<p>(a): The right switch is closed to charge the right capacitor. (b): Johnson noise curren... more <p>(a): The right switch is closed to charge the right capacitor. (b): Johnson noise current yields charge fluctuations in the right capacitor, i.e., a Gaussian noise in the charge. (c): As soon as the right capacitor reaches <i>Q<sub>w</sub></i> the right switch is abruptly opened to keep the charge in the right capacitor and the left switch is closed to discharge the capacitor on the right. (d): The charge in the left capacitor decays exponentially and, within a time interval of a few <i>RC</i>, thermalizes and crosses the zero charge (zero voltage) level. (e): The left switch is abruptly opened and the zero charge (zero voltage) state is preserved in the left capacitor. (f): The force due to the working charge in the right capacitor moves the piston to the right end, which is the end of the full cycle and the same state as where the analysis started; see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0046800#pone-0046800-g010" target="_blank">Figure 10</a>. The piston is at the right end and the capacitor in the right has the work charge <i>Q<sub>w</sub></i>.</p
<p>This simple system is secure only against passive attacks in the idealized case (mathema... more <p>This simple system is secure only against passive attacks in the idealized case (mathematical limit). Security enhancements (including filters) to provide protection against invasive attacks <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0070206#pone.0070206-Kish1" target="_blank">[22]</a>–<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0070206#pone.0070206-Mingesz2" target="_blank">[25]</a> and against other types of vulnerabilities are not shown. In practical applications electronic noise generators emulate an enhanced Johnson noise with a publicly agreed high effective temperature.</p
In his seminal paper, Chua presented a fundamental physical claim by introducing the memristor, &... more In his seminal paper, Chua presented a fundamental physical claim by introducing the memristor, "The missing circuit element". The memristor equations originally supposed to represent a passive circuit element because, with active circuitry, arbitrary elements can be realized without limitations. Therefore, if the memristor equations do not guarantee that the circuit element can be realized by a passive system, the fundamental physics claim about the memristor as "missing circuit element" loses all its weight. Recent work of Chua indicates that certain type of memristor features may imply an active device. To make the question more physical, we incorporate thermodynamics into the study of this question. By using the Second Law of Thermodynamics and thermal noise, we prove that the memristor model represents an active device for an infinitely large number of cases of memristor functions M; particularly, any power function with an odd power exponent, including the ...
Purpose – This paper aims to present the methods of improving selectivity and sensitivity of resi... more Purpose – This paper aims to present the methods of improving selectivity and sensitivity of resistance gas sensors. Design/methodology/approach – This paper compares various methods of improving gas sensing by temperature modulation, UV irradiation or fluctuation-enhanced sensing. The authors analyze low-frequency resistance fluctuations in commercial Taguchi gas sensors and the recently developed tungsten trioxide (WO3) gas-sensing layers, exhibiting a photo-catalytic effect. Findings – The efficiency of using low-frequency fluctuations to improve gas detection selectivity and sensitivity was confirmed by numerous experimental studies in commercial and prototype gas sensors. Research limitations/implications – A more advanced measurement setup is required to record noise data but it will reduce the number of gas sensors necessary for identifying the investigated gas mixtures. Practical implications – Fluctuation-enhanced sensing can reduce the energy consumption of gas detection s...
The unconditionally (that is, information theoretically) secure Kirchhoff-law-Johnson-noise (KLJN... more The unconditionally (that is, information theoretically) secure Kirchhoff-law-Johnson-noise (KLJN) key exchanger operates with two pairs of resistors, one at Alice's side and another one at Bob's end. Whenever the cable resistance is not negligible, the original scheme leaks information to the eavesdropper (Eve). The typical way to reduce this leak is treating the exchanged key by privacy amplification. In the present work our goal is to reduce the leak earlier, during the bit exchange level. So far, the common belief has been that the resistance values in Alice's/Bob's pairs should be very different for an easy separation of the bit values to yield low bit error probability in the key exchange. However, such situation is helping Eve during all the currently known types of attacks owing to higher information leak. We explore the possibility of enhancing the security by narrowing the difference between the resistance values. The impact on security and the cost of reduced communication speed are demonstrated for the Bergou-Scheuer-Yariv attack.
