JP2006279981A - Image verification apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect an altered portion in image data generated by an image generating device such as a digital camera. <P>SOLUTION: If it can be verified that image data generated by an image generating device 10 are not altered, a first verification apparatus embeds electronic watermark data with which an altered part can be detected, into the image data to produce image data with electronic watermark. Furthermore, the first verification apparatus 20 produces second verification data (digital signature) of the image data with electronic watermark. A second verification apparatus 30 verifies whether or not image data are altered using the image data with electronic watermark and the second verification data. If the image data are altered, the second verification apparatus 30 detects which part of the image data is altered. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image verification system, an image verification apparatus, an image verification method, a program, and a recording medium for verifying whether image data generated by an image generation apparatus such as a digital camera has been altered.

In recent years, digital cameras that digitize and store optical images of subjects have been put into practical use.
While image data taken with a digital camera can be easily taken into a personal computer, there is a problem that it can be easily modified on the personal computer. Therefore, there is a problem that the reliability of the image data taken with the digital camera is lower than that of the silver salt photograph and the evidence ability is poor. Therefore, in recent years, a digital camera system having a function of adding a digital signature to image data taken by a digital camera has been proposed. A conventional digital camera system is disclosed in, for example, US Pat. No. 5,499,294 and Japanese Patent Laid-Open No. 9-2000730.

US Pat. No. 5,499,294 Japanese Patent Application Laid-Open No. 9-2000730

  However, even though the conventional digital camera system can verify whether or not the image data has been modified, it cannot detect which part of the image data has been modified.

  The present invention has been made to solve the above-described problems, and an image verification system and an image verification apparatus that can detect a modified portion of image data generated by an image generation apparatus such as a digital camera. An object is to provide an image verification method, a program, and a recording medium.

  One of the image verification systems of the present invention is an image verification system having an image generation device and a first image verification device, wherein the image generation device includes image generation means for generating image data, the image data and the common First verification data generation means for generating first verification data using information, wherein the first image verification device uses the image data, the first verification data, and the common information, First verification means for detecting whether or not the image data has been modified, and when the image data has not been modified, digital watermark data capable of detecting a modified portion is embedded in the image data, and is provided with a digital watermark Embedding means for generating image data; and second verification data generating means for generating second verification data using the image data with digital watermark and secret information. Characterized in that it is a device for.

  One of the image verification systems of the present invention is an image verification system having an image generation device, an information processing device, and a first image verification device, wherein the image generation device includes image generation means for generating image data; A first verification data generating unit configured to generate first verification data using image data and common information, wherein the information processing apparatus converts the image data and the first verification data into the first image verification. A first verification unit that detects whether or not the image data has been modified using the image data, the first verification data, and the common information. And means for embedding digital watermark data capable of detecting a modified portion in the image data when the image data is not modified, and generating image data with the digital watermark By using the embedding means, the image data and the confidential information watermarked, characterized in that it is a device having a second verification data generation means for generating a second verification data.

  An image verification apparatus according to the present invention includes an image verification unit that detects whether or not the image data has been modified using the image data generated by the image generation apparatus, the first verification data, and the common information. In the case where the image data is not modified, an electronic watermark data capable of detecting a modified part is embedded in the image data, and an embedding unit for generating image data with the electronic watermark, the image data with the electronic watermark, and the secret information And verification data generation means for generating second verification data of the image data.

  The image verification method of the present invention includes an image verification step of detecting whether or not the image data has been modified using the image data generated by the image generation device, the first verification data, and the common information; When the image data is not modified, an embedding step of embedding digital watermark data capable of detecting a modified portion in the image data to generate image data with the digital watermark, and the image data with the digital watermark and the secret information And a verification data generation step of generating second verification data of the image data.

  The program of the present invention includes an image verification procedure for verifying whether or not the image data has been modified using the image data generated by the image generation device, the first verification data, and the common information, When image data is not modified, digital watermark data capable of detecting a modified portion is embedded in the image data, and an embedded procedure for generating digital watermarked image data is used, and the digital watermarked image data and secret information are used. And a verification data generation procedure for generating the second verification data of the image data.

  The computer-readable recording medium of the present invention uses an image data generated by an image generation device, first verification data, and common information to verify whether the image data has been altered. A verification procedure, an embedding procedure for embedding digital watermark data capable of detecting a modified portion in the image data when the image data is not modified, and generating image data with the digital watermark; and the image data with the digital watermark And using the secret information, a program for causing the computer to execute a verification data generation procedure for generating the second verification data of the image data is recorded.

  According to the present invention, it is possible to detect a modified portion of image data generated by an image generation device such as a digital camera.

