Prof. Nigel smart answers: What are garbling circuits? What books would you recommend to learn more about public key cryptography? Is cryptography concerned with worst or average case difficulty to solve problems? In the ‘Ask the Professor’ video series, Professor Nigel Smart, a world-renowned expert in applied cryptography, professor at the COSIC group at the KU Leuven and a fellow of the IACR, answers the internet’s’ most interesting questions about cryptography. Based on questions from popular blogs, forums, and social media—this series is relevant for both beginners and advanced crypto enthusiasts alike.