JP2008294805A - Monitoring camera terminal, control method thereof, control program thereof, computer readable recording medium bearing recorded program, monitoring camera terminal managing device, and monitoring camera system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a monitoring camera that can be installed at an arbitrary place, protecting a photographed image against damage while an outsider is difficult to confirm the photographed image. <P>SOLUTION: The monitoring camera terminal comprises an encrypting part 12 which encrypts a photographed image using a terminal-specific encryption key, an image data storing part 15 which stores the image data encrypted by the encrypting part 12, and a wireless communication control part 16 for communication with other monitoring camera terminal by radio. The wireless communication control part 16 transmits the image data encrypted by the encrypting part 12 to other monitoring camera terminal, and receives the image data photographed and encrypted by other monitoring camera terminal. The image data storing part 15 further stores the encrypted image data which the wireless communication control part 16 receives from other monitoring camera terminal. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a surveillance camera network, and more particularly to a surveillance camera system that constructs a surveillance camera network wirelessly and stores images captured by the surveillance camera in an encrypted state in a plurality of devices.

  Conventionally, parking lots that can park a plurality of automobiles have been installed in various facilities such as a residential area, an apartment, an office area, a downtown area, and a shopping center. In recent years, theft of cars parked in such parking lots, parts of cars, and valuables in cars has frequently occurred. Along with the frequent theft, surveillance cameras that install a camera in a parking lot and monitor the parking lot are widely used. There is also a surveillance camera system in which a plurality of surveillance cameras are installed and connected to each other via a network.

  However, if a suspicious person destroys the surveillance camera or disconnects the network of the surveillance camera, there is a possibility that the image taken by the surveillance camera cannot be confirmed.

  With respect to the above problems, in Patent Document 1, a network is constructed with a plurality of monitoring cameras, and when an abnormality occurs, a moving image or a still image before and after the occurrence of an abnormality is photographed with a neighboring monitoring camera, via an external network Techniques for communicating captured images to a server terminal are disclosed.

  Patent Document 2 discloses a technique for transmitting image data of a plurality of surveillance cameras to a parking lot computer device by wireless communication without using a public line.

Patent Document 3 discloses a technique in which a monitoring camera is mounted on a vehicle and an image taken by a computer mounted on the vehicle is transmitted by wire.
JP 2007-72644 A (publication date: March 22, 2007) JP 2006-295366 A (publication date: October 26, 2006) JP 2005-170258 A (publication date: June 30, 2005)

  However, the configurations of Patent Documents 1, 2, and 3 cause the following problems. That is, in the invention described in Patent Document 1, since the captured image is transmitted to the server terminal, it is possible to confirm the captured image when the server terminal is destroyed or the communication line with the server terminal is broken or malfunctions. Can not. Further, in the invention described in Patent Document 2, since the parking lot computer device and the monitoring camera communicate with each other by wireless communication, the monitoring camera can be installed only in a range where the parking lot computer device can communicate. Also, if the parking lot computer device is destroyed, the photographed image cannot be confirmed. Furthermore, in the invention described in Patent Document 3, since communication is performed by wire, the installation location of the monitoring camera is limited, and communication cannot be performed if the cable is disconnected. Similarly to Patent Documents 1 and 2, if the terminal storing the image data is destroyed, the photographed image cannot be confirmed.

  In addition, there is no description about preventing the possibility that a photographed image is confirmed by an outsider.

  The present invention has been made in view of the above-described problems, and its purpose is to install a surveillance camera in an arbitrary place, making it difficult to destroy a captured image, and capturing the captured image as an outsider. It is to realize a surveillance camera terminal or the like that is difficult to confirm.

  In order to solve the above-described problems, a surveillance camera terminal according to the present invention includes an encryption unit that encrypts a captured image with a terminal-specific encryption key, and an image that stores image data encrypted by the encryption unit. A data storage unit and wireless communication means for performing wireless communication with another monitoring camera terminal, wherein the wireless communication means transmits the image data encrypted by the encryption means to the other monitoring camera terminal. The image data captured and encrypted by another monitoring camera terminal is received, and the image data storage unit further stores the encrypted image data received by the wireless communication unit from the other monitoring camera terminal. It is characterized by doing.

  In addition, in order to solve the above-described problem, a monitoring camera terminal control method according to the present invention stores image data encrypted by its own terminal and image data received from another monitoring camera terminal. A method for controlling a surveillance camera terminal comprising a storage unit, comprising: an encryption step for encrypting a captured image with an encryption key unique to the terminal; and a wireless communication step for performing wireless communication with other surveillance camera terminals, In the wireless communication step, the image data encrypted in the encryption step is transmitted to another monitoring camera terminal, and the image data captured and encrypted in the other monitoring camera terminal is received. Yes.

