Display filter — protection from an outside observer.
VINITI, 1996.
Display filter — protection from an outside observer.
In the field of computer security systems, significant investments are often required in information security products such as Kerberos, firewalls, and other hardware and software solutions. However, the possibility of information leakage from computer displays is usually overlooked. To prevent such leakage, the company Focus Computer Products (USA) offers special filters Focus-opti-Plus Privacy installed in front of display screens, making the data displayed on the screens invisible to outside observers. These filters allow only legitimate users and operators to read data from display screens. For all other persons, data records on the screens are presented in a blurred form.
The filter surface transmits incident light and disperses 75% of the transmitted light in a translucent layer at an angle of about 25° in the center of the screen. For any observer looking at the screen in a direction offset from its center line, the screen will appear to be frosted glass.
Defense fee Security Electronics tested two versions of a secure screen with filters: SV 95 for Laptop computers and SV 95-Wide for a standard monitor with a diagonal screen size of 20 cm. Both filters are easily attached to the display and monitor. The filters allow legitimate users to see clearly displayed data on the screen, but when deviating from the center line of the screen, the information presented on it becomes unreadable. Tests have shown that the filters for both screens are a simple means of protecting the data displayed on the screens from unauthorized reading. The price of one filter is less than $100.