JP2012114556A - Camera system comprising multiple encryption function and managing method for the camera system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem associated with a crime prevention camera storing images in encryption for protecting privacy, the problem that the camera cannot support a mode of operation in which browsing of an image requires a consent of three parties or more for protecting the privacy as the proprietor of the camera cannot reproduce an image, requiring two parties to be able to browse the image, that is, first, the proprietor of the camera and second, a party having means for reproduction.SOLUTION: A camera includes plural encryption devices serially interconnected. Additionally to the proprietor of the camera, two parties required to give consent to browsing an image prepare respective encryption keys A (16) and B (17) so that captured images are sequentially encrypted by the respective keys. Browsing the images will only be enabled by the proprietor providing the image data, and provision of the keys A and B for decryption.

Description

  The present invention relates to a security camera, and more particularly to a security camera having a privacy protection function.

  Security cameras installed in public places are effective in preventing crimes before they happen, and are effective in identifying criminals after a crime has occurred. Infringement is a big problem.

  In order to solve this situation, a security camera equipped with an image encryption function has been developed. When this camera saves the captured image, it encrypts it and saves it. The person who can view the image has the means to decrypt the encrypted data, but the person who is trusted by the residents, for example, the police, and other persons including the residents do not have the means to decrypt them. On the other hand, as a person who has been trusted by the residents, assuming that the police are assumed here, the police cannot view the images without receiving the encrypted image data provided by the residents who have security cameras. Therefore, the privacy infringement problem is solved because images can be viewed only when both residents and the police recognize the necessity of image viewing, as in the case of a serious incident.

JP 2009-44311 A

JP 2010-118959 A

  However, the above mechanism works effectively when the user is the security camera owner or administrator. For example, when the government intends to introduce security cameras all over the crime-prone areas, the security cameras are managed by the government rather than the residents. Even if the security camera to be installed is equipped with an encryption function, images can be viewed without the consent of the residents if the government and the police agree in this way. Since the main actors whose privacy should be protected are residents, in this way, privacy protection cannot be achieved even if the security camera has an encryption function.

  In order to solve the above problems, the camera of the present invention includes an imaging device, a plurality of image encryption devices, and an image data recording device.

Images taken by the imaging device are sequentially input to multiple image encryption devices and encrypted. That is, the image is input to the first image encryption device, and the output is input to the second image encryption device, which is repeated by the number of image encryption devices. The output of the last image encryption device is stored in the image data recording device. Here, the key of each image encryption device is that each subject (police, government, local residents, etc.) that needs to agree to be able to view images can decrypt at least one level. And keys are set correspondingly.
If all subjects agree to view the image, such as when a crime occurs, you can decrypt all the encryption performed in the image shooting process by bringing the encryption key that they have. Can be viewed. On the other hand, if at least one subject does not agree to view, the corresponding encryption cannot be removed and the image cannot be viewed. This achieves the original purpose.

  With the camera of the present invention and its operation, it becomes possible to view the image only when the consent of all subjects related to the captured image is obtained, and this can be used to protect privacy, for example. However, the effectiveness of the security camera can be demonstrated.

It is an explanatory diagram of the simplest operation mode of the present invention. It is explanatory drawing at the time of using an RSA public key for image encryption. It is an explanatory diagram when the RSA public key is used for image encryption and the decryption means is provided inside the camera. It is explanatory drawing for demonstrating an example of encryption.

  FIG. 1 is an explanatory diagram of an embodiment in which the subject requiring agreement is the resident and the police, and the present invention is realized in the simplest form. When an image is photographed (11) by the imaging device of the camera, it is encrypted (12) (described as type A encryption) by the first image encryption device using the key (16) (described as key A) provided by the police. ). The output data is further encrypted (13) (described as type B encryption) by the second image encryption device using a key (15) (described as key B) provided by the residents, and the output is stored as an image data recording device. Is recorded (14). To view the image, the encrypted image data recorded is first decrypted (17) by the residents using the second encryption device, and then the first encryption is performed by the police. Since the type A encryption performed by the conversion device is released (18), the image (19) originally taken by the camera can be viewed.