<p>Alice and Bob measure the instantaneous channel voltage and current amplitudes and compa... more <p>Alice and Bob measure the instantaneous channel voltage and current amplitudes and compare them via an authenticated public channel. In this way, they learn all the information Eve can have. Additions to prevent hacking—such as line filters, blinding detectors, <i>etc</i>—are not shown. The notation is the same as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0081810#pone-0081810-g001" target="_blank">Fig. 1</a>.</p
<p>Alice and Bob measure the instantaneous channel voltage and current amplitudes and compa... more <p>Alice and Bob measure the instantaneous channel voltage and current amplitudes and compare them via an authenticated public channel. In this way, they learn all the information Eve can have. Additions to prevent hacking—such as line filters, blinding detectors, <i>etc</i>—are not shown. The notation is the same as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0081810#pone-0081810-g001" target="_blank">Fig. 1</a>.</p
This chapter addresses various subjects, including some open questions related to energy dissipat... more This chapter addresses various subjects, including some open questions related to energy dissipation, information, and noise, that are relevant for nano- and molecular electronics. The object is to give a brief and coherent presentation of the results of a number of recent studies of ours.
This chapter addresses various subjects, including some open questions related to energy dissipat... more This chapter addresses various subjects, including some open questions related to energy dissipation, information, and noise, that are relevant for nano- and molecular electronics. The object is to give a brief and coherent presentation of the results of a number of recent studies of ours.
The imperative need for unconditional secure key exchange is expounded by the increasing connecti... more The imperative need for unconditional secure key exchange is expounded by the increasing connectivity of networks and by the increasing number and level of sophistication of cyberattacks. Two concepts that are theoretically information-secure are quantum key distribution (QKD) and Kirchoff-Law-Johnson-Noise (KLJN). However, these concepts require a dedicated connection between hosts in peer-to-peer (P2P) networks which can be impractical and or cost prohibitive. A practical and cost effective method is to have each host share their respective cable(s) with other hosts such that two remote hosts can realize a secure key exchange without the need of an additional cable or key exchanger. In this article we analyze the cost complexities of cable, key exchangers, and time required in the star network. We mentioned the reliability of the star network and compare it with other network geometries. We also conceived a protocol and equation for the number of secure bit exchange periods needed in a star network. We then outline other network geometries and trade-off possibilities that seem interesting to explore.
The imperative need for unconditional secure key exchange is expounded by the increasing connecti... more The imperative need for unconditional secure key exchange is expounded by the increasing connectivity of networks and by the increasing number and level of sophistication of cyberattacks. Two concepts that are theoretically information-secure are quantum key distribution (QKD) and Kirchoff-Law-Johnson-Noise (KLJN). However, these concepts require a dedicated connection between hosts in peer-to-peer (P2P) networks which can be impractical and or cost prohibitive. A practical and cost effective method is to have each host share their respective cable(s) with other hosts such that two remote hosts can realize a secure key exchange without the need of an additional cable or key exchanger. In this article we analyze the cost complexities of cable, key exchangers, and time required in the star network. We mentioned the reliability of the star network and compare it with other network geometries. We also conceived a protocol and equation for the number of secure bit exchange periods needed in a star network. We then outline other network geometries and trade-off possibilities that seem interesting to explore.
We address the question of low-frequency signals in a short cable, which are often considered as ... more We address the question of low-frequency signals in a short cable, which are often considered as waves in engineering calculations. Such an assumption violates several laws of physics, but exact calculations can be carried out via linear network theory.
We address the question of low-frequency signals in a short cable, which are often considered as ... more We address the question of low-frequency signals in a short cable, which are often considered as waves in engineering calculations. Such an assumption violates several laws of physics, but exact calculations can be carried out via linear network theory.
Driven by analogies with state vectors of quantum informatics and noisebased logic, we propose a ... more Driven by analogies with state vectors of quantum informatics and noisebased logic, we propose a general scheme and elements of neural circuitry for processing and addressing information in the brain. Specifically, we consider random (e.g., Poissonian) trains of finite-duration spikes, and, using the idealized concepts of excitatory and inhibitory synapses, offer a procedure for generating 2 N 1 orthogonal vectors out of N partially overlapping trains ("neuro-bits"). We then show that these vectors can be used to construct 2 2 N 1 1 different superpositions which represent the same number of logic values when carrying or routing information. In quantum informatics the above numbers are the same, however, the present logic scheme is more advantageous because it is deterministic in the sense that the presence of a vector in the spike train is detected by an appropriate coincidence circuit. For this reason it does not require time averaging or repeated measurements of the kind used in standard crosscorrelation analysis or in quantum computing.
Driven by analogies with state vectors of quantum informatics and noisebased logic, we propose a ... more Driven by analogies with state vectors of quantum informatics and noisebased logic, we propose a general scheme and elements of neural circuitry for processing and addressing information in the brain. Specifically, we consider random (e.g., Poissonian) trains of finite-duration spikes, and, using the idealized concepts of excitatory and inhibitory synapses, offer a procedure for generating 2 N 1 orthogonal vectors out of N partially overlapping trains ("neuro-bits"). We then show that these vectors can be used to construct 2 2 N 1 1 different superpositions which represent the same number of logic values when carrying or routing information. In quantum informatics the above numbers are the same, however, the present logic scheme is more advantageous because it is deterministic in the sense that the presence of a vector in the spike train is detected by an appropriate coincidence circuit. For this reason it does not require time averaging or repeated measurements of the kind used in standard crosscorrelation analysis or in quantum computing.