  According to the configuration and method described above, an image captured by the monitoring camera terminal is encrypted with the terminal-specific encryption key, and the encrypted image data is stored in the image data storage unit. At the same time, the encrypted image data is transmitted to another surveillance camera terminal. And the image image | photographed with the surveillance camera terminal is memorize | stored in the image data storage part of an own terminal and another surveillance camera terminal in the encrypted state. As a result, even if the surveillance camera terminal that captured the image is destroyed, the image data of the captured image is also transmitted to other surveillance camera terminals, so all the surveillance camera terminals to which the image data is transmitted are destroyed. Otherwise, the captured image cannot be destroyed. In other words, it is possible to prevent the photographed image from being destroyed. In addition, since encryption is performed using a terminal-specific encryption key, it is possible to prevent an image captured by the own terminal from being confirmed by another monitoring camera terminal.

  In the surveillance camera terminal according to the present invention, the encryption means encrypts the image by calculating an XOR (exclusive OR) between the image data of the photographed image and the character string as the encryption key unique to the terminal. It may be one that performs.

  According to the above configuration, the image data can be encrypted. In particular, by making a character string for calculating XOR with image data a random bit string, encryption that is difficult to decipher can be performed.

  In the surveillance camera terminal according to the present invention, the character string as the terminal-specific encryption key is preferably a character string longer than the file size of the captured image data.

  According to the above configuration, since the character string as the encryption key is longer than the file size of the image data, it is difficult to guess the character string as the encryption key. In particular, even if a plurality of image data are used, it is difficult to obtain a character string as an encryption key. Therefore, it becomes difficult to decrypt without using a character string as an encryption key, and more secure encryption can be performed.

  In the surveillance camera terminal according to the present invention, the wireless communication performed by the wireless communication unit with other surveillance camera terminals may be performed by an ad hoc method in which the terminals communicate directly with each other without using an access point. preferable.

  According to the above configuration, the monitoring camera terminals can directly communicate with each other. As a result, it is not possible to set up an access point and only install a surveillance camera terminal within the communicable range, and install a surveillance camera terminal in an arbitrary place within a range where the surveillance camera terminals can communicate with each other. can do.

  In the surveillance camera terminal according to the present invention, the wireless communication performed by the wireless communication unit with other surveillance camera terminals is a multi-hop method in which the surveillance camera terminals performing wireless communication communicate with each other by a bucket relay method. It is preferable.

  According to said structure, it becomes possible to transmit data via the monitoring camera terminal which can communicate mutually also to the monitoring camera terminal which cannot communicate directly. That is, it is possible to transmit the image data captured by the monitoring camera terminal to the monitoring camera terminal that cannot directly communicate the encrypted image data.

  The surveillance camera terminal according to the present invention may be in-vehicle. By being able to be mounted on a vehicle, it is possible to store an image taken from inside the vehicle and transmit it to another surveillance camera terminal.

  In order to solve the above-described problems, a monitoring camera terminal management device according to the present invention is independent of a network constructed by a plurality of monitoring camera terminals described above performing wireless communication with each other, and each of the plurality of monitoring camera terminals includes And a management device encryption key storage unit that stores the encryption key.

  According to said structure, the monitoring camera management apparatus independent from the network which a monitoring camera terminal construct | stores has memorize | stored the terminal specific encryption key which each monitoring camera terminal has. As a result, even if the surveillance camera terminal that captured the image is destroyed and the encrypted image data is stored only in the other surveillance camera terminal, the encryption key stored in the surveillance camera terminal management device Thus, the image data can be decoded and the image can be confirmed.

  In order to solve the above-described problems, a surveillance camera system according to the present invention includes the surveillance camera terminal described above and the management device described above.

  According to said structure, the image data of the image which the monitoring camera terminal image | photographed is transmitted not only to its own terminal but to other monitoring camera terminals. Thereby, the image captured by the monitoring camera terminal is stored in an encrypted state not only in the terminal itself but also in other monitoring camera terminals. Therefore, even if the own terminal is destroyed, the image data is stored in another monitoring camera terminal, so that the captured image can be prevented from being destroyed. Further, since the image data is encrypted with the terminal-specific encryption key, the image cannot be confirmed without the encryption key. Further, since communication can be performed by wireless communication with each other, the monitoring camera terminal can be installed at an arbitrary place within a range in which wireless communication can be performed with each other.

