JP2004111018A - Digital watermarking device and application device using the same - Google Patents

Abstract

An electronic watermarking apparatus for embedding information in video or audio has a problem that before embedding, watermark information and setting values required for embedding processing are falsified.
An information verification unit (805) verifies an encrypted setting value using verification data of an encryption setting value (811) with verification data, and transmits the verification result to a watermark information embedding unit (802). The information verifying unit 805 transmits the verified encrypted set value to the decryption unit 808. The decryption unit 808 decrypts the encrypted set value. If the verification result from the information verification unit 805 is normal, the watermark information embedding unit 802 embeds the watermark information in the input video / audio data using the verified and decrypted setting values, and outputs it. If the verification result is not normal, the watermark information embedding unit 802 does not output the input video / audio data to the outside of the device.
[Selection] Fig. 9

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a digital watermarking device for embedding information related to copyright protection in predetermined information such as video and audio, and an application device using the digital watermarking device.
[0002]
[Prior art]
In recent years, the spread of DVD (Digital Versatile Disc) has been remarkable, and DVD-based playback devices have been introduced into aircraft and museums.
[0003]
Especially for use in aircraft, the unreleased movie may be screened on the ground, and the content of such unreleased movie etc. will not be leaked to the outside, or even if it is leaked, the leaked content is nowhere. There is a demand for a system that realizes copyright protection so that it can be traced whether or not it has leaked from the Internet.
[0004]
2. Description of the Related Art Conventionally, as a copyright protection method, there is a technique called “digital watermark” for embedding specific information in content such as video and audio (for example, see Patent Document 1).
[0005]
Information to be embedded as a digital watermark (hereinafter referred to as “watermark information”) includes various information such as copy control information for limiting the number of times the content is copied, a content ID, and a copyright holder ID.
[0006]
Most of these pieces of watermark information have 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 activate the copy protection function to restrict the copying action. Also, by embedding the ID of the content or the ID of the copyright holder, even if an illegal copy is created, the watermark information is detected from the content, and the copyright holder is proved from the detected numerical value or symbol. 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, it is important that the numerical values and symbols embedded as the watermark information have no error.
[0008]
In addition, in order for watermark information to be correctly detected from content, it is important that a device for embedding watermark information accurately embeds watermark information in content according to a predetermined correct calculation method or processing procedure.
[0009]
As a technique for preventing falsification of watermark information embedded in content, there is a method of embedding watermark information in content after encrypting the watermark information (see Patent Documents 2 and 3).
[0010]
[Patent Document 1]
Patent No. 3106985
[Patent Document 2]
JP 2001-78013 A
[Patent Document 3]
JP 2002-232412 A
[0011]
[Problems to be solved by the invention]
The watermark information once embedded in the content is difficult to falsify or remove. However, it is relatively easy to falsify the watermark information before it is embedded in the content. That is, the conventional digital watermarking apparatus has a problem that the watermark information itself is falsified before the watermark information is embedded in the content.
[0012]
If the falsified information is embedded in the content, for example, the copy control information of the content becomes a numerical value or a symbol indicating that the content can be copied any number of times, or if the ID of the content or the ID of the copyright holder is originally Different from the numerical values and symbols, copyright holders cannot be proved, and the rights of copyright holders are significantly impaired.
[0013]
In addition, the digital watermarking device performs, at the time of the watermark embedding operation, a set value required for the embedding operation, such as a mode designation value of the embedding operation, various constants and variables used for the embedding operation, a comparison value, a table value, and code data. Often used. The digital watermark device can embed watermark information in a content by a predetermined correct operation method or processing procedure only when these set values are set correctly.
[0014]
The setting values required for such an embedding operation may be falsified when embedding the watermark information in the content. If the set value necessary for the watermark embedding operation is falsified, a predetermined correct operation result cannot be obtained. For example, the signal strength of the watermark information embedded in the content becomes weak, and the removal of the watermark information becomes easy. In addition, there is an adverse effect that embedding is performed differently from the method and procedure assumed by the device on the electronic watermark detection side, and watermark information cannot be detected from the content.
[0015]
The present invention has been made in consideration of the problems of the conventional digital watermarking device, and protects watermark information and setting values required for the operation of the digital watermarking device from tampering, thereby embedding accurate watermarking information accurately in content. Aim.
[0016]
[Means for Solving the Problems]
A first digital watermarking device according to the present invention is a device that performs processing for inputting predetermined information and embedding watermark information in the predetermined information, and includes an information verification unit, a decryption unit, and a watermark information embedding unit. The information verification unit performs verification by inputting setting value information obtained by adding verification data to an encrypted setting value obtained by encrypting a setting value required for watermark information embedding processing. The decryption means decrypts the encrypted set value verified by the information verification means. The watermark information embedding unit embeds the watermark information in the predetermined information input using the setting value decrypted by the decryption unit and outputs the watermark information when the verification result by the information verification unit indicates normal. On the other hand, if the verification result does not indicate normal, the watermark information embedding unit does not output the input predetermined information to the outside of the apparatus, or invalidates and outputs the input predetermined information.
