JP2000156781A - Digital watermark imbedding device, illegality detector and computer-readable storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To imbed an digital watermark that easily detects a fraudulent act onto digital contents, when fraudulence such as forgery is made to the digital contents. SOLUTION: A file of original digital contents such as an image is read from an external storage medium 301, an imbedding device 304 imbeds a digital watermark, including its generating time to the read digital contents, an update time of the file is obtained from a clock 302 and described on the file. At reproduction, the generated time and the updated time are extracted from the file in the case of reproduction and compared, and when the difference is larger than a prescribed value, fraudulence is considered to have been made.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital watermark embedding apparatus for embedding a digital watermark in digital content.
The present invention relates to a fraud detecting device for detecting fraud such as falsification of digital content in which a digital watermark is embedded, and a computer-readable storage medium used for the fraud detecting device.

[0002]

2. Description of the Related Art Compared with conventional analog information, digital information has the characteristics that it can be copied and falsified by a computer or the like without being easily deteriorated, and can be easily transferred through a communication line. Due to these characteristics, digital information tends to be easily copied and redistributed.

As one of the methods for preventing this, there is a method called digital watermark. Digital watermarking is a technique for embedding information in a form that cannot be perceived by humans when digital content in which it is embedded is normally reproduced. In the following description, digital content refers to moving images, still images, audio, computer programs, computer data, and the like.

As a typical information embedding method using a digital watermark, in the case of a digital image, there is a method of embedding a digital watermark by performing an operation on a data value of a digital content, which corresponds to the hue and brightness of a pixel.
A typical example of this method is to divide digital content into blocks and add a predetermined watermark pattern, which is a combination of +1 and -1 for each block, by Digimarc, US Pat. No. 5,636,29.
There is the second method.

[0005] Other typical digital watermark embedding methods include performing frequency conversion such as fast Fourier transform, discrete cosine transform, and wavelet transform on digital contents, adding watermark information to a frequency domain, and then performing inverse frequency conversion. There is a method of performing embedding by performing conversion.

In the method based on the fast Fourier transform, input content is spread by adding a PN sequence and then divided into blocks. Then, Fourier transform is performed for each block, and 1-bit watermark information is embedded in one block. The block in which the watermark information is embedded is subjected to the inverse Fourier transform, and the same PN sequence as the first is added again to obtain the content in which the digital watermark is embedded. This method is described in detail in "Onishi, Oka and Matsui," Method of Watermark Signature of Image Using PN Sequence ", 1997, Proceedings of Symposium on Cryptography and Information Security, SCIS97-26B".

[0007] In the method using the discrete cosine transform, the data is divided into blocks and discrete cosine transform is performed for each block. After embedding 1-bit information in one block, inverse conversion is performed to generate digital watermark embedded content. This method is described in "Nakamura, Ogawa, Takashima" Digital Watermarking Method in Frequency Domain for Copyright Protection of Digital Images "199
7 years, Cryptography and Information Security Symposium, SCIS97-26A ".

The method based on the wavelet transform is a method that does not require the input content to be divided into blocks.
"Ishizuka, Sakai, Sakurai," Experimental Study on Safety and Reliability of Digital Watermarking Technology Using Wavelet Transform "1
997, Symposium on Cryptography and Information Security, SCIS97-26D ”.

[0009] Representative information embedded in a digital content as a digital watermark by the above method includes copyright information and user information. By embedding the copyright information, the user can know that the copyright has been set to the digital content and who the author is. However, whether or not copyright is actually protected depends on the morals of the user. In addition, by embedding user information, a user who has redistributed can be detected from digital content redistributed illegally. However, also in this case, only an effect that gives a warning to the user can be expected.

[0010] In the future, as the infrastructure such as the Internet is further improved and the network society is advanced, it is expected that opportunities for digital contents to be distributed on the network will increase dramatically. Along with that comes the issue of copyright protection. In order to solve this problem, it is considered that a digital watermark is generally embedded in all digital contents including digital contents for which copyright is not set in some cases.

[0011]

However, even when a digital watermark is embedded by a conventional method for copyright protection as described above, whether or not the copyright is protected depends on the user's consciousness. There was a problem that copyright cannot be physically protected.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and can detect fraud on digital contents and can embed a digital watermark that can easily detect fraud on digital contents. It is another object of the present invention to detect fraud and protect the copyright of digital content.

