JP2003304387A - Image management system, electronic watermark embedding device, authentication code managing device, electronic watermark detecting device, and image managing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image management system, an electronic watermark embedding device, authentication code managing device, electronic watermark detecting device, and image managing method which can reduce influence of embedding an electronic watermark in an image upon its picture quality. <P>SOLUTION: The image managing method comprises: embedding an identifier in the image by robust electronic watermarking; managing an authentication code for verifying whether the image is altered by semi-fragile electronic watermarking independently of the image while making it correspond to the identifier; and obtaining the authentication code from the identifier and verifying the authentication code on a semi-fragile basis when verifying whether the image is altered. While the amount of information embedded in the image is reduced to minimize the influence on the image, effective alteration detection can be performed. The authentication code is not embedded in the image, so the authentication code can not be a target of attack and the security is improved. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image management system, a digital watermark embedding device, an authentication code management device, a digital watermark detection device, and an image management method.

[0002]

2. Description of the Related Art With the recent development of network technology, the problem of illegal diversion of digital contents on a network has become apparent. Especially in recent years, documents and invoices have been imported into computers as image data,
The number of companies taking so-called paperless measures for exchanging data using an electronic mail system is increasing,
There is an urgent need to prevent falsification of image data. Therefore, for the purpose of preventing tampering with the image data, it is found that even if some of the image data is tampered with by noise that cannot be recognized by the viewer, it is immediately tampered with. Such noise is embedded in image data. Such a technique of embedding noise that cannot be recognized by a viewer in image data is generally called a digital watermark technique.

Digital watermark technology is roughly classified into two types. One is for the purpose of copyright protection by preventing illegal copying of image data, and is to embed predetermined copyright information and the like in the image data. The digital watermark for copyright protection must not be easily broken even when an image data is attacked by a third party. Such a digital watermark that is not easily broken is called a robust digital watermark. Hereinafter, it is simply referred to as a robust digital watermark.

The other of the digital watermark techniques is for the purpose of preventing falsification of image data, in which a pixel value is changed by a predetermined algorithm for the image data to create image data having a predetermined regularity. To do. The digital watermark for tampering prevention is characterized in that it can be easily broken against tampering of image data by a third party to recognize tampering with the image data. Such an easily broken digital watermark may be a fragile digital watermark or a semi-fragile (semi-fragile) fragile digital watermark.
It is called a digital watermark of the method. Hereinafter, it is simply referred to as a fragile digital watermark or a semi-fragile digital watermark.
The semi-fragile digital watermark has a larger amount of information to embed than the fragile digital watermark, but it is more effective than the fragile digital watermark because it can not only recognize tampering with image data but also detect tampering points. Tamper detection can be performed.

An example of these digital watermarks for tampering detection is
Reference "Digital Watermark of Signum / Semi of Columbia University"
-Frag1le watermark ". less than,
The fragile digital watermark and the semi-fragile digital watermark described in the same document will be described.

The conventional fragile digital watermark / semi-fragile digital watermark described in the above-mentioned document uses n images.
The authentication code (also called a signature) is generated for each area unit by dividing the area into × m areas. The authentication code can be obtained almost uniquely for untampered images,
Also, it means a code that changes when it is tampered with. Therefore, it was necessary to embed the authentication code in block units, and it was necessary to embed an extremely large number of bits. Further, in the semi-fragile digital watermark described in the above-mentioned document, the authentication code is very long, and it is difficult to shorten it by a hash function or the like. Therefore, it is necessary to embed a very long authentication code.

For example, in the fragile digital watermark, 32 × 3 for an image of 640 × 480 pixels.
If it is attempted to detect falsification in units of 2 pixel areas, a 128-bit authentication code (when MD5 is used) is required in the area units, and a 38400-bit authentication code is required for the entire image. In the semi-fragile digital watermark described in the above document, the discrete cosine transform (discrete cosine transform) is used.
Since a 1-bit authentication code is required to detect falsification of 1 coefficient after m: DCT, for example, JPEG (Joint)
Photographic Experts Grou
Even when the authentication code is generated from only the three coefficients from the DC component of each 8 × 8 block after the DCT conversion of p), 144
A 00-bit authentication code is required.