The statistical-physics-based Kirchhoff-law–Johnson-noise (KLJN) key exchange offers a new and si... more The statistical-physics-based Kirchhoff-law–Johnson-noise (KLJN) key exchange offers a new and simple unclonable system for credit/debit card chip authentication and payment. The key exchange, the authentication and the communication are unconditionally secure so that neither mathematics- nor statistics-based attacks are able to crack the scheme. The ohmic connection and the short wiring lengths between the chips in the card and the terminal constitute an ideal setting for the KLJN protocol, and even its simplest versions offer unprecedented security and privacy for credit/debit card chips and applications of physical unclonable functions (PUFs).
In a recent paper, [M. López-Suárez, I. Neri and L. Gammaitoni, Sub-[Formula: see text] micro-ele... more In a recent paper, [M. López-Suárez, I. Neri and L. Gammaitoni, Sub-[Formula: see text] micro-electromechanical irreversible logic gate, Nat. Commun. 7 (2016) 12068] the authors claimed that they demonstrated sub-[Formula: see text] energy dissipation at elementary logic operations. However, the argumentation is invalid because it neglects the dominant source of energy dissipation, namely, the charging energy of the capacitance of the input electrode, which totally dissipates during the full (0-1-0) cycle of logic values. The neglected dissipation phenomenon is identical with the mechanism that leads to the lower physical limit of dissipation (70–100 [Formula: see text] in today’s microprocessors (CMOS logic) and in any other system with thermally activated errors thus the same limit holds for the new scheme, too.
A recent IEEE Access Paper by Gunn, Allison and Abbott (GAA) proposed a new transient attack agai... more A recent IEEE Access Paper by Gunn, Allison and Abbott (GAA) proposed a new transient attack against the Kirchhoff-law-Johnson-noise (KLJN) secure key exchange system. The attack is valid, but it is easy to build a defense for the KLJN system. Here we note that GAA’s paper contains several invalid statements regarding security measures and the continuity of functions in classical physics. These deficiencies are clarified in our present paper, wherein we also emphasize that a new version of the KLJN system is immune against all existing attacks, including the one by GAA.
An absolutely secure, fast, inexpensive, robust, maintenance-free and low-powerconsumption commun... more An absolutely secure, fast, inexpensive, robust, maintenance-free and low-powerconsumption communication is proposed. The states of the information bit are represented by two resistance values. The sender and the receiver have such resistors available and they randomly select and connect one of them to the channel at the beginning of each clock period. The thermal noise voltage and current can be observed but Kirchoff's law provides only a second-order equation. A secure bit is communicated when the actual resistance values at the sender's side and the receiver's side differ. Then the second order equation yields the two resistance values but the eavesdropper is unable to determine the actual locations of the resistors and to find out the state of the sender's bit. The receiver knows that the sender has the inverse of his bit, similarly to quantum entanglement. The eavesdropper can decode the message if, for each bits, she inject current in the wire and measures the voltage change and the current changes in the two directions. However, in this way she gets discovered by the very first bit she decodes. Instead of thermal noise, proper external noise generators should be used when the communication is not aimed to be stealth.
<p>(a): The right switch is closed to charge the right capacitor. (b): Johnson noise curren... more <p>(a): The right switch is closed to charge the right capacitor. (b): Johnson noise current yields charge fluctuations in the right capacitor, i.e., a Gaussian noise in the charge. (c): As soon as the right capacitor reaches <i>Q<sub>w</sub></i> the right switch is abruptly opened to keep the charge in the right capacitor and the left switch is closed to discharge the capacitor on the right. (d): The charge in the left capacitor decays exponentially and, within a time interval of a few <i>RC</i>, thermalizes and crosses the zero charge (zero voltage) level. (e): The left switch is abruptly opened and the zero charge (zero voltage) state is preserved in the left capacitor. (f): The force due to the working charge in the right capacitor moves the piston to the right end, which is the end of the full cycle and the same state as where the analysis started; see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0046800#pone-0046800-g010" target="_blank">Figure 10</a>. The piston is at the right end and the capacitor in the right has the work charge <i>Q<sub>w</sub></i>.</p
<p>This simple system is secure only against passive attacks in the idealized case (mathema... more <p>This simple system is secure only against passive attacks in the idealized case (mathematical limit). Security enhancements (including filters) to provide protection against invasive attacks <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0070206#pone.0070206-Kish1" target="_blank">[22]</a>–<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0070206#pone.0070206-Mingesz2" target="_blank">[25]</a> and against other types of vulnerabilities are not shown. In practical applications electronic noise generators emulate an enhanced Johnson noise with a publicly agreed high effective temperature.</p
In his seminal paper, Chua presented a fundamental physical claim by introducing the memristor, &... more In his seminal paper, Chua presented a fundamental physical claim by introducing the memristor, "The missing circuit element". The memristor equations originally supposed to represent a passive circuit element because, with active circuitry, arbitrary elements can be realized without limitations. Therefore, if the memristor equations do not guarantee that the circuit element can be realized by a passive system, the fundamental physics claim about the memristor as "missing circuit element" loses all its weight. Recent work of Chua indicates that certain type of memristor features may imply an active device. To make the question more physical, we incorporate thermodynamics into the study of this question. By using the Second Law of Thermodynamics and thermal noise, we prove that the memristor model represents an active device for an infinitely large number of cases of memristor functions M; particularly, any power function with an odd power exponent, including the ...
