Digital evidence camera system, decoding key acquisition registration system and digital image edit system

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to a digital evidence camera system, a decryption key acquisition / registration system, and a digital image editing system.

【0002】

[Conventional technology]

Conventionally, for example, photographs and sounds recorded in analog on film or media of a camera have been used as proofs in trials and the like. Due to recent advances in digital technology, devices that record images and sounds as digital data have become widespread. Such digitization has the advantages that it does not deteriorate even if it is copied, it can be distributed quickly using a communication line, and the information content can be easily processed and edited. However, the fact that it is easy to process and edit means that the content of information can be easily falsified, and there is room for doubt about the ability of evidence as information. Therefore, in order to be able to use digital images and sounds as evidence, it is necessary to have a function to prevent falsification of digital data in some way. A camera having such a prevention function is called a digital evidence camera.

【0003】

In order to realize this digital evidence camera, it is considered to apply the electronic signature technology generally used in communication and the like. In a digital signature system, two pairs of keys are used. One is the encryption key, which is called the private key, and the other is the decryption key, which is called the public key. Digital data is encrypted with a private key and decrypted with a public key. A one-way function is used to obtain the public key from the private key, but on the contrary, it is mathematically very difficult to obtain the private key from the public key due to the nature of this one-way function. The private key needs to be strictly managed so that it cannot be used by anyone other than the owner, while the public key is open to the public so that anyone can use it.

【0004】

The method of tampering detection is that the sender first creates a code called Message Digest (hereinafter, MD) from the target digital data using a hash function or the like. The method of extracting MD from the target digital data is open to the public, and anyone with original data can extract MD. By the way, MD has the property that the value changes greatly if the original digital data is slightly different due to the well-known property of the hash function.

【0005】

Next, the extracted MD is encrypted using the private key, and this is sent to the other party together with the original data as a message authentication code (hereinafter referred to as MAC). Here, it is assumed that the public key paired with the private key is surely given to the recipient (it is sufficient that the recipient always has the key, and it may be in the hands of a third party. Absent).

【0006】

The receiving side first obtains MD'from the original data using a hash function or the like in order to check that the original data has not been tampered with. Next, the MAC is decrypted using the public key to obtain the MD, and it is checked whether this MD and MD'match. Even if the original data is tampered with by a third party, since the third party does not have the private key, it is not possible to create a MAC that can be decrypted with the public key, and the values will be different from MD and MD'. From this, it can be seen that the original data has been tampered with by a third party.

【0007】

[Problems to be Solved by the Invention]

As described above, the electronic signature technology can be applied to detect falsification of digital data. However, when the above-mentioned tampering detection method is adopted for a digital evidence camera, the private key as an encryption key must never be leaked, but conventionally, this private key is managed at a high security level. It was not easy, and therefore the evidence capacity of digital images could not be enhanced.

【0008】

Further, in the case of an image, due to the nature of the data, it is often necessary to perform processing such as data compression, area cutout, and caption insertion, but the electronic signature method conventionally applied to document data has been used. , If the data content is changed even slightly, it will be considered that the data has been tampered with. Therefore, the conventional electronic signature system cannot perform any necessary editing due to the nature of the image data as described above.

【0009】

The present invention has been made by paying attention to such a problem, and an object of the present invention is to enhance the proof ability of a digital image and to manage an encryption key at an extremely high security level. Providing a proof camera system and a decryption key acquisition / registration system, and a digital image that can maintain the proof ability of a digital image even if it is edited such as compression, area cutout, and caption insertion, which are necessary due to the nature of the image. To provide an editing system.

【0010】

[Means for solving problems]

In order to achieve the above object, the first invention is a digital evidence camera system that detects falsification of image data obtained by imaging a subject with a camera, and includes an imaging unit for imaging the subject and an imaging unit. Using a camera equipped with an encryption processing unit that creates tampering detection data from image data obtained by imaging using a built-in encryption key in advance, and a decryption key corresponding to the encryption key. It comprises a tampering detection unit that decodes the tampering detection data and detects whether or not the image data has been tampered with based on the result of this decoding.

【0011】

The second invention is a digital evidence camera system that detects falsification of image data obtained by imaging a subject with a camera, and includes an imaging unit for imaging the subject and image data obtained by imaging. Therefore, a camera including an encryption processing unit that creates tampering detection data using a built-in encryption key in advance and a decryption key corresponding to the encryption key are used to decrypt the tampering detection data. The camera comprises a tampering detection unit that detects whether or not the image data has been tampered with based on the result of this decoding, and the camera has a tampering monitoring mode that detects whether or not the image data has been tampered with. A secure mode that encrypts the image data transferred from the camera to the tampering detection unit, an electronic watermark mode that embeds the electronic watermark data in the image data, and a normal mode that performs normal shooting without activating the security function. And has a mode selection unit for selecting at least one desired mode from these modes.

【0012】

Further, the third invention is a decryption key acquisition / registration system, in which an identifier unique to the device and a first decryption key corresponding to the first encryption key generated corresponding to the identifier are obtained. The decryption key storage unit that stores the tampering together with the above and the tampering detection data related to the first decryption key are created by using the second encryption key, and the tampering detection data and the first decryption are created. A decryption key server including a decryption key output unit that outputs a key together with the key, and a decryption key that stores the first decryption key acquired from the decryption key server via a communication means or the like. Using the storage unit and the second decryption key corresponding to the second encryption key, the tampering detection data supplied from the decryption key server via a communication means or the like is decrypted, and the decryption is performed. It includes a tampering detection unit that detects whether or not the first decryption key has been tampered with based on the result of the encryption, and a decryption key acquisition unit including the first decryption key.

