Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Generalized Kirchhoff-Law-Johnson-Noise (KLJN) secure key exchange system using arbitrary resistors  [PDF]
Gergely Vadai,Robert Mingesz,Zoltan Gingl
Computer Science , 2015, DOI: 10.1038/srep13653
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.
Random-resistor-random-temperature Kirchhoff-law-Johnson-noise (RRRT-KLJN) key exchange  [PDF]
Laszlo Bela Kish,Claes-Goran Granqvist
Computer Science , 2015,
Abstract: We introduce two new Kirchhoff-law-Johnson-noise (KLJN) secure key distribution schemes which are generalizations of the original KLJN scheme. The first of these, the Random-Resistor (RR-) KLJN scheme, uses random resistors with values chosen from a quasi-continuum set. It is well-known since the creation of the KLJN concept that such a system could work in cryptography, because Alice and Bob can calculate the unknown resistance value from measurements, but the RR-KLJN system has not been addressed in prior publications since it was considered impractical. The reason for discussing it now is the second scheme, the Random-Resistor-Random-Temperature (RRRT-) KLJN key exchange, inspired by a recent paper of Vadai, Mingesz and Gingl, wherein security was shown to be maintained at non-zero power flow. In the RRRT-KLJN secure key exchange scheme, both the resistances and their temperatures are continuum random variables. We prove that the security of the RRRT-KLJN scheme can prevail at non-zero power flow, and thus the physical law guaranteeing security is not the Second Law of Thermodynamics but the Fluctuation-Dissipation Theorem. Alice and Bob know their own resistances and temperatures and can calculate the resistance and temperature values at the other end of the communication channel from measured voltage, current and power-flow data in the wire. However, Eve cannot determine these values because, for her, there are four unknown quantities while she can set up only three equations. The RRRT-KLJN scheme has several advantages and makes all former attacks on the KLJN scheme invalid or incomplete.
Analysis of an attenuator artifact in an experimental attack by Gunn-Allison-Abbott against the Kirchhoff-law-Johnson-noise (KLJN) secure key exchange system  [PDF]
Laszlo B. Kish,Zoltan Gingl,Robert Mingesz,Gergely Vadai,Janusz Smulko,Claes-Goran Granqvist
Computer Science , 2014, DOI: 10.1142/S021947751550011X
Abstract: A recent paper by Gunn-Allison-Abbott (GAA) [L.J. Gunn et al., Scientific Reports 4 (2014) 6461] argued that the Kirchhoff-law-Johnson-noise (KLJN) secure key exchange system could experience a severe information leak. Here we refute their results and demonstrate that GAA's arguments ensue from a serious design flaw in their system. Specifically, an attenuator broke the single Kirchhoff-loop into two coupled loops, which is an incorrect operation since the single loop is essential for the security in the KLJN system, and hence GAA's asserted information leak is trivial. Another consequence is that a fully defended KLJN system would not be able to function due to its built-in current-comparison defense against active (invasive) attacks. In this paper we crack GAA's scheme via an elementary current comparison attack which yields negligible error probability for Eve even without averaging over the correlation time of the noise.
Elimination of a Second-Law-attack, and all cable-resistance-based attacks, in the Kirchhoff-law-Johnson-noise (KLJN) secure key exchange system  [PDF]
Laszlo B. Kish,Claes-Goran Granqvist
Computer Science , 2014, DOI: 10.3390/e16105223
Abstract: We introduce the so far most efficient attack against the Kirchhoff-law-Johnson-noise (KLJN) secure key exchange system. This attack utilizes the lack of exact thermal equilibrium in practical applications and is based on cable resistance losses and the fact that the Second Law of Thermodynamics cannot provide full security when such losses are present. The new attack does not challenge the unconditional security of the KLJN scheme, but it puts more stringent demands on the security/privacy enhancing protocol than for any earlier attack. In this paper we present a simple defense protocol to fully eliminate this new attack by increasing the noise-temperature at the side of the smaller resistance value over the noise-temperature at the at the side with the greater resistance. It is shown that this simple protocol totally removes Eve's information not only for the new attack but also for the old Bergou-Scheuer-Yariv attack. The presently most efficient attacks against the KLJN scheme are thereby completely nullified.
