On the "cracking" scheme in the paper "A directional coupler attack against the Kish key distribution system" by Gunn, Allison and Abbott

Abstract

Recently, Gunn, Allison and Abbott (GAA) [http://arxiv.org/pdf/1402.2709v2.pdf] proposed a new scheme to utilize electromagnetic waves for eavesdropping on the Kirchhoff-law-Johnson-noise (KLJN) secure key distribution. We proved in a former paper [Fluct. Noise Lett. 13 (2014) 1450016] that GAA's mathematical model is unphysical. Here we analyze GAA's cracking scheme and show that, in the case of a loss-free cable, it provides less eavesdropping information than in the earlier (Bergou)-Scheuer-Yariv mean-square-based attack [Kish LB, Scheuer J, Phys. Lett. A 374 (2010) 2140-2142], while it offers no information in the case of a lossy cable. We also investigate GAA's claim to be experimentally capable of distinguishing - using statistics over a few correlation times only - the distributions of two Gaussian noises with a relative variance difference of less than 10^-8. Normally such distinctions would require hundreds of millions of correlations times to be observable. We identify several potential experimental artifacts as results of poor KLJN design, which can lead to GAA's assertions: deterministic currents due to spurious harmonic components caused by ground loops, DC offset, aliasing, non-Gaussian features including non-linearities and other non-idealities in generators, and the time-derivative nature of GAA's scheme which tends to enhance all of these artifacts.

This version is accepted for publication in Metrology and Measurement Systems

References in corpus (3)

• Noise in the wire: the real impact of wire resistance for the Johnson (-like) noise based secure communicator
• Noise properties in the ideal Kirchhoff-Law-Johnson-Noise secure communication system
• Do electromagnetic waves exist in a short cable at low frequencies? What does physics say?

Cited by in corpus (6)

• Elimination of a Second-Law-attack, and all cable-resistance-based attacks, in the Kirchhoff-law-Johnson-noise (KLJN) secure key exchange system
• Analysis of an attenuator artifact in an experimental attack by Gunn-Allison-Abbott against the Kirchhoff-law-Johnson-noise (KLJN) secure key exchange system
• Resource requirements and speed versus geometry of unconditionally secure physical key exchanges
• Perspective -- On the thermodynamics of perfect unconditional security
• Random Number Generator Attack against the Kirchhoff-Law-Johnson-Noise Secure Key Exchange Protocol
• Nonlinearity Attack against the Kirchhoff-Law-Johnson-Noise (KLJN) Secure Key Exchange Protocol