before embedding, and by stopping or invalidating video and audio output when falsification is detected, it is possible to prevent viewing of video and audio, and to prevent fraud.
[Brief description of the drawings]
FIG. 1 is a block diagram of a digital watermark apparatus according to a first embodiment of the present invention.
FIG. 2 is a diagram showing a system configuration example including a playback device using the digital watermark device according to the present invention.
FIG. 3 is a block diagram of a digital watermark apparatus according to a second embodiment of the present invention.
FIG. 4 is a block diagram of a digital watermark apparatus according to a third embodiment of the present invention.
FIG. 5 is a block diagram of a digital watermark apparatus according to a fourth embodiment of the present invention.
FIG. 6 is a block diagram of a digital watermark apparatus according to a fifth embodiment of the present invention.
FIG. 7 is a block diagram of a digital watermark apparatus according to a sixth embodiment of the present invention.
FIG. 8 is a block diagram of a digital watermark apparatus according to a seventh embodiment of the present invention.
FIG. 9 is a block diagram of a digital watermark apparatus according to an eighth embodiment of the present invention.
FIG. 10 is a diagram showing a configuration of an information reproducing apparatus using a digital watermark apparatus according to the present invention.
FIG. 11 is a diagram showing a configuration of an information recording apparatus using a digital watermark apparatus according to the present invention.
FIG. 12 is a diagram showing a configuration of an information receiving apparatus using a digital watermark apparatus according to the present invention.
FIG. 13 is a diagram showing a configuration of an information transmission apparatus using a digital watermark apparatus according to the present invention.
[Explanation of symbols]
5 Information recording media
10 Disc player
10a Information reproducing apparatus
15, 15a-15h Digital watermarking device
30 Information recording device
35 Information receiver
40 Information transmitter
50 Display device
102, 202, 302, 402, 602, 702, 802 Watermark information embedding unit
105, 205, 508, 608, 708, 808 Decryption unit
305, 405, 505, 605, 705, 805 Information verification unit

Claims (1)

An apparatus for inputting video information and embedding watermark information in the video information,
Information verification means for inputting and verifying setting value information obtained by adding verification data to an encrypted setting value obtained by encrypting a setting value including an embedded signal strength necessary for the watermark information embedding process;
And decryption means for decrypting the encrypted set value having undergone verification by the information validation means,
If the verification result by the information verification means indicates normal, watermark information is embedded in the input video information using the setting value decoded by the decryption means, and output,
An electronic watermarking device comprising: watermark information embedding means for not outputting the input video information to the outside of the device or outputting a dummy video when the verification result does not indicate normality.

Images