  In the above embodiment, the encryption with the key A and the encryption with the key B are performed separately, but it is also possible to combine them and perform the encryption once as one encryption key. For example, the key A is 5 characters, the key B is 5 characters, and the 10 characters concatenated are encrypted as encryption keys. The image is decrypted by concatenating the key A provided by the police and the key B provided by the residents into one key. In this case, the decryption means may be owned by either the police or the residents, and may be owned by a third party other than the both.

  In the above example, the agreement between the residents and the police was considered, but in complex situations, for example, in addition to the residents and the police, it may be better to protect the privacy by requiring the consent of the three parties. is there. In such a case, after the first (type A) and second (type B) encryption, the third (type C) encryption is further performed, and the third encryption (type C) decryption means is provided. It only needs to be owned by the government. If the consent of more people is required, it is sufficient to apply such encryption to the number of people who need consent. In this case as well, as described in the description of encryption with two keys, the key itself may be divided into the required number and encryption may be performed with one key concatenated. In addition, although the protection of privacy is given here as the purpose of this encryption, the function that the image can be viewed only by the agreement of a plurality of persons of the present invention is also used for other purposes where it is necessary. can do.

  In the camera of the present invention described above, a CCD device or the like can be used as the imaging device, and the image encryption device can be realized by an embedded computer and a memory built in the camera. The image data recording device can be a semiconductor recording device such as a hard disk or SD card. Image decoding means can be realized by software running on a personal computer.

  What should be noted in the embodiment shown in FIG. 1 is management of keys for encryption / decryption. Each subject, such as a resident or the police, must not know the key it manages to other subjects. However, in order to encrypt in the camera, the key information must be set and held in the camera, and the key information is easily leaked in the process.

  The embodiment shown in FIG. 2 solves the above-mentioned problem by separating the key into a public key for encryption and a secret key for decryption by using RSA encryption as the encryption method. A private key and a public key are generated for each resident and police.

  In FIG. 2, the resident generates (21) a public key B (24) for encryption and a secret key B (25) for decryption. Similarly, the police generate (22) the public key A (23) and the secret key A (26). The residents and the police each set a public key for image encryption on the camera, but since this is a public key, the image cannot be decrypted even if it is known to other actors. On the other hand, the private key for decryption is managed so that neither the police nor the residents know about it. To restore the image, the residents first decrypt (17) the image data stored in the camera with their private key B (25), and give it to the police. The police similarly decrypts (18) with its own private key (26) and makes it possible to view the image.

  Now, in the camera and operation mode shown in Fig. 2, both residents and police must have a means of decoding image data. One concrete example of this can be realized by a PC and a program running on it. However, the function can be built into the camera more simply. Such an embodiment is shown in FIG.

  The process from image capture to storage is the same as in the embodiment of FIG. 2, but the image is decrypted so that the resident carries the secret key B (25) and the police carry the secret key A (26) and is not known to other subjects. Set to the camera. The type B decryption (31) is executed in the camera by the key brought by the residents, and the type A decryption (32) is executed by the police in the camera, and the image (19) can be browsed. Of course, in this case, when the necessary decryption is completed, the private key information in the camera is discarded.

  In FIGS. 2 and 3, an example has been described in which the subject of the agreement is assumed to be the residents and the police. Of course, the present invention may be applied other than this, and by connecting as many encryption devices as necessary in series. , It can be easily realized even if there are more than three entities that need consent.

Also, in the above embodiment, when the encryption strength is not required to be realized by a public key / private key encryption method such as RSA encryption, the public key is replaced with the encryption key and the private key is replaced with the decryption key. That's fine. In this way, even if the encryption key is known, it cannot be decrypted immediately, so that a certain level of encryption strength is secured, and the encryption and decryption processes do not require a large amount of computation.

Fig. 4 shows an example in which a mosaic image of the original image can be obtained from the image file after the first encryption without any special additional information in the two-stage encryption. This example shows an image encryption method that divides an image into sections that are rougher than the pixels and replaces the pixels in the sections based on the encryption key according to the viewing rights holder. Figure 4 illustrates the case where there are two viewing rights holders. The captured image is divided into 10x10 pixel units, and each element of RGB of 100 pixels, a total of 300 values, is replaced based on the key Kb. In addition, each RGB element of the entire image is replaced based on the key Ka. This result is encrypted to save data. The viewing rights holder has a decryption key, one viewing rights holder has the key Ka, and the other viewing rights holder has both the keys Ka and Kb.

