Prof. Dr. Dagmar Bruss
(Institute for Theoretical Physics III
Heinrich-Heine University  Duesseldorf, Germany)

Quantum Key Distribution: From Principles to Satellite-Based Implementations

Quantum cryptography employs quantum mechanical properties for
cryptographic tasks.  A famous example is quantum key distribution
(QKD), where two parties aim at establishing a common secret random key.
A QKD protocol will be explained, together with the physical
principles underlying its security. An essential figure of merit for
QKD protocols and their practical implementation is the secret key
rate. Regarding implementations of QKD via satellites we provide
a general model for the losses in satellite-based optical links,
including weather dependence, and evaluate the performance
in terms of secret key rates.