From one of my newsletters;
'Blank' display hides computer data
14:55 03 August 2002
NewScientist.com news service
Computer Science Laboratory, Cambridge University
A computer screen that looks blank to anyone not wearing a pair of special polarising glasses has been developed by a Tokyo-based electronics company, Iizuka Denki Kogyo.
The company believes the modified LCD monitor will appeal to financial institutions that need to keep sensitive information safe from prying eyes in a busy environment.
Only authorised viewers wearing the special glasses would be able to read data on the screen. Anyone looking over their shoulder would see nothing at all. "To others, you would look like someone with sunglasses working in front of a totally white screen," said an official in charge of development at IDK.
The displayed data is rendered invisible by doing away with a light-polarising screen from the front of the monitor. All LCD's use this filter to block some of the polarised light that passes through liquid crystals controlled by an electrical current. This makes it possible to display information by defining different parts of the screen in light and colour.
In the IDK system, the polarising filter is effectively moved from the screen to the pair of glasses worn by authorised computer users.
Markus Kuhn, an expert in computer display security at Cambridge University, says the idea would be relatively simple to implement. But he warns that this security measure could be defeated by anyone who can get hold of a pair of correctly configured, light polarising glasses.
Alternatively, Kuhn told New Scientist, simple 3D movie glasses could defeat the system. These have a horizontal polarising filter on one eye and a vertical filter on the other eye.
"By tilting the head up to 45 degrees to either side and switching between both eyes, you can easily observe light at all polarisation angles," he says. Kuhn adds that an opaque shielding device might be simpler way to obstruct prying eyes.
The 15-inch IDK screens are expected to go on sale at the end of 2002 and to cost between $1600 and $2500.
At that price I'm glad I live alone!
Mod Edit: Moved topic to more appropriate forum. ~ Animal
Edited by Animal, 17 July 2006 - 03:36 PM.