  We demonstrate a quantum key distribution with a secure bit rate exceeding 1
Mbit/s over 50 km fiber averaged over a continuous 36-hours period. Continuous
operation of high bit rates is achieved using feedback systems to control path
length difference and polarization in the interferometer and the timing of the
detection windows. High bit rates and continuous operation allows finite key
size effects to be strongly reduced, achieving a key extraction efficiency of
96% compared to keys of infinite lengths.
