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Quantum systems bring unprecedented advantages to the realization of classical cryptographic tasks. A remarkable example is quantum key distribution, which allows two parties, Alice and Bob, to establish a shared secret key that can be used for unconditionally secure communication. Furthermore, the strong correlations exhibited by quantum systems can be explored to construct cryptographic protocols that are secure even when the parties are completely ignorant about the internal working of their devices. This is the device-independent paradigm. In this talk I will introduce the device-independent scenario and comment on recent results on device-independent quantum key distribution. Then I will move to the scenario of many parties and discuss multipartite cryptographic tasks. Finally, I will present new results on bounding the uncertainty of an eavesdropper in this setting, and discuss their application to multipartite cryptographic protocols.

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Gláucia Murta, Heinrich-Heine-Universität Düsseldorf
Seminar Room 0.03, ETP
Contact: D. Gross