KR102347137B1 - Screen data leakage prevention apparatus and method - Google Patents

Abstract

In accordance with one embodiment of the present invention, disclosed is a screen data spillage prevention apparatus. The apparatus includes: a screen data generation part generating screen data; a screen data capture part capturing the generated screen data in real time to acquire the captured screen data; a watermark image generation part generating a watermark image by using a watermark pattern; and a watermark insertion part generating final screen data by inserting the generated watermark image into the captured screen data. The watermark pattern includes an invisible pattern. The watermark image is invisibly formed based on the invisible pattern. The watermark insertion part generates the final screen data such that the watermark image is invisibly overlaid onto the captured screen data. Therefore, the present invention is capable of preventing the spillage of information by identifying a person spilling the information.

Description

Screen data leakage prevention device and method {SCREEN DATA LEAKAGE PREVENTION APPARATUS AND METHOD}

The present invention relates to an apparatus and method for preventing leakage of screen data, and more particularly, to an apparatus and method for inserting a watermark in order to prevent leakage of screen data from a user terminal.

In recent years, almost all tasks or services in life, such as office work, payment service, certificate issuance, banking, and e-commerce, are performed online and in a computerized environment. In such an online and computerized environment, digital content is the subject of information creation, viewing, storage, editing, transmission, and the like. In this case, the digital content may refer to various types of digital information including images, texts, and multimedia, for example, digital documents, moving pictures, and the like.

However, due to the nature of digital information, such digital content is easily copied or transmitted without loss of the information, so it is very vulnerable to leakage through illegal activities. Therefore, in order to provide a sound digital content use environment, a protection means that can prevent digital content from illegal activities, that is, a security system, is essential. For example, digital content may be protected through an encryption/decryption system, a watermark or fingerprinting system, a screen capture prevention system, and the like.

As a conventional watermark for preventing capture, a watermark visible to the human eye is used on the screen, causing a problem in that the user's work on the computer is disturbed.

The screen capture prevention system can be said to be a system for preventing leakage of digital content by illegally capturing, storing, using, and distributing digital content displayed through a terminal such as a PC. Such a screen capture prevention system may be implemented in various forms.

For example, Korean Patent Laid-Open No. 2004-0033540 discloses a screen capture prevention system for digital works. The capture prevention system detects a request for system service and system function use requested by application programs from the system with respect to a system service using an application program, and analyzes a service request pattern to block illegal capture and information change. In addition, Korean Patent Application Laid-Open No. 2006-0032332 discloses a still image capture prevention system that makes it impossible to capture a normal and complete screen when capturing a still image.

However, in these conventional capture prevention systems, maintenance of the system is unavoidable due to the change of the screen capture type and the increase in the screen capture program. That capture prevention function can be useless.

As mentioned above, the conventional capture prevention system inevitably has an excessive cost for system maintenance, and is fundamental to leakage through pictures and videos on the screen, information leakage by screen capture on mobile devices, etc. There is a problem in which human defense is impossible. Accordingly, there is an urgent need to develop a technology capable of reliably and efficiently preventing leakage of digital content due to screen capture.

An object according to an aspect of the present invention for solving the above problems is to output an invisible watermark that is invisible to the human eye on a screen, etc. To provide an apparatus and method.

According to an aspect of the present invention for achieving the above object, there is provided an apparatus for preventing screen data leakage, a screen data generating unit generating screen data, and a screen capturing the generated screen data in real time to obtain the captured screen data A data capture unit, a watermark image generation unit that generates a watermark image by using a watermark pattern, and a watermark insertion that inserts the generated watermark image into the captured screen data to generate final screen data Including a part, wherein the watermark pattern includes an invisible pattern, the watermark image is formed invisibly based on the invisible pattern, and the watermark insertion unit includes: The final screen data may be generated so that the watermark image is invisibly overlaid on the screen data.

The captured screen data includes at least one digital content, the at least one digital content includes at least one of text, an image, and a video, and the watermark The image may be generated to correspond to the at least one digital content.

