We present an entangled-state quantum cryptography system that operated for
the first time in a real world application scenario. The full key generation
protocol was performed in real time between two distributed embedded hardware
devices, which were connected by 1.45 km of optical fiber, installed for this
experiment in the Vienna sewage system. The generated quantum key was
immediately handed over and used by a secure communication application.Comment: 5 pages, 3 figure