Introduction to the theory of quantum computing and information. Explore the rules of quantum mechanics (qubits, unitary transformations, measurements, density matrices); quantum gates and circuits; entanglement; the Bell inequality; protocols for teleportation, quantum key distribution, and other tasks; basic quantum algorithms such as Shor's and Grover's; basic quantum complexity theory; basic quantum error correction; decoherence and the measurement problem; and the challenges of building scalable quantum computers. Previous exposure to quantum mechanics is not required. Three lecture hours a week for one semester. Computer Science 358H and 378H (Topic: Intro to Quantum Info Sci: Hon) may not both be counted. Prerequisite: Computer Science 331 or 331H with a grade of a least C-.