Software screen capture prevention method and device, computer equipment, medium and program product

Abstract

According to the software screenshot prevention method and device, the computer equipment, the medium and the program product, display data needing screenshot prevention is stored in the protection memory area which cannot be accessed by a user computing chip, physical isolation of display data from different sources is achieved on the hardware level, the screenshot prevention method is achieved under an operating system, and the user experience is improved. The safety of the method is effectively improved; no matter whether a user operating system is safe and complete, malicious users cannot perform screen capture operation on display data needing to be protected.

Description

Technical Field

[0001] The present invention belongs to the field of computer technology, and in particular relates to a method, device, computer equipment, medium and program product for preventing software from taking screenshots. Background Art

[0002] In recent years, as the country, enterprises and individual users have paid more and more attention to information security, the protection of the displayed content of information devices has received increasing attention. How to prevent the theft of displayed information by means of screenshots has become an important issue.

[0003] Current anti-screenshot technologies can be divided into the following three categories:

[0004] The first type is implemented at the operating system level, and anti-screenshot is implemented at the application granularity, which is also the most widely used solution. For example, CN115544497A, CN112417533A, CN113486413A, CN115373878A, CN115630391A, CN114780342A and CN115422605A.

[0005] CN115544497A is implemented by extending the Wayland protocol based on Xwayland and Wayland synthesizer in the Wayland environment, and the final screenshot control is implemented by the Wayland synthesizer based on the control list therein. It is implemented by extending the Wayland protocol based on Xwayland and Wayland synthesizer in the Wayland environment, and the final screenshot control is implemented by the Wayland synthesizer based on the control list therein. The control list in the Wayland synthesizer includes a full-screen control list and a sensitive window control list; the Wayland protocol registered in the Wayland synthesizer is a screenshot control extension protocol, and the Wayland synthesizer directly implements screenshot control management of Wanyland applications through this protocol; the protocol registered in Xwayland is an X extension protocol, and the information interaction with the Wayland synthesizer is completed through the X extension protocol, so that the Wayland synthesizer indirectly implements screenshot control management of the X application.

[0006] CN112417533A monitors whether the target method of the target interface is called. If the target method is monitored, the original window attribute data in the target method is obtained; the original window attribute data is modified according to the target data to obtain the target window attribute data. Since the target data is used to set the target interface as an interface that prohibits screenshots, the target interface is displayed according to the target window attribute data, and the anti-screenshot effect of all window objects is reinforced to improve the reinforcement quality, thereby preventing malicious programs from taking screenshots and completely preventing malicious programs from taking screenshots, thereby avoiding information leakage.

[0007] CN113486413A is executed in a computing device, an operating system is running in the computing device, and one or more application programs are running on the operating system. The method includes: when receiving an anti-screenshot opening instruction sent by a first process, opening the anti-screenshot function; when receiving an anti-screenshot closing instruction sent by a second process, judging whether there are other processes that have turned on the anti-screenshot function; if there are other processes that have turned on the anti-screenshot function, the anti-screenshot function is kept turned on; if there are no other processes that have turned on the anti-screenshot function, the anti-screenshot function is closed. The present invention also discloses a corresponding computing device and a readable storage medium. The anti-screenshot processing method of the present invention can ensure the security of confidential documents and will not affect the user's normal screenshot of non-confidential documents.

[0008] The second category decomposes the display data so that a single screenshot operation cannot obtain all the display data. For example, CN112651056A obtains the pre-display content and samples the pre-display content to obtain multiple sampling frames; each sampling frame includes multiple sampling frame pixels; the color ratio of each sampling frame pixel is determined, and multiple display frames are constructed for each sampling frame according to the color ratio; each display frame includes part of the color of the sampling frame; and multiple display frames are sent to the display so that the display displays the content of multiple display frames. The present invention constructs multiple display frames for each sampling frame according to the color ratio of the sampling frame pixel points, so that the display displays the content of multiple display frames, and each display frame only includes part of the color of the sampling frame, so that the screen cutting software and tools cannot capture the complete display content, thereby realizing the protection of the output content of the display screen.