When an authentication code having such a length is to be embedded in an image, there is no margin for error correction coding to withstand lossy compression or duplication.
Also, the effect on the image quality was very large.

Further, in the case of a watermark for a printed document, originally, the amount of bits that can be embedded / extracted robustly was very small, and there was no room to embed a sufficient authentication code.

[0010]

As described above, in the conventional digital watermark, it is necessary to embed an authentication code having an extremely large amount of bits, and the image quality is greatly affected. Further, in the case of a watermark for a printed document, there is no room for embedding a sufficient authentication code to detect falsification of an image, and it is very difficult to detect falsification in small area units.

The present invention has been made in view of the above problems of the conventional digital watermark technology, and an object of the present invention is to reduce the influence on the image quality due to embedding a digital watermark in an image. It is another object of the present invention to provide a new and improved image management system, digital watermark embedding device, authentication code management device, digital watermark detection device, and image management method.

Furthermore, another object of the present invention is to make a margin for embedding a sufficient authentication code, particularly in the case of a watermark for a printed document, and to easily detect falsification in small area units. A new and improved image management system, digital watermark embedding device, authentication code management device, digital watermark detection device, and image management method.

[0013]

In order to solve the above problems, according to the present invention, an identifier is embedded in an image as an electronic watermark and an electronic watermark embedding device for generating an authentication code from the image, an identifier and an authentication code. And an authentication code management device that manages them in association with each other, an identifier is extracted from the image, an authentication code associated with this is acquired from the authentication code management device, and an authentication code is generated from the image. And an electronic watermark detecting device that detects whether the image has been tampered with.

The digital watermark embedding device can embed an identifier in the image using the first digital watermark method and can use more information than the first digital watermark method as an authentication code used for authenticating the image. It is also possible to generate the image from the image using the second digital watermarking method.

The digital watermark embedding device embeds an identifier in the image using the Robust digital watermarking method, and at the same time, uses an authentication code of Fragile or Se.
It is also possible to generate the image from the image using a digital watermark method of mi-Fragile.

The authentication code management device issues an identifier for specifying the image in response to a request from the digital watermark embedding device, stores the identifier and the authentication code in a storage means in association with each other, and stores the digital watermark. It is also possible to take out the authentication code corresponding to the identifier input from the detection device from the storage means and output it to the digital watermark detection device.

The digital watermark detection device extracts an identifier from the image input from the digital watermark embedding device and outputs the identifier to the authentication code management device, and outputs an authentication code associated with the identifier to the authentication code management device. It is also possible to detect the presence or absence of falsification of the image by obtaining the authentication code from the image and comparing the two with each other.

The digital watermark detecting device extracts an identifier R from the image input from the digital watermark embedding device.
The digital watermark of the obst method is extracted and output to the authentication code management device, and the authentication code associated with the identifier is acquired from the authentication code management device.
Authentication code is Fragile method or Semi-Fr
It is also possible to generate an electronic watermark of the agile method from the image and compare both to detect whether the image has been tampered with.

An identifier for identifying the image is embedded in the image as a digital watermark of the first method, and an authentication code used for authenticating the image is a digital watermark of the second method that can use more information than the first method. It is also possible to generate as.

Further, it is possible to print the image in which the identifier is embedded and generate an authentication code from the printed image.

The digital watermark embedding device embeds an identifier in the image as a Robust digital watermark, and uses an authentication code in the Fragile system or S.
It is also possible to generate an electronic watermark of the emi-Fragile method from the image.