[0013]

In order to achieve the above object, in an electronic watermark embedding apparatus according to the present invention, an embedding means for embedding an electronic watermark including the creation time of the digital content in digital content, A file creating means for creating a content file and writing a file update time in the file is provided.

Further, in the fraud detecting apparatus according to the present invention, the creation time and the update time are extracted from the file having the digital content in which the digital watermark including the creation time of the digital content is embedded and in which the file update time is described. And a comparing means for comparing the extracted creation time with the update time.

In another digital watermark embedding apparatus according to the present invention, an embedding means for embedding a digital watermark in a digital content together with a plurality of related information is provided.

In another fraud detection device according to the present invention, there is provided an information extracting means for extracting the plurality of related information from digital contents in which a digital watermark is embedded together with the plurality of related information, and the extracted information. And comparing means for comparing

In the storage medium according to the present invention,
A program for executing a process of embedding a digital watermark including the creation time of the digital content in the digital content and a process of creating a file of the digital content and writing a file update time in the file are stored. are doing.

In another storage medium according to the present invention, a file having digital content in which a digital watermark including a creation time of digital content is embedded and a file in which a file update time is described is described. And a processing unit for executing processing for extracting the extracted time and processing means for comparing the extracted creation time with the update time.

Further, another storage medium according to the present invention stores a program for executing a process of embedding a digital watermark in digital content together with a plurality of related information.

Further, in another storage medium according to the present invention, a process of extracting the plurality of related information from digital content in which a digital watermark is embedded together with the plurality of related information; A program for executing the comparison process is stored.

In another storage medium according to the present invention, a program for executing a process of embedding a digital watermark including a creation time of the digital content in the digital content is stored.

In another storage medium according to the present invention, a digital content file in which a digital watermark is embedded is created, and a program for executing a process of writing a file update time in the file is stored. are doing.

[0023]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a configuration of a general network, and shows an example of a use environment of the present invention. A typical example of the public network 101 is the Internet. The public network 101 includes a distribution server 102 for selling and distributing various digital contents represented by digital images, a police agency 103, a user 104, a local area network (LAN) 10
5 etc. are connected.

The distribution server 102 uses World Wid
It is generally configured by an e-Web server (Web server). The LAN 105 is blocked from the outside by the firewall 106, and only communication having predetermined parameters such as a sender and a type of transmission data is permitted between the LAN 105 and the public network 101.

In the LAN 105, a proxy server 107, a personal computer (PC) 108,
There are a display 109 and a printer 110 connected to the PC 108, another PC 111, a display 112 connected to the other PC 111, a printer 113 directly connected to the LAN 105, and the like. Proxy server 107
Performs control when the PCs 108 and 111 in the LAN 101 access a Web server such as the distribution server 102, and all data communicated between them passes through the proxy server 107.

FIG. 2 is a diagram showing an example of the proxy server 107 having the function of the copyright protection system according to the present embodiment. The system includes a bus 201 used for data exchange between devices in the system, a fraud detecting device 202,
An arithmetic processing unit 203 that operates according to the detection result of the fraud detecting device 202, an I / O port 204, a controller 205 that controls each device, a memory 206 that temporarily stores digital contents input to the system,
It comprises a communication port 207 connected to a network outside the system such as the LAN 105, an external storage device 208 connected to the I / O port 204, and a display 209.

The fraud detecting device 202 detects digital watermark information embedded in digital content by the digital watermark embedding device in advance, and detects that fraudulent processing has been performed on the digital content. When the digital watermark embedding device is mounted on an image input device such as a digital camera or a scanner, the fraud detection device 202 can detect that the digital content input by the image input device has been tampered with. Become.

Further, by creating digital contents with a computer and application software on which a digital watermark embedding device is mounted, a fraudulent detection device 20 detects fraud on the created digital contents.
2 can be detected. The digital watermark embedding device may be mounted on a storage device, a distribution server, a network device, or the like.

In this system, digital contents to be investigated are transmitted to the LA through the communication port 207.
N105 and / or LAN105 and public network 1
01 and so on. The read digital content is temporarily stored in the memory 206. The digital content on the memory 206 is input to the fraud detecting device 202, and it is determined whether or not the content is valid. If the digital content is determined to be legitimate by the fraud detecting device 202, the digital content is distributed to the entity that has requested distribution of the digital content through the communication port 207.