(First embodiment)
Hereinafter, a first exemplary embodiment suitable for the present invention will be described with reference to the drawings.
FIG. 1 is a diagram illustrating a configuration example of an image verification system according to the first embodiment.
The image generation device 10 is a device having a function of generating image data of a subject and a function of generating an image file with primary verification data. The image file with first verification data is an image file including data such as image data, first verification data of the image data, additional information of the image data, and a unique ID of the image generation apparatus 10. The image generation apparatus 10 may be an imaging apparatus such as a digital camera, a digital video camera, or a scanner, or may be an apparatus having a camera unit. Further, the image generation apparatus 10 may be an apparatus such as a facsimile machine or a copying machine having an image reading unit.

  The first verification device 20 is a device having a function of verifying whether image data has been altered using first verification data or the like. The first verification device 20 is also a device having a function of generating an image file with second verification data when the image data is not altered. The image file with second verification data is an image file including data such as image data, second verification data of the image data, additional information of the image data, and a unique ID of the image generation apparatus 10. The first verification device 20 may be an information processing device such as a personal computer.

  The second verification device 30 is a device having a function of verifying whether image data has been altered using second verification data or the like. The second verification device 30 may be an information processing device such as a personal computer.

FIG. 2 is a block diagram illustrating a main functional configuration of the image generation apparatus 10 according to the present embodiment.
Reference numeral 201 denotes an optical sensor such as a CCD (charge coupled device), a microprocessor, and the like, and generates image data I that is image data of a subject.
Reference numeral 203 denotes a memory for storing the common information Kc. This common information Kc is information corresponding to a common key in a common key cryptosystem (DES, Rinjdael, etc.).

Reference numeral 204 denotes a first calculation process that generates a hash value (also referred to as message digest or digest data) H11 of the image data I using the hash function HF1 and common information Kc held in the memory 203. It is a calculating part which performs the 2nd calculation process which converts the hash value H11 produced | generated by this calculation process into the 1st verification data V11. The first verification data V11 is data corresponding to the MAC (Message Authentication Code) of the image data I. The hash function HF1 may be any one of MD-2, MD-4, MD-5, SHA-1, RIPEMD-128, and RIPEMD-160, or another hash function.
Reference numeral 205 denotes a memory that stores a unique ID (for example, a manufacturing number or a serial number of the image generating apparatus 10) that is information unique to the image generating apparatus 10. This unique ID is added to the image file IF1 with first verification data.

Reference numeral 206 denotes an image file generation unit that generates an image file IF1 with first verification data. The image file IF1 with first verification data includes image data I in the data portion, and data such as the first verification data V11 of the image data I, additional information of the image data I, and a unique ID of the image generation device 10 in the header portion. It is an image file that contains. Even if the file format of the image file IF1 with the first verification data is any one of JPEG (JPEG File Interchange Format), TIFF (Tagged Image File Format), and GIF (Graphics Interchange Format), it is an extension of them. Alternatively, other image file formats may be used.
Reference numeral 207 denotes a removable medium (detachable storage medium) such as a magnetic disk, an optical disk, or a memory card, and stores the image file IF1 with first verification data.

A media control unit 208 has a function of writing an image file with first verification data to the removable medium 207 and a function of reading an image file with first verification data from the removable medium 207.
Reference numeral 209 denotes an interface unit that transmits the image file with the first verification data read from the removable medium 207 to the first verification device 20.
An operation unit 210 includes a switch for instructing generation, photographing, or reading of image data of a subject.
A control unit 211 includes a memory and a microcomputer that executes a control program stored in the memory, and controls each function of the image generation apparatus 10. In particular, the memory of the control unit 211 stores a program for controlling the processing procedure of the image generation apparatus 10 described in FIG.

FIG. 3 is a block diagram illustrating a main functional configuration of the first verification device 20 according to the present embodiment.
A media control unit 301 reads the image file IF1 with first verification data from the removable medium 207.
Reference numeral 314 denotes an interface unit that receives the first verification data-added image file IF1 transmitted from the image generation apparatus 10.
A storage unit 302 stores the first verification data-added image file IF1 and the second verification data-added image file IF2.

  A memory 304 stores the table T1. An example of this table T1 is shown in FIG. The table T1 is a management table that manages a plurality of unique IDs, common information Kc corresponding to each unique ID, and secret information Ks corresponding to each common information Kc. For example, when the unique ID is “001”, the common information Kc corresponding to this unique ID is “0x1111”, and the secret information Ks is “0x2222”. The common information Kc and the secret information Ks are information that is secretly managed by the first verification device 20, and are information that is not disclosed to the public. The secret information Ks is information corresponding to a secret key in a public key cryptosystem (such as RSA cryptography).

  A hash value 305 is generated by the first calculation process using the first calculation process that generates the hash value H12 of the image data I using the hash function HF1 and the common information Kc obtained from the memory 304. It is a 1st calculating part which performs the 2nd calculation process which converts H12 into the 1st verification data V12.

