Generalized Kirchhoff-Law-Johnson-Noise (KLJN) secure key exchange system using arbitrary resistors

TL;DR

This paper introduces a generalized KLJN secure key exchange system that maintains unconditional security with fewer limitations, making practical implementation easier and more robust against attacks.

Contribution

It extends the classical KLJN system to a more universal form using arbitrary resistors, enhancing practicality and security.

Findings

The generalized system guarantees unconditional security.

Numerical simulations confirm theoretical predictions.

Less restrictive conditions improve practical robustness.

Abstract

The Kirchhoff-Law-Johnson-Noise (KLJN) secure key exchange system has been introduced as a simple, very low cost and efficient classical physical alternative to quantum key distribution systems. The ideal system uses only a few electronic components - identical resistor pairs, switches and interconnecting wires - to guarantee perfectly protected data transmission. We show that a generalized KLJN system can provide unconditional security even if it is used with significantly less limitations. The more universal conditions ease practical realizations considerably and support more robust protection against attacks. Our theoretical results are confirmed by numerical simulations.