Physical Layer Secure Key Distribution Based on Artificial Amplitude Noise in QAM/QNSC Optical Communication Systems
Shuang Wei, Yajie Li, Kongni Zhu, Chao Lei, Yuang Li, Mengwen Pan, Wei Wang, Yongli Zhao, Jie Zhang
Abstract
In the quantum noise stream cipher (QNSC) system, the low-order plaintext is encrypted by pre-shared keys into high-order ciphertext. However, high-speed optical communication systems have a huge demand for pre-shared keys. On the other hand, the separation of the secure communications sub-system from the secure key distribution (SKD) sub-system increases potential security risks and introduces additional resources overhead. In this letter, we propose an artificial amplitude noise-based SKD scheme (AAN-SKD) in QAM/QNSC to generate secret key for legal parties accordingly. The two orthogonal PAM symbols are superimposed to generate QAM symbols. Thus, the AAN-SKD can also be implemented in PAM modulation. In addition, the data transmission and AAN-SKD are completed in the same channel. Experimental results indicate that the key generation rate and key consistency ratio of the proposed scheme can reach <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$188.22Mbit/s$ </tex-math></inline-formula> and 91%, respectively. Compared with quantum key distribution, the AAN-SKD has the advantage of lower cost, better compatibility, and a higher key rate.