【0013】

Further, the fourth invention is a digital image editing system that detects falsification of image data and edits the image data, and has a filing management unit that manages filing of the image data input via the image input unit. , The first tampering detection data added to the image data in advance is decrypted using the decryption key corresponding to the encryption key used when creating the tampering detection data, and this decryption is performed. A tampering detection unit that detects a tampering state of image data by comparing the first tampering detection data with the image data, an image editing unit that performs various image processing on the image data, and the image. From the edited image data that has undergone various image processing by the editorial department and the data of the edit history by the image editorial department, a second tampering detection data is created using an encryption key different from the encryption key. , It consists of an image file update unit that adds this to the edited image data.

【0014】

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing a configuration of a digital evidence camera system according to the first embodiment of the present invention, which is composed of a digital evidence camera 100 and a falsification inspection device 101. The camera unit 50-1 of the digital evidence camera 100 includes an image pickup means 60 including a photographing lens 1, an image sensor 2, an amplifier 3, an A / D converter 4, and a signal processing unit 5. The subject image incident through the photographing lens 1 is imaged by the image sensor 2. The electric signal obtained by this imaging is amplified by the amplifier 3, converted into a digital signal by the A / D conversion unit 4, subjected to predetermined signal processing by the signal processing unit 5, and then stored in the image memory 6 as image data. It will be remembered. The image data stored in the image memory 6 is displayed on the image display unit 7 as needed.

【0015】

The image data stored in the image memory 6 is converted into a standard image format such as JPEG or TIFF by the file format conversion unit 8. As a result, a file format in which header information data is added to the image data is created ((A) in FIG. 2). Next, the MD creation unit 9 creates an MD by applying a predetermined function such as a hash function to the entire data including the image data or the header ((B) in FIG. 2). Next, in the MAC creation unit 11, the private key K stored in advance in the private key memory 10_private A MAC is created by encrypting the MD using (Camera) ((C) in Fig. 2). Next, the header recording unit 11 stores the created MAC in the image header ((D) in FIG. 2). The filing management unit 13 manages the image file of the file format created in this way.

【0016】

Such an image file is tampered with while being stored in a removable storage medium 17 under the control of the storage medium control unit 15 and carried around, or while being transmitted via the communication line 16 under the control of the communication control unit 14. A tampering detection device 101 is used to detect whether or not the image has been tampered with.

【0017】

That is, the image file stored in the storage medium 17 mounted on the falsification inspection device 101 is read out to the filing management unit 19 under the control of the storage medium control unit 18. Alternatively, the image file is sent to the filing management unit 19 via the communication line 25 under the control of the communication control unit 24. In the filing management unit 19, the image file is separated into MAC and image data (this image data may include header information such as JPEG and TIFF in addition to the image data itself), and the MAC is the decoding unit. It is input to 21 and the image data is input to the MD creation unit 22.

【0018】

In the decryption unit 21, the public key K stored in advance in the public key memory 20_publicMD1 is generated by decoding the MAC using (camera). This public key K_public(Camera) and the above-mentioned private key K_private The (camera) is a key that is paired in the encryption / decryption process. On the other hand, the MD creation unit 22 generates MD2 from the input image data by using a predetermined function such as a hash function. Next, the comparison matching unit 23 compares MD1 and MD2, and if they do not match, it can be determined that the image file has been tampered with by a third party.

【0019】

According to the first embodiment described above, tampering detection data (MAC) is created from the image data using the encryption key in the camera, and the tampering detection data is stored in the image file, for example, in the header information of the image. By writing it, you can check whether the image data has been tampered with. As a result, it is possible to enhance the evidence capacity of a digital image, which is considered to be inferior to an image taken by using a conventional film.

【0020】

Further, the encryption key for creating the falsification detection data must never be leaked to the outside including the camera user, but in the present embodiment, the encryption for creating the falsification detection data is performed. Since the key is stored in the memory area in the camera in advance, the encryption key can be managed at an extremely high security level in terms of hardware.

【0021】

Next, as a second embodiment of the present invention, a digital evidence camera having various modes (multi-mode) will be described. Here, by providing the camera with the following various mode selection functions, it is possible to set desired functions according to the purpose of use of the camera. Here, the various modes are a normal shooting mode in which the security function is not activated, a tampering monitoring mode in which tampering detection data is added to the shot image file, and the copyright information of the shot photo is recorded as a digital watermark in the image file. A digital watermarking mode, a secure mode for encrypting an image file when the image file is stored in a removable storage medium, or when the image file is transmitted by using a communication function, and the like.

【0022】

Hereinafter, the description will be described in more detail with reference to FIG. Those having the same reference number as that of FIG. 1 in FIG. 3 shall have the same function. In the digital evidence camera 102 including the camera units 50-2 in this embodiment, the user can select a desired mode from the various modes described above by the mode selection unit 31.

【0023】

For example, when the normal mode is selected, the image data obtained by imaging the subject by the imaging means 60 is stored in the image memory 6. In this mode, the security mode does not work in particular, and the image data read from the image memory 6 is format-converted by the file format conversion unit 8 and sent to the filing management unit 13 for file management.

【0024】

When the digital watermark mode is selected, the image data is input from the file format conversion unit 8 to the digital watermark creation unit 30, the digital watermark data is embedded in the image data, and then the file format conversion unit 8 is used again. It is returned and the format is converted, and the file is managed by the filing management unit 13.

【0025】

When the falsification prevention mode is selected, the file is managed by the filing management unit 13 after the MAC is added to the header by the method described above with reference to FIG.

