Controlling display brightness, contrast, and/or viewing angle at user authentication screen
Original Publication Date: 2004-Dec-01
Included in the Prior Art Database: 2004-Dec-01
Disclosed is a system and means to prevent the password string from being stolen at the user authentication program running on personal computer (PC). There is a security risk that user may not type the password string into the password prompt but may type it into different window (or program) of the screen so that the typed password will be echoed back to the display without being masked and the password string may be seen and stolen by people around the PC. In addition, it's preferred that even the user ID string can not be seen by other people for better security. This invention explains the means to avoid the security risk by controlling the display of the PC while such user authentication program is running.
Controlling display brightness, contrast, and /or viewing angle at user authentication screen
1. Problem Resolved by the Disclosure
While using PC, it's often required to enter user ID as well as its associated password for user authentication. For example, for BIOS passwords, for logging-on to Windows* operating system, or for entering secured web sites, etc..
Typically, the user is required to enter his/her user ID first. Usually, typed user ID string is displayed on the screen. Then the user is required to enter the password associated with the user ID. Typed password string will not be echoed back but special character(s) such as '*' will be displayed instead in most of the cases. This is to prevent from the password string being stolen by the people around the PC.
But there is a possibility that the user may type the password string into the portion of the screen (i.e. window) which is NOT for entering password. It may be the prompt for the user ID. Or the user may have switched the active window unintentionally and may type the password string into the different application program running on the PC. In that case, typed string (characters) will be displayed without being masked the typed password may be seen and stolen by the people around the PC.
In addition, it's preferred that even the user ID string can not be seen by other people for better security . This invention addresses the solution for the problem stated above.
2. Summary of Disclosure
When the user authentication program runs and it shows the prompt for user ID and/or password, the user authentication program itself or other software program calls the software program that can control the appearances of the PC's display ("display control program" hereafter) and the display control program shall control the display so that the screen becomes difficult to read from the people around the PC . This makes it much more difficult for the people around the PC to read and steal the user ID and the password . There are several possible methods to make the display screen difficult to read and this invention proposes the following four means.
Means 1. Controlling the brightness of the whole screen of the display Means 2. Controlling the contrast of the whole screen of the display Means 3. Controlling the brightness and/or the contrast of the part of the screen of the display Means 4. Controlling the viewing angle of the display
3. How it could be implemented
This invention can be implemented by following two parts.
1. Change or detection of the user authentication program so that the display control program can be called at the beginning and at the end of the user authentication.
2. Display control program including necessary hardware and software mechanism to control brightness/contrast an...