Reference numeral 306 denotes an image verification unit that verifies whether the image data I has been altered using the first verification data V11 and the first verification data V12.
Reference numeral 307 denotes an embedding unit that embeds digital watermark data WM capable of detecting a modified portion in the image data I to generate image data IWM with digital watermark.
Reference numeral 309 denotes a hash value generated by the first calculation process using the first calculation process that generates the hash value H21 of the image data IWM using the hash function HF2 and the secret information Ks obtained from the memory 304. It is a 2nd calculating part which performs the 2nd calculation process which converts H21 into the 2nd verification data V2. The second verification data V2 is data corresponding to the digital signature of the image data IWM. The hash function HF2 may be any one of MD-2, MD-4, MD-5, SHA-1, RIPEMD-128, and RIPEMD-160, or another hash function.

Reference numeral 310 denotes an image file generation unit that generates an image file IF2 with second verification data. The image file IF2 with second verification data includes image data IWM in the data portion, and data such as second verification data V2 of the image data IWM, additional information of the image data IWM, and a unique ID of the image generation device 10 in the header portion. It is an image file that contains.
Reference numeral 311 denotes an interface unit having a function of outputting the image file IF2 with second verification data to an external device.
Reference numeral 312 denotes a display unit that displays information indicating the detection result of the first verification device 20.
A control unit 313 includes a memory and a microcomputer that executes a control program stored in the memory, and controls each function of the first verification device 20. In particular, the memory of the control unit 313 stores a program for controlling the processing procedure of the first verification device 20 described in FIG.

FIG. 4 is a block diagram illustrating a main functional configuration of the second verification device 30 in the present embodiment.
Reference numeral 401 denotes an interface unit having a function of inputting the second verification data-added image file IF2 from an external device.
Reference numeral 402 denotes a storage unit that stores the second verification data-added image file IF2.

  Reference numeral 403 denotes a memory for storing the table T2. An example of this table T2 is shown in FIG. The table T2 is a management table that manages a plurality of unique IDs and public information Kp corresponding to each unique ID. For example, when the unique ID is “001”, the public information Kp corresponding to this unique ID is “0x3333”. The public information Kp is information corresponding to the secret information Ks, and is information corresponding to a public key in a public key cryptosystem (such as RSA cipher).

404 generates the hash value H23 of the image data IWM using the first calculation process for converting the second verification data V2 into the hash value H22 using the public information Kp obtained from the memory 403 and the hash function HF2. It is a calculating part which performs the 2nd calculating process.
An image verification unit 406 verifies whether or not the image data IWM has been altered using the hash value H22 and the hash value H23.

Reference numeral 407 denotes a modified position detection unit that detects a portion where the image data I is modified by extracting the digital watermark data WM from the image data IWM.
Reference numeral 408 denotes a display unit that displays information indicating the detection result of the image verification unit 406 and the detection result of the modified position detection unit 407.
Reference numeral 409 denotes a control unit that includes a memory and a microcomputer that executes a control program stored therein, and controls each function of the second verification device 30. In particular, the memory of the control unit 409 stores a program for controlling the processing procedure of the second verification device 30 described in FIG.

FIG. 5 is a diagram for explaining the processing procedure of the image verification system according to the first embodiment.
Step S501: The image generation unit 201 generates image data I that is image data of a subject in accordance with an instruction from the user.
Step S502: The computing unit 204 generates a hash value H11 of the image data I using the hash function HF1.

Step S503: The computing unit 204 converts the hash value H11 into the first verification data V11 using the common information Kc obtained from the memory 203. The first verification data V11 is data corresponding to the MAC of the image data I.
Step S504: The image file generation unit 206 generates an image file IF1 with first verification data including data such as image data I, first verification data V11, additional information of the image data I, and a unique ID of the image generation device 10. . The media control unit 208 writes the image file IF1 to the removable medium 207.

  Step S505: The user inputs the image file IF1 stored in the removable medium 207 to the first verification device 20 via the removable medium 207 or the interface unit 209. When inputting via the removable medium 207, the media control unit 301 reads the image file IF1 from the removable medium 207 and stores it in the storage unit 302. On the other hand, when inputting via the interface unit 209, the interface unit 314 receives the image file IF 1 transmitted from the image generation device 10 to the first verification device 20 and stores it in the storage unit 302.