In order to solve the above-mentioned problems, according to the present invention, an identifier for identifying an image is issued, and the identifier and the authentication code are associated with each other and stored in the storage means, and the identifier inputted from the outside is stored. There is provided an authentication code management device characterized in that a corresponding authentication code is taken out from the storage means and output to the outside.

In order to solve the above-mentioned problems, according to the present invention, an identifier is extracted from an image and output to the outside, an authentication code associated with the identifier is acquired from the identifier, and the authentication code is obtained from the image. A digital watermark detecting apparatus is provided which is characterized by detecting the presence or absence of falsification of the image by comparing the both.

The digital watermark detection device extracts an identifier from the image as a digital watermark of the Robust method, outputs the digital watermark to the outside, obtains an authentication code associated with the identifier from the digital watermark, and obtains the authentication code from Flag1le.
It is also possible to generate a digital watermark of the method or the Semi-Fragile method from the image, and compare both to detect whether the image has been tampered with.

In order to solve the above-mentioned problems, according to the present invention, an identifier that identifies the image, is embedded in the image as a digital watermark of a predetermined method, and is generated from the image that is used for authentication of the image. The authentication code is managed by associating it with each other; extracting an identifier from the image to obtain an authentication code associated with the identifier, generating an authentication code from the image, comparing the two, and comparing the two. There is provided an image management method characterized by detecting the presence or absence of tampering.

The identifier is embedded in the image as a digital watermark of the first system, and the authentication code is generated from the image as a digital watermark of the second system that can use more information than the first system. Is also possible.

The identifier is embedded in the image as a digital watermark of the Robust method, and the authentication code is the Fragile method or the Semi-Fragi.
It is also possible to generate a digital watermark of the le method from the image.

In order to solve the above problems, the present invention provides an image management system including a digital watermark embedding device, an authentication code management device, and a digital watermark verification device.

The digital watermark embedding device (100a) is
The image is tampered with by the identifier embedding unit (101) for embedding an identifier in the image by the first digital watermark system and the second digital watermark system which can use more information than the first digital watermark system. Authentication code generating means (10) for generating an authentication code for verifying whether or not
2) and are provided.

The authentication code management device (100b) associates the authentication code of the image with the identifier issuing means (106) for issuing the identifier of the image in response to the request from the digital watermark embedding device. Authentication code storage means (10) to be stored in the authentication code storage means (108)
7) and an authentication code extracting unit (109) for extracting the corresponding authentication code from the authentication code storing unit when the identifier is input from the electronic watermark detecting unit (100c) and outputting the authentication code to the electronic watermark verifying unit. It is characterized by that.

The digital watermark detecting device (100c) receives the image from the digital watermark embedding device, extracts an identifier embedded in the image, and outputs the identifier to the authentication code management device (103). An authentication code verification means (104) for verifying whether the image and the authentication code of the image are input and whether the image has been tampered with by the second digital watermark method using the authentication code. It is characterized by that.

In order to solve the above problems, according to the present invention, an image management method is provided. According to the image management method of the present invention, an identifier is embedded in an image by the first digital watermark method, and the image is tampered with by the second digital watermark method which can use more information than the first digital watermark method. An authentication code for verifying whether the image has been broken is associated with the identifier and managed independently of the image, and when verifying whether the image has been tampered with,
It is characterized in that the authentication code is obtained from the identifier and verified by the second digital watermark method using the authentication code.

According to the present invention, the authentication code for detecting the alteration of the image is managed by the authentication code management device, and the image is
Only the identifier (ID) for identifying the authentication code is embedded. At this time, an identifier is embedded in the image by the first digital watermark method with a small amount of information (bit amount), and when tampering is detected, the second digital watermark method using an authentication code is performed.

Here, as the first digital watermarking method,
The robust digital watermark described above can be adopted. Further, as the second digital watermark method, the above-mentioned semi-fragile digital watermark or fragile digital watermark can be adopted. In particular, if a semi-fragile digital watermark is adopted as the second digital watermark method, not only whether the image has been tampered with, but also the tampered portion can be specified.