[0017]
A second digital watermark device according to the present invention is a device for performing processing for inputting predetermined information and embedding watermark information in the predetermined information, and includes a decryption unit, an information verification unit, and a watermark information embedding unit. The decryption unit inputs and decrypts setting value information obtained by encrypting at least a part of a setting value with verification data obtained by adding verification data to a setting value required for watermark information embedding processing. The information verification unit verifies the set value with verification data decrypted by the decryption unit. The watermark information embedding means acquires the verified setting value from the information verifying means when the verification result by the information verifying means indicates normal, and embeds the watermark information in the predetermined information input using the acquired setting value. Output. On the other hand, when the verification result does not indicate normality, the watermark information embedding unit does not output the input predetermined information to the outside of the apparatus, or invalidates and outputs the input predetermined information.
[0018]
A first application apparatus according to the present invention includes a reproducing unit that reproduces a recording medium on which predetermined information is recorded, and the predetermined information reproduced by the reproducing unit, and the digital watermark is embedded in the predetermined information. Device. The reproducing unit inputs the verification result from the information verifying unit of the digital watermarking apparatus, and performs a reproducing operation when the verification result is normal. On the other hand, if the verification result is not normal, the reproducing means does not execute the reproducing operation or invalidates the reproduced output.
[0019]
A second application device according to the present invention is a receiving / decoding means for receiving and decoding predetermined information via a communication medium, and inputs predetermined information received and decoded by the reception / decoding means, and embeds watermark information in the predetermined information. , And the electronic watermarking device described above. The receiving / decoding means receives the verification result from the information verification means of the digital watermarking device, and performs a receiving operation and a decoding operation when the verification result is normal. On the other hand, if the verification result is not normal, the receiving / decoding means does not execute at least one of the receiving operation and the decoding operation, or invalidates its output.
[0020]
A third application device according to the present invention includes the above-described digital watermark device, and recording means for inputting output information from the digital watermark device and recording the information on a recording medium. The recording means receives the verification result from the information verification means of the digital watermark device, and if the verification result is normal, performs a recording operation of the output information from the digital watermark device. On the other hand, if the verification result is not normal, the recording means does not execute the recording operation, or invalidates the output information from the digital watermark device, and then records.
[0021]
A fourth application device according to the present invention includes the above-described digital watermark device, and a coded transmission unit that codes output information from the digital watermark device and transmits the coded information via a communication medium. The encoding and transmitting unit receives the verification result of the information verifying unit of the digital watermarking apparatus, and performs an encoding operation and a transmitting operation of the encoding and transmitting unit when the verification result is normal. On the other hand, if the verification result is not normal, the encoding / transmission unit does not execute at least one of the encoding operation and the transmission operation of the encoding / transmission unit, or invalidates the output information from the digital watermark device, and And transmission operation.
[0022]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of a digital watermark device according to the present invention and an application device using the same will be described with reference to the accompanying drawings.
[0023]
(1st Embodiment)
FIG. 1 is a diagram showing an example of the configuration of a digital watermark device according to the present invention. The digital watermark device 15a 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 a digital watermark device described in the present embodiment and a later-described embodiment 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 reproducing apparatus 10 reproduces the disc medium 1 and outputs video and audio. In particular, the disc reproducing apparatus 10 needs information recorded on the information recording medium 5 for reproduction for realizing 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 the digital watermark embedding process, and the like. These pieces of information are stored in a state where they are encrypted as necessary, and with an electronic signature added. The information necessary for the digital watermark embedding process includes, in the embodiment of the present invention, the encrypted watermark information or the set value, the watermark information or the set value with the verification data, and the encrypted watermark information or the set value with the verification data. This includes watermark information or setting values, or watermark information or setting values to which encrypted verification data is added.
[0027]
The disk medium 1 stores video information and audio information. Since the disc reproducing apparatus 10 uses information recorded on the information recording medium 5 when reproducing the disc medium 1, the information recording medium 5 needs to be inserted. That is, the disk reproducing device 10 can reproduce the disk medium 1 only when the information recording medium 5 is inserted.
[0028]
FIG. 2B is a diagram illustrating a configuration of the disk reproducing device 10. The disk playback device 10 includes a disk drive 11, a decoding unit 13, a digital watermarking device 15, and a D / A conversion unit 17. The digital watermarking device 15 may be any of the digital watermarking 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 decrypted signal is embedded with watermark information by the digital watermarking device 15, converted into an analog signal by the D / A converter 17, and output as a video.
