I have re-encoded all of the DEF CON 18 videos with h.265, significantly reducing the file size while keeping the same quality.

All the old torrents are no longer seeded.
PLEASE download and seed the newer, smaller ones:

Slides https://media.defcon.org/DEF%20CON%2...slides.torrent
Video and Slideshttps://media.defcon.org/DEF%20CON%2...slides.torrent
Hacker Jeopardy https://media.defcon.org/DEF%20CON%2...opardy.torrent