In this way, it is possible to reduce the amount of information to be embedded in an image and minimize the influence on the image, and to effectively detect falsification. Also, because the authentication code is not embedded in the image, the authentication code is not the target of attack,
Security is improved.

Also in the conventional image management system, some kind of management device (server) is indispensable for managing the key, time stamp and the like, and can be realized without drastically changing the configuration of the conventional system.

The digital watermark embedding device further comprises:
Printing means (1) for printing the image in which the identifier is embedded
10) and print image acquisition means (11) for acquiring the image data of the printed image and inputting it to the authentication code generation means.
1), the digital watermark detection apparatus further includes a print image acquisition unit (112) that receives an image as a printed matter, acquires image data of the image, and inputs the image data to the identifier extraction unit and the authentication code verification unit. ) Is preferred.

According to this structure, the authentication code is generated from the image data after printing, thereby generating the authentication code for detecting the falsification of the image after printing which reflects the blurring and blurring caused by printing. You can Further, since it is not necessary to feed back the generated authentication code to the watermark component embedded in the image, the image quality is improved and the process is simplified.

[0039]

BEST MODE FOR CARRYING OUT THE INVENTION Referring to the accompanying drawings,
A preferred embodiment of an image management system, a digital watermark embedding device, an authentication code management device, a digital watermark detection device, and an image management method according to the present invention will be described in detail. In the present specification and the drawings, components having substantially the same functional configuration are designated by the same reference numerals, and duplicate description will be omitted.

(First Embodiment) An image management system according to the first embodiment of the present invention will be described. The image management system 100 includes a digital watermark embedding device 100a and an authentication code management device 10 as shown in FIG.
0b and a digital watermark detection device 100c.

(Digital Watermark Embedding Device 100a) The digital watermark embedding device 100a, as shown in FIG.
ID embedding means 1 for embedding the ID input from the ID input terminal 2 in the image input from the image input terminal 1.
01, an image output terminal 3 for outputting an image after embedding the ID, and an authentication code generating means 1 for generating an authentication code for detecting falsification of the image from the image after embedding the ID.
02 and an authentication code output terminal 4 for outputting the generated authentication code.

The ID embedding means 101 embeds an ID in an image by a method having a small amount of information (bit amount). As such a method, a robust digital watermark which is a digital watermark for copyright protection can be adopted. The authentication code for detecting tampering with the image is an authentication code for detecting tampering in a digital watermark detection device 100c, which will be described later, by a method capable of using a larger amount of information than the robust digital watermark. As such a method, a semi-fragile electronic watermark (or a fragile electronic watermark) that is an electronic watermark for tampering detection can be adopted.

(Authentication Code Management Device 100b) As shown in FIG. 3, the authentication code management device 100b outputs an ID issuing means 106 for issuing an ID to the digital watermark embedding device 100a and the issued ID. An ID output terminal 9, an authentication code input terminal 10 for acquiring an authentication code from the digital watermark embedding device 100a, an authentication code storage unit 107 for storing the obtained authentication code in association with an ID, and an authentication code storage for storing the authentication code. Means 1
08, an ID input terminal 11 for obtaining an ID from a digital watermark detection apparatus 100c described later, and an authentication code extracting means 109 for extracting a corresponding authentication code from the input ID.
And an authentication code output terminal 12 for outputting the taken out authentication code.

(Digital Watermark Detection Device 100c) The digital watermark detection device 100c is, as shown in FIG. 4, an ID extraction means for extracting an ID embedded as a digital watermark in the image input from the image input terminal 5. 103, an ID output terminal 6 for outputting the extracted ID, an authentication code input terminal 7 for inputting an image authentication code, and an authentication code verification means 10 for comparing the authentication code with the input image.
4 and a verification result output terminal 8 for outputting a verification result.