Step S506: The first calculation unit 305 generates a hash value H12 of the image data I obtained from the storage unit 302 using the hash function HF1.
Step S507: Further, the first calculation unit 305 refers to the table T1 in the memory 304 and acquires the common information Kc corresponding to the unique ID obtained from the image file IF1.
Step S508: Furthermore, the first calculation unit 305 converts the hash value H12 into the first verification data V12 using the common information Kc obtained from the memory 304. Then, the first calculation unit 305 supplies the first verification data to the image verification unit 306.
Step S509: The image verification unit 306 compares the first verification data V11 and the first verification data V12, and verifies whether the image data I has been altered.

  When the two first verification data match (that is, when the integrity of the image data I can be verified), the image verification unit 306 detects that the image data I has not been altered. In addition, the image verification unit 306 detects that the image data I has been generated by the image generation device 10. Then, the first verification device 20 causes the display unit 312 to display information indicating that the image data has not been modified, and starts generating second verification data.

  On the other hand, when the two first verification data do not match (that is, when the integrity of the image data I cannot be verified), the image verification unit 306 detects that the image data I has been altered. Then, the first verification device 20 displays information indicating that the image data I has been altered on the display unit 312 and prohibits the generation of the second verification data. That is, the first verification device 20 prohibits the processing from step S510.

Step S510: If the image data I has not been altered, the embedding unit 307 embeds the digital watermark data WM that can detect the altered portion in the image data I, and generates digital watermarked image data IWM.
Step S511: The second calculation unit 309 generates a hash value H21 of the digital watermarked image data IWM using the hash function HF2.
Step S512: Also, the second calculation unit 309 refers to the table T1 in the memory 304 and acquires the secret information Ks corresponding to the unique ID obtained from the image file IF1.

Step S513: Furthermore, the second calculation unit 309 converts the hash value H21 into the second verification data V2 using the secret information Ks obtained from the memory 304. This second verification data is data corresponding to the digital signature of the image data IWM.
Step S514: The file generation unit 310 generates an image file IF2 with second verification data including data such as image data IWM, second verification data V2, additional information of the image data IWM, and unique ID. The image file IF2 generated by the file generation unit 310 is stored in the storage unit 302.
Step S515: The interface unit 311 outputs the image file IF2 to the external device. On the other hand, the interface unit 401 receives the image file IF2 from an external device and stores it in the storage unit 402.

Step S516: The computing unit 404 refers to the table T2 in the memory 403 and acquires the public information Kp corresponding to the unique ID obtained from the image file IF2.
Step S517: The computing unit 404 converts the second verification data V2 into a hash value H22 using the second verification data and the public information Kp obtained from the memory 403.

Step S518: The computing unit 404 generates a hash value H23 of the image data IWM using the hash function HF2.
Step S519: The image verification unit 406 compares the hash value H22 obtained in step S1019 with the hash value H23 obtained in step S1020, and verifies whether the image data IWM has been altered.

  When the two hash values match (that is, when the integrity of the image data IWM can be verified), the image verification unit 406 detects that the image data IWM has not been altered. The image verification unit 406 detects that the image data is generated by the image generation apparatus 10. Then, the second verification device 30 causes the display unit 408 to display information indicating that the image data IWM has not been altered, and starts generating second verification data.

  On the other hand, when the two first verification data do not match (that is, when the integrity of the image data IWM cannot be verified), the image verification unit 406 confirms that the image data IWM has been altered. To detect. Then, the second verification device 30 causes the display unit 408 to display information indicating that the image data has been altered.

  Step S520: If the image data IWM has not been modified, the modified position detection unit 407 extracts the digital watermark data WM from the image data IWM, and detects the modified portion of the image data I. Then, the second verification device 30 causes the display unit 408 to display information indicating the modified portion detected by the modified position detection unit 407.

As described above, according to the image verification system in the first embodiment, it is possible to reliably verify whether the image data generated by the image generation device 10 has been modified, and which part of the image data is modified. It can be detected reliably.
In addition, according to the image verification system in the first embodiment, it is not necessary to significantly improve the performance of the calculation resource of the image generation apparatus 10, so that the cost for the image generation apparatus 10 can be reduced.
Further, according to the first verification device 20 in the first embodiment, since the presence / absence of alteration of the image data is verified using the common information Kc obtained from the unique ID of the image generation device 10, the image data is an image. It can be confirmed reliably whether it is what was produced | generated by the production | generation apparatus 10. FIG.
Further, according to the image verification system in the first embodiment, since the secret information Ks and the public information Kp obtained from the unique ID of the image generation apparatus 10 are verified, whether or not the image data has been modified is verified. The verification device 30 can surely check whether the image data is generated by the image generation device 10.

(Second Embodiment)
Hereinafter, a second embodiment suitable for the present invention will be described with reference to the drawings. In the second embodiment, portions different from the first embodiment will be described in detail.
FIG. 7 is a diagram for explaining a configuration example of an image verification system according to the second embodiment.
The image generation apparatus 10 is an apparatus having the same configuration and function as the image generation apparatus 10 described in the first embodiment. The second verification device 30 is also a device having the same configuration and function as the second verification device 30 described in the first embodiment.
The information processing apparatus 50 is an apparatus having a function of causing the first verification apparatus 60 to verify the image file with the first verification data. The information processing apparatus 50 may be an information processing apparatus such as a personal computer.

