David is a Senior Consultant with Intrepidus Group, where he performs web and iOS application security testing, penetration testing, iOS research, MDM reverse engineering, and other such fun. He's fortunate to have spoken at multiple security conferences on topics from rainbow tables to MDM to puzzle contests.

When not actively engaged in paying work, David loves solving crypto puzzles, working on side projects like KhanFu.com, and, when he remembers the app on his phone, looking for Geocaches. He can be found on Twitter as DarthNull, and is way behind on his puzzle writeups at darthnull.org