[0009] The third category places display data that needs to be protected under the secure world (SWD / TEE). For example, CN111771183A generates image resources for generating a trust zone user interface in the ordinary world; transmits the image resources from the ordinary world to the secure world; and generates the trust zone user interface in the secure world by separating and editing the image resources including multiple objects, wherein the separation and editing are performed in units of objects.

[0010] As mentioned earlier, the solution of implementing anti-screenshot at the operating system level and at the application granularity cannot protect the display data once the underlying user operating system is attacked; the solution of decomposing the display data into multiple frames will still leak some display data and cannot resist the continuous screen recording attack solution; the solution of placing all display data in the secure world (SWD / TEE) will have great efficiency problems and introduce a lot of performance overhead for switching between the normal world and the secure world. Therefore, it is not suitable for display-intensive multimedia, desktop office and other scenarios. Summary of the invention

[0011] In order to solve the problem of preventing screenshots in display-intensive scenes (such as desktop client software, multimedia playback software, etc.), the present invention provides a method, device, computer equipment, medium and program product for preventing software screenshots, so that the prevention of screenshots in display-intensive scenes does not rely on the security and integrity of the operating system itself.

[0012] A method for preventing software from taking screenshots is run on a terminal device, wherein a user computing environment, a protection computing environment and a display control chip are deployed in the terminal device, wherein the user computing environment includes a user memory area and a user computing chip, and the user computing environment runs a user operating system, and the protection computing environment includes a protection memory area and a protection computing chip;

[0013] The method comprises the following steps:

[0014] The display data that does not need to be protected from screenshots is stored in a user memory area that can be accessed by the protection computing chip and the user computing chip, and the display data that needs to be protected from screenshots is stored in a protection memory area that can only be accessed by the protection computing chip and cannot be accessed by the user computing chip, so that a screenshot instruction that only runs on the user computing chip and can only capture the display data in the user memory area cannot capture the display data in the protection memory area;

[0015] The user computing chip and the protection computing chip respond to the display operation command and are used to send the display data to the display connected to the display control chip for display.

[0016] Furthermore, the method for the protection computing chip to send display data to a display connected to the display control chip for display in response to the display operation command is:

[0017] Adopting an agent program running on the user computing chip to intercept the display operation command issued by the user computing chip, and determining the source of the display operation command, wherein the source includes: locally running interactive applications and graphics libraries, commands input by the user's mouse, and display data related commands issued by the cloud network;

[0018] The agent program sends the display data related commands issued by the cloud network to the shared memory pre-opened in the user memory area for storage;

[0019] The agent program sets a task flag and a task number in the shared memory for each display data related command issued by the cloud network, wherein the task flag is divided into an execution completion flag and an unexecuted flag;

[0020] Using a decoding display application running on the protection computing chip to monitor the task flag in the shared memory in real time, reading the task number corresponding to the unexecuted flag and the display data related command;

[0021] The protection computing chip executes the display data related commands and sends the display data to a display connected to the display control chip for display.

[0022] Furthermore, after the protection computing chip executes the display data related command and sends the display data to a display connected to the display control chip for display, the following steps are also performed:

[0023] The protection computing chip generates a command completion instruction for the executed display data related command, and sends the command completion instruction and the task number corresponding to the executed display data related command to the user computing chip;

[0024] The user computing chip modifies the task flag corresponding to the task number in the shared memory to an execution completion flag according to the command completion instruction and the task number corresponding to the executed display data related command.

[0025] Furthermore, locally running interactive applications and graphics libraries, and commands input by the user's mouse are directly executed by the user computing chip.

[0026] Furthermore, the protected memory area is implemented using additional physical memory particles or based on a memory physical isolation device, wherein, when the protected memory area is implemented based on a memory physical isolation device, the user computing chip, the protection computing chip and the memory physical isolation device are placed in the same system chip.

[0027] Furthermore, the display data that needs to be protected from screenshots is obtained from the cloud virtual machine, wherein the display data sent by the cloud virtual machine is encoded into a multimedia code stream, and then, under the protocol maintenance of the network stack provided by the protection computing chip, the display data is cached in the protected memory area in the form of a multimedia code stream.

