Privacy-enhanced Displays by Time-masking Images

This paper describes a method for enhancing the privacy of computer displays in public and semipublic areas. By operating the display at a higher-than-usual frame rate and alternately displaying frames of an arbitrary private image and a computed mask image, unauthorized viewers perceive one image, while authorized viewers with appropriately keyed shutterglasses see an entirely different (and private) image. Although the technique can be defeated, it provides a measure of privacy against casual and opportunistic privacy penetrations.