When the fraud detecting device 202 determines that the digital content is fraudulent, the arithmetic processing device 203 performs one or more of the following processes. After the arithmetic processing device 203 performs an arithmetic process for embedding a visible / invisible digital watermark, such as filtering, encryption, scrambling, and adding noise to the digital content, the communication device 207 sends a digital content distribution request. Output to the performed entity.

The I / O port 204 transfers information about the digital content, such as information on the source from which the digital content has been obtained and / or information on the entity that has read the digital content, and / or the name of the digital content by the arithmetic processing unit 203. External storage device 2 connected to
08 and / or via the communication port 207, the data is written to a database existing in the distribution server 102, the police agency 103, or the like.

The output is stopped under the control of the controller 204. A warning message is generated by the arithmetic processing unit 203, and a warning is displayed on the display 209 or the like connected to the I / O port 204. Further, it is possible to easily configure a system in which a warning is issued to a digital content acquisition source and a third party through a network through the communication port 207.

Next, an embodiment in which the fraud detecting device and the digital watermark embedding device are configured by hardware will be described. The fraud detection device and the digital watermark embedding device can be easily configured by software in addition to hardware.

FIG. 3 is a block diagram showing a first embodiment of the digital watermark embedding device according to the present invention. This apparatus includes an external storage medium 301 such as a magnetic storage medium storing digital contents, a clock 302, a file reading device 303, an embedding device 304, and a file writing device 305.

FIG. 4 shows the file structure of the external storage medium 301.
Is shown schematically in FIG. The file on the external storage medium 301 is
It comprises a directory area 401 and a member area 402.
In the directory area 401, the file name 404 of the file to be stored, the storage start address 403 of the substance of the file in the member area 402, the file update time 405 updated every time the file is edited, read-only, read / write, etc. File attributes 406 and the like are stored for each file. The file area 407 is stored in the member area 402.

Next, the operation will be described. The embedding device 304 embeds a digital watermark by the method described in the background art. At the time of digital watermark embedding, key information for determining the embedding position is required. The embedding device 304 embeds a digital watermark using a unique value stored inside the device as key information.

As the digital watermark embedding method, a method that requires key information at the time of embedding and extraction is used. However, this is merely an example, and other digital watermark embedding methods can be used.

Although a unique value stored inside the apparatus is used as the key information, other values such as input from outside the apparatus can be used. In that case, first, the original digital content stored in the member area 402 of the external storage device 301 is read by the file reading device 303 and input to the embedding device 304. In the embedding device 304, the clock device 30
2 is embedded in the digital content and written into the member area of the external storage medium 301 by the file writing device 305.

At the same time, the file update time in the directory area 401 of the external storage medium 301 is written. At this time, if the original digital content is overwritten with the watermark embedded digital content, the file update time is changed. Embedding device 3
04 embeds the time in the digital content,
In order to enhance security, it is possible to perform processing such as encryption or attaching a digital signature.

When the digital content (file) embedded with the digital watermark is edited by the present apparatus, the digital content embedded as the digital watermark is stored in the directory area of the external storage medium 301 without being changed. Since only the file update time, which is the time at which the file was last changed, is changed, the difference between the creation time and the file update time becomes larger than a predetermined threshold.

Here, the digital signature will be described. Digital signatures indicate that the creator of the message or information has indeed created it, and are often implemented using asymmetric cryptography, but can also be implemented using symmetric cryptography if there is a trusted authority. . Representative digital signatures include RSA signatures, El Gamal signatures, and the like.

In the RSA signature, the message (or the hash value of the message) is encrypted with its own RSA private key,
It is sent to the recipient as a signature along with the message. The receiver compares the received message (or the hash value of the message) with the one obtained by decrypting the signature text with the sender's RSA public key, and if they match, determines that the message is from the correct sender.

Here, the hash value will be described. The hash value h is a short output h which is a compressed value of the long input string X obtained by the hash function f: x → h. In addition, it is a one-way function, and has a property that it is difficult to obtain different inputs x and x 'that satisfy f (x') = f (x). As a typical hash function, MD5 (Me
sage Digest 5), SHA (Secure)
Hash Algorithm). The details of the hash function and the digital signature are described in "Introduction to Cryptography" by Eiji Okamoto (Kyoritsu Shuppan Co., Ltd.).

