Physical layer key generation (PKG) is a promising means to provide on-the-fly shared secret keys by exploiting the intrinsic randomness of the radio channel. However, the performance of PKG is highly dependent on the propagation environments. Due to its feature of controlling the wireless environment, reconfigurable intelligent surface~(RIS) is appealing to be applied in PKG. In this paper, in contrast to the existing literature, we investigate both the constructive and destructive effects of RIS on the PKG scheme. For the constructive aspect, we have identified static and wave-blockage environments as two RIS-empowered-PKG applications in future wireless systems. In particular, our experimental results in a static environment showed that RIS can enhance the entropy of the secret key, achieving a key generation rate (KGR) of 97.39 bit/s with a bit disagreement rate (BDR) of 0.083. In multi-user systems where some remote users are in worse channel conditions, the proposed RIS-assisted PKG algorithm improves the sum secret key rate by more than 2 dB, compared to the literature. Furthermore, we point out that RIS could be utilized by an attacker to perform new jamming and leakage attacks and give countermeasures, respectively. Finally, we outline future research directions for PKG systems in light of the RIS.
翻译:物理层钥匙生成(PKG)是利用无线电频道的内在随机性,提供现场共享秘密密钥的一个很有希望的手段。然而,PKG的性能高度依赖传播环境。由于它控制无线环境的特征,重新配置智能表面~(RIS)吸引在PKG中应用。在本文中,与现有文献相比,我们调查了RIS对PKG机制的建设性和破坏性影响。在建设性方面,我们发现静态和波阻塞环境是未来无线系统中的两个RIS-empower-PKG应用程序。特别是,我们在静态环境中的实验结果表明,RIS能够增强秘密钥匙的灵敏度,达到97.39位/秒的关键生成率(KGR),而零.83的偏差率(BDRDR)。在多用户系统中,一些远程用户处于更差的频道条件下,拟议的RIS-KG算法可以改进总的秘密密钥率,超过2 dB,而与文献系统相比,我们的静态环境实验结果显示,我们最后利用了新的RISG系统来进行新的研究。