[0030]
The digital watermark device 15 reads information necessary for embedding watermark information from the information recording medium 5 and performs a process of embedding watermark information in a video or audio signal reproduced from the disk medium 1 using the information.
[0031]
Returning to FIG. 1, details of the digital watermarking device 15a of the present embodiment will be described. The encrypted watermark information 111 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 and audio data, and the ID of the copyright holder. The watermark information is such information represented by numerical values or symbols. The encryption key used by the decryption unit 105 to decrypt the encryption may be held in the digital watermarking device 15a in advance, or may be provided from outside 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 and audio data, embeds the watermark information decrypted by the decryption unit 105 in the video and audio data, and outputs the watermark information. As a method of embedding a watermark used in the watermark information embedding unit 102, any method of a known digital watermarking technique may be used.
[0033]
As described above, in the present embodiment, the watermark information to be embedded in the video / audio data is input to the device in an encrypted state. The encrypted watermark information is a cipher text whose meaning is indistinguishable even by looking at the notation of numerical values and symbols, and it is difficult to falsify the cipher text so that it is decrypted to the intended value. Therefore, what kind of watermark information is embedded in video and audio can be kept secret from the outside of the apparatus, and further, the act of falsifying the watermark information to an intended value can be prevented.
[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 is decrypted. Instead, it may be embedded in video or audio data as it is. In this case, in FIG. 1, the decryption unit 105 becomes unnecessary, 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, it is possible to decrypt the detected watermark information by providing a decryption unit in the device that detects the watermark information. it can. Since the watermark information is embedded in the video or audio data while being encrypted, there is an effect that 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 device according to the present invention. The digital watermark device 15b has a watermark information embedding unit 202 and a decryption unit 205.
[0036]
An encrypted set value 211 is input to the digital watermark device 15b of the present embodiment. The setting value is information necessary for the watermark information embedding unit 202 to embed the watermark information. The setting values required for the embedding operation include, for example, the following.
-Setting value to select whether to perform embedding operation
When the watermark information embedding unit 202 has a plurality of embedding methods and modes, a set value of a mode for selecting one of them.
-Constants and variables used for embedded operations
-Comparison values and table values used for embedded calculations
-Code data used for embedding processing
−Specification value of embedded signal strength
− Designated values for the location and timing of embedding a watermark in video and audio
-Other various values required for the operation of the watermark information embedding unit 202
[0037]
The encrypted setting value 211 is input to the digital watermark device 15b, 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 receives video / audio data, embeds watermark information in the video / audio data, and outputs the watermark information. At this time, the embedding process is performed using the setting value decrypted by the decryption unit 205 or according to the value of the decrypted setting value.
[0038]
As described above, in the present embodiment, the setting values required for the operation of the watermark information embedding unit 202 are input to the device in an encrypted state. The encrypted set value is a cipher text whose meaning is indistinguishable even by looking at the notation of numerical values and symbols, and it is difficult to falsify the cipher text so that it is decrypted to the intended value. Therefore, what setting value is used by the watermark information embedding unit 202 can be kept secret from the outside of the apparatus, and further, the act of falsifying the setting value of the watermark information embedding unit to an intended value is prevented. it can.
[0039]
(Third embodiment)
FIG. 4 is a diagram showing a third configuration example of the digital watermark device according to the present invention. The digital watermark device 15c has a watermark information embedding unit 302 and an information verification unit 305.
[0040]
The watermark information with verification data 311 is input to the digital watermark device 15c of the present embodiment. The watermark information with verification data 311 is obtained by adding verification data for detecting an error in the information to the watermark information.
[0041]
Here, as a means for detecting an information error, various error detection methods and error detection codes such as a parity check and a CRC (Cyclic Redundancy Check) are generally known. In order to prevent the watermark information from being falsified, it is preferable that the method and the operation formula used for the error detection are hardly analogized. Further, in order to enhance security against tampering, a digital signature using public key encryption may be added as verification data to be added to the watermark information. In this case, the public key required for verifying the signature may be held in advance by the digital watermark device 15c, or may be given from outside the device. Further, other verification means may be used.
[0042]
The information verifying unit 305 has a predetermined error detecting function and a verifying function, and verifies the watermark information by 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 the presence or absence of 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, and if there is no error in the information, acquires the verified watermark information from the information verification unit 305, and inputs the watermark information to the input video. 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 not 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 such an extent that it is difficult to view or output dummy data.