  In the surveillance camera system according to the present invention, wireless communication means for receiving encrypted image data from the above-described surveillance camera terminal and transmitting the received image data to another surveillance camera terminal; and the wireless communication means receives It may include a cameraless terminal provided with an image data storage unit for storing the image data.

  According to the above configuration, the monitoring camera system includes a cameraless terminal that does not include a camera and that only transmits and receives and stores image data. Further, it is possible to further prevent the destruction of the image data by installing the cameraless terminal in a place where a person generally does not enter.

  In other words, since the monitoring camera terminal needs to monitor the monitoring target, the monitoring camera terminal is installed in a place where it can be seen. Therefore, the possibility of being destroyed by a suspicious person is high. On the other hand, if the cameraless terminal is installed in a place where it cannot be seen, for example, in a wall, etc., even if the surveillance camera terminal is destroyed, it is unlikely that the cameraless terminal will be destroyed, preventing image data from being destroyed. it can.

  The surveillance camera terminal may be realized by a computer and a camera. In this case, the surveillance camera terminal is controlled by causing the computer to operate the surveillance camera terminal by operating the computer as the respective means. A program and a computer-readable recording medium on which the program is recorded also fall within the scope of the present invention.

  As described above, the surveillance camera terminal according to the present invention includes an encryption unit that encrypts a captured image using a terminal-specific encryption key, and an image data storage unit that stores image data encrypted by the encryption unit. And wireless communication means for performing wireless communication with other surveillance camera terminals, wherein the wireless communication means transmits the image data encrypted by the encryption means to the other surveillance camera terminals, and other The image data captured by the surveillance camera terminal and encrypted is received, and the image data storage unit further stores the encrypted image data received from the other surveillance camera terminal by the wireless communication means. is there.

  The surveillance camera terminal control method according to the present invention is a surveillance camera terminal comprising an image data storage unit for storing image data encrypted by the own terminal and encrypted image data received from another surveillance camera terminal. A control method, comprising: an encryption step for encrypting a captured image with a terminal-specific encryption key; and a wireless communication step for wirelessly communicating with another surveillance camera terminal. In this method, the image data encrypted by the conversion step is transmitted to another monitoring camera terminal, and the image data shot and encrypted by the other monitoring camera terminal is received.

  Thereby, it is possible to prevent the captured image from being destroyed, and it is possible to prevent the image captured by the own terminal from being confirmed by another monitoring camera terminal.

  The surveillance camera terminal management device according to the present invention is independent of a network constructed by a plurality of the surveillance camera terminals described above performing wireless communication with each other, and stores encryption keys respectively possessed by the plurality of surveillance camera terminals. The management device encryption key storage unit is provided.

  As a result, even if the surveillance camera terminal that captured the image is destroyed and the encrypted image data is stored only in the other surveillance camera terminal, the encryption key stored in the surveillance camera terminal management device Thus, the image data can be decoded and the image can be confirmed.

  Moreover, the surveillance camera system according to the present invention is configured by the surveillance camera terminal described above and the management device described above.

  As a result, even if the own terminal is destroyed, the image data is stored in another surveillance camera terminal, so that the captured image can be prevented from being destroyed. Further, since the image data is encrypted with the terminal-specific encryption key, the image cannot be confirmed without the encryption key. Further, since communication can be performed by wireless communication with each other, the monitoring camera terminal can be installed at an arbitrary place within a range in which wireless communication can be performed with each other.

  One embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a block diagram of surveillance camera terminal 10 according to the present embodiment. As shown in FIG. 1, the monitoring camera terminal 10 includes a camera unit 11, an encryption unit (encryption unit) 12, a storage unit 13, a terminal encryption key storage unit 14, an image data storage unit 15, a wireless communication control unit (wireless). Communication means) 16 and an antenna 17. FIG. 2 is a block diagram of the cameraless terminal 20 according to the present embodiment. As shown in FIG. 2, the cameraless terminal 20 includes an image data storage unit 15, a wireless communication control unit 16, and an antenna 17. And FIG. 3 is a figure which shows the structure of the surveillance camera system 30 which concerns on this Embodiment. As shown in FIG. 3, the surveillance camera system 30 includes a plurality of surveillance camera terminals 10, a plurality of cameraless terminals 20, a management device encryption key storage unit 32, an encryption key creation unit 33, and an encryption key assignment unit 34. It is comprised with the surveillance camera terminal management apparatus 31. FIG. In the surveillance camera system 30, the plurality of surveillance camera terminals 10 and the plurality of cameraless terminals 20 can communicate with each other by wireless communication, and can transmit and receive image data.