The captured screen data includes at least one of a web page, home screen data, folder screen data, and setting screen data, wherein the watermark image corresponds to the captured screen data. can be created

The watermark insertion unit may generate the final screen data so that the watermark image is invisibly overlaid on the entire area of the captured screen data.

The watermark insertion unit may generate the final screen data so that the watermark image is invisibly overlaid on a predetermined area regardless of the contents of the captured screen data.

The watermark pattern is generated by a security policy, and the security policy may include information indicating at least one of a strength and a type of the watermark pattern.

The security policy may be received in real time from a security server connected by at least one of a wired network and a wireless network.

The watermark pattern may include time information.

The apparatus may further include an image analysis unit that analyzes the image of the captured screen data, wherein the watermark image generation unit is a watermark image corresponding to the watermark pattern based on a result analyzed by the image analysis unit. can create

The image analyzer detects at least one of an edge portion and a text portion from the captured screen data, and the watermark image generator includes the detected edge portion and the text portion to correspond to at least one of the detected edge portion and the text portion. You can create a watermark image.

The device may monitor whether an operation related to the insertion of the watermark operates normally, and in response to the monitoring result not operating normally, control the captured screen data not to be displayed.

According to another aspect of the present invention for achieving the above object, a method for preventing screen data leakage includes generating screen data, capturing the generated screen data in real time to obtain captured screen data, a watermark Generating a watermark image using a pattern (watermark pattern) and inserting the generated watermark image into the captured screen data to generate final screen data, wherein the watermark pattern is an invisible pattern (invisible pattern), wherein the watermark image is formed invisibly based on the invisible pattern, and the watermark image is invisibly overlaid on the captured screen data. You can create screen data.

A screen data leakage prevention system according to another aspect of the present invention for achieving the above object is connected through an interface with a client terminal that generates screen data and the client terminal, and uses the screen data generated by the client terminal. Obtaining captured screen data by capturing in real time, generating a watermark image using a watermark pattern, and inserting the generated watermark image into the captured screen data to generate final screen data a watermark embedding device, wherein the watermark pattern includes an invisible pattern, the watermark image is formed invisibly based on the invisible pattern, and the watermark embedding device may generate the final screen data so that the watermark image is invisibly overlaid on the captured screen data.

The client terminal may control the screen data not to be displayed in response to abnormal connection or synchronization with the watermark embedding device.

According to the device and method for preventing screen data leakage of the present invention, if there is an information leaker through a method such as taking a monitor screen with a mobile phone camera, capturing a screen and sharing it using an invisible watermark, the leaker is caught and captured It is effective in preventing information leakage through

1 is a conceptual diagram schematically showing a system in which a screen data leakage prevention method according to an embodiment of the present invention is used;
2 is a conceptual diagram illustrating a method of inserting a watermark into screen data according to an embodiment of the present invention;
3 is a block diagram showing the configuration of an apparatus for preventing screen data leakage utilizing an image analysis result according to an embodiment of the present invention;
4 is a conceptual diagram for explaining a method of generating a watermark corresponding thereto and determining an embedding mode based on the type of captured screen data;
5 is a view for explaining a method of inserting a watermark by utilizing characters and edge areas in screen data;
6 is a conceptual diagram schematically showing a system in which a screen data leakage prevention method according to another embodiment of the present invention is used;
7 is a block diagram schematically illustrating an apparatus for extracting a watermark according to an embodiment of the present invention.

Since the present invention can have various changes and can have various embodiments, specific embodiments are illustrated in the drawings and described in detail.

However, this is not intended to limit the present invention to specific embodiments, and it should be understood to include all modifications, equivalents and substitutes included in the spirit and scope of the present invention.

Terms such as first, second, etc. may be used to describe various elements, but the elements should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, a first component may be referred to as a second component, and similarly, a second component may also be referred to as a first component. and/or includes a combination of a plurality of related listed items or any of a plurality of related listed items.

When an element is referred to as being “connected” or “connected” to another element, it is understood that it may be directly connected or connected to the other element, but other elements may exist in between. it should be On the other hand, when it is said that a certain element is "directly connected" or "directly connected" to another element, it should be understood that the other element does not exist in the middle.