【0026】

When the tampering detection mode is selected, the image file acquired from an external device (PC, tampering inspection device, etc.) via the storage medium 17 or the communication line 16 and sent to the falsification management unit 13 is tampered with. The presence or absence is detected. That is, the image data to which the MAC is added is separated into the MAC and the image data, the image data is input from the filing management unit to the MD creation unit 33, and the MAC is input to the decoding unit 34. The MD creation unit 33 generates an MD from the input image data by using a predetermined function such as a hash function. In addition, the decryption unit 34 uses the public key K stored in the public key memory 35._publicGenerate MD'using (camera). The comparison matching unit 32 compares MD and MD'and determines whether or not they match. If they do not match, it can be seen that the image data has been tampered with by a third party.

【0027】

Further, the secure mode is used when storing image data in a storage medium. In this case, the image data is read from the filing management unit 13 and input to the encryption unit 36. The encryption unit 36 encrypts this image data using the shared key stored in the shared key memory 37, and sends the encrypted image data to the filing management unit 13 again. After that, the encrypted image data is written to the removable storage medium 17 under the control of the recording medium control unit 15.

【0028】

The secure mode is also used when transmitting an image file via a communication line. In this case, the image data is read from the filing management unit 13 and input to the encryption unit 36. The encryption unit 36 encrypts this image data using the shared key stored in the shared key memory 37, and the encrypted image data is controlled by the communication control unit 14 via an external device (PC,) via the communication line 16. Send to tampering inspection device, etc.).

【0029】

According to the second embodiment described above, for example, when taking a snapshot image, it is taken in the normal mode, when it is taken as a proof image, it is in a falsification monitoring mode, and for an image whose copyright is to be protected. You can protect the copyright by shooting in the digital watermark mode. Furthermore, if you want to take a highly confidential image and send the image file safely, you can safely save and send the data by selecting the secure mode. In addition, by combining a plurality of modes, one camera can be used for various purposes due to the above effects.

【0030】

A third embodiment of the present invention will be described below with reference to FIG. In FIG. 4, those having the same reference numbers as those in FIG. 1 shall have the same functions. Further, although the communication function of FIG. 1 and the configuration of various modes of FIG. 3 are omitted here, it goes without saying that these functions may be provided. In the digital evidence camera 103 having the camera unit 50-3, the image data obtained by photographing the subject by the image pickup means 60 is stored in the image memory 6. The image data is read from the image memory 6 by the file format conversion unit 8 and converted into a standard image format such as JPEG or TIFF. As a result, a file format in which header information data is added to the image data is created ((A) in FIG. 5).

【0031】

At the same time, the personal authentication information is read from the personal authentication IC card 40 mounted on the camera unit 50-3 under the control of the IC card control unit 41 and input to the file format conversion unit 8 for personal authentication in the header. Information is recorded as shown in (B) of FIG. Next, the MD creation unit 9 creates an MD by applying a predetermined function such as a hash function to the entire data or image data and personal authentication data ((C) in FIG. 5). Next, in the MAC creation unit 11, the private key K stored in advance in the private key memory 10_private A MAC is created by encrypting the MD using (camera) ((D) in Fig. 5). The header recording unit 12 stores the MAC in the image header in addition to the image header information data and the personal authentication data. As a result, the image file is saved in the filing management unit 13 in the image format as shown in FIG. 5 (E) and is managed as a file.

【0032】

A falsification detection device 104 is used to detect whether or not such an image file has been tampered with while being stored in a removable storage medium 17 under the control of the storage medium control unit 15 and carried.

【0033】

That is, the image file stored in the storage medium 17 mounted on the falsification inspection device 104 is read out to the filing management unit 19 under the control of the storage medium control unit 18. In the filing management unit 19, the data required for the image file to obtain the MAC and the above-mentioned MAC, that is, the entire data excluding the MAC, or the image data (this image data includes JPEG, TIFF, etc. in addition to the image data itself. The data required for obtaining the MAC is input to the MD creation unit 22, and the MAC is input to the decoding unit 21. Further, the personal authentication data is also input to the personal information reading unit 22.

【0034】

In the decryption unit 21, the public key K stored in advance in the public key memory 20_publicMD1 is generated by decoding the MAC using (camera). On the other hand, the MD creation unit 22 generates MD2 from the input image data by using a predetermined function such as a hash function. Next, the comparison matching unit 23 compares MD1 and MD2, and if they do not match, it can be determined that they have been tampered with by a third party.

【0035】

In addition, the personal information reading unit 42 identifies the photographer by reading the personal authentication data. Here, the identification of the photographer is meaningful only when it is confirmed that the image data has not been tampered with.

【0036】

According to the third embodiment described above, by adding the information for personal authentication when creating the data for detecting falsification of the image data, not only the presence or absence of falsification of the image but also the image photographer can be specified. In particular, here, as the information for personal authentication of the photographer, the data for tampering detection is created from the data obtained by combining the image data and the data for personal authentication using the encryption key, so that one tampering detection is performed. The data can detect falsification of image data and falsification of photographer's personal authentication data. If the photographer's personal authentication data has not been tampered with, the photographer can be identified from the personal authentication data.

【0037】

A fourth embodiment of the present invention will be described below. In FIG. 6, reference figures similar to those in FIG. 1 shall have the same function. Further, although the communication function of FIG. 1 and the configuration of various modes of FIG. 3 are omitted here, it goes without saying that these functions may be provided. In the digital evidence camera system 105 having the camera unit 50-4, the image data obtained by photographing the subject by the image pickup means 60 is stored in the image memory 6. The image data is read from the image memory 6 by the file format conversion unit 8 and converted into a standard image format such as JPEG or TIFF. As a result, a file format in which header information data is added to the image data is created ((A) in FIG. 7). Next, the MD creation unit 9 generates MD1 or MD2 ((B), (B)'in FIG. 7) from the entire data or image data using a predetermined function such as a hash function. The MD1 and MD2 may be the same. MD1 is input to the MAC creation unit 11. In the MAC creation unit 11, the private key K stored in advance in the private key memory 10_private MAC is calculated using (camera) to create MAC1 ((C) in Fig. 7). This MAC1 is sent to the header recording unit 12.