FIG. 5 shows a first example of a fraud detecting device according to the present invention.
It is a block diagram showing an embodiment. This apparatus includes an external storage medium 501, a digital watermark extraction device 502, and a comparison device 503.

The input to the apparatus is the digital content to be investigated stored in the external storage medium 501. The digital content output as legitimate by the present device is digital content in which a digital watermark is embedded by the digital watermark embedding device of FIG. 3 and thereafter, no tampering by an attack such as falsification or image conversion is performed. .

In the digital watermark extracting device 502, the digital watermark embedding device 304 performs the frequency conversion performed at the time of embedding on the digital content. In addition, the digital watermark extracting device 502 stores a unique value inside the device, similarly to the embedding device 304 in FIG. 3, and the value of the unique value is the same as the unique value of the embedding device 304.

The digital watermark extracting device 502 extracts embedded information from the digital content that has been subjected to the frequency conversion processing by using the unique value. The extraction method is detailed in the literature cited in the prior art. When the embedding device 304 uses a method that does not perform frequency conversion when embedding a digital watermark, the digital watermark extracting device 502 also does not perform frequency conversion and extracts information from digital contents and eigenvalues. Further, similarly to the digital watermark embedding device 304, other extraction methods can be used, and a unique value may be input from outside.

The digital content input to the present apparatus is input to a digital watermark extracting device 502, and the time embedded as a digital watermark is read out.
Enter 3 The comparison device 503 includes the external storage medium 50.
The file update time recorded in No. 1 is also input. The comparison device 503 compares the two input times and compares the two times.
If the difference between the two times is greater than a predetermined threshold, it is determined that the digital content has been tampered with.

Next, a second embodiment of the digital watermark embedding device and the fraud detecting device will be described. In the present embodiment, the resistance of the digital watermark is used, and therefore, the resistance will be described first. Whether data embedded as a digital watermark can be correctly extracted when data compression or filtering processing is performed on digital content in which the digital watermark is embedded is referred to as digital watermark resistance.

The stronger the resistance, the more the embedded information remains even after performing these processes. When a digital watermark is embedded by a method having a low tolerance, the possibility that information is destroyed increases even if a small amount of processing is performed on digital content.

FIG. 6 is a block diagram showing a second embodiment of the digital watermark embedding device according to the present invention. This device includes a storage device 601 and an embedding device 602.
If the embedding device 602 uses an embedding method that is weak enough to break the digital watermark even if the digital content with the digital watermark embedded therein is slightly falsified, the fraud detection device can detect even a slight fraud. In addition, by improving the resistance of digital watermarking,
It is possible to configure a fraud detecting device that allows slight fraud on digital contents.

The input to the present apparatus is digital information, an information sequence to be embedded as a digital watermark, and position information represented by coordinate values for embedding the information sequence as an electronic watermark in the entire digital content. Here, the information sequence is obtained by encoding information unique to digital content, information of an entity for embedding an electronic watermark, copyright information, information of a user who acquires digital content, and the like.

After the input information sequence is temporarily stored in the storage device 601, it is input to the embedding device 602 together with the embedding position information, and is repeatedly embedded in the entire digital content at positions where they do not interfere with each other.

FIG. 7 is a block diagram showing a second embodiment of the fraud detecting apparatus according to the present invention. This device includes a digital watermark extraction device 701, a storage device 702 for storing extracted information, and a comparison device 703. The input to the present apparatus is digital content to be investigated and embedded position information represented by coordinate values indicating the position where the digital watermark is embedded.

The digital contents output as legitimate by the present apparatus are digital contents in which a digital watermark has been embedded by the digital watermark embedding apparatus shown in FIG. 6 and which has not been tampered with.

When digital contents and embedded position information are input to the apparatus, a digital watermark extracting apparatus 701 is provided.
As a result, all information repeatedly embedded in the entire digital content is extracted. This information is stored in the storage device 7
02 are separately stored in the storage unit 02 and then compared by the comparison device 703. When there is a difference in the information, the comparing device 703 determines that the digital content has been tampered with.

Since the digital watermark is embedded by a method with low durability, if the digital content is tampered with or otherwise altered, at least one of the plurality of embedded information is destroyed. .

Here, it is assumed that the same information is embedded in the entire digital content. However, different information is embedded in the entire digital content by the digital watermark embedding device, and the relevance is checked by the fraud detecting device. A device for detecting validity can be easily configured.

