His research interests span distributed systems, security, and operating systems, with a particular emphasis on digital currencies and self-organizing systems. He is the inventor of Karma, the first cryptocurrency based on Proof of Work that predated Bitcoin. He is also known for having co-discovered the biggest known protocol flaw in the Nakamoto Consensus, for having fought mining centralization, for developing security measures to protect high-value digital assets from theft, and for anticipating the DAO hack. He runs the popular blog Hacking, Distributed.