Kish Laszlo B, Abbott Derek, Granqvist Claes G
Department of Electrical and Computer Engineering, Texas A&M University, College Station, Texas, United States of America.
School of Electrical and Electronic Engineering, University of Adelaide, Adelaide, South Australia, Australia.
PLoS One. 2013 Dec 16;8(12):e81810. doi: 10.1371/journal.pone.0081810. eCollection 2013.
Recently, Bennett and Riedel (BR) (http://arxiv.org/abs/1303.7435v1) argued that thermodynamics is not essential in the Kirchhoff-law-Johnson-noise (KLJN) classical physical cryptographic exchange method in an effort to disprove the security of the KLJN scheme. They attempted to demonstrate this by introducing a dissipation-free deterministic key exchange method with two batteries and two switches. In the present paper, we first show that BR's scheme is unphysical and that some elements of its assumptions violate basic protocols of secure communication. All our analyses are based on a technically unlimited Eve with infinitely accurate and fast measurements limited only by the laws of physics and statistics. For non-ideal situations and at active (invasive) attacks, the uncertainly principle between measurement duration and statistical errors makes it impossible for Eve to extract the key regardless of the accuracy or speed of her measurements. To show that thermodynamics and noise are essential for the security, we crack the BR system with 100% success via passive attacks, in ten different ways, and demonstrate that the same cracking methods do not function for the KLJN scheme that employs Johnson noise to provide security underpinned by the Second Law of Thermodynamics. We also present a critical analysis of some other claims by BR; for example, we prove that their equations for describing zero security do not apply to the KLJN scheme. Finally we give mathematical security proofs for each BR-attack against the KLJN scheme and conclude that the information theoretic (unconditional) security of the KLJN method has not been successfully challenged.
最近，贝内特和里德尔（BR）（http://arxiv.org/abs/1303.7435v1）认为，热力学在基尔霍夫定律 - 约翰逊噪声（KLJN）经典物理加密交换方法中并非必不可少，试图以此来反驳KLJN方案的安全性。他们试图通过引入一种由两个电池和两个开关组成的无耗散确定性密钥交换方法来证明这一点。在本文中，我们首先表明BR的方案不符合物理实际，其假设的某些元素违反了安全通信的基本协议。我们所有的分析都是基于一个技术上无限制的伊芙，她具有无限精确且快速的测量能力，仅受物理和统计规律的限制。对于非理想情况以及主动（侵入性）攻击，测量持续时间和统计误差之间的不确定性原理使得伊芙无论测量精度或速度如何，都无法提取密钥。为了表明热力学和噪声对安全性至关重要，我们通过十种不同的方式以100%的成功率通过被动攻击破解了BR系统，并证明相同的破解方法对采用约翰逊噪声以热力学第二定律为安全基础的KLJN方案不起作用。我们还对BR的其他一些说法进行了批判性分析；例如，我们证明了他们描述零安全性的方程不适用于KLJN方案。最后，我们给出了针对KLJN方案的每次BR攻击的数学安全性证明，并得出结论，KLJN方法的信息理论（无条件）安全性尚未受到成功挑战。