In the digital watermark embedding apparatus shown in FIG. 6, by inputting the quantization step corresponding to the embedding position together with the embedding position information to the embedding apparatus 602, the embedding of the electronic watermark is performed with the intensity changed partially. Is possible. As a result, a quantization step corresponding to the embedding position is input to the extraction device 701 of the fraud detecting device together with the embedding position information, and the embedding information can be extracted using the quantization step corresponding to the embedding position, thereby protecting digital contents. The strength of the function can be partially changed.

As an example, an embodiment of an embedding device applicable to the embedding device 602 and a corresponding extracting device will be described as a third embodiment. FIG. 8 is a block diagram showing an apparatus for embedding a digital watermark having low resistance to digital content. The input to this apparatus is the embedding position information, the data value constituting the digital content, and the embedding information encoded into a binary number, and the data value of the digital content with the digital watermark embedded therein is output.

The present apparatus includes a switch 801 for dividing an input data value into a data value to be embedded with a digital watermark and a data value not to be embedded, and an arithmetic unit 8
02, a storage device 803.

The data value of the digital content input to the apparatus is divided into a data value to be embedded and a non-embedded data value by a switch 801 controlled by embedding position information. The data value to be embedded is input to the arithmetic unit 802, and the embedded information is embedded as follows.

First, the absolute value of the data value is divided by a predetermined number. The predetermined number at this time is called an intensity, and the quotient is called a quantization step. The higher the strength, the stronger the watermark's resistance. Next, each data value is changed to match the product of the quantization step and the integer. The integer used here is called an index. At this time, if the embedded information is 1, the index is an odd (even) number, and if the embedded information is 0, the index is an even (odd) number. The data value in which the embedding information is embedded is temporally matched by the storage device 803 with the data value that was not targeted for embedding,
Is output.

FIG. 9 is a block diagram showing an embodiment of an extracting device for extracting a digital watermark embedded by the above method. Inputs to the present apparatus are digital content in which a digital watermark is embedded, and embedded position information. The apparatus outputs embedded information extracted from digital contents.

The input digital content is divided into a data value in which a digital watermark is embedded and a data value in which the digital watermark is not embedded by a switch 901 controlled by the embedding position information. The data is input to the arithmetic unit 902. Arithmetic unit 90
In step 2, the same quantization step as that of the arithmetic unit 802 is possessed, the embedded information is extracted by examining the index of each data value, and the extracted information is set as the output of the unit.

Next, an example of a hardware configuration of a copyright protection device configured by using a fraud detection device will be described. The copyright protection device is easily configured not only with hardware but also with software. FIG. 10 is a block diagram showing a first embodiment of a digital content copyright protection device configured by using a fraud detection device.

When this device is mounted on a display,
If the image is valid, the original image is displayed. If the image is invalid, only the filtered image is displayed. Also, when mounted on a printer, the original image can be printed if it is a legitimate image, but only the filtered image can be printed as an illegal image.

As a result, even if an unauthorized image is obtained, it is difficult to actually use the image, so that copyright protection is realized. Further, the present invention can be mounted not only on a printer and a display but also on other network components, peripheral devices, computers, and the like.

This apparatus comprises a storage device 1001, a fraud detecting device 1002 according to each of the above embodiments, and a fraud detecting device 10
02, which is controlled by the output of the digital content and includes a switch 1003 for determining whether the digital content is output after being transformed or output as it is, and an arithmetic unit 1004.

The digital content input to the present apparatus is checked by the fraud detecting device 1002 for fraud and stored in the storage device 1001. The digital content stored in the storage device 1001 is input to the switch 1003, and when the fraud detecting device 1002 determines that the digital content is normal, it becomes the output of the copyright protection device as it is, and when it is determined that the digital content is fraudulent. Is input to the arithmetic unit 1004.

The digital contents are stored in the arithmetic unit 1004
Thus, processing such as filtering is performed. If the digital content is determined to be illegal, the digital content filtered is output from the copyright protection device. Here, filtering is described as an example of processing by the arithmetic device 1004, but it is clear that other processing such as scrambling may be used.

FIG. 11 shows a copyright protection apparatus according to a second embodiment. In this apparatus, in particular, when the input is limited to a digital image, fraud was detected by replacing the arithmetic processing unit 1004 in FIG. 10 with a frequency conversion device 1104, a low-pass filter 1105, and an inverse frequency conversion device 1106. In such a case, the digital image is output with a reduced resolution.