The terms used in the present application are only used to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present application, terms such as “comprise” or “have” are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but one or more other features It should be understood that this does not preclude the existence or addition of numbers, steps, operations, components, parts, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related art, and should not be interpreted in an ideal or excessively formal meaning unless explicitly defined in the present application. does not

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings. In describing the present invention, in order to facilitate the overall understanding, the same reference numerals are used for the same components in the drawings, and duplicate descriptions of the same components are omitted.

Digital content may refer to various types of digital information including images, texts, multimedia, and the like, for example, digital documents, moving pictures, and the like.

In addition, screen data is data displayed on the screen of the client terminal, and may or may not include digital content. Furthermore, multiple windows may be opened to include a plurality of digital contents.

The screen data may include a general web page, a home screen (or desktop screen) of a computer or mobile terminal, a folder screen, a user setting screen, and the like.

1 is a conceptual diagram schematically illustrating a system in which a screen data leakage prevention method according to an embodiment of the present invention is used. 1 , the screen data leakage prevention system according to an embodiment of the present invention may include a security server 105 and a client terminal 100 .

Referring to FIG. 1 , the security server 105 and the client terminal 100 are connected by at least one of a wired network and a wireless network. The security server 105 is a server device that controls the security policies of the plurality of client terminals 100 , and may be implemented as a general computing device and/or a large-capacity server system. The security server 105 may transmit the security policy to the client terminal 100 at any time or periodically. The security policy provided by the security server 105 may include information indicating basic information for forming a watermark pattern. For example, information indicating at least one of basic information such as user personal information (user ID, name, company number, resident registration number, etc.), client terminal information (IP address, MAC address, IMEI, etc.), current time information, etc. By including it, the watermark pattern generator 130 of the client terminal 100 may instruct on which information to generate the watermark pattern. In addition, the security policy may include information designating the strength of the watermark. That is, transparency of the watermark pattern may be specified as a security policy. In another example, the security server 105 may include a direct encryption module to provide encrypted watermark pattern information to the client terminal 100 .

The client terminal 100 is implemented as a computing device including a memory and a processor, and is a device including a watermark insertion module to prevent leakage of screen data. This may be called a watermark insertion device, a screen data prevention device, a user terminal and a terminal, and the like. The client terminal 100 may be implemented as a PC, a laptop, a smart phone, a personal digital assistance (PDA), a digital TV, or the like.

The client terminal 100 may include a display unit 160 for displaying information. The display unit 160 may be, for example, a liquid crystal display (LCD) panel, a plasma display panel (PDP), or an organic light emitting diode (OLED) panel. The client terminal 100 controls to display various data on the screen according to the user's work situation. In addition, the watermark image is inserted into the data displayed on the screen so that when the screen data is photographed by a photographing device or directly captured by the terminal 100, the leakage path can be checked.

The client terminal 100 includes a screen data generating unit 110 , a screen data capturing unit 120 , a watermark pattern generating unit 130 , a watermark image generating unit 140 , and a synthesizing unit 150 , and a display unit. (160).

The screen data generator 110 is a component that generates data displayed on the screen, and is a component that generates data to be displayed on the screen of the terminal by a program executed in the terminal 100 . As described above, screen data refers to data displayed on a screen, and may include at least one digital content. Also, any digital content may not be included. That is, since a general desktop screen, a folder screen, etc. of a PC or mobile device are data displayed through the display unit 160 , such data may also be included in the screen data. Digital content includes text content by document authoring programs such as word, Excel, Hangul (hwp), presentation content (PPT), and pdf, image content such as photos, and video content such as videos can do. The screen data generator 110 may generate one or more digital contents as screen data according to a user's manipulation.

