Phil Mackenzie, Lucent Bell Laboratories

This talk is actually a combination of two talks, both with the same title! The "first" talk shows how to construct real world physical examples of basic concepts in theoretical cryptography, such as commitments and zero-knowledge proofs. These involve easily constructed props and interaction with the audience, and would be suitable for teaching those with no prior background in cryptography. The "second" talk takes the basic concepts of commitments and zero-knowledge proofs, and shows that in the real world (say, on the Internet), the security of these concepts breaks down, due to issues such as concurrency and active network attacks. Then it shows how to repair these concepts, specifically by adding a recently developed notion of "simulation soundness", and finally presents efficient instantiations of simulation-sound commitments and zero-knowledge proofs.

The "second" talk includes results from joint work with Juan Garay (Bell Labs) and Ke Yang (Carnegie Mellon University)