  The first verification device 60 is a device having a function of verifying whether image data has been altered using first verification data or the like. The first verification device 60 is also a device having a function of generating an image file with second verification data. The first verification device 60 may be any device that is difficult to analyze and leak common information Kc and secret information Ks described later. Therefore, the first verification device 60 may be, for example, an IC card (or a storage medium with a microprocessor) or a server computer having the information processing device 50 as a client. When the information processing apparatus 50 is a server computer, the first verification apparatus 60 and the information processing apparatus 50 are connected via a network such as a LAN, a wireless LAN, a WAN, or the Internet.

FIG. 8 is a block diagram illustrating a main functional configuration of the information processing apparatus 50 according to the second embodiment.
A media control unit 801 reads the image file IF1 with first verification data from the removable medium 207.
Reference numeral 807 denotes an interface unit that receives the image file IF1 with first verification data transmitted from the image generation apparatus 10.
A storage unit 802 stores the first verification data-added image file IF1 and the second verification data-added image file IF2.

Reference numeral 803 denotes a function for transmitting the image file IF1 with the first verification data to the first verification device 60, a function for receiving the detection result of the first verification device 60, and the second verification data transmitted from the first verification device 60. An interface unit having a function of receiving the attached image file IF2.
Reference numeral 804 denotes an interface unit having a function of outputting the image file IF2 with second verification data to an external device.
Reference numeral 805 denotes a display unit that displays information indicating the detection result of the first verification device 30.
A control unit 806 includes a memory and a microcomputer that executes a control program stored in the memory, and controls each function of the information processing apparatus 50. In particular, the memory of the control unit 806 stores a program for controlling the processing procedure of the information processing apparatus 50 described with reference to FIG.

FIG. 9 is a block diagram illustrating a main functional configuration of the first verification device 60 according to the second embodiment.
Reference numeral 901 denotes a function of receiving the image file IF1 with first verification data transmitted from the information processing apparatus 50, a function of transmitting the detection result of the first verification apparatus 60 to the information processing apparatus 50, and an image with second verification data. This is an interface unit having a function of transmitting the file IF2 to the information processing apparatus 50.
Reference numeral 902 denotes a storage unit that stores the first verification data-added image file IF1 and the second verification data-added image file IF2.

  Reference numeral 904 denotes a memory for storing the table T1. An example of this table T1 is shown in FIG. The table T1 is a management table that manages a plurality of unique IDs, common information Kc corresponding to each unique ID, and secret information Ks corresponding to each common information Kc. For example, when the unique ID is “001”, the common information Kc corresponding to this unique ID is “0x1111”, and the secret information Ks is “0x2222”. The common information Kc and the secret information Ks are information that is secretly managed by the first verification device 60 and are information that is not disclosed to the public. The secret information Ks is information corresponding to a secret key in a public key cryptosystem (such as RSA cryptography).

Reference numeral 905 denotes a hash value generated by the first calculation process using the first calculation process that generates the hash value H12 of the image data I using the hash function HF1 and the common information Kc obtained from the memory 904. It is a 1st calculating part which performs the 2nd calculation process which converts H12 into the 1st verification data V11.
Reference numeral 906 denotes an image verification unit that verifies whether the image data I has been altered using the first verification data V11 and the first verification data V12.
Reference numeral 907 denotes an embedding unit that embeds digital watermark data WM capable of detecting a modified position in the image data I to generate digital watermarked image data IWM.

  Reference numeral 909 denotes a hash value generated in the first calculation process using the first calculation process for generating the hash value H21 of the image data IWM using the hash function HF2 and the secret information Ks obtained from the memory 904. It is a 2nd calculating part which performs the 2nd calculation process which converts H21 into the 2nd verification data V2. The second verification data V2 is data corresponding to the digital signature of the image data IWM.

  Reference numeral 910 denotes an image file generation unit that generates the image file IF2 with the second verification data. The image file IF2 with second verification data includes image data IWM in the data portion, and data such as second verification data V2 of the image data IWM, additional information of the image data IWM, and a unique ID of the image generation device 10 in the header portion. It is an image file that contains.

  A control unit 911 includes a memory and a microcomputer that executes a control program stored in the memory, and controls each function of the first verification device 60. In particular, the memory of the control unit 911 stores a program for controlling the processing procedure of the first verification device 60 described in FIG.

