密钥提取中降低密钥不一致率的量化方法研究

Research on Quantization Method of Reducing Bit Disagreement Rate in Secret Key Extraction

在现有的基于无线信道特征的物理层密钥提取方法中,合法通信双方量化门限附近的测量值有较大可能被量化到门限两侧,从而造成收发双方生成密钥的不匹配。针对这一问题,有学者提出了基于量化隔离带的信道量化方法,通过删除量化隔离带内的测量值以降低生成密钥不一致率,但影响了密钥生成速率。对此,文章提出一种基于量化隔离带的自适应信道量化方法(ACQG),通过对量化隔离带内的测量值进行自适应调整,在保证密钥一致性的基础上提高了密钥生成速率。为了进一步提高生成密钥一致性,文章在ACQG的基础上又提出了自适应修正信道量化方法(MACQ)。仿真结果表明,与传统密钥提取算法相比,文中方法可以有效提高密钥提取速率和生成密钥一致性。

In the existing PHY key extraction method based on wireless radio channel characteristics, the measurements which near to a threshold are likely to be quantized to the sides of the threshold in high probability at two legitimate nodes, resulting in bit disagreement in generated secret key. In order to solve this problem, this paper proposes an adaptive channel quantization with guard-band （ ACQG） method, which can reduce the bit disagreement rate in generated secret key by adaptively modifying the measurements which located in the guard- band. In order to further improve the bit agreement in generated key, this paper proposes a modified adaptive channel quantization （MACQ） method based on ACQG. Simulation results show that, compared with the traditional key extraction algorithm, the proposed methods can improve the rate of key extraction and bit agreement in generated key effectively.