JP4600810B2 - Monitoring system and authentication method in monitoring system - Google Patents

Description

  The present invention relates to a monitoring system, and in particular, when imaging a monitoring target and transmitting an image signal, the monitoring system for determining whether or not an image to be monitored should be originally monitored and authenticating the monitoring system It relates to the improvement of the method.

An image monitoring system in which an image captured by a camera is displayed on a monitor for monitoring or recorded by a VTR or a disk recorder is widely used. In such an image monitoring system, a photograph of the same image as the subject to be monitored is placed in front of the camera lens and the subject itself is replaced, or another subject that closely resembles the subject to be monitored by changing the position of the camera. There is a risk that the subject will be misrepresented, such as taking pictures and obscuring surveillance, and committing a crime during that time. Particularly in recent years, network monitoring systems that digitize and compress monitoring images captured by a network camera, transmit the images to a remote location using a network, and view and record the images have been used. There is a high risk that the camera will be fraudulently because the location where the camera is installed and the place where the image is viewed are separated.
A proposal using an identifier as shown in FIG. 8 has been made for such subject misrepresentation (see, for example, Patent Document 1 below).

According to Patent Document 1 below, a signal indicating a unique identifier (ID) is sent to a target object 102 as a subject, a non-removable wireless tag 101 is attached, and an imaging camera (simply referred to as a camera in FIG. 8). ) ID information is received from the wireless tag 101 received via the antenna 103a of the RF receiver 103 at the time of imaging by 104, ID information is decoded, information related to imaging from the imaging camera 104 and other information and ID Information is combined by a composite generator 105 to generate composite data, and this composite data is embedded in captured image data as a digital watermark and used for authentication.
JP 2000-261751 A (FIG. 1, paragraphs 0027 to 0031)

However, the method of Patent Document 1 does not authenticate the optical image itself reflected on the screen, but merely authenticates that the identifier is in the vicinity of the camera. Even if it is placed on the opposite side, this is authenticated as normal. As described above, the conventional method has a problem in that reliable authentication cannot be performed.
Accordingly, it is an object of the present invention to provide a monitoring system and an authentication method in the monitoring system that can reliably authenticate an authentic image without erroneously recognizing an image that is not authentic as an authentic image. .

  In order to achieve the above object, the present invention arranges a display device including a light emitting element that emits light based on a specific code in an image to be captured, images a light emission pattern of the light emitting element together with a monitoring target, and By determining whether or not the light emission pattern is based on a specific code, it is determined whether or not the image is a genuine image and is authenticated.

That is, according to the present invention, a display device that generates a lighting pattern corresponding to an authentication code composed of a plurality of bits by turning on or off a light emitting element ;
Imaging the pre Symbol display device with the monitored, and an imaging device for transmitting an image captured,
And a monitoring terminal which displays the images transmitted from the imaging device,
The monitoring terminal further includes
An image recognition means for identifying the lighting of the light emitting element from the image transmitted from the imaging device,
Encoding means for generating a code consisting of a plurality of bits based on lighting of the light emitting element identified by the image recognition means;
Authentication means for authenticating the code generated by the encoding means;
Comprising Ru monitoring system is provided.

According to the present invention, a lighting step for generating a lighting pattern corresponding to an authentication code consisting of a plurality of bits by turning on or off the light emitting element ;
Imaging the previous SL-emitting element with the monitored, and an imaging step of transmitting the image captured,
An image recognition step of identifying the lighting of the light emitting element from the captured the image by the image pickup step,
A coding step for generating a code consisting of a plurality of bits based on lighting of the light emitting element identified in the image recognition step ;
An authentication step of authenticating the code generated in the encoding step;
Authentication method in monitoring system that Yusuke is provided.

  In the monitoring system and the authentication method in the monitoring system of the present invention, a display device including a light emitting element that emits light based on a specific code is arranged in an image to be captured, and a light emission pattern of the light emitting element is imaged together with a monitoring target. Since it is determined whether or not the light emission pattern is based on a specific code, it can be authenticated by determining whether or not the monitored object is a genuine image.

  Hereinafter, a monitoring system and an authentication method in the monitoring system of the present invention will be described with reference to the accompanying drawings. 1 is a system configuration diagram of a network monitoring system showing an embodiment of the monitoring system of the present invention, FIG. 2 is an external view of a security box used as a display device in FIG. 1, and FIG. 3 is a security box in FIG. 4 is an example of a captured image of the camera in FIG. 1, FIG. 5 is a block diagram showing the configuration of the monitoring terminal in FIG. 1, and FIG. 6 shows the operation of the security box in FIG. FIG. 7 is a flowchart showing authentication in the monitoring system shown in FIG. In FIG. 1, the network camera 12 is arranged to image a subject (monitoring target) (not shown). The security box 11 is disposed within the imaging range of the network camera 12. An output signal from the network camera 12 is transmitted to the monitoring terminal 14 via the network 13.

