  We report the first quantum key distribution (QKD) systems capable of
delivering sustainable, real-time secure keys continuously at rates exceeding
10 Mb/s. To achieve such rates, we developed high speed post-processing
modules, achieving maximum data throughputs of 60 MC/s, 55 Mb/s, and 108 Mb/s
for standalone operation of sifting, error correction and privacy amplification
modules, respectively. The photonic layer of the QKD systems features
high-speed single photon detectors based on self-differencing InGaAs avalanche
photodiodes, phase encoding using asymmetric Mach-Zehnder interferometer, and
active stabilization of the interferometer phase and photon polarisation. An
efficient variant of the decoy-state BB84 protocol is implemented for security
analysis, with a large dataset size of $10^8$ bits selected to mitigate
finite-size effects. Over a 2 dB channel, a record secure key rate of 13.72
Mb/s has been achieved averaged over 4.4 days of operation. We confirm the
robustness and long-term stability on a second QKD system continuously running
for 1 month without any user intervention.
