AbstractA new class of computers, so-called quantum computers, will soon be able to crack common encryption algorithms. Quantum key distribution is a promising solution to stay secure in the age of the quantum computer, which is progressively getting industrialized in recent years. Worldwide, point-to-point quantum key distribution links are combined into larger and larger testbed networks, which approach more and more commercially usable networks. Topics like certification and standardization have become increasingly important for quantum key distribution.