Image management system 1 according to the present embodiment
00 is configured as described above. Next, the operation of the image management system 100 will be described. First, the operation of embedding a digital watermark will be described with reference to FIGS. FIG. 1 shows steps S1 to S4 showing the relationship between devices and the operation when embedding a digital watermark. FIG. 5 shows a processing flow from the viewpoint of an image.

(Step S1) The digital watermark embedding device 100a sends the I code to the authentication code management device 100b.
D Issue request.

(Step S2) Authentication Code Management Device 10
The ID issuing means 106 of 0b generates a new ID, and
Output from the D output terminal 9. Digital watermark embedding device 1
00a is the I generated by the authentication code management device 100b.
D is acquired from the ID input terminal 2, and the ID embedding unit 1
Enter 01. As shown in FIG. 5, the ID embedding unit 101 adds I to the image input from the image input terminal 1.
The ID input from the D input terminal 2 is embedded as a robust digital watermark.

(Step S3) The authentication code generating means 102 of the digital watermark embedding device 100a outputs the ID output from the ID embedding means 101, as shown in FIG.
An authentication code of a semi-fragile electronic watermark (or a fragile electronic watermark) is generated from the image after embedding and is output from the authentication code output terminal 4. As the authentication code of the semi-fragile digital watermark, for example, the method of generating the authentication code of Columbia University shown in the above document is used.

The authentication code storage means 107 of the authentication code management device 100b is the digital watermark embedding device 1
The authentication code generated in 00a is received from the authentication code input terminal 10 and is stored in the authentication code storage unit 108 in association with the ID passed to the digital watermark embedding device 100a in step S2.

(Step S4) As shown in FIG. 5, the ID embedding means 101 of the digital watermark embedding device 100a applies to the image input from the image input terminal 1 the ID input from the ID input terminal 2 by a robust electronic device. The image embedded with the watermark and embedded with the ID is output from the image output terminal 3.

The image after embedding the ID output from the image output terminal 3 of the digital watermark embedding device 100a is shown in FIG.
As shown in, the information is disclosed to a third party by being uploaded to an internet service, for example. The above is the operation when embedding a digital watermark.

Next, the operation at the time of detecting the digital watermark will be described with reference to FIGS. FIG. 1 shows each step S showing the relationship between each device and the operation at the time of digital watermark detection.
4 to S7 are shown. FIG. 6 shows a processing flow from the viewpoint of an image.

(Step S4) The image output from the digital watermark embedding device 100a is, for example, on the Internet service as described above. As shown in FIG. 6, the image on the Internet is downloaded to the electronic watermark detection device 100c by, for example, a search server. The digital watermark detection apparatus 100c inputs an image in which an ID is embedded as a robust digital watermark from the image input terminal 5.

(Step S5) As shown in FIG. 6, the ID extraction means 103 of the digital watermark detection apparatus 100c extracts the ID embedded as a robust digital watermark from the input image and outputs it to the ID output terminal 6. Output. The authentication code management device 100b is a digital watermark detection device 100c.
The ID output from is acquired from the ID input terminal 11.

(Step S6) Authentication Code Management Device 10
The authentication code extracting means 109 of 0b
The authentication code associated with D is retrieved and acquired from the authentication code stored in the authentication code storage means 108, and if it exists, an output is output from the verification result output terminal 12 as shown in FIG. To do. Digital watermark detection device 100
In c, the authentication code output from the authentication code management device 100b is acquired from the authentication code input terminal 7.

(Step S7) Digital Watermark Detection Device 10
As shown in FIG. 6, the authentication code verification means 0c of 0c verifies whether the image input from the image input terminal 5 has been tampered with from the input authentication code, and outputs the verification result to the verification result output terminal 8 Output from. The above is the operation when the digital watermark is detected.

