A countermeasure for compromising electromagnetic emanations of wired keyboards

confidential data are often transmitted by computer keyboards. Electromagnetic waves are emitted as they contain electronic components. Very sensitive information like keystrokes can be revealed by these emanations. Most of the modern computer keyboards generate compromising emanations. Best practical attack can fully recover up to 95% of the keystrokes of a PS/2 keyboard at a distance up to 20 meters, even through walls. Some counter measures have been indicated in some previous work. But, those are not cost effective and convenient. So, we propose a model of a device which can be cost effective and convenient. It can jam the emanation. Compromising emanations before and after jamming are also shown and compared.