[0045]
As described above, in the present embodiment, the watermark information embedded in the video / audio data is input to the device with the verification data added. Therefore, even if the input watermark information is falsified, since the verification data is added, the falsification of the watermark information is detected as an information error in the information verification unit. When an error in the information 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, falsification of the watermark information can be prevented.
[0046]
(Fourth embodiment)
FIG. 5 is a diagram showing a fourth configuration example of the digital watermarking device according to the present invention. The digital watermark device 15d has a watermark information embedding unit 402 and an information verification unit 405.
[0047]
The set value 411 with verification data is input to the digital watermark device 15d of the present embodiment. The setting value 411 with verification data is obtained by adding verification data for detecting an error in the setting value to a setting value required for the embedding operation of the watermark information embedding unit 402. The set values and the verification data are the same as those described in each of the second embodiment and the third embodiment.
[0048]
The information verification unit 405 verifies the setting value using the verification data in the verification data-added setting value 411, 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 obtains a verified setting value from the information verification unit 405 when there is no error in the information. After that, the watermark information embedding unit 402 embeds watermark information into 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 verified setting value, and outputs the video / audio data in which the watermark information is embedded to the outside.
[0050]
On the other hand, when the verification result transmitted from the information verification unit 405 indicates that there is an error in the information, the watermark information embedding unit 402 does not output the input video / audio data to the outside of the device. The watermark information embedding unit 402 may output the video / audio data after invalidating the video / audio data to such an extent that it is difficult to view or outputting dummy data instead of not outputting the video / audio data to the outside of the apparatus.
[0051]
As described above, in the present embodiment, the setting value required for the operation of the watermark information embedding unit 402 is input to the apparatus in a state where the verification data is added. As a result, even if the set value is falsified, since the verification data is added, the information verification unit detects the falsification of the set value as an information error. When an error in the information 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, the act of falsifying the set value required for the operation of the watermark information embedding unit can be prevented.
[0052]
(Fifth embodiment)
FIG. 6 is a diagram showing a fifth configuration example of the digital watermark device 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 encrypted verification data is input to the digital watermark device 15e of the present 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 a 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 decrypted watermark information with verification data to the information verification unit 505. Here, the decrypted watermarked data with verification data is data in a state where the encryption of the watermark information with encrypted verification data 510 is decrypted, and includes the watermark information and the verification data.
[0055]
The information verification unit 505 verifies the decrypted watermarked data with 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 the verified watermark information from the information verification unit 505 when there is no error in the information. After that, the watermark information embedding unit 502 embeds the obtained watermark information in the input video and audio data, and outputs the video and audio data with the embedded watermark information to the outside.
[0057]
On the other hand, when the verification result transmitted from the information verification unit 505 indicates that there is an error in the information, 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 and output the video / audio data to such 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.
[0058]
As described above, in the present embodiment, the verification data is added to the watermark information to be embedded in the video / audio data, and at least a part of the verification information is input to the device in an encrypted state. As a result, the meaning of the encrypted information can not be understood by looking at the notation of numerical values and symbols, so it is possible to conceal what kind of numbers and symbols are embedded as watermark information from the outside of the device become. Furthermore, it is difficult to falsify the ciphertext so that it is decrypted to the intended value. Further, even if this cipher text is falsified into an appropriate numerical value or symbol, the falsification of the watermark information is detected as an information error in the information verification unit because the verification data is added. When an error in the information 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 prevent the watermark information from being concealed from the outside of the apparatus, and to prevent the watermark information from being falsified to an appropriate numerical value by a combination of 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 watermark device according to the present invention. The digital watermark device 15f includes a watermark information embedding unit 602, an information verification unit 605, and a decryption unit 608.
[0060]
The set value 611 with encryption verification data is input to the digital watermark device 15f of the present embodiment. The set value 611 with encrypted verification data is generated by first adding verification data to the set value and encrypting all or part of the data obtained by combining the set value and the verification data. The verification data and the set values 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 obtained setting value with decrypted verification data to the information verification unit 605. The setting value with decrypted verification data is data in a state where the encryption of the setting value with encryption verification data 611 is decrypted, and includes the setting value after decryption and the verification data.
[0062]
The information verification unit 605 verifies the presence or absence of an error in the decrypted set value using the 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 a verified set value from the information verification unit 605 when there is no information error in the set value. After that, 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 verified setting value, and outputs the video / audio data in which the watermark information is embedded to the outside of the device.
[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 device. Note that the watermark information embedding unit 602 may invalidate and output the video and audio data to such an extent that it is difficult to view or output dummy data instead of not outputting the video and audio data to the outside of the apparatus.