For example, when the apparatus is mounted on a display, a legitimate image can be viewed at a high resolution, but an illegal image can be viewed only at a low resolution. Further, when the printer is mounted on a printer, a printer can be configured that can print a regular image at a high resolution but can print an unauthorized image only at a low resolution.

In FIG. 11, the fraud detecting device 1002
However, if it is determined that the input digital image is invalid, the digital image stored in the storage device 1001 is converted to the frequency domain by the frequency conversion device 1104, and the high frequency is converted by the low-pass filter 1105. It is cut and returned to the spatial domain by the inverse frequency converter 1106. Through this series of operations, the digital image is compressed, so that a copyright protection function can be realized.

FIG. 12 shows a third embodiment of the copyright protection device. By using an encryption device 1204 in place of the arithmetic device 1004 in FIG. The digital content is encrypted and output. For example, by mounting this copyright protection device on a hard disk or the like, the distribution server 102 of FIG.
Anyone can download and save digital content, but if it is an illegal digital image, the storage is done in an encrypted state, so the stored data can only be read with the correct decryption key. Can not. Considering the use of this apparatus for copyright protection, it is appropriate that the decryption key be owned by a fair third party, such as the police.

In FIG. 12, the fraud detecting device 1002
However, if it is determined that the input digital content is unauthorized, the digital content stored in the storage device 1001 is output after being encrypted by the encryption device 1204. Thereby, the copyright protection function can be realized. The encryption used here is a common key encryption method such as DES, and a public key encryption method such as RSA (for details of each encryption, Eiji Okamoto, "Introduction to Cryptography")
See Kyoritsu Publishing Co., Ltd.).

FIG. 13 shows a fourth embodiment of the copyright protection apparatus. By using an adder 1304 in place of the arithmetic unit 1004, when the illegality of the inputted digital content is detected, The digital content is input with noise and output.

This device is effectively mounted on an output device such as a display or a printer. When falsified digital content is input, the output of the output device equipped with the present device becomes digital content with noise. It is apparent that the device can be mounted on devices other than the display and the printer.

In FIG. 13, when the fraud detecting device 1002 determines that the digital content is fraudulent,
The digital content stored in the storage device 1001 is input to an addition device 1304 together with a bit string, added, and output. As a result, noise is added to the digital content, and the digital content can be made unsuitable for use. The bit string added here may represent meaningful information in addition to random noise and regular noise. Thereby, the copyright protection function can be realized.

FIG. 14 shows a fifth embodiment of the copyright protection device. By using a watermark embedding device 1404 in place of the arithmetic device 1004, a digital watermark is embedded and output in illegal digital contents. It is something to do.

By embedding a visible digital watermark by the watermark embedding device 1404, the copyright protection device is mounted on an output device such as a printer or a display, so that when the digital content is detected as illegal, the digital content can be embedded in the digital content. An image including characters and marks is output.

If an invisible digital watermark is embedded, the digital watermark can be embedded in an external storage device or the like, and the digital watermark can be used as the digital watermark.
Source information is embedded. This ensures that the information will not be embedded in digital content unless it involves unauthorized images, thus protecting privacy and
Further, when an illegal image is involved, the above information is embedded, thereby enabling the police and the like to conduct an investigation, thereby protecting privacy. It is apparent that the device can be mounted on other devices other than the printer, the display and the external storage device.

In FIG. 14, when it is determined that the input digital content is unauthorized, the fraud detecting device 1002 stores the digital content stored in the storage device 1001 together with the embedding information in the watermark embedding device 1.
404 is input. Digital watermark embedding device 1404
Then, an electronic watermark is embedded in digital content.
Thereby, the copyright protection function can be realized.

FIG. 15 shows a sixth embodiment of the copyright protection device. This device is a fraud detection device 150.
1, a switch 1502 controlled by the output of the fraud detecting device 1501, and a database 1503 for storing user information of a user who has fraudulently executed digital contents. The input to the apparatus is the digital content to be investigated and the user information of the source of the digital content.

When digital contents are input to the apparatus, the fraud detecting apparatus 1501 checks whether the digital contents are fraudulent. Fraud detection device 15
01 is input to the switch 1502, and when the digital content is illegal, the switch 1502 inputs the source information of the digital content to the database 1503 and stores it. If it is valid, the source information is not stored.