Purpose – This paper aims to present the methods of improving selectivity and sensitivity of resi... more Purpose – This paper aims to present the methods of improving selectivity and sensitivity of resistance gas sensors. Design/methodology/approach – This paper compares various methods of improving gas sensing by temperature modulation, UV irradiation or fluctuation-enhanced sensing. The authors analyze low-frequency resistance fluctuations in commercial Taguchi gas sensors and the recently developed tungsten trioxide (WO3) gas-sensing layers, exhibiting a photo-catalytic effect. Findings – The efficiency of using low-frequency fluctuations to improve gas detection selectivity and sensitivity was confirmed by numerous experimental studies in commercial and prototype gas sensors. Research limitations/implications – A more advanced measurement setup is required to record noise data but it will reduce the number of gas sensors necessary for identifying the investigated gas mixtures. Practical implications – Fluctuation-enhanced sensing can reduce the energy consumption of gas detection s...
The unconditionally (that is, information theoretically) secure Kirchhoff-law-Johnson-noise (KLJN... more The unconditionally (that is, information theoretically) secure Kirchhoff-law-Johnson-noise (KLJN) key exchanger operates with two pairs of resistors, one at Alice's side and another one at Bob's end. Whenever the cable resistance is not negligible, the original scheme leaks information to the eavesdropper (Eve). The typical way to reduce this leak is treating the exchanged key by privacy amplification. In the present work our goal is to reduce the leak earlier, during the bit exchange level. So far, the common belief has been that the resistance values in Alice's/Bob's pairs should be very different for an easy separation of the bit values to yield low bit error probability in the key exchange. However, such situation is helping Eve during all the currently known types of attacks owing to higher information leak. We explore the possibility of enhancing the security by narrowing the difference between the resistance values. The impact on security and the cost of reduced communication speed are demonstrated for the Bergou-Scheuer-Yariv attack.
<p>Alice and Bob measure the instantaneous channel voltage and current amplitudes and compa... more <p>Alice and Bob measure the instantaneous channel voltage and current amplitudes and compare them via an authenticated public channel. In this way, they learn all the information Eve can have. Additions to prevent hacking—such as line filters, blinding detectors, <i>etc</i>—are not shown. The notation is the same as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0081810#pone-0081810-g001" target="_blank">Fig. 1</a>.</p
<p>Alice and Bob measure the instantaneous channel voltage and current amplitudes and compa... more <p>Alice and Bob measure the instantaneous channel voltage and current amplitudes and compare them via an authenticated public channel. In this way, they learn all the information Eve can have. Additions to prevent hacking—such as line filters, blinding detectors, <i>etc</i>—are not shown. The notation is the same as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0081810#pone-0081810-g001" target="_blank">Fig. 1</a>.</p
This chapter addresses various subjects, including some open questions related to energy dissipat... more This chapter addresses various subjects, including some open questions related to energy dissipation, information, and noise, that are relevant for nano- and molecular electronics. The object is to give a brief and coherent presentation of the results of a number of recent studies of ours.
This chapter addresses various subjects, including some open questions related to energy dissipat... more This chapter addresses various subjects, including some open questions related to energy dissipation, information, and noise, that are relevant for nano- and molecular electronics. The object is to give a brief and coherent presentation of the results of a number of recent studies of ours.
The imperative need for unconditional secure key exchange is expounded by the increasing connecti... more The imperative need for unconditional secure key exchange is expounded by the increasing connectivity of networks and by the increasing number and level of sophistication of cyberattacks. Two concepts that are theoretically information-secure are quantum key distribution (QKD) and Kirchoff-Law-Johnson-Noise (KLJN). However, these concepts require a dedicated connection between hosts in peer-to-peer (P2P) networks which can be impractical and or cost prohibitive. A practical and cost effective method is to have each host share their respective cable(s) with other hosts such that two remote hosts can realize a secure key exchange without the need of an additional cable or key exchanger. In this article we analyze the cost complexities of cable, key exchangers, and time required in the star network. We mentioned the reliability of the star network and compare it with other network geometries. We also conceived a protocol and equation for the number of secure bit exchange periods needed in a star network. We then outline other network geometries and trade-off possibilities that seem interesting to explore.
