Iridium Pager Hacking. Turns out messages are not encrypted at all, and can be captured by any one over wide geographical ranges (~1000 km). https://www.youtube.com/watch?v=xCf5JFpOkDs&index=36&list=PL...
Security Analysis of Estonia's Internet Voting System. https://www.youtube.com/watch?v=JY_pHvhE4os&index=37&list=PL...
AMD x86 SMU firmware analysis. Not watched it yet, but topic seems interesting. https://www.youtube.com/watch?v=yE_PMcwltzo&index=16&list=PL...
And of course the SS7 talks showing glaring flaws in mobile networks:
Mobile self-defense. https://www.youtube.com/watch?v=GeCkO0fWWqc&index=10&list=PL...
SS7: Locate. Track. Manipulate. https://www.youtube.com/watch?v=lQ0I5tl0YLY&index=4&list=PLO...
SS7map: mapping vulnerability of the international mobile roaming infrastructure https://www.youtube.com/watch?v=SfPC9IHCW-U&index=27&list=PL...