Re: detecting keystokes via satellite

From: Markus Kuhn (n05W27+mgk25_at_cl.cam.ac.uk)
Date: 07/07/05 

Date: 7 Jul 2005 12:35:58 GMT

"Nathan Gant" <NGANT17@peoplepc.com> writes:
|> Is it possible for overhead satellites to detect the infrared or Van Eyk
|> signature of the keystrokes coming from a typical PC?

The paper

  http://www.cl.cam.ac.uk/~mgk25/ieee02-optical.pdf

explains (in section 6.3) how you can calculate a theoretical upper
limit (due to shot noise) for the range at which a passive
eavesdropping attack on an IR channel works. You just need
to plug in some numbers for your particular scenario
(in particular: bit rate, transmitter luminosity, background
luminosity within the receiver band).

Markus