  First, the surveillance camera terminal 10 will be described. The camera unit 11 includes an optical system and an imaging device, converts an optical image that has passed through the optical system into an electrical signal by the imaging device, and transmits the electrical signal to the encryption unit 12 as image data.

  The encryption unit 12 encrypts the received image data and causes the image data storage unit 15 to store the encrypted image data. The encryption is performed as follows.

  That is, a terminal-specific encryption key is stored in the terminal encryption key storage unit 14. Here, the encryption key is a random character string with a random number longer than the file size of the image data. Then, the encryption unit 12 performs encryption by calculating XOR between the received image data and a random character string that is an encryption key.

  Thus, it is difficult to decrypt the calculated result data, that is, the encrypted image data. This is because the random character string, which is the encryption key, is longer than the file size of the image data, so it is difficult to estimate using a plurality of image data. In addition, it is difficult for a holder of another terminal to which image data is transmitted from the monitoring camera terminal 10 to decode the image data of the own terminal. Furthermore, it is difficult to calculate the encryption key even if a plurality of different image data of the same terminal is used. In wireless communication, there is a risk of eavesdropping, but it can be said that this encrypted image data is highly safe because it is difficult to decrypt even if it is eavesdropped.

  Further, the image data cannot be decrypted to the original information unless the same encryption key is used. Even if the terminal that captured the image is destroyed, the encryption key is also stored in the management device encryption key storage unit 32 of the surveillance camera terminal management device 31. Data can be decrypted.

  Note that once the image data before calculating the XOR is obtained, the encryption key can be known, and the subsequent encryption is meaningless. However, in order to obtain image data before calculating the XOR of a certain terminal, there is only a method of photographing from the same point as the terminal or entering the terminal. In this case, image data of a person who performs the work is transmitted to another terminal by transmitting image data described later. Therefore, unless all terminals are destroyed, the image data of the person who performed the work remains somewhere. Thus, the present embodiment also has a physical security effect.

  The storage unit 13 is a storage unit including a terminal encryption key storage unit 14 and an image data storage unit 15. The terminal encryption key storage unit 14 stores an encryption key used when the encryption unit 12 performs encryption. The image data storage unit 15 stores the image data encrypted by the encryption unit 12 and the image data received and encrypted by the other surveillance camera terminal received via the wireless communication control unit 16 and the antenna 17. I remember it. A specific example of the storage unit 13 is a flash memory.

  The wireless communication control unit 16 transmits the image data encrypted by the encryption unit 12 to the other monitoring camera terminal 10 or the cameraless terminal 20 via the antenna 17. Further, the encrypted image data transmitted from the other monitoring camera terminal 10 or the cameraless terminal 20 is received and stored in the image data storage unit 15. In addition, search, discovery, and determination of a transmission destination terminal that transmits image data are performed. Furthermore, depending on the communication method, the number of hops is confirmed, the number of hops is reduced, and image data is discarded.

  Here, wireless communication with the other monitoring camera terminal 10 or the camera-less terminal 20 will be described. Wireless communication between terminals may be performed by an ad hoc method and a multi-hop method. The ad hoc method is a wireless communication method in which terminals directly communicate with each other without using an access point. Thereby, if it connects with either terminal by radio | wireless communication, it can belong to the network constructed | assembled when terminals communicate by radio | wireless by a relay function. The multi-hop method refers to a method for communicating data using a bucket relay method. The hop count is the number of times data is relayed. For example, if the number of hops is 3, data is relayed from its own terminal to three terminals.

  Next, the cameraless terminal 20 will be described. The cameraless terminal 20 is obtained by removing the camera unit 11, the encryption unit 12, and the terminal encryption key storage unit 14 from the monitoring camera terminal 10. The image data storage unit 15, the wireless communication control unit 16, and the antenna 17 function in the same manner as the surveillance camera terminal 10. That is, the wireless communication control unit 16 receives encrypted image data from the other monitoring camera terminal 10 and stores it in the image data storage unit 15. In addition, the received encrypted image data is transmitted to another monitoring camera terminal 10.

  As described above, the monitoring camera system 30 includes the plurality of monitoring camera terminals 10, the plurality of cameraless terminals 20, and the monitoring camera terminal management device 31. The monitoring camera terminal management device 31 includes a management device encryption key storage unit 32.

