论文标题
对具有任意电阻的“广义” KLJN密钥交换器的评论：权力，阻抗，安全性
Comments on the "Generalized" KLJN Key Exchanger with Arbitrary Resistors: Power, Impedance, Security
论文作者
论文摘要
在（自然）科学报告5（2015）13653中，Vadai，Mingesz和Gingl（VMG）引入了新的Kirchhoff Law-Law-law-Johnson-Noise（KLJN）安全密钥交换器，该键换器具有4个任意电阻器（而不是在原始系统中形成2个相同的电阻配对）。他们指出，在这个具有非零功率流的新的，VMG-KLJN的非平衡系统中，两个（HL和LH）位值在交换过程中的安全性与原始KLJN方案中的安全性一样强。此外，他们声称，在实际条件下，他们的VMG-KLJN协议“支持对攻击的更强大保护”。首先，我们研究了具有4个任意电阻的VMG-KLJN系统的功率流和热平衡问题。然后，我们引入了一种新的KLJN协议，该协议允许从4个电阻中选择3个电阻器，而在交换单位位期间，它仍然以零功率流量运行，通过利用第4个电阻器的特定值和用于交换的（HL和LH）位值设置的二进制温度设置。然后，我们表明，通常，具有超过2个任意电阻器的KLJN方案（包括上述新协议）容易利用电缆中的寄生能力和电感来进行4次新的被动攻击，而原始的KLJN方案自然可以免疫这些新攻击。这些攻击利用的安全漏洞的核心是HL和LH案例中的不同线阻力。因此，相反，上面引用的声明并说明了实际的VMG-KLJN系统的安全性不如原始KLJN方案。我们介绍了另外2个经过修改的非平衡KLJN系统，以消除针对这些攻击中的某些（但不是全部）的漏洞。但是，其价格是选择第四电阻和信息泄漏的任意性丧失仍然大于零。
In (Nature) Science Report 5 (2015) 13653, Vadai, Mingesz and Gingl (VMG) introduce a new Kirchhoff-law-Johnson-noise (KLJN) secure key exchanger that operates with 4 arbitrary resistors (instead of 2 arbitrary resistance values forming 2 identical resistor pairs in the original system). They state that in this new, VMG-KLJN, non-equilibrium system with nonzero power flow, the security during the exchange of the two (HL and LH) bit values is as strong as in the original KLJN scheme. Moreover, they claim that, at practical conditions, their VMG-KLJN protocol "supports more robust protection against attacks". First, we investigate the power flow and thermal equilibrium issues of the VMG-KLJN system with 4 arbitrary resistors. Then we introduce a new KLJN protocol that allows the arbitrary choice of 3 resistors from the 4, while it still operates with zero power flow during the exchange of single bits by utilizing a specific value of the 4th resistor and a binary temperature set for the exchanged (HL and LH) bit values. Then we show that, in general, the KLJN schemes with more than 2 arbitrary resistors (including our new protocol mentioned above) are prone to 4 new passive attacks utilizing the parasitic capacitance and inductance in the cable, while the original KLJN scheme is naturally immune against these new attacks. The core of the security vulnerability exploited by these attacks is the different line resistances in the HL and LH cases. Therefore, on the contrary of the statement and claim cited above, the practical VMG-KLJN system is less secure than the original KLJN scheme. We introduce another 2, modified, non-equilibrium KLJN systems to eliminate the vulnerability against some - but not all - of these attacks. However the price for that is the loss of arbitrariness of the selection of the 4th resistor and the information leak still remains greater than zero.
