利用LDPC编译码构建无线密钥协商协议的研究

发布时间：2018-06-29 23:51

本文选题：低密度奇偶校验码 + 比特翻转　；参考：《信号处理》2017年08期

【摘要】：基于无线信道特征的密钥生成过程中,为了降低通信双方生成的密钥不一致率常采取的措施是密钥协商。通常的密钥协商过程是在BSC信道下进行密钥协商,但是协商的效率较低。为了提高密钥协商的效率,本文提出一种在等效信道下基于LDPC编译码的协议机制。在此协议机制中,无线信道下采用Mathur[1-2]等人提出的Level-Crossing算法(LCA)提取密钥的过程构成了本协议中的等效信道,该机制对LCA提取后的密钥协商信息进行建模,推导了等效信道的最佳似然比,并据此采用LDPC码简单的加权比特翻转等译码算法[3-5]来有效进行密钥协商。将等效信道下LDPC码加权比特译码算法用于协商过程的性能和BSC信道下协商后的性能进行仿真,在SNR大于6 d B的前提下,仿真结果表明:1)在相同低门限的条件下,和LCA算法生成的初始密钥相比较,利用LDPC码比特翻转译码等算法在等效信道下和在BSC信道下协商后的密钥不一致率比初始密钥不一致率降低1至2个数量级;2)在等效信道下利用简单加权比特翻转译码算法进行密钥协商后的密钥不一致率比BSC信道下协商后的密钥不一致率降低大约1个数量级。
[Abstract]:In the process of key generation based on wireless channel characteristics, key agreement is often adopted to reduce the inconsistent rate of key generated by both sides of the communication. The common key agreement process is based on BSC channel, but the efficiency of key agreement is low. In order to improve the efficiency of key agreement, this paper proposes a protocol mechanism based on LDPC in equivalent channel. In this protocol, the Level-Crossing algorithm (LCA) proposed by Mathur [1-2] under the wireless channel constitutes the equivalent channel in this protocol. The mechanism models the key agreement information after LCA extraction. The optimal likelihood ratio of the equivalent channel is derived, and a simple weighted bit flipping decoding algorithm [3-5] is used for key agreement. The weighted bit decoding algorithm of LDPC codes in equivalent channel is used to simulate the performance of the negotiation process and the negotiated performance in BSC channel. The simulation results show that when the SNR is greater than 6 dB, the simulation results show that: 1) under the same low threshold, Compared with the initial key generated by the LCA algorithm, The key inconsistency rate of LDPC code bit flipping decoding algorithm under equivalent channel and BSC channel is reduced by 1 to 2 orders of magnitude than that of initial key inconsistency rate.) in equivalent channel, simple weighted bit inversion is used. The key inconsistency rate of the decoding algorithm is about 1 order of magnitude lower than that of the BSC channel.
【作者单位】：南京邮电大学通信与信息工程学院;
【基金】：国家自然科学基金(61372123,61271335)
【分类号】：TN918.4

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