  The management device encryption key storage unit 32 stores all encryption keys that the surveillance camera terminal 10 has. Thereby, even if the surveillance camera terminal 10 storing the encryption key is destroyed, the encrypted image data stored in the other surveillance camera terminal 10 or the cameraless terminal 20 can be decrypted.

  The encryption key creation unit 33 creates an encryption key for encryption by the monitoring camera terminal 10. The encryption key assignment unit 34 assigns the encryption key created by the encryption key creation unit 33 to each monitoring camera terminal 10 and stores the assigned encryption key in the terminal encryption key storage unit 14 of the monitoring camera terminal 10.

  Next, a flow from generation of an encryption key to image capture, storage, and transmission will be described with reference to FIG. FIG. 4 is a flowchart showing a flow from generation of an encryption key to image capture, storage, and transmission.

  First, the surveillance camera terminal management device 31 generates an encryption key for each surveillance camera terminal 10 (S401). As described above, this is a random character string using random numbers longer than the image data. Then, the monitoring camera terminal management device 31 stores the generated encryption key in the terminal encryption key storage unit 14 of each monitoring camera terminal 10 (S402). Next, the surveillance camera terminal management device 31 is removed from the wireless network constructed by the surveillance camera terminal 10 and the cameraless terminal 20 (S403).

  Then, the surveillance camera terminal 10 stores the encryption key in the terminal encryption key storage unit 14 (S404), and then performs photographing with the camera (S405). Next, the encryption unit 12 encrypts the image data of the captured image (S406). Then, the encrypted image data is stored in the image data storage unit 15 (S407).

  Next, the wireless communication control unit 16 searches for the monitoring camera terminal 10 or the cameraless terminal 20 that is the transmission destination for transmitting the encrypted image data (S408). When the destination terminal is found and determined, the encrypted image data is transmitted to the terminal (S409).

  Next, the flow of processing for transmitting image data to another terminal will be described with reference to FIG. FIG. 5 is a flowchart showing a flow of processing for transmitting image data to another terminal. Note that wireless communication between terminals is performed by a multi-hop method.

  First, the monitoring camera terminal 10 sets the number of communication hops (S501). Here, N is assumed. Then, the encryption unit 12 encrypts and stores the captured image (S502). Next, the wireless communication control unit 16 searches for the monitoring camera terminal 10 or the cameraless terminal 20 that is the transmission destination for transmitting the encrypted image data (S503). Depending on the routing algorithm, there may be a constant search. Then, the wireless communication control unit 16 determines a transmission destination terminal (S504). In this case, one terminal may be selected at random from the adjacent terminals in the routing table, or one hop broadcast may be transmitted and selected from the terminals that have returned.

  Next, the wireless communication control unit 16 transmits the image data with the remaining hop count N added to the selected terminal (S505). Then, if there is image data transmitted from the selected terminal, it is received and the number of remaining hops added to the image data is decreased by 1 (S506).

  Next, the wireless communication control unit 16 determines whether there is image data having a remaining hop count in the image data storage unit 15 (S507). If there is image data with the remaining hop count (YES in S507), the image data is transmitted to the selected terminal (S508). Then, returning to S506, if there is image data transmitted from the transmission destination terminal, it is received and the number of remaining hops is decreased by one.

  On the other hand, if there is no image data with the remaining hop count in the image data storage unit 15 (NO in S507), the process ends.

  If the image data received from another terminal is the same as the image data stored in the own terminal, the number of remaining hops of the received image data is set to 0 and the image data is discarded.

(Specific example when this embodiment is used)
Next, a specific example using the present embodiment will be described with reference to FIGS. FIG. 6 is a diagram illustrating a case where the car 61 is provided with the monitoring camera terminal 10 and the cameraless terminal 20 is provided in the parking lot wall in the parking lot. FIG. 7 shows an example of the surveillance camera terminal 10, where (a) is a surveillance camera terminal 10 provided with a camera in a personal computer, and (b) is a surveillance equipped with a camera in a PDA (Personal digital assistant). When the camera terminal 10 is used, (c) is a case where the microcomputer is provided with a camera and the surveillance camera terminal 10 is used.