The imperative need for unconditional secure key exchange is expounded by the increasing connecti... more The imperative need for unconditional secure key exchange is expounded by the increasing connectivity of networks and by the increasing number and level of sophistication of cyberattacks. Two concepts that are theoretically information-secure are quantum key distribution (QKD) and Kirchoff-Law-Johnson-Noise (KLJN). However, these concepts require a dedicated connection between hosts in peer-to-peer (P2P) networks which can be impractical and or cost prohibitive. A practical and cost effective method is to have each host share their respective cable(s) with other hosts such that two remote hosts can realize a secure key exchange without the need of an additional cable or key exchanger. In this article we analyze the cost complexities of cable, key exchangers, and time required in the star network. We mentioned the reliability of the star network and compare it with other network geometries. We also conceived a protocol and equation for the number of secure bit exchange periods needed in a star network. We then outline other network geometries and trade-off possibilities that seem interesting to explore.
We address the question of low-frequency signals in a short cable, which are often considered as ... more We address the question of low-frequency signals in a short cable, which are often considered as waves in engineering calculations. Such an assumption violates several laws of physics, but exact calculations can be carried out via linear network theory.
We address the question of low-frequency signals in a short cable, which are often considered as ... more We address the question of low-frequency signals in a short cable, which are often considered as waves in engineering calculations. Such an assumption violates several laws of physics, but exact calculations can be carried out via linear network theory.
Driven by analogies with state vectors of quantum informatics and noisebased logic, we propose a ... more Driven by analogies with state vectors of quantum informatics and noisebased logic, we propose a general scheme and elements of neural circuitry for processing and addressing information in the brain. Specifically, we consider random (e.g., Poissonian) trains of finite-duration spikes, and, using the idealized concepts of excitatory and inhibitory synapses, offer a procedure for generating 2 N 1 orthogonal vectors out of N partially overlapping trains ("neuro-bits"). We then show that these vectors can be used to construct 2 2 N 1 1 different superpositions which represent the same number of logic values when carrying or routing information. In quantum informatics the above numbers are the same, however, the present logic scheme is more advantageous because it is deterministic in the sense that the presence of a vector in the spike train is detected by an appropriate coincidence circuit. For this reason it does not require time averaging or repeated measurements of the kind used in standard crosscorrelation analysis or in quantum computing.
Driven by analogies with state vectors of quantum informatics and noisebased logic, we propose a ... more Driven by analogies with state vectors of quantum informatics and noisebased logic, we propose a general scheme and elements of neural circuitry for processing and addressing information in the brain. Specifically, we consider random (e.g., Poissonian) trains of finite-duration spikes, and, using the idealized concepts of excitatory and inhibitory synapses, offer a procedure for generating 2 N 1 orthogonal vectors out of N partially overlapping trains ("neuro-bits"). We then show that these vectors can be used to construct 2 2 N 1 1 different superpositions which represent the same number of logic values when carrying or routing information. In quantum informatics the above numbers are the same, however, the present logic scheme is more advantageous because it is deterministic in the sense that the presence of a vector in the spike train is detected by an appropriate coincidence circuit. For this reason it does not require time averaging or repeated measurements of the kind used in standard crosscorrelation analysis or in quantum computing.
The statistical-physics-based Kirchhoff-law–Johnson-noise (KLJN) key exchange offers a new and si... more The statistical-physics-based Kirchhoff-law–Johnson-noise (KLJN) key exchange offers a new and simple unclonable system for credit/debit card chip authentication and payment. The key exchange, the authentication and the communication are unconditionally secure so that neither mathematics- nor statistics-based attacks are able to crack the scheme. The ohmic connection and the short wiring lengths between the chips in the card and the terminal constitute an ideal setting for the KLJN protocol, and even its simplest versions offer unprecedented security and privacy for credit/debit card chips and applications of physical unclonable functions (PUFs).
In a recent paper, [M. López-Suárez, I. Neri and L. Gammaitoni, Sub-[Formula: see text] micro-ele... more In a recent paper, [M. López-Suárez, I. Neri and L. Gammaitoni, Sub-[Formula: see text] micro-electromechanical irreversible logic gate, Nat. Commun. 7 (2016) 12068] the authors claimed that they demonstrated sub-[Formula: see text] energy dissipation at elementary logic operations. However, the argumentation is invalid because it neglects the dominant source of energy dissipation, namely, the charging energy of the capacitance of the input electrode, which totally dissipates during the full (0-1-0) cycle of logic values. The neglected dissipation phenomenon is identical with the mechanism that leads to the lower physical limit of dissipation (70–100 [Formula: see text] in today’s microprocessors (CMOS logic) and in any other system with thermally activated errors thus the same limit holds for the new scheme, too.