【0038】

On the other hand, MD2 is input to the personal authentication IC card 40'mounted on the camera unit 50-4 via the IC card control unit 41. With the IC card 40'for personal authentication, the private key K stored in the internal private key memory_private Create MAC2 by encrypting MD2 using (IC card) ((C)'in Fig. 7). This MAC2 is sent to the header recording unit 12 via the IC card control unit 41.

【0039】

The header recording unit 12 stores MAC1 and MAC2 in the image header in addition to the image header information data. As a result, the image file is saved in the filing management unit 13 in the image format as shown in FIG. 7 (D) and is managed as a file.

【0040】

A falsification detection device 106 is used to detect whether or not such an image file has been tampered with while being stored in a removable storage medium 17 under the control of the storage medium control unit 15 and carried.

【0041】

That is, the image file stored in the storage medium 17 mounted on the falsification inspection device 106 is read out to the filing management unit 19 under the control of the storage medium control unit 18.

【0042】

In the filing management unit 19, the image file is separated into MAC1 and MAC2 and image data (this image data may include header information such as JPEG and TIFF in addition to the image data itself), and MAC1 is decoded. It is input to the conversion unit 21-1, and the image data is input to the MD creation unit 22-1. In the decryption unit 21-1, the public key K stored in advance in the public key memory 20'_publicMD1 is generated by decoding MAC1 using (camera). Public key K_public(Camera) and private key K_private The (camera) is a key that is paired in the encryption / decryption process. On the other hand, the MD creation unit 22-1 generates MD1'from the input image data using a predetermined function such as a hash function. Next, the comparison matching unit 23-1 compares MD1 and MD1', and if they do not match, it can be determined that they have been tampered with by a third party.

【0043】

Similarly, MAC2 is input to the decoding unit 21-2, and the image data is input to the MD creation unit 22-2. In the decryption unit 21-2, the public key K stored in advance in the public key memory 20'_publicMD2 is generated by decoding MAC2 using (IC card). Public key K_public(IC card) and private key K_private (IC card) is a key that is paired in the encryption / decryption process.

【0044】

On the other hand, the MD creation unit 22-2 generates MD2'from the input image data by using a predetermined function such as a hash function. Next, the comparison matching unit 23-2 can compare MD2 and MD2'and identify the photographer when they match.

【0045】

According to the fourth embodiment described above, by adding the information for personal authentication when creating the data for detecting falsification of the image data, not only the presence or absence of falsification of the image but also the image photographer can be specified. In particular, here, since the second tampering detection data created by a device outside the camera is used as the information for personal authentication of the photographer, the second tampering detection data includes e-mail, electronic commerce, etc. It is possible to apply the electronic signature used in the information system of. Therefore, it is possible to construct a digital evidence camera system linked with a socially-based information system such as an electronic notary public office or electronic commerce.

【0046】

The fifth embodiment of the present invention will be described below. The fifth embodiment relates to a digital image editing system using an image server configured by hardware such as a board and a PCMCIA card. Here, for the sake of simplicity, the minimum configuration of the image server is assumed.

【0047】

Conventionally, in the method using the falsification detection data used for the document data, it is considered that the original data has been tampered with even if it is slightly modified. However, due to the nature of the image data, processing such as compression, cropping, and caption insertion is often required. In the case of a photograph using film, it is equivalent to printing only the necessary part on photographic paper or writing a comment on the back of the photograph. If there is a good reason, such processing is not tampering. As a method for determining whether or not legitimate processing has been performed, there is a method of recording the processing history of what kind of processing has been performed on the original image data.

【0048】

In the present embodiment, by using the image server, the image subjected to processing such as compression of image data, cropping of a part of the area, addition of caption, etc. is falsified by a device other than the image server together with the history of the processing. Try to detect if it is.

【0049】

FIG. 8 is a diagram showing the configuration of the image server system 107 of the fifth embodiment. For example, as shown in FIG. 11, an image server 107 composed of a personal computer 107-1 and a PCMCIA card that can be attached to the personal computer 107-1. Consists of -2.

【0050】

The operation of the fifth embodiment will be described below with reference to the flowchart of FIG. First, the filing management unit 72 acquires an image file in the format shown in FIG. 9A from the storage medium 70 under the control of the storage medium control unit 71. Alternatively, the image file is acquired from the external device 93 via the communication line 77 under the control of the communication control unit 78 (step S1). In this case, an image file can be easily input from an external device by providing a connection terminal such as a serial cable, SCSI, IrDA, etc. that can be directly connected to the filing management unit 72. Further, the same effect can be obtained even when a network connection terminal such as Ethernet is provided. Next, the MAC verification unit 73 receives an image file from the filing management unit 72 and verifies MAC1 (step S2). That is, the filing management unit 72 separates the image file into MAC1 and image data, MAC1 is input to the decoding unit 75, and the image data is input to the MD creation unit 76. The decryption unit 75 is the public key K stored in the public key memory 74._publicDecode using (camera) to create MD1. In addition, the MD creation unit 76 creates MD1'using a predetermined function such as a hash function. By comparing MD1 and MD1', the comparison matching unit 79 sends a verification result regarding whether or not the image taken by the camera has been tampered with to the filing management unit 72.

【0051】

If it has not been tampered with, the image file is input from the filing management unit 72 to the image editing unit 93, and the user edits the image using the image editing tool 80 (step S3). In this case, the contents of the image file are displayed on the image display device 82, and the user 91 requests various processes or inputs data using the data input device (keyboard, mouse, etc.) 84 while looking at this screen. .. Reference numeral 83 is a user interface between the user 91 and the image server 107. The editing history is recorded in the editing history recording unit 81. At the same time, the edit history recording unit 81 reads the personal authentication information from the personal authentication IC card 92 under the control of the IC card control unit 85 and records it in the edit history. The above editing is continued until the user gives an instruction to stop editing and the judgment in step S5 becomes NO.

