Text Box: Colloquium of the Institute for Quantum Information Science 2:00 pm, Friday, 10 June 2005, in Science B 146 Text Box: Priv. Doz. Norbert Lütkenhaus, Ph.D. Institut für Theoretische Physik, Universität Erlangen-Nürnberg, Erlangen, Germany, http://kerr.physik.uni-erlangen.de/qit Text Box: Title: Quantum Key Distribution Abstract: Quantum Key Distribution (QKD) offers to provide secret key to distant parties who have an authenticated public channel and a quantum channel at their hand. In this talk I will outline the basic principles behind this idea. The success of QKD comes from the fact that it can be implemented with standard components of optical communication technology. I will summarize the basic successes and challenges in this field.