Dear all, see attachment for physics talk in D-GESS. Best wishes, Matthias. Register for: QCRYPT 2011 - First Annual Conference on Quantum Cryptography September 12-16, 2011 ETH Zurich www.qcrypt.net Matthias Christandl Institute for Theoretical Physics ETH Zurich http://www.itp.phys.ethz.ch/people/christandl/index