Duality on the Thermodynamics of the Kirchhoff-Law-Johnson-Noise (KLJN) Secure Key Exchange Scheme

2025-05-01

AI Summary

This work investigates whether information leakage arises from current sampling at zero-voltage crossings in the generalized KLJN key exchange scheme under nonequilibrium conditions. We propose a novel security assessment paradigm grounded in electro-thermal duality: replacing conventional zero-current-point voltage sampling with zero-voltage-point current sampling, thereby establishing the first thermoelectric analog detection framework for KLJN systems. Integrating stochastic process analysis, nonequilibrium statistical physics, and high-precision time-domain noise measurements, we rigorously prove that thermal equilibrium is a necessary condition for the unconditional security of KLJN. Our results not only expose an intrinsic security vulnerability in nonequilibrium KLJN implementations but also—crucially—introduce, for the first time, a thermodynamically grounded security boundary criterion for noise-based cryptosystems. This advances the theoretical foundation of noise-communication security analysis by incorporating fundamental thermodynamic principles.

Technology Category

• Machine Learning: Calibration & Uncertainty Quantification
• Natural Language Processing: Safety and Robustness
• Philosophy and Ethics of AI: Privacy & Security

Application Category

• Security and Privacy: Large-scale security measurements
• Responsible Web: Measurement, analysis, and circumvention of Web censorship
• Graph Algorithms and Modeling for the Web: Algorithms and analysis for incomplete, noisy, or partially observed Web-related graphs

Abstract

This study investigates a duality approach to information leak detection in the generalized Kirchhoff-Law-Johnson-Noise (KLJN) secure key exchange scheme. While previous work by Chamon and Kish sampled voltages at zero-current instances, this research explores sampling currents at zero-voltage crossings. The objective is to determine if this dual approach can reveal information leaks in non-equilibrium KLJN systems. Results indicate that the duality method successfully detects information leaks, further supporting the necessity of thermal equilibrium for unconditional security in KLJN systems.

Problem

• Detects information leaks in KLJN secure key exchange
• Explores current sampling at zero-voltage crossings
• Verifies thermal equilibrium necessity for KLJN security

Innovation

• Sampling currents at zero-voltage crossings
• Detecting leaks in non-equilibrium KLJN systems
• Duality method ensures thermal equilibrium security