FIG. 10 is a diagram for explaining the processing procedure of the image verification system according to the second embodiment.
Step S1001: The image generation unit 201 generates image data I that is image data of a subject in accordance with an instruction from a user.
Step S1002: The computing unit 204 generates a hash value H11 of the image data I using the hash function HF1.

Step S1003: The computing unit 204 converts the hash value H11 into the first verification data V11 using the common information Kc obtained from the memory 203. The first verification data V11 is data corresponding to the MAC of the image data I.
Step S1004: The image file generation unit 206 generates an image file IF1 with first verification data including data such as image data I, first verification data V11, additional information of the image data I, and a unique ID of the image generation device 10. . The media control unit 208 writes the image file IF1 to the removable medium 207.

  Step S1005: The user inputs the image file IF1 stored in the removable medium 207 to the information processing apparatus 50 via the removable medium 207 or the interface unit 209. When input is made via the removable medium 207, the media control unit 801 reads the image file IF1 from the removable medium 207 and stores it in the storage unit 802. On the other hand, when inputting via the interface unit 209, the interface unit 807 receives the image file IF 1 transmitted to the information processing apparatus 50 and stores it in the storage unit 802.

Step S1006: When the first verification device 60 verifies the image file IF1, the interface unit 803 transmits the image file IF1 to the first verification device 60. The interface unit 901 receives the image file IF1 and supplies it to the storage unit 902.
Step S1007: The first calculation unit 905 generates a hash value H12 of the image data I obtained from the storage unit 902 using the hash function HF1.

Step S1008: Also, the first calculation unit 905 refers to the table T1 in the memory 904 and acquires common information Kc corresponding to the unique ID obtained from the image file IF1.
Step S1009: Furthermore, the first calculation unit 905 converts the hash value H12 into the first verification data V12 using the common information Kc obtained from the memory 904.
Step S1010: The image verification unit 906 compares the first verification data V11 and the first verification data V12, and verifies whether or not the image data I has been altered.

  When the two first verification data match (that is, when the integrity of the image data I can be verified), the image verification unit 906 detects that the image data I has not been altered. In addition, the image verification unit 906 detects that the image data I is generated by the image generation apparatus 10. Then, the first verification device 60 notifies the information processing device 50 that the image data I has not been modified, and starts generating second verification data.

  On the other hand, when the two first verification data do not match (that is, when the integrity of the image data I cannot be verified), the image verification unit 906 confirms that the image data I has been altered. To detect. Then, the first verification device 60 notifies the information processing device 50 that the image data I has been altered, and prohibits the generation of the second verification data. That is, the first verification device 60 prohibits the processes after step S1011.

Step S1011: When the image data I is not altered, the embedding unit 907 embeds the digital watermark data WM that can detect the altered portion in the image data I, and generates the digital watermarked image data IWM.
Step S1012: The second calculation unit 909 generates a hash value H21 of the digital watermarked image data IWM using the hash function HF2.
Step S1013: Also, the second calculation unit 909 refers to the table T1 in the memory 904 and acquires the secret information Ks corresponding to the unique ID obtained from the image file IF1.

Step S1014: Further, the second calculation unit 909 converts the hash value H21 into the second verification data V2 using the secret information Ks obtained from the memory 904. This second verification data is data corresponding to the digital signature of the image data IWM.
Step S1015: The file generation unit 910 generates an image file IF2 with second verification data including data such as the image data IWM, the second verification data V2, additional information of the image data IWM, and a unique ID. The image file IF2 generated by the file generation unit 910 is stored in the storage unit 902.
Step S1016: The interface unit 901 transmits the image file IF2 to the information processing apparatus 50. The interface unit 803 receives the image file IF2 transmitted from the first verification device 60 and stores it in the storage unit 802.

Step S1017: The interface unit 804 transmits the image file IF2 to the external device. On the other hand, the interface unit 401 receives the image file IF2 from the external device and stores it in the storage unit 402.
Step S1018: The computing unit 404 refers to the table T2 in the memory 403 and acquires the public information Kp corresponding to the unique ID obtained from the image file IF2.
Step S1019: The calculation unit 404 converts the second verification data V2 into the hash value H22 using the public information Kp obtained from the memory 403.

Step S1020: The computing unit 404 generates a hash value H23 of the image data IWM using the hash function HF2.
Step S1021: The image verification unit 406 compares the hash value H22 obtained in step S1019 with the hash value H23 obtained in step S1020, and verifies whether the image data IWM has been altered.

  When the two hash values match (that is, when the integrity of the image data IWM can be verified), the image verification unit 406 detects that the image data IWM has not been altered. In addition, the image verification unit 406 detects that the image data IWM is generated by the image generation apparatus 10. Then, the second verification device 30 causes the display unit 408 to display information indicating that the image data IWM has not been altered.

