Explore a groundbreaking framework for executing complex smart contracts on Bitcoin in this 20-minute conference talk from USENIX Security '19. Dive into FastKitten, a practical solution that leverages trusted computing environments (TEEs) to enable efficient off-chain contract execution at low costs. Learn about the protocol's setup and round phases, security properties, and how it handles malicious actors. Discover how FastKitten overcomes Bitcoin's limitations in supporting complex smart contracts, and see its practical application through a provably fair online poker game implementation. Gain insights into the future of decentralized cryptocurrencies and smart contract execution in this comprehensive presentation by Lisa Eckey from Technische Universität Darmstadt, Germany.