Real-time adaptive 4–64 QAM, 20–60 Gbit/s quantum noise stream cipher transmission over 320 km with FPGA-based transmitter and receiver

We demonstrate a real-time adaptive 4-64 QAM, 20-60 Gbit/s quantum noise stream cipher transmission over 320 km with an FPGA-based transmitter and receiver. The QAM data multiplicity can be randomly changed on-line, which increases the encryption security.