基于EMD的物理层生成密钥方案在车辆通信中的研究

Research on EMD-Based Physical Layer Key Generation Scheme in Vehicle Communication

摘要: 利用信道内在的随机性和互惠性来生成实现车辆安全通信所需的共享密钥是一种有效的方法。然而，由于一些因素，当通信双方完成相互探测信道后，获得的信道测量序列之间存在许多差别。当这些测量值直接用来生成密钥序列，会导致较高的比特不匹配率，给信息协商阶段增加一定的负荷。在这篇文章中，我们利用经验模态分解(EMD)来预处理这些测量序列，得到的序列经过量化及编码、信息协商和保密增强等步骤，生成最后的共享密钥。我们做了一些实验来评估该方案，实验结果表明，经过EMD方法预处理后，通信双方的信道探测序列间差异明显减少，并且生成的共享密钥通过了随机性测试。

Abstract: It is an effective method to use the inherent randomness and reciprocity of the channel to generate the shared key needed to realize the secure communication of the vehicle. However, due to some factors, there are some discrepancies between the channel measurement sequences obtained after the two communication parties complete the mutual detection of channels. In addition, when these measured values are directly used to generate the key sequence, it will lead to a high bit mismatch rate and add a certain load to the information reconciliation stage. In this article, we use Empirical Mode Decomposition (EMD) to preprocess these measurements, and the resulting sequence undergoes quantification and coding, information reconciliation and privacy amplification steps to generate the final shared key. Moreover, we have done some experiments to evaluate the scheme. The results demonstrate that after the preprocessing of the EMD scheme, the difference between the channel detection sequences of the communicating parties is significantly reduced, and the generated shared key has passed the randomness test.