Institute for Quantum Information Seminar

The realization of devices which harness the laws of quantum mechanics represents an exciting challenge at the interface of modern technology and fundamental science. A perfect example of the power of such quantum primitives is the concept of "quantum money". A dishonest holder of a quantum bank-note will invariably fail in any forging attempts; indeed, under assumptions of ideal measurements and decoherence-free memories such security is guaranteed by the no-cloning theorem. In any practical situation, however, noise, decoherence and operational imperfections abound. Thus, the development of secure "quantum money"-type primitives capable of tolerating realistic infidelities is of both practical and fundamental importance. We focus on approaches with minimal technological requirements consisting of the ability to prepare, store and measure single qubit. In this talk I will present and formally analyze the security and noise tolerance of such protocols and find tight fidelity thresholds.