The screen data capture unit 120 is a component that captures screen data displayed on the screen. It may be captured in real time, or it may be captured periodically. In the present specification, capture may include an actual capture operation for an actual screen, such as a print screen function in a PC, and acquire/receive the screen generated by the screen data generating unit 110 as it is may be implemented as That is, the capture operation may be performed in a form in which the screen data generating unit 110 directly displays data on the screen and then captures it, but the capture operation (strictly speaking, data acquisition) in the form of bringing the data before displaying it on the screen as it is. action) may be performed.

The watermark pattern generator 130 is a component that generates a watermark pattern according to the security policy from the security server 105 . If the security server 105 receives a security policy to generate a watermark pattern with the user's personal information, the watermark pattern generation unit 130 provides information on at least one of user ID, address, company number, resident registration number, and phone number. can be used to create a watermark pattern. In this case, the security policy can specify even which information of personal information to use to generate the watermark. The watermark pattern may include two or more pieces of information. For example, a watermark pattern may be formed by a plurality of pieces of personal information or a combination of one piece of personal information and one piece of terminal information. In another example, if the security server 105 directly transmits an encrypted pattern in order to increase security strength, the watermark pattern generator 130 directly receives it and generates a watermark pattern.

According to an embodiment of the present invention, the watermark pattern generator 130 may generate an inconspicuous pattern (invisible pattern). An invisible watermark pattern can be created by adjusting the transparency. For example, an invisible watermark pattern may be generated using preset transparency. The preset transparency includes transparency greater than or equal to a threshold value. The transparency may be set to a fixed value or may be set to a value that is variable in proportion to a pixel value of the screen data. In addition, it is possible to implement an invisible watermark by adjusting the watermark display position as well as transparency. A watermark may be arranged on a text or an edge portion, or a background portion to make it invisible.

The watermark image generating unit 140 images the watermark pattern generated by the watermark pattern generating unit 130 to generate a watermark image. In this case, an invisible watermark image may be generated using the invisible watermark pattern.

The synthesizing unit 150 generates final screen data by synthesizing the screen data captured by the screen data capturing unit 120 and the watermark image generated by the watermark image generating unit 140 . In this case, the final screen data is generated so that the watermark is displayed invisibly by overlaying the watermark image on the captured screen data. Basically, the synthesizing unit 150 may operate in the form of constantly inserting the generated watermark image regardless of the contents of the screen data. In another example, a watermark having a corresponding form may be generated based on the type of screen data and the object analysis result. On the other hand, in the synthesis method, not only an overlay method, but also an alpha-blending method and/or a pixel sum method for mixing screen data and a watermark image with a constant coefficient may be used. Meanwhile, the synthesizing unit 150 may be referred to as a watermark image insertion unit.

Then, the display unit 160 displays the final screen data synthesized by the synthesis unit 150 .

In this way, the final screen data displayed on the display unit 160 is invisible, but includes a watermark, so that the data is captured or captured through the photographing equipment 170 or the terminal 100 itself. Even if is leaked, a watermark hidden in the screen data can be extracted through the watermark extraction device 180, and an outflow path can be checked using the extracted watermark.

According to an embodiment of the present invention, it may further include means for monitoring whether at least one of the modules related to watermark insertion is operating normally. In this case, in response to the watermark-related module not operating normally, the screen data may not be decrypted in a security program in the client terminal 100 such as DRM. In another example, if a watermark pattern is not generated, a special overlay may be covered on the screen to make the screen image invisible.

2 is a conceptual diagram illustrating a method of inserting a watermark into screen data according to an embodiment of the present invention.

Referring to the uppermost drawing of FIG. 2 , the terminal may display various data on the screen. Internet windows, document authoring program files such as Word or Excel, and video or image files can also be played. Then, data to be displayed on the screen is captured to prepare for synthesis with the watermark image.

The terminal generates a watermark pattern to generate a watermark image. In this case, the watermark pattern (encrypted form) may be directly received from the security server, or the terminal may directly generate a watermark pattern corresponding to the security policy by receiving the security policy. If the security policy indicates to generate a watermark pattern based on IP information, the terminal creates a watermark pattern based on its own IP address information. Since the security policy is changed according to time, it is also possible to create a water mark corresponding to the corresponding time zone. For example, it is possible to generate different watermarks according to the passage of time, such as inserting IP information in the morning and inserting user personal information in the afternoon.