[0028] Furthermore, the display data that needs to be protected from screenshots is obtained through a direct external interface of the protected memory area, or through encrypted transmission of the user memory area.

[0029] Furthermore, the protection computing chip is a computing chip that specifically processes the protection memory area, an independent computing chip, or a multiplexed user computing chip based on a secure world mechanism.

[0030] A software screenshot prevention device runs on a terminal device, including a user computing environment, a protection computing environment, and a display control chip deployed in the terminal device, wherein the user computing environment includes a user memory area and a user computing chip, and the user computing environment runs a user operating system, and the protection computing environment includes a protection memory area and a protection computing chip;

[0031] The display data that does not need to be protected from screenshots is stored in a user memory area that can be accessed by the protection computing chip and the user computing chip, and the display data that needs to be protected from screenshots is stored in a protection memory area that can only be accessed by the protection computing chip and cannot be accessed by the user computing chip, so that a screenshot instruction that only runs on the user computing chip and can only capture the display data in the user memory area cannot capture the display data in the protection memory area;

[0032] The user computing chip and the protection computing chip respond to the display operation command and are used to send the display data to the display connected to the display control chip for display.

[0033] A computer device includes a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of a method for preventing software from taking screenshots when executing the computer program.

[0034] A computer-readable storage medium stores a computer program, which implements the steps of a method for preventing software from taking screenshots when executed by a processor.

[0035] A computer program product includes a computer program, and when the computer program is executed by a processor, the steps of a method for preventing software from taking screenshots are implemented.

[0036] Beneficial effects:

[0037] 1. The present invention provides a method for preventing software screenshots, which stores display data that needs to be prevented from being screenshotted in a protected memory area that cannot be accessed by a user's computing chip, achieves physical isolation of display data from different sources at the hardware level, and implements the anti-screenshot method under the operating system, thereby effectively improving the security of the method; regardless of whether the user's operating system is secure and complete, malicious users cannot perform screenshot operations on the display data that needs to be protected.

[0038] 2. The present invention provides a method for preventing software screenshots, which can achieve efficient display data isolation and screenshot prevention when using an independent protection computing chip, without generating additional world switching performance overhead, thereby ensuring the performance of display update-intensive applications.

[0039] 3. The present invention provides a method for preventing software screenshots. Under the best practice, the display chip, user computing chip, protection computing chip and memory isolation device are placed in the same chip, which greatly reduces costs and improves efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A principle block diagram of an anti-software screenshot processing provided by the present invention;

[0041] Figure 2 A schematic diagram of the anti-screenshot process based on the cloud terminal scenario provided by the present invention;

[0042] Figure 3 This is a schematic diagram of a shared memory communication model provided by the present invention. DETAILED DESCRIPTION

[0043] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.

[0044] In view of the existing anti-screenshot technical solutions, the present invention intends to solve three technical problems:

[0045] 1. Implement anti-screenshot protection under the user's operating system to ensure that even if the user's operating system is attacked, malicious users still cannot steal display data.

[0046] 2. Implement display data protection at the physical memory level, and protect all display data based on hardware so that it cannot be intercepted.

[0047] 3. Only focus on the display data that needs to be protected, and keep the display data that users do not need to protect in the real world. Only process the display data that users need to protect in the secure world, and the display data of the two worlds can be switched at will and seamlessly integrated. No additional performance overhead is generated for switching between the ordinary world and the secure world.

[0048] Based on this, the present invention provides a method for preventing software screenshot processing, which runs on a terminal device, such as Figure 1 As shown, it includes a user computing environment, a protection computing environment and a display control chip, wherein the user computing environment includes a user memory area and a user computing chip and runs a user operating system, and the protection memory area includes a protection memory area and a protection computing chip;

[0049] Among them, the protection memory area needs to be isolated from the user memory area and implemented using additional physical memory particles or based on a memory physical isolation device. Among them, when the protection memory area is implemented based on a memory physical isolation device, the protection computing chip and the memory physical isolation device are placed in the same system chip.