[0065]
As described above, in the present embodiment, the verification data is added to the set value necessary for the operation of the watermark information embedding unit 602, and the set value is input to the apparatus in a state where a part or the whole is encrypted. As a result, the meaning of the encrypted information cannot be understood by looking at the notation of numerical values and symbols, and therefore, what setting value is used to operate the watermark information embedding unit is kept secret from the outside of the device. It becomes possible. Further, since it is difficult to falsify the ciphertext so that it is decrypted to the intended value, it is possible to prevent the setting value from being falsified to the intended value. Further, even if this ciphertext is falsified to an appropriate numerical value or symbol, since the verification data is added, the information verification unit detects the falsification of the set value as an information error. When an error in the information 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 prevent the setting value from being concealed from the outside of the apparatus, and to prevent the setting value from being falsified to an appropriate value by a combination of 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 watermarking device 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 the present 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 with verification data 711, 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 if there is no error in the watermark information, acquires the decrypted watermark information from the decryption unit 708.
[0070]
As described above, the watermark information embedding unit 702 performs the process of acquiring decrypted watermark information through the process of the decryption unit 708 only when the verification result indicates that there is no error in the information. It is preferable because useless processing is reduced. The reason is that if the verification result indicates that there is an error in the information, there may be an error in the verified encrypted watermark information or the decrypted watermark information. This is because the decryption process in the decryption unit 708 is wasted because it is not performed. The watermark information embedding unit 702 may always obtain the decrypted watermark information through the processing of the decryption unit 708 irrespective of the verification result.
[0071]
The watermark information embedding unit 702 refers to the verification result transmitted from the information verification unit 705, and when there is no error in the information, embeds the decrypted watermark information in the input video / audio data, and the watermark information is embedded. The 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 error in the information, the watermark information embedding unit 702 does not output the input video / audio data to the outside of the device. Note that the watermark information embedding unit 702 may output the video / audio data after invalidating the video / audio data to such an extent that it is difficult to view or outputting dummy data instead of not outputting the video / audio data to the outside of the apparatus.
[0073]
As described above, in the present embodiment, the watermark information to be embedded in the video / audio data is input to the apparatus in a state where the watermark information is encrypted and further the verification data is added. As a result, the meaning of the encrypted information can not be understood by looking at the notation of numerical values and symbols, so it is possible to conceal what numerical values and symbols are embedded as watermark information from the outside of the device become. Furthermore, it is difficult to falsify the ciphertext so that it is decrypted to the intended value. Further, even if this cipher text is falsified into an appropriate numerical value or symbol, the falsification of the watermark information is detected as an information error in the information verification unit because the verification data is added. When an error in the information 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 before the decryption unit, falsification of the watermark information can be detected quickly.
[0074]
From the above, the watermark information is concealed from the outside of the apparatus, and furthermore, the combination of the information verification unit and the watermark information embedding unit also prevents the falsification of the watermark information into an appropriate numerical value. Detection can be performed in a short time.
[0075]
In the present embodiment, the encrypted watermark information from the information verifying unit 705 is decrypted by the decryption unit 708 and then embedded in the video / audio data. A configuration may be employed in which the watermark information is embedded in video or audio without decoding. In this case, in FIG. 8, the decryption unit 708 becomes unnecessary, and the configuration is such that the verified encrypted watermark information from the information verification unit 705 is directly input to the watermark information embedding unit 702. In this configuration, since the watermark information is embedded in the video or audio in an encrypted state, the detected watermark information can be decrypted by providing a decryption unit in the device that detects the watermark information. . Then, since the watermark information is embedded in the video or audio in a state of being encrypted, 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 device 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]
An encryption setting value 811 with verification data is input to the digital watermark device 15h of the present embodiment. The encryption setting value with verification data 811 is obtained by encrypting a setting value and adding verification data to the encrypted setting value. Here, the verification data and the set values 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 encryption setting value with verification data 811, and transmits the verification result to the watermark information embedding unit 802. The information verification unit 805 transmits the verified encrypted set 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 error in the information.
[0080]
As described above, the watermark information embedding unit 802 performs a process of obtaining a decrypted set value through the process of the decryption unit 808 only when there is no error in the information based on the verification result, which is wasteful. This is preferable because it requires less processing.
[0081]
The reason is that if there is an error in the verification result, there may be an error in the verified encrypted setting value or the decrypted setting value, and it cannot be used as the setting value. This is because the decryption processing in the decryption unit 808 becomes useless. Note that the watermark information embedding unit 802 may obtain a decrypted set value that has been processed by 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 error in the information, the watermark information embedding unit 802 embeds the 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. I 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 and audio data input to the watermark information embedding unit 802 to the outside of the device. Note that the watermark information embedding unit 802 may invalidate and output the video / audio data to such 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.
