Error-Rate Controlled Thresholding Method for Bit Acceptance for KLJN Communication Scheme

This work introduces a novel thresholding method to control the error rate in the Kirchhoff-Law–Johnson-Noise (KLJN) secure key exchange system, offering precise trade-off tuning between bit acceptance and security. We provide an analytical approach to calculate the probability density functions (PDFs) of voltage and current noise for each KLJN state and propose a thresholding mechanism that leverages the inverse cumulative distribution function to guarantee a desired error probability ([Formula: see text]). Additionally, the rate of dropped bits ([Formula: see text]) is evaluated to quantify performance losses due to thresholding. This integrated analytical approach enhances the practical applicability of KLJN systems, offering error-tunable key exchange mechanisms.