As described above, according to this embodiment, the following effects can be obtained. (A) Since the authentication code is not embedded in the image, the authentication code is not a target of attack, and security is improved. (B) ID embedded in the image as a robust digital watermark
Has a much smaller number of bits than the semi-fragile authentication code, so the image quality after watermark embedding is dramatically improved. (C) Even in the conventional image management system, a management device (server) is often required for managing keys and time stamps, and can be realized by a system similar to that system.

(Second Embodiment) An image management system according to a second embodiment of the present invention will be described. As shown in FIG. 1, the image management system 200 includes a digital watermark embedding device 200a and an authentication code management device 20.
0b and a digital watermark detection device 200c.

(Digital Watermark Embedding Device 200a) The digital watermark embedding device 200a, as shown in FIG.
ID embedding means 1 for embedding the ID input from the ID input terminal 2 in the image input from the image input terminal 1.
01 and a printing unit 11 for printing an image after embedding an ID
0, a print image acquisition unit 111 that acquires an image image after printing, an authentication code generation unit 102 that generates an authentication code for detecting falsification of an image from an image after ID embedding, and the generated authentication code The authentication code output terminal 4 for outputting

As described above, in the present embodiment, the configuration of the digital watermark embedding device 100 of the first embodiment is
The configuration further includes a printing unit 110 that prints the D-embedded image, and a print image acquisition unit 111 that optically reads (scans) the printed image image, for example. In the present embodiment, the electronic watermark embedding device 200a does not have the image output terminal 3 for outputting the image after the ID is embedded. This corresponds to the electronic watermark detection device 200c described later reading an image from a printed matter.

Authentication code management apparatus 200 of the present embodiment
Since b has the same configuration as the authentication code management apparatus 100b of the first embodiment shown in FIG. 3, duplicated description will be omitted.

(Digital Watermark Detection Device 200c) As shown in FIG. 8, the digital watermark detection device 200c converts the printed image into a print image acquisition unit 112 and an image input from the print image acquisition unit 112. On the other hand, ID extraction means 103 for extracting the ID embedded as a digital watermark
An ID output terminal 6 for outputting the extracted ID, an authentication code input terminal 7 for inputting an image authentication code, an authentication code verification means 104 for comparing the authentication code with the input image, and a verification result. The configuration is characterized by having a verification result output terminal 8 for outputting.

As described above, in the present embodiment, the print image obtained by, for example, optically reading (scanning) the printed image is added to the configuration of the digital watermark detection apparatus 100c of the first embodiment. The configuration is characterized by further including an acquisition unit 112. In the present embodiment, the electronic watermark detection device 200c does not have the image input terminal 5 for inputting the image after the ID is embedded. This corresponds to the above-mentioned digital watermark embedding device outputting an image as a printed matter.

Image management system 2 according to the present embodiment
00 is configured as described above. Next, regarding the operation of the image management system 200, an operation different from that of the first embodiment will be described.

Regarding the operation at the time of embedding a digital watermark, in the present embodiment, the printing means 110 acquires the image after ID embedding from the ID embedding means 101 and performs printing. The print image acquisition unit 111 scans the image printed by the printing unit 110 and acquires the printed image data. The image data obtained by this is the same image data as the printed image, including the deterioration of resolution caused by printing, image blurring, blurring, and misalignment.

(Step S3) Authentication code generating means 10
2 generates an authentication code from the printed image image obtained from the print image acquisition means 111 and outputs it from the authentication code output terminal 4.

Other operations are the same as those in the first embodiment.

(Step S4) Regarding the operation at the time of detecting the digital watermark, in the present embodiment, the print image acquisition means 112 is used.
Scans the printed image and acquires image data.

Other operations are the same as those in the first embodiment.

As described above, according to this embodiment, in addition to the above effects (a) to (c), there are the following effects. (D) By generating the authentication code from the image data after printing, it is possible to generate an authentication code for detecting tampering of the image after printing that reflects bleeding or blurring due to printing. (E) Since the generated authentication code does not need to be fed back to the watermark component embedded in the image, the image quality is improved and the process is simplified.

