Russell Impagliazzo studies hard problems, the limits of cryptography, the nature of randomness and more.Russell Impagliazzo, a computer scientist at the University of California, San Diego, uses his vivid imagination to study the difficulty of computational problems.Jesse Aragon for Quanta MagazineIntroductionImagine you’re on a quest to understand the very nature of computation. You’re deep in the wilderness, far from any paths, and inscrutable messages are carved into the trunks of trees all ...