Results from the SECOQC quantum-key-distribution network

The rapid progress of QKD in theory and experiment has been reflected by a number of successful demonstrations during the last years. Many groups all over the world have put forward QKD-links, operating in the standard point-to-point mode. However, broad proliferation of QKD systems is slowed down by a number of road blocks: the point-to-point paradigm and correspondingly the quadratic scaling of the necessary initial secrets with the number of users, the question of integration in existing networks, high price and also by issues like missing standards. As a result, QKD appears still to be forced into a narrow niche market.