Information for

Quantum computing


Contact person: Richard Cleve,

Group members:  

Richard Cleve, Ben Reichardt, John Watrous


Quantum information formulates the notion of information in a manner that accounts for the quantum mechanical behaviour of our world. In this framework, models of computation and communication that harness the strange power of quantum mechanics have been proposed and investigated. In particular, quantum computers are computing devices can exist in several states simultaneously and their computation paths can interfere with each other. They can perform some tasks exponentially faster than any classical computer (restricted to the laws of classical physics). For example, a quantum computer can factor an n-bit integer in time polynomial in n, whereas all known classical algorithms require exponential time to do this. It follows that a quantum computer can easily break many public-key cryptosystems, such as RSA. There are, however, quantum public-key cryptosystems based on the uncertainty principle, that are provably secure against any (classical or quantum) attack.

Quantum computing in the School of Computer Science is focused on the theoretical aspects of quantum computing, including the design and analysis of quantum algorithms, cryptographic protocols, quantum fault tolerance, and various issues in information and complexity theory.