Additionally, the watermark pattern may include time information. The time information may be the current time. Alternatively, it may be the reception and creation time of a specific file. The time information may be changed in real time or according to a preset period (in units of 1 minute). For example, date and time information in the format of 20210203 11:13 can be generated as a watermark pattern. Through this, it is possible to infer the leakage time later. Moreover, it is also possible to create a watermark pattern through a combination of personal information (ID information) such as KimJY and time information of 20210203 11:13.

Meanwhile, the generated watermark pattern is preferably processed invisibly. For invisible processing of the watermark pattern, the security policy may include information related to optimal transparency or strength. For example, when 95% transparency is indicated in the security policy, the terminal processes the watermark pattern with 95% transparency to make it almost invisible. In another example, by adjusting the size of the watermark pattern, it is possible to use a method of manufacturing the watermark pattern in a size that is minimized to the extent that the watermark pattern can be extracted later by a watermark extraction apparatus and a human cannot recognize it.

The terminal may have a watermark library that stores information related to the watermark pattern. In the corresponding library, various information related to watermark pattern generation may be stored. Not only user personal information and terminal information, but also information on a method of generating an encrypted pattern based on specific information may be included. In addition, information on various methods of generating a watermark pattern based on time information may be included.

Then, the terminal creates a watermark image by imaging the generated pattern. The middle drawing of FIG. 2 is an example of this. The watermark image may be generated with a size corresponding to the size of the screen. Alternatively, it may be generated in a size corresponding to a specific area in the screen. In particular, the watermark image may be generated only in the digital content (eg, Excel file) area. It is also possible to create a watermark image only in the folder area or text area.

Since the watermark pattern is created invisibly, it is preferable that the watermark image is also created invisibly. Through this, it is desirable to prevent the actual operator from feeling the insertion of the watermark on the screen data, thereby preventing the leakage of the screen data without interfering with the work.

After generating the watermark image, the previously captured screen data and the invisibly generated watermark image are synthesized to be overlaid. Since the watermark image may have invisible transparency, it can be revealed only when the watermark is extracted through the watermark extraction device without affecting the screen data.

3 is a block diagram illustrating a configuration of an apparatus for preventing screen data leakage using an image analysis result according to an embodiment of the present invention. As shown in FIG. 3 , the device may further include an image analyzer 325 in the configuration of the client terminal device of FIG. 1 .

Referring to FIG. 3 , the terminal device may further include an image analysis unit 325 for analyzing the screen data captured by the screen data capture unit 320 , and the image analysis unit 325 analyzes the captured screen data. Thus, the analysis result is provided to the watermark pattern generator 330 and/or the watermark image generator 340 .

The image analyzer 325 may execute an object analysis algorithm, and may analyze objects in the captured screen data based on this. Accordingly, it can be determined in what form the captured screen data is configured. That is, it is possible to determine whether the screen data is composed of web page type data, video or image type data, or text (numbers and characters) type data, and where specific types of data are located. It can be determined what shape (color, size, etc. can be determined) is configured in the . In addition, an object area in which one or more objects included in the screen data are located and a background area surrounding the corresponding objects may be distinguished and recognized.

In particular, the image analyzer 325 may calculate the survival rate of the watermark. That is, it is possible to calculate the probability of surviving the best when the watermark exists in which part and in what form.

The image analysis result recognized in this way is provided to the watermark pattern generator 320 and/or the watermark image generator 340 to generate a watermark pattern based thereon, and/or the watermark pattern It is possible to properly create a watermark image from The watermark pattern generator 320 and/or the watermark image generator 340 generates a corresponding watermark pattern and/or watermark image based on the image analysis result. In the present specification, speaking of a watermark pattern, since it is associated with a watermark image, it can be interpreted as a watermark image, and vice versa. Hereinafter, a method of generating a watermark pattern and/or an image according to an image analysis result will be described in more detail with reference to FIGS. 4 to 5 .