  As shown in FIG. 6, the monitoring camera terminal 10 and the cameraless terminal 20 perform wireless communication with each other. The surveillance camera terminal 10 includes a central processing unit (CPU), a battery, a storage device, a wireless local area network (LAN) adapter, and a camera. Since the camera only needs to be controlled by the CPU, serial connection or USB (universal serial bus) connection is conceivable. Since it is only necessary to be able to communicate with other terminals through a wireless LAN, the CPU and OS (operating system) are not particularly limited. Wireless communication is established by a multi-hop method. There are two types of network protocols. One is a Reactive type that performs communication after requesting a route, and the other is a Proactive type that always exchanges route information. Here, it is possible to take a battery from the car, but considering the long-time operation, the reactive type that saves power is preferable.

  Reactive route setting includes AODV (the Ad-hoc On-Demand Distance Vector routing), DSR (the Dynamic Source Routing Protocol for Mobile Ad Hoc Networks), DYMO (Dynamic MANET On-demand Routing), etc. .

  The surveillance camera terminal 10 encrypts and stores an image captured by the camera, and transmits the encrypted image to another surveillance camera terminal 10 or the cameraless terminal 20.

  Here, in order to reduce the number of shots, a difference from the previous shooting may be taken, and the image may be stored only when the difference exceeds a threshold value.

  The encryption is performed using a random character string having a bit length longer than the image data that is the encryption key stored in each surveillance camera terminal 10. For the image data of the photographed image, an encryption key and XOR are calculated. Since the encryption key is unique to the terminal itself, the original image data cannot be confirmed on other terminals. The encryption key is stored in the monitoring camera terminal management device 31 together with the own terminal. Therefore, even if the terminal itself is broken or stolen, the image data can be decoded from the information stored in the monitoring camera terminal management device 31.

  8 is an image taken by the camera, FIG. 9 is an encryption key stored in each surveillance camera terminal 10, and FIG. 10 is image data obtained by encrypting the image data of FIG. 8 with the encryption key of FIG. . As shown in FIG. 10, the content of the image cannot be confirmed from the encrypted image data.

  The cameraless terminal 20 receives image data from the other surveillance camera terminal 10 and stores it in the image data storage unit 15.

  Moreover, the other terminal which transmits the image data which the monitoring camera terminal 10 image | photographed changes according to the parking condition of a car. If the number of communication hops is 1, information such as image data is exchanged with the terminal discovered by broadcasting. If multiple terminals are found, it communicates with one of them. When the number of communication hops is 2 or more, the number of hops is added to each image data, and the number of hops is decreased every time another terminal receives the image data. If the same image is received, the hop count is set to 0 and the image data is discarded. As a result, at least two terminals or more store the same image data.

  Further, during the time period when the monitoring camera terminal 10 is not shooting, packets are transmitted / received to / from other terminals. When another surveillance camera terminal 10 takes a picture and receives a broadcast notification, it sends a communication request to that terminal. And when a reply is received, the image data which the said terminal image | photographed is received and the number of hops is decreased. If image data with a hop count of 1 or more is stored, it is simultaneously transmitted to the partner terminal. The partner terminal also reduces the number of hops of the received image data and completes communication.

  With the above-described configuration, the image data of the captured image is stored in the own terminal and other terminals. By the way, the file size of one photograph is about 5 kB. When a 1 GB CF (compact flash) card or SD (secure digital) card is used as the external storage device, approximately 200,000 images can be stored. For example, when sharing image data of nine terminals, the upper limit is 20,000 images per terminal. Even if it is a place where people frequently go in and out, 10,000 images per day are sufficient, so even if the image data of nine terminals is shared, it is possible to store image data for two full days or more. . This is a sufficient storage capacity as a security function.

  In recent years, storage media of 2 GB or more have become cheap, and a CF card type HDD (hard disk drive) can easily obtain a 6 GB HDD or the like, so that the storage capacity is sufficient.

  In the present embodiment, the image data of each terminal is transmitted to another terminal. Thereby, even if the terminal is destroyed or stolen, the administrator can acquire image data by using the encryption key stored in the monitoring camera terminal management device 31. It is possible to specify how many terminals share the same image data by specifying the number of multi-hops. However, in the transmission / reception of image data, when image data received in the past by a certain terminal is received again, even if the number of hops remains, the number of hops is set to 0 and is not transmitted to other terminals. This is because the case where there is no hop destination even though the number of hops remains is taken into consideration. When the surveillance camera terminal 10 that has captured an image belongs to a network constructed by wireless communication between terminals, the same image data is stored by at least two terminals.

  In addition, this embodiment has the following security effects. That is, when a certain terminal is destroyed, the terminal takes a video of the criminal until just before the destruction. Conventionally, the image data is lost at the stage of destruction. However, in this embodiment, since image data is transmitted to another terminal, the administrator obtains image data that the criminal is considered to be photographed from the image data stored in the other terminal. Can do. In order to erase the trace of the crime, it is necessary to destroy other terminals as well. However, since the other terminal similarly transmits image data to the other terminal, the trace of the crime cannot be erased unless all the terminals existing on the network are destroyed.

