Current and voltage based bit errors and their combined mitigation for the Kirchhoff-law-Johnson-noise secure key exchange

TL;DR

This paper analyzes bit errors in the KLJN secure key exchange, showing error probabilities decay exponentially with exchange duration, and proposes a combined voltage-current mode to improve error mitigation.

Contribution

It introduces a combined voltage-current mode for KLJN key exchange that enhances error mitigation compared to single-mode schemes.

Findings

Error probability decays exponentially with bit exchange period.

Combined mode offers superior fidelity in error removal.

Error decay behavior is similar in voltage and current measurement modes.

Abstract

We classify and analyze bit errors in the current measurement mode of the Kirchhoff-law-Johnson-noise (KLJN) key distribution. The error probability decays exponentially with increasing bit exchange period and fixed bandwidth, which is similar to the error probability decay in the voltage measurement mode. We also analyze the combination of voltage and current modes for error removal. In this combination method, the error probability is still an exponential function that decays with the duration of the bit exchange period, but it has superior fidelity to the former schemes.