The preferred embodiments of the image management system, digital watermark embedding device, authentication code management device, digital watermark detection device, and image management method according to the present invention have been described above with reference to the accompanying drawings. The invention is not limited to such an example. It is obvious to those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea described in the claims, and naturally, these are also within the technical scope of the present invention. It is understood that it belongs.

For example, the ID issuing means 106 may generate not only the ID but also a session key necessary for watermark generation, and the authentication code storage means 108 may store the authentication code and the session key in association with the ID. In that case,
Authentication code generation means 102, authentication code verification means 104
May use the session key to generate and verify the authentication code.

Further, the authentication code generating means 102 may encrypt the authentication code by a secret key method or a public key method. In the case of the public key method, the authentication code generating means 102
May encrypt the authentication code with the private key, and the authentication code verification means 104 may decrypt the authentication code with the public key.

The authentication code generation means 102 may compress the authentication code, and the authentication code verification means 104 may decompress the authentication code.

The authentication code management device is not particularly required to be in the form of a server, and may simply be a storage medium (for example, a floppy (registered trademark) disk or a CD-ROM) that stores the authentication code in association with the ID.

Print image acquisition means 11 of the second embodiment
1 may be incorporated in the printing unit 110.

Printed image acquisition means 11 of the second embodiment
1 may output an image produced by a printer processor that produces a printed image in the printing means 110 without scanning the image.

[0078]

As described above, according to the present invention,
It has the following effects. (A) Since the authentication code is not embedded in the image, the authentication code is not a target of attack, and security is improved. (B) Normally, the identifier (ID) has a much smaller number of bits than the authentication code, so the image quality after watermark embedding is dramatically improved. (C) Even with the conventional digital watermark, a server is often required to manage keys and time stamps, but it can be realized with a system similar to that system.

Further, according to the present invention, there are the following effects. (D) By generating the authentication code from the image data after printing, it is possible to generate an authentication code for detecting tampering of the image after printing that reflects bleeding or blurring due to printing. (E) Since the generated authentication code does not need to be fed back to the watermark component embedded in the image, the image quality is improved and the process is simplified.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an example of an image management system.

FIG. 2 is an explanatory diagram illustrating an example of the digital watermark embedding device according to the first embodiment.

FIG. 3 is an explanatory diagram showing an example of an authentication code management device.

FIG. 4 is an explanatory diagram showing an example of the digital watermark detection apparatus according to the first embodiment.

FIG. 5 is an explanatory diagram showing an example of an operation when embedding a digital watermark.

FIG. 6 is an explanatory diagram showing an example of an operation when a digital watermark is detected.

FIG. 7 is an explanatory diagram illustrating an example of a digital watermark embedding device according to a second embodiment.

FIG. 8 is an explanatory diagram illustrating an example of a digital watermark detection device according to a second embodiment.

[Explanation of symbols]

1 Image input terminal 2 ID input terminal 3 image output terminal 4 Authentication code output terminal 5 Image input terminal 6 ID output terminal 7 Authentication code input terminal 8 Verification result output terminal 9 ID output terminal 10 Authentication code input terminal 11 ID input terminal 12 Verification result output terminal 100 image management system 100a Digital Watermark Embedding Device 100b Authentication code management device 100c Digital Watermark Detection Device 101 ID embedding means 102 authentication code generation means 103 ID extraction means 104 authentication code verification means 106 ID issuing means 107 authentication code storage means 108 authentication code storage means 109 Authentication code retrieval means 110 printing means 111 Print image acquisition means 112 print image acquisition means

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Claims (15)