4 is a conceptual diagram for explaining a method of generating a watermark corresponding to a watermark and determining an embedding mode based on the type of captured screen data.

Referring to FIG. 4 , the image analysis unit analyzes the contents of the captured screen data, and outputs the analysis result to the watermark pattern generation unit so that a watermark pattern and/or image corresponding to the type of data can be generated. and/or provided to the watermark image generator. For example, if the screen data is composed of a word file, the watermark of the first mode is created, in the case of an Excel file in the second mode, in the case of a video file in the third mode, and in a general web page. Then, the watermark of the Nth mode is generated. The type, intensity, and/or position of the watermark may be differently generated according to each mode. Specifically, in the case of a Word or Excel file with a lot of text, the watermark is similarly generated in the form of text and overlaid on the corresponding file area (Word/Excel area). When video or image content exists in the captured screen data, the watermark image is calculated from the watermark pattern, the range of watermark pixel values, etc. are calculated based on the pixel values mainly used in the video or image in the screen A watermark image may be generated with pixel values within the calculated range. In particular, in this case, it is desirable to make the watermark image look like noise of the target moving picture or image content.

When a plurality of different contents are included in the captured screen data, the watermark of the first mode for the first area of the first content and the watermark of the second mode for the second area of the second content are included can make it happen

Also, different synthesis methods may be used according to the type of screen data. For example, a general overlay method may be used for text data, and an alpha blending method set to a specific coefficient may be used for video or image data.

FIG. 5 is a diagram for explaining a method of inserting a watermark by using text and an edge area in screen data.

Referring to FIG. 5 , as described above, the image analysis unit determines at which position the invisible watermark will survive well in relation to the original screen data, and transmits the determination result to the watermark pattern generator and/or the watermark. It is provided by the image generator. In particular, since invisibility and the survival rate of the watermark are in inverse proportion, it may not be easy to survive the watermark above a certain probability while guaranteeing the preset invisibility. In order to overcome this relationship, the image analysis unit calculates a high survival rate when a watermark is produced at a location and in what form in an invisibility situation, and provides it to the watermark pattern generation unit and/or the watermark image generation unit do.

In one example, the image analyzer detects an edge region in the captured screen data, and uses the image analysis result to generate a watermark pattern and/or a watermark image in the edge region to the watermark pattern generator and/or watermark. It is provided by the image generator. Since the watermark can survive well in the edge area, information on the edge area in the screen (including pixel information such as the location and size (thickness) or length of the edge area, and the luminance/color of the edge area) It is provided to the watermark pattern generator and/or the watermark image generator to support generation of an appropriate watermark pattern and/or image corresponding to each edge area. The watermark pattern and/or image generating unit generates an invisible watermark pattern and/or image by using the position, size, length, and pixel information of the edge region. In this case, if there are a plurality of edge regions, a plurality of different watermarks may be generated. In some cases, it is also possible to select one or more edges that provide an environment in which the watermark can best survive among the plurality of edge regions, and control so that the watermark corresponding to the selected edge region is overlaid only on the selected edge region. have.

In another example, the image analyzer may extract a portion of the text area existing in the screen data. Then, information on the corresponding text area may be provided to the watermark pattern generator and/or the watermark image generator. The information on the text area may include information on the type of text (eg, letters, numbers, symbols, etc.), a location, a font, and a text size. The watermark pattern and/or image generator generates a watermark of a corresponding form based on the information on the text area. For example, in a character area having a 12-size "clear gothic" font, a watermark pattern may be generated with 12-size characters of the same font and controlled to be arranged around the corresponding area. In this case, it is also preferable to display only the small size. In this case, if there are a plurality of text areas, a plurality of different watermarks may be generated. In some cases, it is possible to select one or more number of text parts that provide an environment in which the watermark can best survive among the plurality of text areas, and control so that only the selected text area can the corresponding watermark be overlaid. may be

Additionally, the image analyzer divides the object area and the background area in the captured screen data, and provides the information to the watermark pattern generator and/or the watermark image generator. In particular, it is preferable to use this to invisibly overlay the screen data by arranging the watermark pattern and/or watermark image in an inconspicuous background area.