【0052】

Since the edited image file and the editing history data are sent to the filing management unit 72, the filing management unit 72 records the editing history information in the image header in the format shown in FIG. 9 (B) (step S6). ). When leaving the information that identifies the camera that took the picture, the camera information is also recorded in the image header in the format shown in (C) of FIG.

【0053】

Next, the edited image file and the edit history data are input from the filing management unit 72 to the MD creation unit 87 of the image file update unit 86, and MD2 is created using a predetermined function such as a hash function. Next, the MAC creation unit 88 uses the private key K of the image server 107 stored in advance in the private key memory 90._private Create MAC2 by encrypting MD2 using (Image Server) (step S7). The header recording unit 89 records this MAC2 in the image header in the format shown in (D) of FIG. 9 (step S8). When leaving the information that identifies the camera, the format is as shown in (E) of Fig. 9. The image file to which MAC2 is added is sent to the filing management unit 72, and then this image file is stored in the removable storage medium 70 under the control of the storage medium control unit 71, or the communication control unit 78. Is sent to the external device 93 via the communication line 77 and stored under the control of.

【0054】

According to the fifth embodiment described above, by using the image server, it is possible to confirm what kind of processing has been performed from the original image file and whether or not the image content has been changed by a device other than the image server. Even if necessary processing such as compression or area cutting is performed due to the nature of the image data, it will not be tampered with. Further, when creating the falsification detection data to be added to the image file after editing on the image server, the user who edited the image can be specified by using the personal authentication data as well.

【0055】

The sixth embodiment of the present invention will be described below. In the sixth embodiment, the image server in the fifth embodiment is configured by software started on a PC or the like. Here, for the sake of simplicity, the minimum configuration of the image server is assumed.

【0056】

FIG. 10 is a diagram showing a configuration of an image server system 108 configured by installing an image server on a PC. Here, only the points different from the configuration of the fifth embodiment shown in FIG. 8 will be described.

【0057】

In the sixth embodiment, as shown in FIG. 10, the MAC creation unit 88 and the private key K_private The private key memory 90 in which the memory is stored is provided not inside the image server system 108 but inside the IC card 109 which can be attached to and detached from the image server 108. Further, the IC card control unit 85 is provided inside the image file update unit 86'of the image server system 108.

【0058】

The edited image file and the edit history data are input to the MD creation unit 87 of the image file update unit 86', and MD2 is created using a predetermined function such as a hash function. This MD2 is sent to the MAC creation unit 88 of the IC card 109 under the control of the IC card control unit 85. MAC creator 88 uses MD2 as private key K_private Create MAC2 by encrypting using (IC card). This MAC2 is sent to the header recording unit 89 under the control of the IC card control unit 85 and recorded in the image header in the format shown in (D) or (E) of FIG. As in the fifth embodiment, the personal authentication information may be stored in the IC card 109, read out, and recorded in the editing history.

【0059】

According to the sixth embodiment described above, in addition to the effect of the fifth embodiment, the encryption key management and the encryption process are configured by a detachable storage medium such as an IC card, and image editing and editing are performed. Since other functions such as history data creation are configured by software, it has the effect of being able to build an image server at low cost.

【0060】

The seventh embodiment of the present invention will be described below. The seventh embodiment relates to a decryption key acquisition / registration system, and is composed of a public key server mechanism, a tampering inspection device, and an image server public key acquisition / registration mechanism. As shown in FIG. 13 (A), the private key as encryption and the public key as the decryption key used in this embodiment are devices such as a digital camera 220, an image server 221, and an IC card 222, depending on the manufacturer. It is generated by the key generation mechanism 120 at the time of manufacture, and the private key is built in and registered in the device. After registration, this private key will be immediately and securely erased.

【0061】

Further, the public key is stored in the recording medium 203 by the key registration unit 202 of the public key server mechanism 110 shown in FIG. 13 (B) in association with the serial number as an identifier unique to the device.

【0062】

When the falsification detection device and the public key acquisition / registration mechanism 111 of the image server detect falsification of an image taken by, for example, the digital camera 220, the serial number of the device is changed from the public key acquisition unit 212 to the communication control unit 211 and communication. It is transmitted to the key search unit 204 via the lines 210 and 209 and the communication control unit 208. The key search unit 204 reads the public key corresponding to the serial number of the device from the storage medium 203 and sends it to the MD creation unit 205. The MD creation unit 205 creates an MD using a predetermined function such as a hash function and sends it to the MAC creation unit 206. The MAC creation unit 206 creates a MAC using the private key stored in advance in the private key memory 207, and together with the public key, the public key via the communication control unit 208, the communication line 209, the communication line 210, and the communication control unit 211. Send to acquisition unit 212. The public key acquisition unit 212 sends the acquired public key and the serial number of the device to the public key registration unit 214. The public key registration unit 214 registers the public key and the serial number of the device in the public key memory 213.

【0063】

At the same time, the public key data is sent from the public key acquisition unit 212 to the MD creation unit 216, and the MAC is sent to the decryption unit 217. The MD creation unit 216 creates an MD from the data of this public key using a predetermined function such as a hash function. The decryption unit 217 is the public key K of the key management server stored in the public key memory 218._publicCreate MD'by decrypting the MAC using (key management server). The comparison matching unit 215 compares MD and MD'and detects tampering depending on whether or not they match. The MAC verification here is to confirm whether the public key of the camera or image server obtained by the communication means was obtained from a legitimate key management server, and whether it was tampered with during communication. Is the purpose.