A recent IEEE Access Paper by Gunn, Allison and Abbott (GAA) proposed a new transient attack agai... more A recent IEEE Access Paper by Gunn, Allison and Abbott (GAA) proposed a new transient attack against the Kirchhoff-law-Johnson-noise (KLJN) secure key exchange system. The attack is valid, but it is easy to build a defense for the KLJN system. Here we note that GAA’s paper contains several invalid statements regarding security measures and the continuity of functions in classical physics. These deficiencies are clarified in our present paper, wherein we also emphasize that a new version of the KLJN system is immune against all existing attacks, including the one by GAA.
An absolutely secure, fast, inexpensive, robust, maintenance-free and low-powerconsumption commun... more An absolutely secure, fast, inexpensive, robust, maintenance-free and low-powerconsumption communication is proposed. The states of the information bit are represented by two resistance values. The sender and the receiver have such resistors available and they randomly select and connect one of them to the channel at the beginning of each clock period. The thermal noise voltage and current can be observed but Kirchoff's law provides only a second-order equation. A secure bit is communicated when the actual resistance values at the sender's side and the receiver's side differ. Then the second order equation yields the two resistance values but the eavesdropper is unable to determine the actual locations of the resistors and to find out the state of the sender's bit. The receiver knows that the sender has the inverse of his bit, similarly to quantum entanglement. The eavesdropper can decode the message if, for each bits, she inject current in the wire and measures the voltage change and the current changes in the two directions. However, in this way she gets discovered by the very first bit she decodes. Instead of thermal noise, proper external noise generators should be used when the communication is not aimed to be stealth.
In a recent article, Nature Communications 7 (2016) 12068, the authors claimed that they demonstr... more In a recent article, Nature Communications 7 (2016) 12068, the authors claimed that they demonstrated sub-kBT energy dissipation at elementary logic operations. However, the argumentation is invalid because it neglects the dominant source of energy dissipation, namely, the charging energy of the capacitance of the input electrode, which totally dissipates during the full (0-1-0) cycle of logic values. The neglected dissipation phenomenon is identical with the mechanism that leads to the lower physical limit of dissipation (70-100 kBT) in today's microprocessors (CMOS logic) and in any other system with thermally activated errors thus the same limit holds for the new scheme, too. In a recent article [1], the authors claim that they demonstrate sub-k B T energy dissipation at elementary logic operations. In the experiments, they use Micro-Electromechanical Cantilevers (MEC) where the attractive electrostatic forces toward the input electrode(s) controlling the position of the cantilever tip. The Authors discuss an OR gate however, for the sake of simplicity but without the loss of generality, we investigate a Follower logic gate in this paper. Two separate tip positions define the two logic values, 0 and 1, respectively. These logic values and tip positions correspond to driving voltages 0 and U 1 on the input electrode. The energy dissipation (due to friction) in the cantilever is measured during changing the logic value and the Authors correctly conclude that the energy dissipation due to friction can be made smaller than k B T. This is the point where we must ask: Does this approach account for all the major energy loss phenomena determining the lower limit of energy dissipation or is there any dominant but neglected component? The answer is straightforward: The considerations in [1] neglected the energy dissipation due to charging and discharging the input capacitance, which are the same dissipation phenomena [2-6] that determine the lower limits of dissipation (70-100 k B T) [3] not only in today's microprocessors (CMOS logic) but also in any other system with thermally activated errors [2-4]. Thus the same dissipation limit (70-100 k B T) holds for the new scheme in [1], too.
A recent IEEE Access Paper by Gunn, Allison and Abbott (GAA) proposed a new transient attack agai... more A recent IEEE Access Paper by Gunn, Allison and Abbott (GAA) proposed a new transient attack against the Kirchhoff-law–Johnson-noise (KLJN) secure key exchange system. The attack is valid, but it is easy to build a defense for the KLJN system. Here we note that GAA’s paper contains several invalid statements regarding security measures and the continuity of functions in classical physics. These deficiencies are clarified in our present paper, wherein we also emphasize that a new version of the KLJN system is immune against all existing attacks, including the one by GAA.
