I first heard about MultiPath TCP (MPTCP) in 2007 when I met Olivier Bonaventure in Louvain-la-Neuve, Belgium.
In the meantime MPTCP has been gaining a ton of traction, from having Apple using it for Siri on iOS to large loadbalancer vendors like F5 supporting it and even large-scale media covering it's advantages.
If you want a primer on MPTCP you should check out the suprisingly readable RFC, or even this article by Olivier Bonaventure. There is also a ton of information on the Linux Kernel MultiPath TCP project multipath-tcp.org.
Anyway, the point of this post is to share a Security oriented presentation that I did on a MPTCP a while back. Enjoy.