  On the other hand, when the two first verification data do not match (that is, when the integrity of the image data IWM cannot be verified), the image verification unit 406 confirms that the image data IWM has been altered. To detect. Then, the second verification device 30 causes the display unit 408 to display information indicating that the image data has been altered.

  Step S1022: If the image data IWM has not been modified, the modified position detection unit 407 extracts the digital watermark data WM from the image data IWM, and detects the modified portion of the image data I. Then, the second verification device 30 causes the display unit 408 to display information indicating the modified portion detected by the modified position detection unit 407.

As described above, according to the image verification system in the second embodiment, it is possible to reliably verify whether the image data generated by the image generation device 10 has been modified, and which part of the image data is modified. It can be detected reliably.
In addition, according to the image verification system in the second embodiment, it is not necessary to significantly improve the performance of the calculation resource of the image generation apparatus 10, and thus the cost for the image generation apparatus 10 can be reduced.

Further, according to the first verification device 60 in the second embodiment, the presence or absence of alteration of the image data is verified using the common information Kc obtained from the unique ID of the image generation device 10, so that the image data is an image. It can be confirmed reliably whether it is what was produced | generated by the production | generation apparatus 10. FIG.
Further, according to the second verification device 30 in the second embodiment, the presence / absence of alteration of the image data is verified using the secret information Ks and the public information Kp obtained from the unique ID of the image generation device 10. Whether or not the image data is generated by the image generation apparatus 10 can be confirmed with certainty.
According to the image verification system in the second embodiment, the first verification device 60 is realized by an IC card (or a storage medium with a microprocessor) or a server computer using the information processing device 50 as a client. Thus, the possibility of leakage of the common information Kc and the secret information Ks can be reduced, and the safety of these data can be improved.

This embodiment can be realized by a computer executing a program. Further, means for supplying a program to a computer, for example, a recording medium such as a CD-ROM in which such a program is recorded, or a transmission medium such as the Internet that transmits such a program can also be applied as an embodiment of the present invention. The above program, recording medium, and transmission medium are included in the scope of the present invention. As the recording medium, for example, a flexible disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.
It should be noted that each of the above-described embodiments is merely an example of the embodiment for carrying out the present invention, and the technical scope of the present invention should not be construed in a limited manner. It is. That is, the present invention can be implemented in various forms without departing from the technical idea or the main features thereof.

It is a figure explaining the example of 1 composition of the image verification system in a 1st embodiment. It is a block diagram explaining the main function structures of the image generation apparatus 10 in 1st Embodiment. It is a block diagram explaining the main functional structures of the 1st verification apparatus 20 in 1st Embodiment. It is a block diagram explaining the main functional structures of the 2nd verification apparatus 30 in 1st Embodiment. It is a figure explaining the process sequence of the image verification system in 1st Embodiment. It is a figure which shows an example of table T1 and table T2. It is a figure explaining the example of 1 structure of the image verification system in 2nd Embodiment. It is a block diagram explaining the main function structures of the information processing apparatus 50 in 2nd Embodiment. It is a block diagram explaining the main function structures of the 1st verification apparatus 60 in 2nd Embodiment. It is a figure explaining the process sequence of the image verification system in 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image production | generation apparatus 20,60 1st verification apparatus 30 2nd verification apparatus 50 Information processing apparatus

Claims (31)