[Claims] 1. An electronic watermark embedding device that embeds an identifier as a digital watermark in an image and generates an authentication code from the image, an authentication code management device that manages the identifier and the authentication code in association with each other, and an identifier from the image. And an authentication code associated with the extracted authentication code are acquired from the authentication code management device, an authentication code is generated from the image, and both are compared to detect whether the image has been tampered with. An image management system comprising: 2. The digital watermark embedding device embeds an identifier in the image using the first digital watermark method, and stores an authentication code used for authenticating the image in more information than the first digital watermark method. The image management system according to claim 1, wherein the image management system is generated from the image using a second digital watermark method that can be used. 3. The digital watermark embedding device embeds an identifier into the image by using the Robust digital watermark method, and at the same time, uses an authentication code of Fragile or S.
The image management system according to claim 1 or 2, wherein the image management system is generated from the image using an electronic watermark method of emi-Fragile. 4. The authentication code management device issues an identifier for specifying the image in response to a request from the digital watermark embedding device, stores the identifier and the authentication code in a storage unit in association with each other, The image management system according to any one of claims 1 to 3, wherein an authentication code corresponding to an identifier input from the digital watermark detection device is taken out from the storage means and output to the digital watermark detection device. . 5. The digital watermark detection device extracts an identifier from the image input from the digital watermark embedding device, outputs the identifier to the authentication code management device, and outputs an authentication code associated with the identifier to the authentication code. While obtaining from the management device, the authentication code is generated from the image,
The image management system according to any one of claims 1 to 4, wherein the two are compared to detect whether the image has been tampered with. 6. The digital watermark detection apparatus extracts an identifier as a Robust type digital watermark from the image input from the digital watermark embedding apparatus, outputs the identifier to the authentication code management apparatus, and associates it with the identifier. The authentication code is acquired from the authentication code management device, and the authentication code is obtained using the Fragile method or Semi-
The image management system according to claim 5, wherein the image management system generates a digital watermark of the Fragile method from the image and compares the two to detect whether the image has been tampered with. 7. An identifier for identifying the image is embedded in the image as a digital watermark of the first system, and an authentication code used for authenticating the image is of a second system that can use more information than the first system. A digital watermark embedding device, which is generated as a digital watermark. 8. The digital watermark embedding apparatus according to claim 7, further comprising: printing the image in which the identifier is embedded, and generating an authentication code from the printed image. 9. The digital watermark embedding device embeds an identifier in the image as a Robust type digital watermark and generates an authentication code from the image as a Fragile type or Semi-Fragile type digital watermark. The digital watermark embedding device according to claim 7. 10. An identifier for identifying an image is issued, an identifier and an authentication code are stored in association with each other in a storage unit, and an authentication code corresponding to an identifier input from the outside is taken out from the storage unit and externally stored. An authentication code management device characterized by outputting. 11. An identifier is extracted from an image, output to the outside, an authentication code associated with the identifier is acquired therefrom, an authentication code is generated from the image, and both are compared to tamper with the image. A digital watermark detecting device, characterized by detecting the presence or absence of a watermark. 12. The digital watermark detecting device extracts an identifier from the image as a digital watermark of a Robust method, outputs the digital watermark to the outside, obtains an authentication code associated with the identifier from there, and outputs the authentication code to Frag1.
The digital watermark of the Le method or the Semi-Fragile method is generated from the image, and both are compared to detect the presence or absence of falsification of the image.
The electronic watermark detection device according to. 13. An identifier, which identifies the image and is embedded in the image as a digital watermark of a predetermined method, and an authentication code generated from the image, which is used for authentication of the image, are managed in association with each other; While extracting the identifier from the image and acquiring the authentication code associated with this,
An image management method, wherein an authentication code is generated from the image, and both are compared to detect whether the image has been tampered with. 14. The identifier is embedded in the image as a digital watermark of a first method, and the authentication code is generated from the image as a digital watermark of a second method that can use more information than the first method. 14. The image management method according to claim 13, wherein: 15. The identifier is embedded in the image as a digital watermark of a Robust method, and the authentication code is a Fragile method or Semi-Fra.
The image management method according to claim 13 or 14, wherein the image management method is generated from the image as a digital watermark of a gile method.