【0064】

The public key registered in the public key server 110 may be delivered to the user by a secure means such as mail. According to the seventh embodiment described above, the decryption key of the falsification detection data can be obtained by sending the serial number of the device to the decryption key (public key) server. Therefore, for example, when the decryption key server can be used from the Internet, the falsification detection data can be acquired from anywhere in the world based on the serial number of the camera.

【0065】

The eighth embodiment of the present invention will be described below. The eighth embodiment relates to the prevention of falsification of the multi-resolution image. If a part of the document file is modified, the sentences will not be connected or the meaning will change, and the content will be different from the original file. On the other hand, since image data has high redundancy, the subject can often be recognized even if some editing such as changing the resolution is performed. Therefore, on the side of using the image, the image size at the time of shooting is larger than necessary, and it is desired to reduce the resolution or the unnecessary part is captured, so that only the necessary part may be cut out. However, normally, it is necessary to prepare an image server for tampering prevention, edit the image inside the server, and add the MAC again.

【0066】

Therefore, in the eighth embodiment, in order to solve the above problem, the image of the falsification prevention camera is saved in a format that retains the multi-resolution image. FIG. 14 is a diagram showing a configuration of an eighth embodiment of the present invention. In the digital evidence camera unit 112, the image data obtained by imaging the subject by the imaging means 60 is stored in the image memory 6. Next, this image data is input to the image reduction unit 300 and converted into images having a plurality of types of resolutions. At this time, when the user specifies the minimum resolution for which tampering is to be guaranteed through the MAC creation resolution indicator 302, this is sent to the MD creation unit 9 via the filing management unit 13. The MD creation unit 9 creates an MD using a predetermined function such as a hash function.

【0067】

On the other hand, the private key memory 10 is created from the camera-specific data stored in the camera-specific data memory 301 and the personal authentication information read from the personal authentication IC card 40 under the control of the IC card control unit 41. The secret key that was created is remembered. The MAC creation unit 11 uses this private key to encrypt the MD created by the MD creation unit 9, creates a MAC, and sends it to the filing management unit 13. The filing management unit 13 collects image data of a plurality of types of resolutions into one file, further adds a MAC created from the data of the above specified resolutions to the image data, and stores the storage medium under the control of the storage medium control unit 15. Save to 17.

【0068】

FIG. 16 is a diagram for explaining the image data file of the present embodiment. As shown in FIG. 16, the conversion from high resolution to low resolution is specified in advance. MAC creation A MAC is created from the resolution data specified by the resolution indicator 302 that guarantees tampering prevention, and recorded in the header of the image data or another MAC management file.

【0069】

On the other hand, the falsification inspection device 113 reads MAC and image data from the storage medium 17 under the control of the storage medium control unit 18 and sends the MAC and image data to the falsification management unit 19. The filing management unit 9 sends the MAC to the decoding unit 21 and the image data to the image memory 303. The decryption unit 21 creates MD1 by decrypting the MAC using the public key. Further, the image data stored in the image memory 303 is reduced by the image reduction unit 304 by a predetermined reduction method, and then sent to the MD creation unit 22 to create MD2 using a predetermined function such as a hash function. .. The match comparison unit 23 determines whether or not the image data has been tampered with by comparing MD1 and MD2.

【0070】

A ninth embodiment of the present invention will be described below with reference to FIG. The ninth embodiment is intended to hold a multi-resolution image and prevent falsification of an image format in which each resolution image is stored in units of small blocks of a certain size. The reason why small blocks are stored as a unit in this image format is that a part of the image can be referred to at high speed.

【0071】

The operation of the digital evidence camera 114 is the same as that of the digital evidence camera 112 described above, but in this embodiment, the image reduction / division unit 305 is provided, and images having a plurality of resolutions are created here, and FIG. As shown, the image is divided into blocks of a certain size. The filing management unit 13 creates a MAC for each small block and writes the MAC in the header for each small block. The image file with MAC is stored as an original image in the storage medium 17 under the control of the recording medium control unit 15.

【0072】

During shooting, Yu is not necessary imaging range or an entire resolution of the image over The generally necessary parts of the cutout or the required resolution of an image from the original image read from the storage medium 17 by using the editing software 306 in the PC115 To create. The user inputs the position, size, resolution, etc. of the required image portion into the image editing unit 306 as editing parameters 307. The filing management unit 13 extracts an image block at a corresponding position from an image having a corresponding resolution and saves it in another image file.

【0073】

When the falsification detection device 116 inspects falsification, the edited image is read from the storage medium 17 to the filing management unit 19 under the control of the storage medium control unit 18. The falsification detection unit 308 detects falsification of the edited image. At this time, if the MAC originally added for each small block is added to the new file as it is, the user can cut out the image area while keeping the image as evidence without preparing a tamper-proof image server. And editing work such as changing the resolution can be performed. In addition, when performing filter processing such as contrast enhancement and smoothing, the original image can be guaranteed for the filtered image by adding data recording the filtering procedure without changing the pixel value itself. become.

【0074】

The specific embodiment described above includes an invention having the following configuration. 1. A digital evidence camera system that detects falsification of image data obtained by imaging a subject with a camera. It is built in in advance from an imaging unit for capturing the subject and image data obtained by imaging. A camera equipped with an encryption processing unit that creates tampering detection data using an encryption key and a decryption key corresponding to the encryption key are used to decrypt the tampering detection data, and the decryption is performed. A digital proof camera system comprising a tampering detection unit that detects whether or not the image data has been tampered with based on the result. (Effect of action) According to the present invention, falsification detection data is created from image data using an encryption key in the camera, and the falsification detection data is decrypted using a decryption key corresponding to the encryption key. By converting the image data, it can be confirmed whether or not the image data has been tampered with. As a result, it is possible to enhance the evidence capacity of a digital image, which is considered to be inferior to an image taken by using a conventional film.