[0050] The protection computing chip is a computing chip dedicated to processing the protection memory area, an independent computing chip, or a reused user computing chip based on the secure world (SWD / TEE) mechanism; in addition, if the secure world (SWD / TEE) mechanism is used to reuse the user computing chip, it will bring additional world switching overhead, and form a protection computing environment with the protection memory area. The protection computing chip executes instructions to control the storage of data in the protection memory area.

[0051] The display control chip needs to have the function of fetching data from the user memory area and the protection memory area respectively and performing composite display.

[0052] The user memory area is a memory area used by users, and is also used to store display data that does not need to be protected from screenshots.

[0053] Furthermore, the anti-software screenshot processing method comprises the following steps:

[0054] The display data that does not need to be protected from screenshots is stored in a user memory area that can be accessed by the protected computing chip, and the display data that needs to be protected from screenshots is stored in a protected memory area that cannot be accessed by the user computing chip, so that a screenshot instruction that only runs on the user computing chip and can only capture the display data in the user memory area cannot capture the display data in the protected memory area;

[0055] The user computing chip and the protection computing chip respond to the display operation command and are used to send the display data to the display connected to the display control chip for display.

[0056] It should be noted that the display data that needs to be protected from screenshots is obtained through the direct external interface of the protected memory area, or through encrypted transmission in the user memory area, or can be obtained from a cloud virtual machine, wherein the display data sent by the cloud virtual machine is encoded into a multimedia code stream, and then under the protocol maintenance of the network stack provided by the protection computing chip, the display data is cached in the protected memory area in the form of a multimedia code stream.

[0057] The following describes how to implement the anti-software screenshot processing process of the present invention using a cloud terminal scenario. Figure 2 As shown, the user operates the keyboard, mouse and other peripherals on the cloud terminal, enters the user name and password on the cloud terminal display interface, logs in to the cloud and obtains the display data of the cloud virtual machine and then sends it to the cloud terminal for display. The display data obtained from the cloud virtual machine is generally encoded into a multimedia code stream and decoded and displayed on the cloud terminal. This part is also the display data that needs to be protected from screenshots. In practice, an independent security core is used as a protection computing chip, and the display chip, user computing chip, protection computing chip (independent security core) and memory isolation device are placed in the same system chip (SoC).

[0058] That is to say, based on the usage scenario of the cloud terminal, the display data has three sources, the locally running interactive applications and graphics library, the user's mouse input, and the display data sent from the cloud network (S203). The first two data are processed by the user computing environment, that is, the user computing chip calculates and places the display data in the user memory area for display. This part is consistent with the display mode of other computer devices. The display data sent from the cloud network enters the protected computing environment from the network for processing. It is first transmitted to the network port of the cloud terminal device through the network, and the data is cached in the protected memory area under the protocol maintenance of the network stack of the protected computing environment.

[0059] Finally, the display control chip reads data from the user memory and the protection memory respectively for mixed operation, and then displays it on the display (S302). In this way, since the display data to be protected is always in the protection memory area, the possibility of screenshots from the user computing environment is fundamentally prevented.

[0060] The following describes how the cloud terminal system works normally in the anti-screenshot implementation solution, that is, how the user computing environment and the protection computing environment communicate with each other.

[0061] Specifically, Figure 3 As shown, the method for the protection computing chip to send display data to a display connected to the display control chip for display in response to the display operation command is:

[0062] S1: Adopt an agent program running on the user computing chip to intercept the display operation command issued by the user computing chip, and determine the source of the display operation command, wherein the source includes: locally running interactive applications and graphics libraries, commands input by the user's mouse, and display data related commands issued by the cloud network, such as login, logout, etc.; wherein, locally running interactive applications and graphics libraries, and commands input by the user's mouse are directly executed by the user computing chip.

