in IEEE Symposium on Security and Privacy, Proceedings of SSP'08, pp. 158-169, July 2008.
We present a novel eavesdropping technique for spying at a distance on data that is displayed on an arbitrary computer screen, including the currently prevalent LCD monitors. Our technique exploits reflections of the screen's optical emanations in various objects that one commonly finds in close proximity to the screen and uses those reflections to recover the original screen content. Such objects include eyeglasses, tea pots, spoons, plastic bottles, and even the eye of the user. We have demonstrated that this attack can be successfully mounted to spy on even small fonts using inexpensive, off-the-shelf equipment (less than 1500 dollars) from a distance of up to 10 meters. Relying on more expensive equipment allowed us to conduct this attack from over 30 meters away, demonstrating that similar attacks are feasible from the other side of the street or from a close-by building. We additionally establish theoretical limitations of the attack; these limitations may help to estimate the risk that this attack can be successfully mounted in a given environment.
This publication is accompanied by links to downloadable versions of this publication. These documents do not necessarily correspond exactly to the cited version. Instead, in most cases full, updated or preliminary versions are provided. For access to the official version, follow the "Official version" link to the publishers site.
Slides used in my talks are available upon personal request, as long as you agree not to disseminate them to a wider audience or make them available online. If in doubt, please ask.