【0075】

Further, the encryption key for creating the falsification detection data must never be leaked to the outside including the camera user, but in the present invention, the encryption key for creating the falsification detection data is used. Is stored in the camera in advance, so the encryption key can be managed at an extremely high security level in terms of hardware. 2. The encryption processing unit is characterized in that the falsification detection data is created by encrypting the data obtained by applying a predetermined function to the image data by using the encryption key. 1 Described digital evidence camera system. (Effect of action) Data for falsification detection by encrypting the data obtained by applying a predetermined function (for example, hash function) so that the change appears greatly even if the degree of falsification of the image data is small. Therefore, it is possible to provide tampering detection data that can more reliably detect tampering. 3. The falsification detection unit compares the data obtained by applying the predetermined function to the image data with the data obtained by decoding the falsification detection data with the decoding key. 2. The digital evidence camera system according to the configuration 2, wherein it detects whether or not the image data has been tampered with. (Effect of action) Since the tampering detection data is used, tampering detection can be performed more reliably. 4. The digital evidence camera system according to the configuration 1, wherein the encryption processing unit creates the falsification detection data based on the encryption key and the personal authentication data. (Effect of action) By adding information for personal authentication when creating data for detecting falsification of image data, it is possible to identify not only the presence or absence of falsification of the image but also the image photographer. 5. The encryption processing unit creates a first tampering detection data from the image data using the encryption key, and uses the personal authentication data from the image data to detect a second tampering. The digital evidence camera system according to the configuration 4, wherein data is created and the first and second tampering detection data are combined to form the tampering detection data. (Action effect) Since the first tampering detection data created from the image data and the second tampering detection data created from the photographer's personal authentication data are used together as the tampering detection data, the second It is possible to apply the tampering detection data of the above in the same way as the electronic signature used in other information systems such as e-mail and electronic commerce, and cooperate with social infrastructure information systems such as electronic public certificate offices and electronic commerce. It is also possible to build a digital evidence camera system that has been removed. 6. The second encryption processing unit is provided with a storage unit that stores the personal authentication data and the encryption key, and a second encryption processing unit that creates a second tampering detection data from the personal authentication data. The digital evidence camera system according to the configuration 4, wherein the encryption processing unit is detachably configured with respect to the camera. (Effect of action) A second encryption processing unit that stores personal authentication data and encryption key and creates second tampering detection data is provided on a medium (IC card, etc.) that can be attached to and detached from the camera. Therefore, if this medium is carried, even if the camera of another person who is not normally used is used, it is possible to surely confirm the personal authentication and the presence or absence of falsification of the captured image. 7. The digital evidence according to the configuration 4, wherein the encryption processing unit creates the falsification detection data by using the encryption key from the data obtained by combining the image data and the personal authentication data. Camera system. (Action effect) In the case of the method of creating tampering detection data using the encryption key from the data obtained by combining the image data and the personal authentication data as the photographer's personal authentication information, one tampering is performed. With the detection data, it is possible to detect falsification of image data and falsification of photographer's personal authentication data. If the photographer's personal authentication data has not been tampered with, the photographer can be identified from the personal authentication data. 8. A digital evidence camera system that detects falsification of image data obtained by imaging a subject with a camera. It is built in in advance from an imaging unit for capturing the subject and image data obtained by imaging. A camera equipped with an encryption processing unit that creates tampering detection data using an encryption key and a decryption key corresponding to the encryption key are used to decrypt the tampering detection data, and the decryption is performed. The camera comprises a tampering detection unit that detects whether or not the image data has been tampered with based on the result, and the camera has a tampering monitoring mode that detects whether or not the image data has been tampered with. It has a secure mode that encrypts the image data transferred to the tampering detection unit, an electronic watermark mode that embeds the electronic watermark data in the image data, and a normal mode that performs normal shooting without activating the security function. A digital evidence camera system comprising a mode selection unit for selecting at least one desired mode from these modes. (Action effect) By equipping the camera with various mode selection functions, it is possible to set desired functions according to the purpose of use of the camera. For example, when taking a snapshot, shoot in normal mode, when shooting a proof image, tampering monitoring mode, and for images for which you want to protect the copyright, shoot in digital watermark mode. Can be protected. Furthermore, if you want to take a highly confidential image and send the image file safely, you can safely save and send the data by selecting the secure mode. In addition, by combining a plurality of modes, one camera can be used for various purposes due to the above effects. 9. The decryption key storage unit that stores the device-specific identifier and the first decryption key corresponding to the first encryption key generated corresponding to this identifier, and the first decryption key storage unit. Decryption including a decryption key output unit that creates tampering detection data related to the decryption key using the second encryption key and outputs the tampering detection data together with the first decryption key. A decryption key server, a decryption key storage unit that stores the first decryption key acquired from the decryption key server via a communication means, and a second decryption corresponding to the second encryption key. Whether or not the first decryption key has been tampered with based on the result of decryption of the tampering detection data supplied from the decryption key server via a communication means or the like using the encryption key. A decryption key acquisition / registration system characterized by comprising a decryption key acquisition unit provided with a tampering detection unit for detecting the above. (Effect of action) According to the present invention, the decryption key of the falsification detection data can be obtained by sending the serial number of the device to the decryption key server. Therefore, for example, when the decryption key server can be used from the Internet, the falsification detection data can be acquired from anywhere in the world based on the serial number of the camera. 10. A digital image editing system that detects falsification of image data and edits the image data. A filing management unit that manages filing of image data input via the image input unit, and a filing management unit that manages filing of the image data in advance. The given first tampering detection data is decrypted using the decryption key corresponding to the encryption key used when creating the tampering detection data, and the decrypted first tampering detection is performed. A tampering detection unit that detects a tampered state of image data by comparing the data for use with the image data, an image editing unit that performs various image processing on the image data, and various image processing by the image editing unit. From the edited image data that has been subjected to the above and the data of the editing history by the image editing unit, a second tampering detection data is created using an encryption key different from the encryption key, and this has been edited. A digital image editing system characterized by consisting of an image file update unit that is added to image data. (Effect of action) According to the present invention, since the tampering detection data is created by combining the image data and the editing history, it is possible to confirm what kind of editing processing has been applied to the original image, and further. , It is possible to detect whether or not image editing processing is performed by a system other than the system concerned. 11. The image file update unit is detachable from the digital image editing system, stores the personal authentication information and the other encryption key, and uses the other encryption key for the personal authentication information. The digital image editing system according to the configuration 10, wherein the second tampering detection data is created. (Effect) Encryption key management and encryption processing are performed with a removable storage medium such as an IC card, and other functions such as image editing and edit history data creation are configured by software, which is low. You can build an image server at a cost. 12. The digital image editing system described in Configuration 9, which is characterized in that personal authentication information is recorded together with the editing history. (Action effect) By including the information for personal authentication in the image data including the image editing history data, the person who edited the image can be identified. 13. The image input unit is characterized in that image data stored in an external storage medium is input by directly connecting to the image filing unit (cable, IrDA) or by connecting via a communication line. The digital image editing system described in configuration 9. (Effect) By equipping the image filing section of the image server with a terminal for direct connection such as serial cable, SCSI, IrDA, and a terminal for network connection such as Ethernet, it is possible to easily input an image file from an external device. it can. 14. The image data is multi-resolution image data stored as a set of a plurality of image data having different resolutions, and the encryption processing unit creates the tampering detection data, so that the multi-resolution image data The digital evidence camera system according to configuration 1 or 10, further comprising a selection unit for selecting at least one image data having a desired resolution. (Action effect) By defining the resolution that guarantees tampering detection at the time of recording, the user who uses the image can use the desired resolution image without depending on the resolution at the time of shooting. 15. The image data is multi-resolution image data stored as a set of a plurality of image data having different resolutions, and each image data in the multi-resolution image data is stored in units of predetermined small blocks. The digital proof camera system according to the configuration 1 or 10, wherein the encryption processing unit creates the tampering detection data in units of the small blocks. (Effect of action) By adding tampering detection data for each small block, tampering detection can be performed even for an image that has undergone image editing such as cropping, without preparing a dedicated server.