[0063] S2: The agent program sends the display data related commands issued by the cloud network to the shared memory pre-opened in the user memory area for storage;

[0064] S3: The agent program sets a task flag and a task number for each display data related command issued by the cloud network in the shared memory, and writes the display data related command, wherein the task flag is divided into an execution completion flag and an unexecuted flag;

[0065] S4: using a decoding display application running on the protection computing chip to monitor the task flag in the shared memory in real time, and reading the task number corresponding to the unexecuted flag and the display data related command;

[0066] The protection computing chip executes the display data related commands and sends the display data to a display connected to the display control chip for display;

[0067] S5: The protection computing chip generates a command completion instruction for the executed display data related command, and sends the command completion instruction and the task number corresponding to the executed display data related command to the user computing chip;

[0068] S6: The user computing chip modifies the task flag corresponding to the task number in the shared memory to an execution completion flag according to the command completion instruction and the task number corresponding to the executed display data related command. That is, the user computing chip can quickly determine the completion progress of the task according to the flag.

[0069] The present invention solves three problems in software logic:

[0070] 1. Who controls the hybrid logic of the display control chip? Controlled by the user computing chip, this will bring great flexibility. Since the display data is isolated in the protected memory area, even if a malicious user controls the display control chip, it will not be able to complete the screenshot operation.

[0071] 2. How to synchronize the user computing environment and the protection computing environment. Because it is worthless to simply isolate the display data in a completely inaccessible area to prevent screenshots, the user computing environment must be able to use the display data in the protection memory in a controlled manner to have actual value. In order to solve this problem, the present invention uses a memory communication-based method to indirectly operate the display data in the protection memory, that is, the user computing environment communicates with the protection computing environment by reading and writing the user memory area to send display operation instructions, and the protection computing environment operates the display content after receiving these operation instructions.

[0072] 3. Where does the data in the protected memory area come from? It can be obtained directly from an external interface (network, etc.), or it can be obtained after being encrypted and transmitted through the user memory area.

[0073] Based on the above anti-software screenshot processing method, the present invention also provides an anti-software screenshot device, a computer device, a computer-readable storage medium and a computer program product;

[0074] Among them, an anti-software screenshot device runs on a terminal device, including a user computing environment, a protection computing environment and a display control chip deployed in the terminal device, wherein the user computing environment includes a user memory area and a user computing chip, and the user computing environment runs a user operating system, and the protection computing environment includes a protection memory area and a protection computing chip;

[0075] The display data that does not need to be protected from screenshots is stored in a user memory area that can be accessed by the protection computing chip and the user computing chip, and the display data that needs to be protected from screenshots is stored in a protection memory area that can only be accessed by the protection computing chip and cannot be accessed by the user computing chip, so that a screenshot instruction that only runs on the user computing chip and can only capture the display data in the user memory area cannot capture the display data in the protection memory area;

[0076] The user computing chip and the protection computing chip respond to the display operation command and are used to send the display data to the display connected to the display control chip for display.

[0077] Furthermore, the computer device includes a memory and a processor, the memory stores a computer program, and the processor implements the steps of the above-mentioned anti-software screenshot method when executing the computer program. A computer-readable storage medium stores a computer program, and the computer program implements the steps of the anti-software screenshot method when executed by the processor. A computer program product includes a computer program, characterized in that the computer program implements the steps of the above-mentioned anti-software screenshot method when executed by the processor.

[0078] In summary, the present invention provides a method, device, computer equipment, medium and program product for preventing software screenshots, which realizes physical isolation of display data from different sources at the hardware level, realizes the anti-screenshot method under the operating system, and effectively improves the security of the method. Regardless of whether the user's operating system is safe and complete, malicious users cannot perform screenshot operations on the display data that needs to be protected.

[0079] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art may certainly make various corresponding changes and modifications based on the present invention, but these corresponding changes and modifications should all fall within the scope of protection of the claims attached to the present invention.