A new method to generate fingerprints of chemical agents has been introduced in this paper. The m... more A new method to generate fingerprints of chemical agents has been introduced in this paper. The method is based on the use of the zero-crossing statistics at fluctuation-enhanced sensing. It is a new version of Ben Kedem's original method based on low-pass filters. To improve computation time and energy efficiency, high-pass filtering is used, and in doing this in the simplest possible way, local zero levels for short-time subwindows are defined and a zero-crossing counting by the use of such windows is carried out. The method turns out to be an effective tool to identify noise processes with different spectra or amplitude distribution, with at least 1000 times less calculation and correspondingly lower energy need than that of the Kedem or the fast Fourier transform methods. We demonstrate the usability of the method by the analysis and recognition of different stochastic processes with similar and different spectra.
Weak physical uncloneable function (WPUF) encryption key means that the manufacturer of the hardw... more Weak physical uncloneable function (WPUF) encryption key means that the manufacturer of the hardware can clone the key but anybody else is unable to so that. Strong physical uncloneable function (SPUF) encryption key means that even the manufacturer of the hardware is unable to clone the key. In this paper, first we introduce a "ultra"-strong PUF with intrinsic dynamical randomness, which is not only not cloneable but it also gets renewed to an independent key (with fresh randomness) during each use via the unconditionally secure key exchange. The solution utilizes the Kirchhoff-law-Johnson-noise (KLJN) method for dynamical key renewal and a one-time-pad secure key for the challenge/response process. The secure key is stored in a flash memory on the chip to provide tamper-resistance and non-volatile storage with zero power requirements in standby mode. Simplified PUF keys are shown: a strong PUF utilizing KLJN protocol during the first run and noise-based logic (NBL) hyperspace vector string verification method for the challenge/response during the rest of its life or until it is re-initialized. Finally, the simplest PUF utilizes NBL without KLJN thus it can be cloned by the manufacturer but not by anybody else.
In his seminal paper, Chua presented a fundamental physical claim by introducing the memristor, "... more In his seminal paper, Chua presented a fundamental physical claim by introducing the memristor, "The missing circuit element". The memristor equations originally supposed to represent a passive circuit element because, with active circuitry, arbitrary elements can be realized without limitations. Therefore, if the memristor equations do not guarantee that the circuit element can be realized by a passive system, the fundamental physics claim about the memristor as "missing circuit element" loses all its weight. Recent work of Chua indicates that certain type of memristor features may imply an active device. To make the question more physical, we incorporate thermodynamics into the study of this question. By using the Second Law of Thermodynamics and thermal noise, we prove that the memristor model represents an active device for an infinitely large number of cases of memristor functions M; particularly, any power function with an odd power exponent, including the situation of linear M. This situation implies rectifier features and, according to the Brillouin paradox, driving a passive circuit element of rectifying feature with thermal noise would allow the construction of perpetual motion machines. The memristor equations require an active device at infinitely many situations.
The statistical-physics-based Kirchhoff-law–Johnson-noise (KLJN) key exchange offers a new and si... more The statistical-physics-based Kirchhoff-law–Johnson-noise (KLJN) key exchange offers a new and simple unclonable system for credit/debit card chip authentication and payment. The key exchange, the authentication and the communication are unconditionally secure so that neither mathematics-nor statistics-based attacks are able to crack the scheme. The ohmic connection and the short wiring lengths between the chips in the card and the terminal constitute an ideal setting for the KLJN protocol, and even its simplest versions offer unprecedented security and privacy for credit/debit card chips and applications of physical unclonable functions.
The feasibility of fluctuation-enhanced sensing (FES) for the detection and classification of dif... more The feasibility of fluctuation-enhanced sensing (FES) for the detection and classification of different gases using a single chemiresistive microsensor has been investigated through experimental measurements and data analyses. A nanostructured semiconducting metal oxide film has been used as a chemiresistive sensor in the experiments. Similarity fingerprints have been introduced to be used with the FES signatures, and combining similarity fingerprints with slope fingerprints results in a considerable increase in the classification accuracy attained by both Linear Discriminant Analysis (LDA) and Support Vector Machine (SVM) classification techniques.
Weak unclonable function (PUF) encryption key means that the manufacturer of the hardware can clo... more Weak unclonable function (PUF) encryption key means that the manufacturer of the hardware can clone the key but not anybody else. Strong unclonable function (PUF) encryption key means that even the manufacturer of the hardware is unable to clone the key. In this paper, first we introduce an " ultra " strong PUF with intrinsic dynamical randomness, which is not only unclonable but also gets renewed to an independent key (with fresh randomness) during each use via the unconditionally secure key exchange. The solution utilizes the Kirchhoff-law-Johnson-noise (KLJN) method for dynamical key renewal and a one-time-pad secure key for the challenge/response process. The secure key is stored in a flash memory on the chip to provide tamper-resistance and nonvolatile storage with zero power requirements in standby mode. Simplified PUF keys are shown: a strong PUF utilizing KLJN protocol during the first run and noise-based logic (NBL) hyperspace vector string verification method for the challenge/response during the rest of its life or until it is re-initialized. Finally, the simplest PUF utilizes NBL without KLJN thus it can be cloned by the manufacturer but not by anybody else.
