Design by Contract
I am currently working on some research projects aimed at fusing Design by Contract and Bounded Exhaustive Testing. The follow-up to that is a slightly more general project consisting of installing runtime monitors on python objects. That project consists of Higher-order contracts (e.g. allowing you to install a precondition which requires a parameter to be a method which satisfies a postcondition).
Software Protection / Reverse Engineering
A while ago, Jay Freeman (saurik) and I were reading about various reverse engineering techniques and contemplating how to defeat them. We wrote a small white paper about it. I later ended up working on a reverse engineering project with Anacapa Sciences.