Creating and sharing knowledge for telecommunications

Seminar - Improving classical authentication over a quantum channel

on 03-05-2013

... Paulo Mateus, SQIG - IT / IST - UTL

May 3, 2013, Friday, 16h15m.

Abstract: We introduce a quantum protocol to authenticate classical messages that can be used to replace Wegman-Carter's classical authentication scheme in quantum key distribution (QKD) protocols. We show that the proposed scheme achieves greater conditional entropy of the seed for the intruder given her (quantum) observation than the classical case. Our protocol is an improvement over a classical scheme by Brassard, taking advantage of quantum channel properties. It is motivated by information-theoretical results. However by adopting it, QKD becomes a fully quantum protocol. We prove that quantum resources can improve both the secrecy of the key generated by the PRG and the secrecy of the tag obtained with a hidden hash function. We conclude that the proposed quantum encoding offers more security than the classical scheme and, by applying a classical result, we show that it can be used under noisy quantum channels. Joint work with F. Assis, A. Stojanovic and Y. Omar.

Room: 3.10, Mathematics

Support: SQIG/Instituto de Telecomunicações with support from FCT and FEDER namely by the FCT project PEst-OE/EEI/LA0008/2011.

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Talk - Opportunities at the interface between quantum (nano) physics and biology

on 18-04-2013

... Alipasha Vaziri, University of Vienna

18/04/2013, 15:00 ­ Room P3.10, Mathematics Building, IST.

In this talk I will present and discuss a few recent biophysics methodologies that have opened up the way to study a series of new biological questions ranging to single molecule studies to control of read out of neuronal network activity. The topics will include amongst others such-super resolution microscopy, single molecule techniques and optogenetics. I will introduce the basics of the methods followed by case examples of their application in specific biological or biophysical questions. In addition I will point out to a few recent developments a physics based approach to biological questions has led to the discovery of new principles that are now leading to the new field of quantum biology, where non-trivial quantum effects such as quantum coherence are thought to be generated through dynamic interactions with relevance for biological function. More Information..