Secret key generation (SKG) between authenticated devices is a pivotal task for secure communications. Diffie-Hellman (DH) is de-facto standard but not post-quantum secure. In this paper, we shall invent and analyze a new security primitive that is specifically designed for WPAN. For WPAN, wireless channel-based SKG has been proposed but was not widely deployed due to its critical dependence on the channel's entropy which is uncontrollable. We formulate a different approach: We still exploit channel properties but mainly hinge on the reciprocity of the wireless channel and not on the channel's entropy. The radio advantage comes from the use of full duplex communication. We show that in this situation both legitimate parties can agree on a common secret key even without ever probing the channel at all. At the core is a new bisparse blind deconvolution scheme for which we prove correctness and information-theoretic, i.e. perfect, security. We show that, ultimately, a secret key can be extracted and give a lower bound for the number of secret key bits which is then verified by experiments.

翻译：认证设备间的密钥生成（SKG）是安全通信的关键任务。Diffie-Hellman（DH）作为事实标准却不具备后量子安全性。本文提出并分析一种专为无线个人区域网（WPAN）设计的新型安全原语。针对WPAN，基于无线信道的SKG方案虽已被提出，但由于其严重依赖不可控的信道熵值而未被广泛部署。我们提出一种不同思路：仍利用信道特性，但主要依据无线信道的互易性而非信道熵值。无线电优势来自全双工通信的运用。研究表明，在此情境下合法双方甚至无需进行信道探测即可协商出共同密钥。其核心是一种新型双稀疏盲反卷积机制，我们证明了该机制的正确性与信息论意义上的完美安全性。最终，我们展示了如何提取密钥并给出密钥比特数的下界，该下界已通过实验验证。