Combined Optical Fiber Transmission System Based on QNSC and BER-LM

A quantum noise stream cipher (QNSC) is a physical layer encryption technology based on noise. Bit error rate loopback measurement (BER-LM) method to measure the BER of channel and extract characteristics. Then, characteristics can be extracted, consensus keys obtained through negotiation. In previous studies, key distribution were implemented in independent channels. this paper, we propose scheme that combines these two technologies single fiber achieve encrypted transmission distribution. We verified 20 Gbps QPSK coherent optical system with PSK/QNSC scheme. The results show by reasonably setting negotiation bit position, could negotiation, requirements performance met. When position was set seven, Q-factor nine, which met error-free condition 7% forward correction (FEC) limit.