The watermark pattern generator and/or the watermark image generator may set the watermark pattern and/or the transparency of the image to correspond to the pixel value of the screen data among the image analysis results. That is, as the color of the screen data is displayed darker, the transparency is lowered, and when the color is displayed lighter, a method of matching high transparency may be used.

6 is a conceptual diagram schematically illustrating a system in which a screen data leakage prevention method according to another embodiment of the present invention is used.

Referring to FIG. 6 , the watermark embedding apparatus 600 may be implemented as a device separate from the client terminal 602 that generates screen data. That is, only the screen data generating unit of the embodiment of FIG. 3 exists in the end 602 of the client terminal, and the screen data capture unit 610, the image analysis unit 620, the watermark pattern generation unit 630, and the watermark image The generating unit 640 and the combining unit 650 may be implemented to be arranged in a separate watermark embedding apparatus 600 . An operation of each component may be the same as or similar to that of FIGS. 1 and 3 .

In the embodiment of FIG. 6 , the client terminal 602 and the watermark embedding apparatus 600 may be connected by an interface (or cable) supporting HDMI and HP (High-bandwidth Digital Content Protection (HDCP)). . Screen data of the client terminal 602 may be provided to the watermark embedding apparatus 600 using the above interface. In this case, the watermark embedding apparatus 600 may be connected to a peripheral device of the client terminal 602 through a set-top box or a cable box to perform an operation related to watermark embedding. Through this, by executing burdensome tasks such as image analysis and watermark generation and insertion in the separately installed watermark embedding device 600, the overhead in the client terminal 602 performing the actual work is reduced. can be reduced

Screen data to which a watermark is added through the watermark embedding device 600 is provided to the display unit 660 . The display unit 660 may be a component included in the client terminal 602 or may be a separate device connected to the client terminal 602 .

Meanwhile, if the watermark embedding apparatus 600 is not synchronized with the client terminal 602 (eg, synchronized through encryption), it is possible to control not to display the screen of the client terminal 602 . Also, similarly to the above description, if the watermark embedding device 600 is not normally connected in the client terminal 602, the image is not properly displayed on the screen because the image is not decoded in a security program such as DRM. can be controlled

7 is a block diagram schematically illustrating an apparatus for extracting a watermark according to an embodiment of the present invention. As shown in FIG. 7 , the watermark extraction apparatus according to an embodiment of the present invention includes a leaked screen data input unit 710 , a watermark extraction unit 720 , a watermark restoration unit 730 , and a decoding unit 740 . ) may be included.

Referring to FIG. 7 , the leaked screen data input unit 710 receives the leaked screen data (image form) through screen capture, photo taking, and the like. The input screen data may be an image of a screen in which a watermark image is invisibly overlaid on the original screen data.

The watermark extraction unit 720 may extract a watermark from the screen image input from the leaked screen data input unit 710 .

The watermark restoration unit 730 restores the watermark extracted by the watermark extraction unit 720 . In this case, the watermark extraction unit 720 and the watermark restoration unit 730 may extract and restore the watermark without the original screen data. Also, even when only a part of the watermark image or pattern is extracted, not the entire watermark pattern can be restored.

The decryption unit 740 decrypts the restored watermark to obtain information related to leakage. Information related to leakage may correspond to information for generating a watermark pattern. This may include user personal information (user ID, address, company number, etc.), terminal information (IP address, MAC address, IMEI, etc.) and/or time information. The user may infer a process related to the leak based on the decrypted user personal information, terminal information, and/or time information.

Although described above with reference to the drawings and embodiments, it does not mean that the scope of protection of the present invention is limited by the drawings or embodiments, and those skilled in the art will appreciate the spirit of the present invention described in the claims below. And it will be understood that various modifications and changes can be made without departing from the scope of the present invention.

