Davide Balzarotti Marco Cova Giovanni Vigna ClearShot: Eavesdropping on Keyboard Input from Video. 170-183 2008 IEEE Symposium on Security and Privacy http://doi.ieeecomputersociety.org/10.1109/SP.2008.28 conf/sp/2008 db/conf/sp/sp2008.html#BalzarottiCV08