利用概率整形提升非对称Y-00协议密钥分发速率OA

In the era of explosive growth in communication data,secure key distribution is urgently required to guarantee information security.Different from key distribution based on deterministic algorithms,physical-layer key distribution has attracted extensive attention owing to the inherent randomness of physical processes.Typical physical-layer key distribution methods mainly include quantum key distribution,ultra-long fiber laser,chaotic laser synchronization,fiber channel reciprocity,and the Y-00 protocol.In particular,key distribution schemes based on the Y-00 protocol exhibit great application potential,as they require no additional hardware and are fully compatible with existing optical fiber communication systems. In this paper,we propose a novel key distribution scheme combining the probability shaping technology with the Y-00 protocol.This scheme significantly optimizes signal transmission performance by adjusting the occurrence probability of QAM constellation points,thereby effectively improving the key distribution rate(KDR).Meanwhile,we analyze the effects of different probability shaping factors on the KDR and the system security,and select the optimal value as the system parameter.Furthermore,privacy amplification is introduced to compress the initial key sequence to strengthen the security of the final key,and guarantee that eavesdroppers cannot obtain any effective key information.Experimental results demonstrate that the proposed method achieves a KDR of 13.76 Mbit/s over a 25 km of standard single-mode fiber.This method provides a feasible solution for exploring a high-speed and secure physical layer key distribution compatible with current optical communication systems.