Physical layer key generation from the wireless channel is an emerging area of interest to provide confidentiality and authentication. One of the main challenges in this domain is to increase the length of the generated secret key while maintaining its randomness and uniformity. In this letter, new dimensions for wireless channel-based key generation are proposed for orthogonal frequency division multiplexing (OFDM) systems. The novel perspective of the proposed work lies in the generation of key bits not only from the magnitudes of OFDM subchannels as it has conventionally been done but also from the number and positions/indices of those subchannels, whose channel gains are above the mean of the respective subblock. The effectiveness of the proposed algorithms is evaluated in terms of key generation rate and key mismatch rate. It is shown in the simulation results that the involvement of the proposed dimensions can double the key generation rate compared to conventional algorithms.

中文翻译：

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一种提高基于通道的密钥生成率的新方案


从无线信道生成物理层密钥是提供机密性和身份验证的新兴兴趣领域。该领域的主要挑战之一是增加生成的密钥的长度，同时保持其随机性和均匀性。在本文中，为正交频分复用 （OFDM） 系统提出了基于无线信道的密钥生成的新维度。拟议工作的新视角在于，不仅从传统上所做的 OFDM 子信道的大小中生成关键位，而且还从那些子信道的数量和位置/索引中生成，这些子信道的信道增益高于相应子块的平均值。根据密钥生成率和密钥不匹配率来评估所提出的算法的有效性。仿真结果表明，与传统算法相比，所提出的维度的参与可以将密钥生成率提高一倍。