When browsing the image, the viewing right person inputs the decryption key and the key that he / she owns into the image browsing device, and after the image browsing device decrypts the image with the decryption key, based on the input key, Undo the replacement of the image components and display the image. If the only key entered is Ka, the replacement inside each 10x10 image cannot be undone, so the image with the components of each 10x10 image still replaced is displayed. When the input keys are Ka and Kb, it is possible to undo the replacement in each 10x10 image, so the captured image is displayed as it is.

If the only key entered is Ka, the resulting image is averaged (mosaiced) to 10x10 pixels to make the image easy to see. This averaged image matches the original image with 10x10 pixels averaged (mosaiced). This is because each 10x10 pixel has only been replaced, and its average value does not change.

In this example, the replacement encryption is only one stage. For example, the first stage is 3 × 3 pixels, the second stage is 6 × 6 pixels, the third stage is 12 × 12 pixels, and the encryption key is 4 By using four levels of encryption, you can set the strength of viewing rights in four ways. In other words, the image having only the key Ka can be obtained by performing the averaging operation of 12 × 12 pixels to obtain the same mosaiced image when the same averaging operation is performed on the current image. Similarly, a person with key Ka and key Kb can obtain a 6 × 6 pixel mosaic image. A person with key Ka, key Kb, and key Kc can obtain a 3 × 3 pixel mosaic image. All the keys, keys Ka, key Kb, key Kc and key Kd can obtain the same image as the original image.

In the above example, the processing of the pixels in the category is a simple replacement, but various other methods can be considered. If you only want to store the average value of the luminance values of each RGB in the pixel, you can create an appropriate combination of numbers that adds up to zero for each pixel. In addition, the above replacement operation may be added.

The above process is also effective when the camera is used in an environment connected to the Internet. For example, by making a mechanism that automatically provides keys through the Internet according to the urgency and severity of criminal investigations by courts, etc., it becomes possible to conduct more rapid investigations.

The memory may be installed in a distributed or centralized location different from the camera, but in order to reduce the amount of data communication, it is preferable that each camera has a built-in memory. When sending necessary image files over the Internet, the efficiency of the entire system can be improved by sending only the necessary parts.

By making the format of the image file unique, playback can be performed only by dedicated software, and safety is further enhanced.

Claims (11)

A camera equipped with an imaging device, an image encryption device with multiple keys, and an image data recording device. 2. The camera according to claim 1, wherein an encryption method is employed in which a key used for encryption in an encryption device and a key required for decryption are not the same. 3. The camera according to claim 2, further comprising means capable of decrypting an image by temporarily inputting a key necessary for decryption from the outside. The camera according to claim 2, wherein a public key of a public key cryptosystem is used as a key used for encryption in an encryption device, and a secret key thereof is used as a key used for decryption. 4. The camera according to claim 3, wherein a public key of public key cryptography is used as a key used for encryption in an encryption device, and a secret key is used as a key used for decryption. 2. The camera according to claim 1, wherein each of a plurality of subjects who need to agree to view an image has a unique encryption key, and is configured to sequentially encrypt images using all of the keys. A camera operation method in which each subject has a means to decrypt with their own key when it becomes necessary. The camera according to claim 2, wherein each of a plurality of entities that need to agree to view an image has a unique encryption key, and is configured to sequentially encrypt images using all of the keys. A camera operation method in which each subject has a means to decrypt with their own key when it becomes necessary. 4. The camera according to claim 3, wherein each of a plurality of subjects who need to agree to view an image has a unique encryption key, and is configured to sequentially encrypt images using all of the keys. A camera operation method in which each subject browses an image by inputting a decryption key into the camera when it becomes necessary. The camera according to claim 4, wherein each of a plurality of entities that need to agree to view an image has a unique encryption key, and is configured to sequentially encrypt images using all of the keys. A camera operation method in which each subject has a means to decrypt with their own key when it becomes necessary. 6. The camera according to claim 5, wherein each of a plurality of entities that need to agree to view an image has a unique encryption key, and the images are sequentially encrypted using all of the keys. A camera operation method in which each subject browses an image by inputting a decryption key into the camera when it becomes necessary. The image is divided into sections rougher than the pixels, and processing based on the encryption key is applied to the pixels in each of the sections. 9 cameras.