What kind of noise guarantees security for the Kirchhoff-Loop-Johnson-Noise key exchange?  [PDF]
Robert Mingesz,Gergely Vadai,Zoltan Gingl
Computer Science , 2014, DOI: 10.1142/S0219477514500217
Abstract: This article is a supplement to our recent one about the analysis of the noise properties in the Kirchhoff-Law-Johnson-Noise (KLJN) secure key exchange system [Gingl and Mingesz, PLOS ONE 9 (2014) e96109, doi:10.1371/journal.pone.0096109]. Here we use purely mathematical statistical derivations to prove that only normal distribution with special scaling can guarantee security. Our results are in agreement with earlier physical assumptions [Kish, Phys. Lett. A 352 (2006) 178-182, doi: 10.1016/j.physleta.2005.11.062]. Furthermore, we have carried out numerical simulations to show that the communication is clearly unsecure for improper selection of the noise properties. Protection against attacks using time and correlation analysis is not considered in this paper.
Securing vehicle communication systems by the KLJN key exchange protocol  [PDF]
Y. Saez,X. Cao,L. B. Kish,G. Pesti
Computer Science , 2014, DOI: 10.1142/S0219477514500205
Abstract: We review the security requirements for vehicular communication networks and provide a critical assessment of some typical communication security solutions. We also propose a novel unconditionally secure vehicular communication architecture that utilizes the Kirchhoff-law-Johnson-noise (KLJN) key distribution scheme.
Protection against the man-in-the-middle-attack for the Kirchhoff-loop-Johnson(-like)-noise cipher and expansion by voltage-based security  [PDF]
Laszlo B. Kish
Physics , 2005, DOI: 10.1142/S0219477506003148
Abstract: It is shown that the original Kirchhoff-loop-Johnson(-like)-noise (KLJN) cipher is naturally protected against the man-in-the-middle (MITM) attack, if the eavesdropper is using resistors and noise voltage generators just like the sender and the receiver. The eavesdropper can extract zero bit of information before she is discovered. However, when the eavesdropper is using noise current generators, though the cipher is protected, the eavesdropper may still be able to extract one bit of information while she is discovered. For enhanced security, we expand the KLJN cipher with the comparison of the instantaneous voltages via the public channel. In this way, the sender and receiver has a full control over the security of measurable physical quantities in the Kirchhoff-loop. We show that when the sender and receiver compare not only their instantaneous current data but also their instantaneous voltage data then the zero-bit security holds even for the noise current generator case. We show that the original KLJN scheme is also zero-bit protected against that type of MITM attack when the eavesdropper uses voltage noise generators, only. In conclusion, within the idealized model scheme, the man-in-the-middle-attack does not provide any advantage compared to the regular attack considered earlier. The remaining possibility is the attack by a short, large current pulse, which described in the original paper as the only efficient type of regular attacks, and that yields the one bit security. In conclusion, the KLJN cipher is superior to known quantum communication schemes in every respect, including speed, robustness, maintenance need, price and its natural immunity against the man-in-the-middle attack.
Facts, myths and fights about the KLJN classical physical key exchanger  [PDF]
Laszlo B. Kish,Derek Abbott,Claes-Goran Granqvist,He Wen
Computer Science , 2014, DOI: 10.1142/S2010194514603627
Abstract: This paper deals with the Kirchhoff-law-Johnson-noise (KLJN) classical statistical physical key exchange method and surveys criticism - often stemming from a lack of understanding of its underlying premises or from other errors - and our related responses against these, often unphysical, claims. Some of the attacks are valid, however, an extended KLJN system remains protected against all of them, implying that its unconditional security is not impacted.
Noise Properties in the Ideal Kirchhoff-Law-Johnson-Noise Secure Communication System  [PDF]
Zoltan Gingl, Robert Mingesz
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0096109
Abstract: In this paper we determine the noise properties needed for unconditional security for the ideal Kirchhoff-Law-Johnson-Noise (KLJN) secure key distribution system using simple statistical analysis. It has already been shown using physical laws that resistors and Johnson-like noise sources provide unconditional security. However real implementations use artificial noise generators, therefore it is a question if other kind of noise sources and resistor values could be used as well. We answer this question and in the same time we provide a theoretical basis to analyze real systems as well.
Current Injection Attack against the KLJN Secure Key Exchange  [PDF]
Hsien-Pu Chen,Muneer Mohammad,Laszlo B. Kish
Physics , 2015,
Abstract: The Kirchhoff-law-Johnson-noise (KLJN) scheme is a statistical/physical secure key exchange system based on the laws of classical statistical physics to provide unconditional security. We used the LTSPICE industrial cable and circuit simulator to emulate one of the major active (invasive) attacks, the current injection attack, against the ideal and a practical KLJN system, respectively. We show that two security enhancement techniques, namely, the instantaneous voltage/current comparison method, and a simple privacy amplification scheme, independently and effectively eliminate the information leak and successfully preserve the system's unconditional security.
Page 1 /100
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.