  However, in this embodiment, there is a cameraless terminal 20. Since the cameraless terminal 20 does not need to be monitored, it can be installed in a place where it cannot be seen from the surroundings. For example, it can be installed semi-permanently by being installed in a wall, connected to a network with a wired cable, storing image data in a storage area on a remote server, and continuing to supply power. As long as such terminals exist, it is difficult for the criminal to destroy all terminals. Therefore, the administrator can always know the act of destroying a certain terminal. This has a great security effect that is very useful for finding criminals.

  Finally, in a conventional surveillance camera system using a network, there is a surveillance server that aggregates captured images. Therefore, if the monitoring server itself is destroyed or the network to the monitoring server is destroyed, there is a risk that the system becomes invalid. In addition, the monitoring camera needs to be directly connected to the network connected to the monitoring server by wire or wireless, and there is a restriction on the installation location.

  On the other hand, in the embodiment of the present invention, since each terminal transmits and receives information such as image data, it is not necessary that a certain terminal and all other terminals can communicate directly. If communication with any terminal is possible, data such as image data can be shared with all terminals by transmitting / receiving data, that is, relaying data. In addition, each terminal can be installed in an automobile, and the phase of a network constructed by each terminal performing wireless communication changes as the automobile enters and exits. Therefore, by using an ad hoc routing protocol, it is possible to cope with a change in phase and communicate with a remote terminal in multihop. And it is possible to move the installation place of the surveillance camera in a fluid manner. Further, since the images are shared between terminals, a computer device for centralized management is unnecessary. A terminal that does not have a camera can be hidden. Furthermore, even if the terminal, which is a recording medium, is stolen, images taken with other surveillance cameras cannot be viewed because they are encrypted.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims. That is, embodiments obtained by combining technical means appropriately changed within the scope of the claims are also included in the technical scope of the present invention.

  Finally, each block of the monitoring camera terminal 10 and the cameraless terminal 20, in particular, the encryption unit 12 and the wireless communication control unit 16 may be configured by hardware logic, or by software using a CPU as follows. It may be realized.

  In other words, the monitoring camera terminal 10 and the cameraless terminal 20 are configured such that a CPU that executes instructions of a control program that realizes each function, a ROM (read only memory) that stores the program, and a RAM (random access memory) that expands the program. And a storage device (recording medium) such as a memory for storing the program and various data. The object of the present invention is to enable the computer to read the program codes (execution format program, intermediate code program, source program) of the control program for the monitoring camera terminal 10 and the cameraless terminal 20 which are software for realizing the functions described above. The recorded recording medium is supplied to the monitoring camera terminal 10 and the cameraless terminal 20, and the computer (or CPU or MPU (microprocessor unit)) reads and executes the program code recorded on the recording medium. Achievable.

  Examples of the recording medium include a tape system such as a magnetic tape and a cassette tape, a magnetic disk such as a floppy (registered trademark) disk / hard disk, a CD-ROM (compact disc read-only memory) / MO (magneto-optical) / Disc systems including optical disks such as MD (Mini Disc) / DVD (digital video disk) / CD-R (CD Recordable), card systems such as IC cards (including memory cards) / optical cards, or mask ROM / EPROM ( An erasable programmable read-only memory) / EEPROM (electrically erasable and programmable read-only memory) / semiconductor memory system such as a flash ROM can be used.

  Further, the surveillance camera terminal 10 and the cameraless terminal 20 may be configured to be connectable to a communication network, and the program code may be supplied via the communication network. The communication network is not particularly limited. For example, the Internet, intranet, extranet, LAN, ISDN (integrated services digital network), VAN (value-added network), CATV (community antenna television) communication network, virtual private network (Virtual private network), telephone network, mobile communication network, satellite communication network, etc. can be used. In addition, the transmission medium constituting the communication network is not particularly limited. For example, IEEE (institute of electrical and electronic engineers) 1394, USB, power line carrier, cable TV line, telephone line, ADSL (asynchronous digital subscriber loop) line Wireless such as IrDA (infrared data association) and remote control such as remote control, Bluetooth (registered trademark), 802.11 wireless, HDR (high data rate), mobile phone network, satellite line, terrestrial digital network, etc. But it is available. The present invention can also be realized in the form of a computer data signal embedded in a carrier wave in which the program code is embodied by electronic transmission.

