Noise in the wire: the real impact of wire resistance for the Johnson (-like) noise based secure communicator

TL;DR

This paper re-evaluates the effect of wire resistance on Johnson-like noise secure communication, showing that its impact is less significant in practice than previously estimated, based on fluctuation-dissipation principles.

Contribution

It corrects prior estimations of wire resistance impact in Johnson-like noise secure communicators using fundamental physical theorems.

Findings

Wire resistance impact is lower than earlier estimates.

Practical secure communication is less affected by wire resistance.

Analysis based on fluctuation-dissipation and linear response theorems.

Abstract

We re-evaluate the impact of wire resistance on the noise voltage and current in the Johnson-(like)-noise based secure communicator, correcting the result presented in [Physics Letters A 359 (2006) 737]. The analysis shown here is based on the fluctuation-dissipation and the linear response theorems. The results indicate that the impact of wire resistance in practical communicators is significantly lower than the previous estimation.