  In the block diagram of the security box 11 in FIG. 3, the security box 11 has a time acquisition unit 31, an authentication code generation unit 32, an output unit 33, and display units 21, 22, 23, 24, and 25. In FIG. 4, the display units 21, 22, 23, 24, and 25 of the security box 11 are lighting areas 41, 42, 43, 44, and 45 captured by the network camera 12 shown in FIG. The monitoring terminal 14 illustrated in FIG. 5 includes a network interface 51, an image decompression unit 52, an image output unit 53, an image recognition unit 54, a time acquisition unit 55, and an authentication unit 56. As shown in FIG. 2, the security box 11 includes display units 21 to 25 made up of LEDs and the like. In this embodiment, five LEDs are provided.

  The time acquisition unit 31 of the security box 11 acquires the current time using a radio clock. For example, assume that the current time is 10:30 am on August 1, 2004 (step S1 in FIG. 6). Then, the authentication code generation unit 32 of the security box 11 generates an authentication code based on the current time (200408011030) acquired by the time acquisition unit 31 (step S2). For example, an authentication code is generated using a public key encryption key such as RSA or a common key encryption key such as DES. Assume that the generated authentication code is 10011101010111100101 with 20 bits. Then, the output unit 33 first divides the authentication code into 5 bits such as 10011, 10101, 01111, and 00101. Then, according to the first 5 bits, 5 LEDs are lit for a predetermined time, for example, 1 second. Since the first 5 bits are 10011, LED21 is on, LED22 is off, LED23 is off, LED24 is on, and LED25 is on (step S3).

  Then, after one second has elapsed, the LEDs 21 to 25 are turned on according to the second 5 bits 10101 (step S4). Then, after one second has passed, the LEDs 21 to 25 are turned on according to the third 5 bits 01111 (step S5). After one second has passed, the LEDs 21 to 25 are turned on according to the fourth 5-bit 00101 (step S6). In this way, the LEDs are sequentially turned on. When all the 20 bits have been turned on after the fourth lighting has passed for 1 second, all the LEDs are turned off for 1 second thereafter (step S7). If this one-second turn-off is identified, a 20-bit turn-off can be made. When the lighting for one second ends, the process returns to step S1 to acquire the current time again, generate a code based on the current time, and turn on the LED. In this way, the LED is turned on repeatedly. Note that the predetermined time of 1 second in the present embodiment needs to be longer than the frame rate of the video of the camera (the number of frames of the image per second), so it is preferable that it can be set for each system.

  Also, depending on the authentication code generation method, if the light emission pattern is completely extinguished (00000 when divided into 5 bits), it may be mistaken for reset, so the reset extinction time is longer than the display of the light emission pattern, etc. It is preferable to perform a prohibition process so that all the lights are not turned off (00000 in a state of being divided into 5 bits) when the setting is made or when the authentication code is generated.

  Such a security box 11 is placed in the imaging area of the network camera 12 in advance for monitoring. Then, an image once taken by the network camera 12 as shown in FIG. 4 is sent to the monitoring terminal 14 through the network 13. The monitoring terminal 14 sets the areas 41 to 45 using a mouse or the like where the five LEDs of the security box 11 are located by looking at the sent image.

When monitoring is started, the network camera 12 captures an image as shown in FIG. 4, performs processing such as digitization and image compression, and sends the image to the network.
The network interface 51 of the monitoring terminal 14 receives the image sent from the network camera 12, and the image expansion unit 52 expands the image to obtain an image. The image output unit 53 outputs the image to a monitor (not shown) and monitors it. Display an image.

  On the other hand, a security box 11 is shown in a part of the image, and LEDs are shown in designated lighting areas 41 to 45. The image recognition unit 54 of the monitoring terminal 14 recognizes the five designated lighting areas 41 to 45, and identifies whether the LED is lit or not (step S71 in FIG. 7).

  First, it is determined whether or not all the LEDs are turned off for one second (step S72). When all the lights are turned off for 1 second, acquisition of the authentication code is started thereafter. First, when the LED is lit, it is identified and the first 5 bits are acquired (step S73). Now, if LED21 is turned on, LED22 is turned off, LED23 is turned off, LED24 is turned on, and LED25 is turned on, 10011 is obtained. Then, after 1 second, image recognition is performed again to obtain 10101 as the second 5 bits (step S74), to obtain 01111 as the third 5 bits (step S75), and finally as the fourth 5 bits, 00101. Is obtained (step S76).

  When four 5-bit signals are obtained, a 20-bit authentication code such as 10011101010111100101 is generated (step S77). Then, it is determined whether or not the authentication code has been acquired (step S78) .If the authentication code cannot be acquired, a display indicating that the authentication code has not been issued is output from the image output unit 53 and displayed on the monitor screen (step S79). . If the authentication code can be acquired, the authentication unit 56 decrypts the authentication code acquired by the image recognition unit 54 with the public key to obtain the original current time (step S80).

