As a computer scientist I have worked on the design and analysis of algorithms, including algorithms for combinatorial and geometric problems. For the last twenty-five years I have been working on quantum computation. I showed that it was possible to use a quantum computer, a hypothetical machine that exploits the properties of quantum mechanics, to factor large numbers efficiently, and thus break the widely used Rivest-Shamir-Adelman cryptosystem. I subsequently showed that it was possible to design quantum-error-correcting codes that protect quantum information from decay and decoherence, and that these could be used to design fault-tolerant circuits for a quantum computer, dramatically reducing the error tolerances required to build such a computer. Recently, I have also been working on quantum information theory, trying to analyze how much information can be transmitted over a quantum channel. Unlike the classical case, for which there is essentially only one capacity given by the formula of Shannon, in the quantum case the capacity depends on whether the information to be transmitted is classical or quantum, and what auxiliary resources are available.

Research Interests

I am working on quantum algorithms, quantum cryptographic protocols, and quantum information theory.

Membership Type


Election Year


Primary Section

Section 34: Computer and Information Sciences

Secondary Section

Section 32: Applied Mathematical Sciences