Russell Impagliazzo

Russell Impagliazzo is a computer scientist known for his work in computational complexity, which studies how difficult problems are to solve with computers. He proposed a framework classifying problems into five main scenarios: some are efficiently solvable, some are hard but solvable in principle, and others are truly resistant to efficient algorithms, even if solutions exist. This classification helps researchers understand the limits of computation and guides efforts to develop better algorithms or prove certain problems are inherently difficult. His work provides a way to think about the difficulty of problems in computer science and influences research in cryptography and algorithm design.