【0076】

[Effect of the invention]

According to the present invention, it is possible to provide a digital proof camera system and a decryption key acquisition / registration system that can enhance the proof ability of a digital image and manage the encryption key at an extremely high security level. Further, it is possible to provide a digital image editing system that can maintain the proof ability of a digital image even after editing such as compression, region cutting, and insertion of captions, which are necessary due to the nature of the image.

[Simple explanation of drawings]

[Figure 1]

It is a figure which shows the structure of the digital evidence camera system which concerns on 1st Embodiment of this invention.

[Figure 2]

It is a figure which shows the procedure until MAC is added to image data.

[Fig. 3]

It is a figure which shows the structure of the digital evidence camera which concerns on 2nd Embodiment of this invention.

[Fig. 4]

It is a figure which shows the structure of the digital evidence camera system which concerns on 3rd Embodiment of this invention.

[Fig. 5]

It is a figure which shows the procedure until the personal authentication data and MAC are added to the image data.

[Fig. 6]

It is a figure which shows the structure of the digital evidence camera system which concerns on 4th Embodiment of this invention.

[Fig. 7]

It is a figure which shows the procedure until MAC1 and MAC2 are added to the image data.

[Fig. 8]

It is a figure which shows the structure of the image server system which concerns on 5th Embodiment of this invention.

[Fig. 9]

It is a flowchart for demonstrating operation of 5th Embodiment.

[Fig. 10]

It is a figure which shows the structure of the image server system which concerns on 6th Embodiment of this invention.

[Fig. 11]

It is a figure which shows the configuration example of the image server system of 5th Embodiment.

[Fig. 12]

It is a figure which shows the configuration example of the image server system of 6th Embodiment.

[Fig. 13]

It is a figure which shows the structure of the decryption key acquisition / registration system which concerns on 7th Embodiment of this invention.

[Fig. 14]

It is a figure which shows the structure of the digital evidence camera system which concerns on 8th Embodiment of this invention.

[Fig. 15]

It is a figure which shows the structure of the digital evidence camera system which concerns on 9th Embodiment of this invention.

[Fig. 16]

It is a figure for demonstrating the image data file which concerns on 8th Embodiment.

[Fig. 17]

It is a figure for demonstrating the image data file which concerns on 9th Embodiment.

[Explanation of symbols]

1 ... Imaging lens, 2 ... Image sensor, 3 ... Amplifier, 4 ... A / D converter, 5 ... Signal processing unit, 6 ... image memory, 7 ... Image display, 8 ... File format converter, 9 ... MD Creation Department, 10 ... private key memory, 11 ... MAC Creator, 12 ... Header recording section, 13 ... Filing Management Department, 14 ... Communication control unit, 15 ... Storage medium control unit, 16 ... communication line, 17 ... storage medium, 18 ... Storage medium control unit, 19 ... Filing Management Department, 20 ... Public key memory, 21 ... Decryptor, 22 ... MD Creation Department, 23 ... Comparison match part, 24 ... Communication control unit, 25 ... communication line, 50-1 ... Camera part, 60 ... Imaging means, 100 ... Digital Evidence Camera, 101 ... Falsification inspection device.