The database 1503 exists in a distribution server, a police agency, or the like, and is appropriately written through a network. The data written in the database 1503 is used by a police organization or the like at the time of criminal investigation. Further, as the data to be written in the database 1503, in addition to the above-mentioned source user information, obtained user information, copyright information, digital content names, and the like are effective.

FIG. 16 is a block diagram showing a seventh embodiment of the copyright protection device. The apparatus outputs the input digital content when the input digital content is recognized as valid, and otherwise outputs nothing. In other words, if this device is mounted on a printer, and if an attempt is made to print an improper image,
No output. When mounted on a display, an unauthorized image is not displayed, and when mounted on a storage device, unauthorized digital data is not stored.

This apparatus comprises a fraud detecting device 1601 and a switch 1602 controlled by the fraud detecting device 1601. Digital contents input to this device are
Input to the fraud detection device 1601 and the switch 1602,
Only when the fraud detection device 1601 determines that the digital content is valid, the switch 1602 switches to the output side, and the digital content is output.

In this embodiment, a device that does not output all of the digital contents is configured. However, a device that does not output a part of the digital contents, for example, a device that outputs a color digital image, and the luminance and brightness of the image are ,
A device that does not output any parameters such as R, G, and B can be easily configured.

FIG. 17 is a block diagram showing an eighth embodiment of the copyright protection device. This device outputs a warning when the input digital content is found to be illegal. This apparatus is mounted on a PC, a display, a printer, or the like, and issues a warning to a user who attempts to use an image.
7, the firewall 106, the distribution server 102, and the like. When installed in these, it is also possible to issue a warning through a network to operators such as users, police, distribution servers, etc. who have distributed illegal content.

This apparatus comprises a fraud detecting device 1701 and a warning generating device 170 controlled by the fraud detecting device 1701.
Consists of two. The digital content input to the apparatus is input to a fraud detecting device 1701 to detect whether the digital content is fraudulent. If the information is illegal, the warning generation device 1702 warns the warning destination. If the digital content is legitimate,
Do nothing.

By using a plurality of copyright protection devices according to the above embodiments in combination, a copyright protection device having multiple copyright protection functions can be constructed. Further, by combining a plurality of fraud detecting devices and digital watermark embedding devices according to the embodiments, various fraud detecting devices and digital watermark embedding devices can be configured.

Next, a storage medium according to another embodiment of the present invention will be described. The present invention can be configured by hardware, but can also be configured by a computer system including a CPU and a memory. When constituted by a computer system, the memory constitutes a storage medium according to the present invention. That is, a storage medium storing a program code of software for executing the operation described in each of the above-described embodiments is used in a system or an apparatus, and the CPU of the system or apparatus executes the program code stored in the storage medium. By reading and executing, the object of the present invention can be achieved.

The storage medium includes ROM, R
Semiconductor memory such as AM, optical disk, magneto-optical disk,
A magnetic medium or the like may be used, and these may be configured and used in a CD-ROM, a floppy disk, a magnetic medium, a magnetic card, a nonvolatile memory card, or the like.

Therefore, by using this storage medium in a system or apparatus other than the system or apparatus shown in each figure, the system or the computer reads out and executes the program code stored in the storage medium. The same functions as those of the above embodiments can be realized, the same effects can be obtained, and the object of the present invention can be achieved.

An OS running on a computer
When performing part or all of the processing, or after the program code read from the storage medium is written to a memory provided in an extended function board or an extended function unit connected to the computer, Even when the CPU or the like provided in the above-mentioned extended function board or extended function unit performs a part or all of the processing based on the instruction of the program code, the same functions as those of the above embodiments can be realized and the same functions can be realized. Effect can be obtained,
The object of the present invention can be achieved.

[0097]

As described above, according to the digital watermark embedding apparatus and the related storage medium according to the present invention, even if digital content is fraudulently performed, a digital watermark that can easily detect fraudulently can be detected later. Can be embedded in digital content.

Further, according to the fraud detecting apparatus and the related storage medium according to the present invention, based on the digital watermark extracted from the digital content embedded by the digital watermark embedding apparatus, any illegal operation is performed on the digital content. Can be easily detected.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a general public network and devices connected to the public network.

FIG. 2 is a configuration diagram of a network equipped with a copyright protection system function.

