Patent ID: 8683199

Claim:
A screen information protection system for protecting information on a screen in a computer having a memory which image data can be written to and read from, when image data in the memory is displayed on the screen in response to a drawing command of an application program associated with a security label, comprising: label map storage means having on-screen security label map information corresponding to a screen display area in the memory, and having at least one off-screen buffer label map information corresponding to an off-screen buffer; detecting means for detecting a command to read image data from a read area in the memory, the read area designated by the application program; and control means for checking at least one of the on-screen security label map information or the at least one off-screen buffer label map information corresponding to the read area in the label map storage means in response to the detection by the detecting means, and for prohibiting the application program from performing read operation from the read area in response to the security label of the application program being lower in level than that of the read area.