Comments on the "Generalized" KLJN Key Exchanger with Arbitrary Resistors: Power, Impedance, Security

Abstract

In (Nature) Science Report 5 (2015) 13653, Vadai, Mingesz and Gingl (VMG) introduce a new Kirchhoff-law-Johnson-noise (KLJN) secure key exchanger that operates with 4 arbitrary resistors (instead of 2 arbitrary resistance values forming 2 identical resistor pairs in the original system). They state that in this new, VMG-KLJN, non-equilibrium system with nonzero power flow, the security during the exchange of the two (HL and LH) bit values is as strong as in the original KLJN scheme. Moreover, they claim that, at practical conditions, their VMG-KLJN protocol "supports more robust protection against attacks". First, we investigate the power flow and thermal equilibrium issues of the VMG-KLJN system with 4 arbitrary resistors. Then we introduce a new KLJN protocol that allows the arbitrary choice of 3 resistors from the 4, while it still operates with zero power flow during the exchange of single bits by utilizing a specific value of the 4th resistor and a binary temperature set for the exchanged (HL and LH) bit values. Then we show that, in general, the KLJN schemes with more than 2 arbitrary resistors (including our new protocol mentioned above) are prone to 4 new passive attacks utilizing the parasitic capacitance and inductance in the cable, while the original KLJN scheme is naturally immune against these new attacks. The core of the security vulnerability exploited by these attacks is the different line resistances in the HL and LH cases. Therefore, on the contrary of the statement and claim cited above, the practical VMG-KLJN system is less secure than the original KLJN scheme. We introduce another 2, modified, non-equilibrium KLJN systems to eliminate the vulnerability against some - but not all - of these attacks. However the price for that is the loss of arbitrariness of the selection of the 4th resistor and the information leak still remains greater than zero.

References in corpus (60)

• Hacking commercial quantum cryptography systems by tailored bright illumination
• Device calibration impacts security of quantum key distribution
• Experimentally faking the violation of Bell's inequalities
• Trojan-horse attacks threaten the security of practical quantum cryptography
• Totally Secure Classical Communication Utilizing Johnson (-like) Noise and Kirchoff's Law
• After-gate attack on a quantum cryptosystem
• Risk analysis of Trojan-horse attacks on practical quantum key distribution systems
• Laser damage helps the eavesdropper in quantum cryptography
• Thermal blinding of gated detectors in quantum cryptography
• Controlling a superconducting nanowire single-photon detector using tailored bright illumination
• Homodyne-detector-blinding attack in continuous-variable quantum key distribution
• Johnson(-like)-Noise-Kirchhoff-Loop Based Secure Classical Communicator Characteristics, for Ranges of Two to Two Thousand Kilometers, via Model-Line
• Laser seeding attack in quantum key distribution
• Security loophole in free-space quantum key distribution due to spatial-mode detector-efficiency mismatch
• Resilience of gated avalanche photodiodes against bright illumination attacks in quantum cryptography
• Decoy state quantum key distribution with imperfect source
• Creation of backdoors in quantum communications via laser damage
• Laser damage attack against optical attenuators in quantum key distribution
• Attacks exploiting deviation of mean photon number in quantum key distribution and coin tossing
• Testing random-detector-efficiency countermeasure in a commercial system reveals a breakable unrealistic assumption
• Noise in the wire: the real impact of wire resistance for the Johnson (-like) noise based secure communicator
• Notes on Recent Approaches Concerning the Kirchhoff-Law-Johnson-Noise-based Secure Key Exchange
• Invisible Trojan-horse attack
• Insecurity of detector-device-independent quantum key distribution
• On the security of the Kirchhoff-law-Johnson-noise (KLJN) communicator
• Implementation vulnerabilities in general quantum cryptography
• Critical analysis of the Bennett-Riedel attack on secure cryptographic key distributions via the Kirchhoff-law-Johnson-noise scheme
• Protection against the man-in-the-middle-attack for the Kirchhoff-loop-Johnson(-like)-noise cipher and expansion by voltage-based security
• Eavesdropping and countermeasures for backflash side channel in quantum cryptography
• Tailored bright illumination attack on distributed-phase-reference protocols
• Totally secure classical networks with multipoint telecloning (teleportation) of classical bits through loops with Johnson-like noise
• Generalized Kirchhoff-Law-Johnson-Noise (KLJN) secure key exchange system using arbitrary resistors
• Noise properties in the ideal Kirchhoff-Law-Johnson-Noise secure communication system
• Errors and their mitigation at the Kirchhoff-law-Johnson-noise secure key exchange
• Do electromagnetic waves exist in a short cable at low frequencies? What does physics say?
• Information theoretically secure, enhanced Johnson noise based key distribution over the smart grid with switched filters
• Current and voltage based bit errors and their combined mitigation for the Kirchhoff-law-Johnson-noise secure key exchange
• Enhanced secure key exchange systems based on the Johnson-noise scheme
• On the "cracking" scheme in the paper "A directional coupler attack against the Kish key distribution system" by Gunn, Allison and Abbott
• Optimised quantum hacking of superconducting nanowire single-photon detectors
• Physical uncloneable function hardware keys utilizing Kirchhoff-law-Johnson-noise secure key exchange and noise-based logic
• Eavesdropper's ability to attack a free-space quantum-key-distribution receiver in atmospheric turbulence
• Unconditionally secure computers, algorithms and hardware, such as memories, processors, keyboards, flash and hard drives
• Controlling single-photon detector ID210 with bright light
• Effective Privacy Amplification for Secure Classical Communications
• Securing vehicle communication systems by the KLJN key exchange protocol
• Elimination of a Second-Law-attack, and all cable-resistance-based attacks, in the Kirchhoff-law-Johnson-noise (KLJN) secure key exchange system
• Random-resistor-random-temperature Kirchhoff-law-Johnson-noise (RRRT-KLJN) key exchange
• On KLJN-based secure key distribution in vehicular communication networks
• A universal setup for active control of a single-photon detector
• What kind of noise guarantees security for the Kirchhoff-Loop-Johnson-Noise key exchange?
• Analysis of an attenuator artifact in an experimental attack by Gunn-Allison-Abbott against the Kirchhoff-law-Johnson-noise (KLJN) secure key exchange system
• Finite-key-size effect in commercial plug-and-play QKD system
• Resource requirements and speed versus geometry of unconditionally secure physical key exchanges
• Optical control of single-photon negative-feedback avalanche diode detector
• Comments On "A New Transient Attack On The Kish Key Distribution System"
• Cable Capacitance Attack against the KLJN Secure Key Exchange
• Enhanced usage of keys obtained by physical, unconditionally secure distributions
• Generalized DC loop current attack against the KLJN secure key exchange scheme
• Comment on "Inherent security of phase coding quantum key distribution systems against detector blinding attacks" [Laser Phys. Lett. 15, 095203 (2018)]

Cited by in corpus (4)

• Communication by Means of Thermal Noise: Towards Networks with Extremely Low Power Consumption
• Deterministic Random Number Generator Attack against the Kirchhoff-Law-Johnson-Noise Secure Key Exchange Protocol
• Perspective -- On the thermodynamics of perfect unconditional security
• Kirchhoff Meets Johnson: In Pursuit of Unconditionally Secure Communication