  Surveillance cameras can be installed in any location, and it is difficult to destroy captured images, and it is difficult for outsiders to check the captured images. The present invention can be applied to a camera, for example, a surveillance camera in a parking lot where an unspecified number of cars are parked.

1, showing an embodiment of the present invention, is a block diagram illustrating a main configuration of a surveillance camera terminal. FIG. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1, showing an embodiment of the present invention, is a block diagram illustrating a main configuration of a cameraless terminal. 1, showing an embodiment of the present invention, is a block diagram illustrating a main configuration of a surveillance camera system. FIG. It is a flowchart which shows the flow from the production | generation of an encryption key to imaging | photography of an image, a preservation | save, and transmission in the said embodiment. It is a flowchart which shows the flow of the process which transmits the image data to another terminal in the said embodiment. It is a figure which shows the specific example using the said this Embodiment. It is a figure which shows the example of the said monitoring camera terminal. It is a figure which shows the image image | photographed with the camera in the said embodiment. It is the figure which displayed the encryption key in the said embodiment. It is the figure which displayed the encrypted image data in the said embodiment.

Explanation of symbols

10 surveillance camera terminal 11 camera unit 12 encryption unit (encryption means)
DESCRIPTION OF SYMBOLS 13 Memory | storage part 14 Terminal encryption key memory | storage part 15 Image data memory | storage part 16 Wireless communication control part (wireless communication means)
17 Antenna 20 Terminal without Camera 30 Surveillance Camera System 31 Surveillance Camera Terminal Management Device 32 Management Device Encryption Key Storage Unit

Claims (12)

An encryption means for encrypting the captured image with a terminal-specific encryption key;
An image data storage unit for storing the image data encrypted by the encryption unit;
Wireless communication means for performing wireless communication with other surveillance camera terminals,
The wireless communication means transmits the image data encrypted by the encryption means to another monitoring camera terminal, receives the image data captured and encrypted by the other monitoring camera terminal,
The surveillance camera terminal, wherein the image data storage unit further stores encrypted image data received by the wireless communication unit from another surveillance camera terminal.   The surveillance camera terminal according to claim 1, wherein the encryption means performs encryption by calculating an XOR between image data of a photographed image and a character string as an encryption key unique to the terminal.   The surveillance camera terminal according to claim 2, wherein the character string as an encryption key unique to the terminal is a character string longer than a file size of photographed image data. Wireless communication performed by the wireless communication means with other surveillance camera terminals is as follows:
The surveillance camera terminal according to claim 1, wherein the surveillance camera terminal performs an ad hoc system, which is a system in which terminals directly communicate with each other without using an access point. The wireless communication performed by the wireless communication means with other surveillance camera terminals is further
The surveillance camera terminal according to claim 4, wherein the surveillance camera terminals that perform wireless communication are multi-hop systems that communicate data by a bucket relay system.   The surveillance camera terminal according to any one of claims 1 to 5, wherein the surveillance camera terminal can be mounted on a vehicle. A monitoring camera terminal control method comprising an image data storage unit for storing image data encrypted by the terminal itself and encrypted image data received from another monitoring camera terminal,
An encryption step for encrypting the captured image with a terminal-specific encryption key;
Including a wireless communication step of performing wireless communication with other surveillance camera terminals,
In the wireless communication step, the image data encrypted in the encryption step is transmitted to another monitoring camera terminal, and the image data captured and encrypted in the other monitoring camera terminal is received. To control the surveillance camera terminal.   A surveillance camera terminal control program for operating the surveillance camera terminal according to any one of claims 1 to 6, wherein the surveillance camera terminal control program causes a computer to function as each of the above means.   A computer-readable recording medium on which the surveillance camera terminal control program according to claim 8 is recorded.   A plurality of surveillance camera terminals according to any one of claims 1 to 6, independent of a network constructed by performing wireless communication with each other, storing encryption keys respectively possessed by the plurality of surveillance camera terminals. A monitoring camera terminal management device comprising a management device encryption key storage unit.   A surveillance camera system comprising the plurality of surveillance camera terminals according to any one of claims 1 to 6 and the management device according to claim 10. Wireless communication means for receiving encrypted image data from the surveillance camera terminal according to any one of claims 1 to 6 and transmitting the received image data to another surveillance camera terminal;
The surveillance camera system according to claim 11, further comprising a cameraless terminal including an image data storage unit that stores image data received by the wireless communication unit.