This talk should introduce the general 30c3 participant with several components of long distance quantum communication.
Quantum key distrution, popularized under the name quantum cryptography, is the widest known branch of quantum communication. It describes the secure exchange of a secret key in public, protected by physical laws. Several components are necessary to extend over long distances, which are actively researched. An introduction will be given into the theoretical and experimental requirements for quantum communication. The concept of the quantum repeater, with its components, quantum memory and entanglement swapping, will be discussed in detail.