[0084]
As described above, in the present embodiment, the setting value required for the operation of the watermark information embedding unit is input to the device in a state where the setting value is encrypted and further the verification data is added. As a result, the meaning of the encrypted information cannot be understood by looking at the notation of numerical values and symbols, and therefore, what setting value is used to operate the watermark information embedding unit is kept secret from the outside of the device. It becomes possible. Further, since it is difficult to falsify the ciphertext so that it is decrypted to the intended value, it is possible to prevent the setting value from being falsified to the intended value. Further, even if this ciphertext is falsified to an appropriate numerical value or symbol, since the verification data is added, the information verification unit detects the falsification of the set value as an information error. When an error in the information 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 before the decryption unit, the falsification of the set value can be detected quickly.
[0085]
From the above, the setting value is concealed from the outside of the device, and further, by combining the information verification unit and the watermark information embedding unit, the act of falsifying the setting value to an appropriate value is prevented. Detection can be performed in a short time.
[0086]
(Ninth embodiment)
FIG. 10 shows a configuration of an information reproducing apparatus which is one of the applied devices using the above digital watermarking apparatus. The information reproducing device 10a includes a data reproducing device 909 and a digital watermark device 901. The digital watermarking apparatus 901 has basically the same configuration as the digital watermarking apparatus 15c described in the third embodiment, but differs in that the verification result from the information verification unit 905 is output to the outside of the apparatus. . That is, the verification result from the information verification unit 905 is transmitted to the data reproducing device 909.
[0087]
The data reproducing device 909 is a device that reproduces and outputs a recording medium 1a on which video and audio are recorded, such as a tape, a disk, and a memory card. The video / audio data output from the data reproducing device 909 is transmitted to the digital watermark device 901. Watermark information with verification data is input to the information verification unit 905. 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 reproducing device 909.
[0088]
The data reproducing device 909 refers to the verification result transmitted from the digital watermark device 901 and executes the reproducing operation of the recording medium 1a when there is no error in the information. As a result, video / audio data is output from the data reproducing device 909 and transmitted to the watermark information embedding unit 902 of the digital watermarking 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 with the embedded watermark information to the outside of the device.
[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 error in the information. Instead of not performing the operation of reproducing the recording medium 1a, the data reproducing device 909 may invalidate and output the video / audio data to such an extent that it is difficult to view or output dummy data. In this case, since the watermark information embedding unit 902 cannot obtain normal video / audio data, the watermark information embedding process may or may not be performed. As a result, no video or audio data is output from the information reproducing apparatus 10a, or invalid video and audio data is output.
[0090]
In the above description, an example has been described in which the digital watermarking apparatus described in the third embodiment is modified and used as the digital watermarking apparatus 901, but the configuration of the digital watermarking apparatus 901 is not limited to this. That is, in the digital watermarking apparatus having the information verifying unit described in the fourth to eighth embodiments, the configuration is changed so that the verification result by the information verifying 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 enables not only verification of watermark information but also verification of set values.
[0091]
As described above, in the present embodiment, the information verification unit included in the digital watermarking device verifies the watermark information and the set value, thereby detecting tampering of the information, and further transmitting the verification result to the playback device. Therefore, the playback device does not execute the playback of the video and audio data. As a result, when tampering is performed, not only the video and audio cannot be viewed, but also the output source of the video and audio data is stopped, so that the video and audio data no longer exists as a signal inside the device. Prevention of stealing, etc., can realize safe and reliable protection measures. As described above, the falsification of the watermark information and the set values can be prevented, and a secure system configuration can be provided.
[0092]
(Tenth embodiment)
FIG. 11 shows a configuration of an information recording device which is one of the applied devices using the above-described digital watermarking device. The information recording device 30 includes a digital watermark device A01 and a data recording device A09.
[0093]
The digital watermarking apparatus A01 has the same basic configuration as the digital watermarking apparatus 15c described in the third embodiment, but differs in that a verification result from the information verification unit A05 can be output to the outside of the apparatus. . The data recording device A09 is a device that records video and audio on a recording medium such as a tape, a disk, and a memory card.
[0094]
The verification result from the information verification unit A05 is transmitted to the data recording device A09. The video / audio data in which the watermark information is embedded is transmitted to the recording device A09. 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 the verified watermark information from the information verification unit A05, and embeds the watermark information into 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 a recording operation when there is no error in the information. 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, when there is an information error, the data recording device A09 does not execute the recording operation. Instead of performing the recording operation, the data recording device A09 invalidates the video / audio data transmitted from the digital watermarking device A01 to such a degree that it is difficult to view, or records, or records dummy data. Is also good. At this time, since 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 watermarking apparatus described in the third embodiment is modified and used as the digital watermarking apparatus A01 has been described, but the configuration of the digital watermarking apparatus A01 is not limited to this. That is, in the digital watermarking apparatus having the information verifying unit described in the fourth to eighth embodiments, the configuration is changed so that the verification result by the information verifying unit can be output to the outside of the digital watermarking apparatus A01. It can be used as the digital watermark device A01 of the embodiment. This enables not only verification of watermark information but also verification of set values.