Claims

1. A method for preventing software from taking screenshots, running on a terminal device, characterized in that: The terminal device is deployed with a user computing environment, a protection computing environment and a display control chip, wherein the user computing environment includes a user memory area and a user computing chip, and the user computing environment runs a user operating system, and the protection computing environment includes a protection memory area and a protection computing chip; The method comprises the following steps: The display data that does not need to be protected from screenshots is stored in a user memory area that can be accessed by the protection computing chip and the user computing chip, and the display data that needs to be protected from screenshots is stored in a protection memory area that can only be accessed by the protection computing chip and cannot be accessed by the user computing chip, so that a screenshot instruction that only runs on the user computing chip and can only capture the display data in the user memory area cannot capture the display data in the protection memory area; The user computing chip and the protection computing chip respond to the display operation command and are used to send the display data to the display connected to the display control chip for display.

2. A method for preventing software from taking screenshots according to claim 1, characterized in that: The method for the protection computing chip to send display data to a display connected to the display control chip for display in response to the display operation command is: Adopting an agent program running on the user computing chip to intercept the display operation command issued by the user computing chip, and determining the source of the display operation command, wherein the source includes: locally running interactive applications and graphics libraries, commands input by the user's mouse, and display data related commands issued by the cloud network; The agent program sends the display data related commands issued by the cloud network to the shared memory pre-opened in the user memory area for storage; The agent program sets a task flag and a task number in the shared memory for each display data related command issued by the cloud network, wherein the task flag is divided into an execution completion flag and an unexecuted flag; Using a decoding display application running on the protection computing chip to monitor the task flag in the shared memory in real time, reading the task number corresponding to the unexecuted flag and the display data related command; The protection computing chip executes the display data related commands and sends the display data to a display connected to the display control chip for display.

3. A method for preventing software from taking screenshots as claimed in claim 2, characterized in that: After the protection computing chip executes the display data related command and sends the display data to the display connected to the display control chip for display, the following steps are further performed: The protection computing chip generates a command completion instruction for the executed display data related command, and sends the command completion instruction and the task number corresponding to the executed display data related command to the user computing chip; The user computing chip modifies the task flag corresponding to the task number in the shared memory to an execution completion flag according to the command completion instruction and the task number corresponding to the executed display data related command.

4. A method for preventing software from taking screenshots as claimed in claim 2, characterized in that: Locally running interactive applications and graphics libraries, as well as commands entered by the user's mouse, are directly executed by the user computing chip.

5. A method for preventing software from taking screenshots as claimed in claim 1, characterized in that: The protected memory area is implemented using additional physical memory particles or based on a memory physical isolation device, wherein when the protected memory area is implemented based on a memory physical isolation device, the user computing chip, the protection computing chip and the memory physical isolation device are placed in the same system chip.

6. A method for preventing software from taking screenshots as claimed in claim 1, characterized in that: The display data that needs to be protected from screenshots is obtained from the cloud virtual machine, where the display data sent by the cloud virtual machine is encoded into a multimedia code stream, and then cached in the protected memory area in the form of a multimedia code stream under the protocol maintenance of the network stack provided by the protection computing chip.

7. A method for preventing software from taking screenshots as claimed in claim 1, characterized in that: The display data that needs to be protected from screenshots is obtained through a direct external interface of the protected memory area, or through encrypted transmission in the user memory area.

8. A method for preventing software from taking screenshots as claimed in claim 1, characterized in that: The protection computing chip is a computing chip that specifically processes the protection memory area, an independent computing chip, or a multiplexed user computing chip based on a secure world mechanism.

9. A device for preventing software from taking screenshots, running on a terminal device, characterized in that: It includes a user computing environment, a protection computing environment and a display control chip deployed in the terminal device, wherein the user computing environment includes a user memory area and a user computing chip, and the user computing environment runs a user operating system, and the protection computing environment includes a protection memory area and a protection computing chip; The display data that does not need to be protected from screenshots is stored in a user memory area that can be accessed by the protection computing chip and the user computing chip, and the display data that needs to be protected from screenshots is stored in a protection memory area that can only be accessed by the protection computing chip and cannot be accessed by the user computing chip, so that a screenshot instruction that only runs on the user computing chip and can only capture the display data in the user memory area cannot capture the display data in the protection memory area; The user computing chip and the protection computing chip respond to the display operation command and are used to send the display data to the display connected to the display control chip for display.

10. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 8 are implemented.

11. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 8 are implemented.

12. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 8 are implemented.

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