October 2009 - ITP-quantumseminare

[QI] QI Seminar
by Dejan D. Dukaric 26 Oct '09

26 Oct '09

Dear All, This weeks research day on Tuesday will be at the Computer Science Building. Speaker: Matthias Fitzi Title: Side-Channel Attacks Time: 5 pm Place: IFW D42 Abstract: We present different side-channel attacks on cryptographic systems. As a related example, we demonstrate how to play a Cello Suite by Johann Sebastian Bach on a computer screen such that it can be received by radio. Cheers, Dejan

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talk next week
by Roger Colbeck 16 Oct '09

16 Oct '09

Hi all, Next Tuesday's talk will be by Christian Schaffner (CWI) at 5pm in HIT K51. Title and abstract below. Roger --- Improving the Security of Quantum Protocols via Commit-and-Open We consider two-party quantum protocols starting with a transmission of some random BB84 qubits followed by classical messages. We show a general "compiler" improving the security of such protocols: if the original protocol is secure against an "almost honest" adversary, then the compiled protocol is secure against an arbitrary computationally bounded (quantum) adversary. The compilation preserves the number of qubits sent and the number of rounds up to a constant factor. The compiler also preserves security in the bounded-quantum-storage model (BQSM), so if the original protocol was BQSM-secure, the compiled protocol can only be broken by an adversary who has large quantum memory and large computing power. This is in contrast to known BQSM-secure protocols, where security breaks down completely if the adversary has larger quantum memory than expected. We show how our technique can be applied to quantum identification and oblivious transfer protocols.

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talk tomorrow
by Roger Colbeck 12 Oct '09

12 Oct '09

Hi all, Tomorrow's talk will be in HIT K51 at 5pm by Cyril Stark. Title and Abstract below. See you there! Roger --- Breaking degeneracies: a route towards a thermally stable version of the Toric Code? I will try to explain an idea which might render the Toric Code stable against thermal interactions - at least to some extent. A repetition of some of the Toric Code basics will be followed by an illustration of the problems that arise when you let the Toric Code interact with a thermal environment: the interaction causes thermal excitations in the system that may lead to errors in the quantum computation if they move around the torus. Subsequently, I will describe a research project which is targeted at the suppression of the free movement of the thermally excited states enabling error correction at the end of the computation.

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[QI] QI Seminar
by Dejan D. Dukaric 05 Oct '09

05 Oct '09

Dear All, This weeks research day on Tuesday will be at the Computer Science Building. Speaker: Stefan Wolf Title: Classical and Quantum Entropic Security Time: 5 pm Place: IFW E42 (as the door will be locked you can call me to open the door: 27433) Abstract: Is it possible to encrypt a message with a short key such that even a computationally unbounded adversary gets no useful information? We discuss answers that have been given to this question, for classical as well as quantum messages. Cheers, Dejan

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