[0100]
As described above, in the present embodiment, the information verification unit included in the digital watermarking apparatus verifies the watermark information and the setting value, thereby detecting tampering of the information and transmitting the verification result to the recording apparatus. Thus, there is a feature that the recording apparatus itself does not record the video and audio data, thereby preventing the falsification of the watermark information and the set value.
[0101]
(Eleventh embodiment)
In the ninth embodiment, an application example of the digital watermark device to the information reproducing device has been described. In the present embodiment, an application example of the digital watermark device to the information receiving device will be described. As shown in FIG. 12, the information receiving device 35 includes a receiving / decoding device B09 that receives coded video and audio via radio waves and lines, decodes and outputs the coded video and audio, and a digital watermarking 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 receiving / decoding device B09 refers to the verification result from the digital watermark device 901 and does not execute the receiving operation and / or the decoding operation if there is an error in the watermark information or the setting value information. The digital watermarking apparatus 901 executes the receiving operation and the decoding operation, and outputs the received and decoded video and audio information. The digital watermarking device 901 embeds a digital watermark in the output information from the receiving and decoding device B09 and outputs the information.
[0103]
Instead of not performing the receiving operation and / or the decoding operation, the receiving / decoding device B09 may invalidate and output the video / audio data to such an extent that it is difficult to view, or may output dummy data. As described in the tenth embodiment, another digital watermarking device having an information verifying unit can be used as the digital watermarking device 901.
[0104]
As described above, according to the present information receiving apparatus, tampering with watermark information and set values can be detected, and if tampering is detected, the received information is not correctly transmitted, thereby preventing fraud.
[0105]
(Twelfth embodiment)
In the tenth embodiment, an application example of the digital watermark device to the information recording device has been described. In the present embodiment, an application example of the digital watermark device to the information transmission device will be described. As shown in FIG. 13, the information transmitting device 40 includes a digital watermark device A01 and an encoded transmitting device C09. The coded transmitting device C09 is a device that codes video or audio and transmits the coded video or audio via radio waves or lines. The configuration and operation of the digital watermark device A01 are the same as those described in the eleventh embodiment.
[0106]
The encoding and transmitting device C09 refers to the verification result from the digital watermarking device A01, does not execute the encoding operation and / or the transmitting operation when there is an error in the watermark information and the setting value information, and when there is no error. The encoding operation and the transmission operation are executed only for.
[0107]
In addition, instead of not performing the encoding operation and / or the transmitting operation, the encoding transmission device C09 invalidates the video / audio data and then encodes the audio / video data to such an extent that it is difficult to view, or transmits after invalidating the dummy data. Data may be encoded or dummy data may be transmitted. As described in the eleventh embodiment, another digital watermark device having an information verification unit can be used as the digital watermark device A01.
[0108]
As described above, according to the present information transmitting apparatus, falsification of the watermark information and the set value can be detected, and when the falsification is detected, correct information is not transmitted.
[0109]
In each of the embodiments of the present invention described above, an example has been described in which the watermark information uses information stored in advance on a medium other than the content storage medium such as an IC card. However, the present invention is not limited to this. 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 the information stored in the content storage medium include the medium ID of the medium, the ID of the content, and the ID of the copyright holder. Examples of the information possessed by the device include an ID of the device, date and time information possessed by a timer of the device, an ID of a user of the device, and the like. By embedding such information as watermark information while protecting it by the method described in each embodiment of the present invention, for example, the above information is detected as watermark information from illegally copied video and audio. A clue to tracking the source.
[0110]
Further, in each embodiment of the present invention, an example has been described in which watermark information and setting values are read from a medium such as an IC card and used, but 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 required 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 described in each embodiment of the present invention while protecting the watermark information and the set value.
[0111]
The apparatus of each embodiment of the present invention described above may be realized by hardware, but 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 which watermark information is added, but other types of information may be used.
[0112]
【The invention's effect】
According to the present invention, in a digital watermarking device or an application device using the digital watermarking device, the watermark information and a setting value required for the operation of embedding the watermark information are kept secret from the outside of the device. Tampering can be prevented. Also, before embedding, falsification of watermark information and set values can be detected, and video or audio output can be stopped or invalidated at the time of falsification detection, so that video and audio cannot be viewed and illegal acts can be prevented.