Claims (14)

a screen data generation unit generating screen data;
a screen data capture unit that captures the generated screen data in real time to obtain the captured screen data;
a watermark image generator for generating a watermark image by using a watermark pattern; and
A watermark insertion unit for generating final screen data by inserting the generated watermark image into the captured screen data,
The watermark pattern includes an invisible pattern,
The watermark image is formed invisibly based on the invisible pattern,
The watermark insertion unit generates the final screen data so that the watermark image is invisibly overlaid on the captured screen data,
The captured screen data is divided into first screen data and second screen data,
The first screen data includes at least one digital content, and the at least one digital content is classified into text, an image, and a video,
The second screen data is classified into at least one of a web page, home screen data, folder screen data, and setting screen data,
A screen data leakage prevention apparatus for inserting a watermark by utilizing an invisible watermark insertion mode corresponding to the classified type of screen data. delete delete The method of claim 1,
The watermark insertion unit generates the final screen data so that the watermark image is invisibly overlaid on the entire area of the captured screen data. The method of claim 1,
The device for preventing screen data leakage, wherein the watermark insertion unit generates the final screen data so that the watermark image is overlaid invisibly on a predetermined area regardless of the contents of the captured screen data. The method of claim 1,
The watermark pattern is generated by the security policy,
The security policy includes information indicating at least one of a strength and a type of the watermark pattern, the screen data leakage prevention apparatus. 7. The method of claim 6,
The security policy is received in real time from a security server connected by at least one of a wired network and a wireless network,
The security server periodically allocates information indicative of basic information for forming a watermark pattern, a screen data leakage prevention device. The method of claim 1,
The watermark pattern includes time information, screen data leakage prevention device. The method of claim 1,
Further comprising an image analysis unit to analyze the image of the captured screen data,
The watermark image generating unit generates a corresponding watermark image from the watermark pattern based on a result analyzed by the image analysis unit, the screen data leakage prevention apparatus. 10. The method of claim 9,
The image analysis unit detects at least one of an edge part and a character part from the captured screen data,
and the watermark image generating unit generates the watermark image to correspond to at least one of the detected edge portion and the text portion. The method of claim 1,
An apparatus for preventing screen data leakage by monitoring whether an operation related to the insertion of a watermark operates normally, and controlling the captured screen data not to be displayed in response to a non-normal operation as a result of the monitoring. generating screen data;
acquiring the captured screen data by capturing the generated screen data in real time;
generating a watermark image using a watermark pattern; and
Including the step of inserting the generated watermark image in the captured screen data to generate final screen data,
The watermark pattern includes an invisible pattern,
The watermark image is formed invisibly based on the invisible pattern,
generating the final screen data so that the watermark image is invisibly overlaid on the captured screen data,
The captured screen data is divided into first screen data and second screen data,
The first screen data includes at least one digital content, and the at least one digital content is classified into text, an image, and a video,
The second screen data is classified into at least one of a web page, home screen data, folder screen data, and setting screen data,
A method for preventing screen data leakage, wherein a watermark is inserted using an invisible watermark embedding mode corresponding to the classified type of screen data. a client terminal generating screen data; and
It is connected to the client terminal through an interface, captures the screen data generated by the client terminal in real time to obtain the captured screen data, and generates a watermark image using a watermark pattern, the capture and a watermark embedding device for generating final screen data by inserting the generated watermark image into the screen data,
The watermark pattern includes an invisible pattern,
The watermark image is formed invisibly based on the invisible pattern,
The watermark embedding device generates the final screen data so that the watermark image is invisibly overlaid on the captured screen data,
The captured screen data is divided into first screen data and second screen data,
The first screen data includes at least one digital content, and the at least one digital content is classified into text, an image, and a video,
The second screen data is classified into at least one of a web page, home screen data, folder screen data, and setting screen data,
A screen data leakage prevention system for inserting a watermark by utilizing an invisible watermark insertion mode corresponding to the classified type of screen data. 14. The method of claim 13,
The screen data leakage prevention system, wherein the client terminal controls the screen data not to be displayed in response to an abnormal connection or synchronization with the watermark embedding device.

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