Tamara Denning Kevin Fu Tadayoshi Kohno Absence Makes the Heart Grow Fonder: New Directions for Implantable Medical Device Security. 2008 HotSec http://www.usenix.org/events/hotsec08/tech/full_papers/denning/denning.pdf conf/uss/2008hotsec db/conf/uss/hotsec2008.html#DenningFK08