FIG. 3 is a block diagram showing a first embodiment of a digital watermark embedding device according to the present invention.

FIG. 4 is a configuration diagram conceptually showing a file configuration of an external storage medium.

FIG. 5 is a block diagram showing a first embodiment of a fraud detecting device according to the present invention;

FIG. 6 is a block diagram showing a digital watermark embedding device according to a second embodiment of the present invention.

FIG. 7 is a block diagram showing a second embodiment of the fraud detection device according to the present invention.

FIG. 8 is a block diagram showing a digital watermark embedding device according to a third embodiment of the present invention.

FIG. 9 is a block diagram showing a third embodiment of the fraud detecting device according to the present invention.

FIG. 10 is a first example of a copyright protection device using a fraud detection device.
It is a block diagram showing an embodiment.

FIG. 11 is a block diagram showing a second embodiment of the copyright protection device.

FIG. 12 is a block diagram showing a third embodiment of the copyright protection device.

FIG. 13 is a block diagram showing a fourth embodiment of the copyright protection device.

FIG. 14 is a block diagram showing a fifth embodiment of the copyright protection device.

FIG. 15 is a block diagram showing a sixth embodiment of the copyright protection device.

FIG. 16 is a block diagram showing a seventh embodiment of the copyright protection device.

FIG. 17 is a block diagram showing an eighth embodiment of the copyright protection device.

[Explanation of symbols]

 202 fraud detection device 203 arithmetic processing device 205 controller 208 external storage device 301, 401, 501 external storage medium 302 clock 303 file reading device 304, 602 embedding device 305 file writing device 502, 701 extraction device 503, 703 comparison device 601, 702 , 803 Storage device 801, 901 Switch 802, 902 Arithmetic device

Continued on the front page F-term (reference)

Claims (18)

[Claims] 1. An embedding means for embedding an electronic watermark including the creation time of the digital content in the digital content, and a file creation means for creating a file of the digital content and writing a file update time in the file. An electronic watermark embedding device characterized by comprising: 2. Time extracting means for extracting the creation time and the update time from a file having digital content in which a digital watermark including a creation time of the digital content is embedded and having a file update time described therein; And a comparing means for comparing the created time with the updated time. 3. An electronic watermark embedding device comprising an embedding means for embedding a plurality of pieces of information related to digital contents as an electronic watermark. 4. The digital watermark embedding device according to claim 3, wherein the digital watermark has low durability. 5. The digital watermark embedding device according to claim 3, wherein the plurality of related information are the same information. 6. The digital watermark embedding device according to claim 3, wherein the plurality of related information items are different information items. 7. The digital watermark embedding device according to claim 1, wherein said digital watermark embedding means embeds a plurality of digital watermarks having different tolerances. 8. An information extracting means for extracting the plurality of pieces of related information from digital content in which a digital watermark is embedded together with a plurality of pieces of related information, and a comparing means for comparing the plurality of pieces of extracted information. A fraud detection device, characterized in that: 9. A process for embedding a digital watermark including the creation time of the digital content in the digital content, and a process of creating a file of the digital content and writing a file update time in the file. Computer-readable storage medium storing a program for performing the program. 10. A process for extracting the creation time and the update time from a file having digital content in which a digital watermark including a creation time of the digital content is embedded and having a file update time described therein; A computer-readable storage medium storing a program for executing a process of comparing a creation time and an update time. 11. A computer-readable storage medium storing a program for executing a process of embedding a plurality of pieces of related information as digital watermarks in digital content. 12. The computer-readable storage medium according to claim 11, wherein the digital watermark has low durability. 13. The computer-readable storage medium according to claim 11, wherein the plurality of pieces of related information are the same information. 14. The computer-readable storage medium according to claim 11, wherein said plurality of related information is different information. 15. The computer-readable storage medium according to claim 11, wherein the processing for embedding the digital watermark embeds a plurality of digital watermarks having different durability. 16. A program for executing a process of extracting a plurality of related information from digital content in which a digital watermark is embedded together with a plurality of related information, and a process of comparing the extracted plurality of information. A computer-readable storage medium that stores the information. 17. A computer-readable storage medium storing a program for executing a process of embedding a digital watermark including a creation time of the digital content in the digital content. 18. A computer-readable storage medium storing a program for creating a digital content file in which a digital watermark is embedded, and executing a process of writing a file update time in the file.