基于LDPC硬判决算法的高效数据协调方法

Efficient reconciliation using LDPC hard decision for quantum key distribution

数据协调是量子密钥分发中必不可少的一个环节,其主要目的是纠正量子通信筛选后信息的错误图案,使合法通信双方获得一致的密钥信息。为了提高协调算法的纠错效率,选择了一种基于硬判决迭代译码算法的LDPC码对QKD中的密钥序列进行数据协调,相较于传统的协调方法如级联码、卷积码、Winnow方案,采用低复杂度的LDPC比特翻转算法的正向协调方案具有较强的时效性,尤其是在0.4~0.6的码率时协调效率达到最高。

Reconciliation is a significant procedure in quantum key distribution（ QKD） system. It is employed to extract secure secret key from the sifted information by correcting error codes between two legal users. In this paper,we proposed an reconciliation protocol through employing a low density parity-check（ LDPC） code based on hard decision decoding algorithm in QKD system. From numerical simulation while it yields low complexity comparable to the existing LDPC-based reconciliation protocols and the performance of our proposed scheme is superior to conventional Winnow and CASCADE protocols,especially at the rate of 0. 4 ~ 0. 6,the reconciliation efficiency reaches the maximum value.