An image verification system having an image generation device and a first image verification device,
The image generation device includes:
Image generation means for generating image data;
A first verification data generating unit that generates first verification data using the image data and the common information;
The first image verification device includes:
Using the image data, the first verification data and the common information, first verification means for verifying whether the image data has been modified;
If the image data is not modified, embedding means for embedding digital watermark data capable of detecting a modified portion in the image data and generating image data with a digital watermark;
An image verification system comprising: a second verification data generation unit configured to generate second verification data using the digital watermarked image data and secret information.   The image verification system according to claim 1, wherein the common information is information corresponding to a common key in a common key cryptosystem.   The image verification system according to claim 1, wherein the secret information is information corresponding to a secret key in a public key cryptosystem.   4. The image verification system according to claim 1, wherein when the image data is altered, the second verification data generation unit prohibits generation of the second verification data. 5. . The image verification system further includes a second image verification device,
The second image verification device includes:
Second verification means for verifying whether the digital watermarked image data has been altered using the digital watermarked image data, the second verification data, and public information;
2. The apparatus according to claim 1, further comprising: a modified part detection unit configured to extract the digital watermark data from the digital watermarked image data and detect a modified part when the digital watermarked image data is modified. 5. The image verification system according to any one of 1 to 4.   The image verification system according to claim 5, wherein the public information is information corresponding to a public key in a public key cryptosystem.   The image verification system according to claim 1, wherein the image generation apparatus is a digital camera, a digital video camera, a scanner, a facsimile apparatus, or a copying machine.   The image verification system according to claim 1, wherein the first image verification device is an IC card or a storage medium with a microprocessor. An image verification system having an image generation device, an information processing device, and a first image verification device,
The image generation device includes:
Image generation means for generating image data;
A first verification data generating unit that generates first verification data using the image data and the common information;
The information processing apparatus includes:
An apparatus for transmitting the image data and the first verification data to the first image verification apparatus;
The first image verification device includes:
Using the image data, the first verification data and the common information, first verification means for verifying whether the image data has been modified;
If the image data is not modified, embedding means for embedding digital watermark data capable of detecting a modified portion in the image data and generating image data with a digital watermark;
An image verification system comprising: a second verification data generation unit configured to generate second verification data using the digital watermarked image data and secret information.   The image verification system according to claim 9, wherein the common information is information corresponding to a common key in a common key cryptosystem.   The image verification system according to claim 9 or 10, wherein the secret information is information corresponding to a secret key in a public key cryptosystem.   The image verification system according to any one of claims 9 to 11, wherein when the image data is altered, the second verification data generation unit prohibits generation of the second verification data. . The image verification system further includes a second image verification device,
The second image verification device includes:
Second verification means for verifying whether the digital watermarked image data has been altered using the digital watermarked image data, the second verification data, and public information;
2. The apparatus according to claim 1, further comprising: a modified part detection unit configured to extract the digital watermark data from the digital watermarked image data and detect a modified part when the digital watermarked image data is modified. The image verification system according to any one of 9 to 12.   The image verification system according to claim 13, wherein the public information is information corresponding to a public key in a public key cryptosystem.   The image verification system according to claim 9, wherein the image generation device is a digital camera, a digital video camera, a scanner, a facsimile device, or a copying machine.   The image verification system according to claim 9, wherein the first image verification device is an IC card or a storage medium with a microprocessor.   The image verification system according to claim 9, wherein the first image verification apparatus is a server computer that uses the information processing apparatus as a client. Image verification means for verifying whether the image data has been modified using the image data generated by the image generation device, the first verification data, and the common information;
If the image data is not modified, embedding means for embedding digital watermark data capable of detecting a modified portion in the image data and generating image data with a digital watermark;
An image verification apparatus, comprising: verification data generation means for generating second verification data of the image data using the digital watermarked image data and secret information.   The image verification apparatus according to claim 18, wherein the common information is information corresponding to a common key in a common key cryptosystem.   The image verification apparatus according to claim 18, wherein the secret information is information corresponding to a secret key in a public key cryptosystem.   21. The image verification apparatus according to claim 18, wherein when the image data is altered, the verification data generation unit prohibits generation of the second verification data.   The image verification apparatus according to any one of claims 18 to 21, wherein the image verification apparatus is an IC card or a storage medium with a microprocessor.   The image verification apparatus according to claim 18, wherein the image generation apparatus is a digital camera, a digital video camera, a scanner, a facsimile apparatus, and a copying machine. An image verification step of verifying whether or not the image data has been modified using the image data generated by the image generation device, the first verification data, and the common information;
If the image data is not modified, an embedding step of embedding digital watermark data capable of detecting a modified portion in the image data and generating image data with a digital watermark;
And a verification data generation step of generating second verification data of the image data using the digital watermarked image data and secret information.   The image verification method according to claim 24, wherein the common information is information corresponding to a common key in a common key cryptosystem.   26. The image verification method according to claim 24, wherein the secret information is information corresponding to a secret key in a public key cryptosystem.   27. The image verification method according to claim 24, wherein when the image data is altered, the verification data generation step prohibits generation of the second verification data.   The image verification method according to any one of claims 24 to 27, wherein the image verification method is executed by an IC card or a storage medium with a microprocessor.   29. The image verification method according to claim 24, wherein the image generation apparatus is a digital camera, a digital video camera, a scanner, a facsimile apparatus, or a copying machine. An image verification procedure for verifying whether or not the image data has been modified using the image data generated by the image generation device, the first verification data, and the common information;
If the image data is not modified, an embedding procedure for embedding digital watermark data capable of detecting a modified portion in the image data and generating image data with a digital watermark;
A program for causing a computer to execute a verification data generation procedure for generating second verification data of the image data using the image data with digital watermark and secret information. An image verification procedure for verifying whether or not the image data has been modified using the image data generated by the image generation device, the first verification data, and the common information;
If the image data is not modified, an embedding procedure for embedding digital watermark data capable of detecting a modified portion in the image data and generating image data with a digital watermark;
A computer-readable recording medium storing a program for causing a computer to execute a verification data generation procedure for generating second verification data of the image data using the digital watermarked image data and secret information.

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