[Brief description of the drawings]
FIG. 1 is a block diagram of a digital watermark device according to a first embodiment of the present invention;
FIG. 2 is a diagram showing an example of a system configuration including a playback device using a digital watermark device according to the present invention.
FIG. 3 is a block diagram of a digital watermark device according to a second embodiment of the present invention;
FIG. 4 is a block diagram of a digital watermark device according to a third embodiment of the present invention;
FIG. 5 is a block diagram of a digital watermark device according to a fourth embodiment of the present invention;
FIG. 6 is a block diagram of a digital watermark device according to a fifth embodiment of the present invention;
FIG. 7 is a block diagram of a digital watermark device according to a sixth embodiment of the present invention;
FIG. 8 is a block diagram of a digital watermark device according to a seventh embodiment of the present invention.
FIG. 9 is a block diagram of a digital watermark device 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 device according to the present invention.
FIG. 11 is a diagram showing a configuration of an information recording device using a digital watermark device according to the present invention.
FIG. 12 is a diagram showing a configuration of an information receiving device using a digital watermark device according to the present invention.
FIG. 13 is a diagram showing a configuration of an information transmission device using a digital watermark device according to the present invention.
[Explanation of symbols]
5 Information recording media
10 Disc playback device
10a Information reproducing device
15, 15a-15h Digital watermarking device
30 Information recording device
35 Information receiver
40 Information transmission device
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 (7)

An apparatus for performing a process of inputting predetermined information and embedding watermark information in the predetermined information,
An information verification unit for inputting and verifying setting value information obtained by adding verification data to an encrypted setting value obtained by encrypting a setting value required for the watermark information embedding process, and performing verification by the information verification unit. When the verification result by the information verifying means indicates normality, the watermark information is embedded in the input predetermined information using the setting value decrypted by the decryption means. A watermark information embedding means for not outputting the inputted predetermined information to the outside of the apparatus when the verification result does not indicate normality, or for invalidating and outputting the inputted predetermined information. An electronic watermark device characterized by the above-mentioned. An apparatus for performing a process of inputting predetermined information and embedding watermark information in the predetermined information,
Decryption means for decrypting by inputting setting value information obtained by encrypting at least a part of the setting value with verification data obtained by adding verification data to the setting value required for the watermark information embedding process,
Information verification means for verifying the setting value with verification data decrypted by the decryption means,
If the verification result by the information verification unit indicates normal, obtain a verified setting value from the information verification unit, embed watermark information in the input predetermined information using the obtained setting value, and output it. If the verification result does not indicate normality, the input predetermined information is not output to the outside of the device, or the input predetermined information is invalidated and output, and watermark information embedding means is provided. Digital watermarking device. 3. The digital watermarking device according to claim 1, wherein the information verification unit performs verification by an electronic signature using public key cryptography. 3. A digital watermarking apparatus according to claim 1, wherein said reproducing means inputs a predetermined information reproduced by said reproducing means and embeds watermark information in said predetermined information. With
The reproducing unit inputs a verification result from the information verifying unit of the digital watermarking apparatus, and performs a reproducing operation of the reproducing unit when the verification result is normal, and performs a reproducing operation when the verification result is not normal. An application apparatus which does not execute the reproduction operation of the above, or invalidates the reproduction output of the reproduction means. Reception decoding means for receiving and decoding predetermined information via a communication medium,
The digital watermarking device according to claim 1 or 2, wherein predetermined information received and decoded by the reception decoding means is input, and watermark information is embedded in the predetermined information.
The receiving / decoding means inputs a verification result from the information verification means of the digital watermarking apparatus, and performs a receiving operation and a decoding operation when the verification result is normal, and performs the receiving operation when the verification result is not normal. An application apparatus, wherein at least one of an operation and a decoding operation is not executed, or an output of the receiving and decoding means is invalidated. 3. A digital watermarking device according to claim 1 or 2, and recording means for inputting output information from the digital watermarking device and recording the information on a recording medium,
The recording unit receives a verification result from the information verification unit of the digital watermark device, and when the verification result is normal, performs a recording operation of output information from the digital watermark device, and the verification result is not normal. In such a case, the recording apparatus does not execute the recording operation, or invalidates the output information from the digital watermark apparatus, and records the information. 3. A digital watermarking device according to claim 1 or 2, and an encoding transmission unit that encodes output information from the electronic watermarking device and transmits the information via a communication medium,
The encoding / transmission unit inputs a verification result of the information verification unit of the digital watermark device, and when the verification result is normal, performs an encoding operation and a transmission operation of the encoding / transmission unit, and performs the verification result. Is not normal, at least one of the encoding operation and the transmission operation of the encoding transmission unit is not executed, or the encoding operation and the transmission operation are performed after invalidating the output information from the digital watermark device. Characteristic application equipment.

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