  On the other hand, the time acquisition unit 55 of the monitoring terminal 14 acquires the current time (200408011030) using a radio clock (step S81) and collates it with the decrypted authentication code (step S82). If the difference between the two as a result of the collation is less than or equal to a predetermined time (for example, 30 seconds), it means that it is authenticated that the currently captured image is an image of the legitimate security box 11, and authentication is OK. Is displayed from the image output unit 53 and displayed on the monitor screen (step S83).

  If an authentication code is obtained but the difference between the two is greater than a predetermined time (for example, 30 seconds), there is a high possibility that some form of falsification has been made, so a warning such as “Authentication NG” is displayed. Is output from the image output unit 53 and displayed on the monitor screen (step S84). The authentication work is thus completed, the process returns to step S72, and the operation for acquiring the next authentication code is started in the same manner as the above-described operation.

  As described above, the network monitoring system of the present invention can authenticate the optical image itself captured by the camera, so that the subject itself can be replaced by placing a photograph of the same image as the subject to be monitored in front of the camera lens. , Not only can it detect counterfeit tampering, such as changing the camera position and imaging another subject that closely resembles the subject to be monitored, but also if the identifier is moved from a predetermined position It can be detected and reliable authentication can be performed. Also, since the monitored image itself is used for authentication data, there is no need to embed a special receiving device or digital watermark, just add a security box and authentication software using the conventional network camera as it is. The system is simple and can be implemented easily.

  In this embodiment, the LED has been described as being identified by lighting, but without being particular about this, the color of the LED can be changed, or characters and two-dimensional barcodes can be displayed using a 7-segment LED, liquid crystal panel, etc. Needless to say, the same effect can be obtained as long as it can be identified through an image. Furthermore, if an infrared light emitting element is used and this is imaged by a monitoring camera with high infrared sensitivity, it is not known that the light is on, and a system with high secrecy can be constructed. In this embodiment, a plurality of LEDs are used to form a lighting pattern corresponding to a plurality of bits, but a single LED is used to correspond to a plurality of bits within a predetermined time in the time axis direction. An on / off pattern may be formed. Furthermore, it is possible to turn on and off in the time axis direction using multiple LEDs, or to form a pattern by combining LEDs that follow a fixed lighting pattern within a certain time and LEDs that turn on and off along the time axis. .

  In addition, this security box will detect this when it is removed, such as loosening the mounting screw, and will not be lit unless it performs special processing such as entering an ID. More preferred. In the present embodiment, the current time is obtained by using a radio clock, encrypted, and authenticated. However, the present time is obtained by using a time server on the network without being particular about this. Data other than the current time may be encrypted and authenticated.

1 is a system configuration diagram of a network monitoring system which is an embodiment of a monitoring system of the present invention. FIG. It is an external view of the security box as a display apparatus in FIG. It is a block diagram which shows the structure of the security box in FIG. It is an example of the captured image in the network monitoring system in FIG. It is a block diagram which shows the structure of the monitoring terminal in FIG. It is a flowchart which shows operation | movement of the security box in FIG. It is a flowchart of the authentication in the network monitoring system in FIG. It is a system block diagram of the conventional monitoring system.

Explanation of symbols

11 Security box (display device)
12 Network camera
13 network
14 Monitoring terminal
21, 22, 23, 24, 25 Display (LED)
31, 55 Time acquisition unit
32 Authentication code generator
33 Output section
41, 42, 43, 44, 45 Lighting area
51 Network interface
52 Image expansion
53 Image output section
54 Image recognition unit
56 Authentication Department

Claims (4)

A display device that generates a lighting pattern corresponding to an authentication code consisting of a plurality of bits by turning on or off the light emitting element ;
Imaging the pre Symbol display device with the monitored, and an imaging device for transmitting an image captured,
And a monitoring terminal which displays the images transmitted from the imaging device,
The monitoring terminal further includes
An image recognition means for identifying the lighting of the light emitting element from the image transmitted from the imaging device,
Encoding means for generating a code consisting of a plurality of bits based on lighting of the light emitting element identified by the image recognition means;
Authentication means for authenticating the code generated by the encoding means;
With Ru monitoring system. The authentication code is based on time information;
The monitoring system according to claim 1, wherein the authentication unit authenticates the code based on time information. A lighting step for generating a lighting pattern corresponding to an authentication code consisting of a plurality of bits by turning on or off the light emitting element;
An imaging step of imaging the light emitting element together with a monitoring target and transmitting the captured image;
An image recognition step for identifying lighting of the light emitting element from the image captured in the imaging step;
A coding step for generating a code consisting of a plurality of bits based on lighting of the light emitting element identified in the image recognition step;
An authentication step of authenticating the code generated in the encoding step;
An authentication method in a monitoring system having. The authentication code is based on time information;
The authentication method in the monitoring system according to claim 3, wherein the authentication step authenticates the code based on time information.

Images