基于极化码的单步量子密钥分发后处理

量子密钥分发结合一次一密的加密方案可以在理论上保证通信的无条件安全性。然而，量子密钥后处理过程中的误码纠错和密性放大两个步骤引入了较高的处理延时，影响了最终安全密钥生成速率以及量子密钥分发系统的实用性。故此，本文提出一种基于极化码的单步高效量子密钥后处理算法，根据Wyner窃听信道模型分析合法通信双方以及窃听者的信道容量，设计可同时满足可靠性和安全性的极化码码字结构用于量子密钥分发后处理，从而实现在一次编译码步骤中同时完成误码纠错和密性放大，将两个处理步骤合二为一，降低了系统复杂度和处理延时。实验结果表明，在量子比特误码率0,0.08]范围内，所提出算法可同时满足纠后误码率10-7的可靠性条件以及窃听信息量10-14的安全性条件，码长为220比特时，译码吞吐率可达3Mbps，采用并行算法的译码吞吐率可达86Mbps。

Polar Codes-based One-step Post-processing for Quantum Key Distribution

Quantum key distribution guarantees the unconditional security of communication by combining with the one-time pad encryption scheme. However, the error correction and privacy amplification of quantum key distribution post-processing result in high processing delay, influencing the final secret key generation rate and the practicality of quantum key distribution system. Therefore, this paper proposes a one-step post-processing algorithm based on polar codes for quantum key distribution. By analyzing the channel capacity of the two legal communicators and the eavesdropper respectively under wyners wiretap channel model, this paper designs a codeword structure of polar codes which could satisfy the reliability and security for quantum key distribution post-processing, so that the error correction and privacy amplification could be completed synchronously in every encoding and decoding. Combining the two processing steps into one, it reduces the system complexity and the processing delay. Experimental results show the proposed algorithm could satisfy the reliability condition that bit error rate less than 10-7 after error correction and the security condition that the information eavesdropping less than 10-14 in the quantum bit error rate 0,0.08], and the decoding throughput could achieve 3Mbps and 86Mbps with parallel decoding under the code length 220.