A new method to generate fingerprints of chemical agents has been introduced in this paper. The m... more A new method to generate fingerprints of chemical agents has been introduced in this paper. The method is based on the use of the zero-crossing statistics at fluctuation-enhanced sensing. It is a new version of Ben Kedem's original method based on low-pass filters. To improve computation time and energy efficiency , high-pass filtering is used, and in doing this in the simplest possible way, local zero levels for short-time subwindows are defined and a zero-crossing counting by the use of such windows is carried out. The method turns out to be an effective tool to identify noise processes with different spectra or amplitude distribution, with at least 1000 times less calculation and correspondingly lower energy need than that of the Kedem or the fast Fourier transform methods. We demonstrate the usability of the method by the analysis and recognition of different stochastic processes with similar and different spectra.
We have developed a simple way to generate binary patterns based on spectral slopes in different ... more We have developed a simple way to generate binary patterns based on spectral slopes in different frequency ranges at fluctuation-enhanced sensing. Such patterns can be considered as binary "fingerprints" of odors. The method has experimentally been demonstrated with a commercial semiconducting metal oxide (Taguchi) sensor exposed to bacterial odors (Escherichia coli and Anthrax-surrogate Bacillus subtilis) and processing their stochastic signals. With a single Taguchi sensor, the situations of empty chamber, tryptic soy agar (TSA) medium, or TSA with bacteria could be distinguished with 100% reproducibility. The bacterium numbers were in the range of 2.5 × 10 4-10 6. To illustrate the relevance for ultra-low power consumption, we show that this new type of signal processing and pattern recognition task can be implemented by a simple analog circuitry and a few logic gates with total power consumption in the microWatts range.
The statistical-physics-based Kirchhoff-law–Johnson-noise (KLJN) key exchange offers a new and si... more The statistical-physics-based Kirchhoff-law–Johnson-noise (KLJN) key exchange offers a new and simple unclonable system for credit/debit card chip authentication and payment. The key exchange, the authentication and the communication are unconditionally secure so that neither mathematics-nor statistics-based attacks are able to crack the scheme. The ohmic connection and the short wiring lengths between the chips in the card and the terminal constitute an ideal setting for the KLJN protocol, and even its simplest versions offer unprecedented security and privacy for credit/debit card chips and applications of physical unclonable functions (PUFs).
Fluctuation-enhanced sensing (FES) comprises the analysis of the stochastic component of the sens... more Fluctuation-enhanced sensing (FES) comprises the analysis of the stochastic component of the sensor signal and the utilization of the microscopic dynamics of the interaction between the agent and the sensor. We study the relationship between the measurement time window and the statistical error of the measurement data in the simplest case, when the output is the mean-square value of the stochastic signal. This situation is relevant at any practical case when the time window is finite, for example, when a sampling of the output of a fluctuation-enhanced array takes place; or a single sensor's activation (temperature, etc.) is stepped up; or a single sensor's output is monitored by sampling subsequently in different frequency windows. Our study provides a lower limit of the relative error versus data window size with different types of power density spectra: white noise, 1/f (flicker, pink) noise, and 1/f 2 (red) noise spectra.
We survey and show our earlier results about three different ways of fluctuation-enhanced sensing... more We survey and show our earlier results about three different ways of fluctuation-enhanced sensing of bio agent, 1) the phage-based method for bacterium detection published earlier; 2) sensing and evaluating the odors of microbes; and 3) spectral and amplitude distribution analysis of noise in light scattering to identify spores based on their diffusion coefficient.
The goal of this paper is to explore the possibility to detect and identify bacteria by sensing t... more The goal of this paper is to explore the possibility to detect and identify bacteria by sensing their odor via fluctuation-enhanced sensing with commercial Taguchi sensors. The fluctuations of the electrical resistance during exposure to different bacterial odors, Escherichia coli and anthrax-surrogate Bacillus subtilis, have been measured and analyzed. In the present study, the simplest method, the measurement and analysis of power density spectra was used. The sensors were run in the normal-heated and the sampling-and-hold working modes, respectively. The results indicate that Taguchi sensors used in these fluctuation-enhanced modes are effective tools of bacterium detection and identification even when they are utilizing only the power density spectrum of the stochastic sensor signal.
—Conventional agent sensing methods normally use the steady state sensor values for agent classif... more —Conventional agent sensing methods normally use the steady state sensor values for agent classification. Many sensing are needed in order to correctly classify multiple agents in mixtures. Fluctuation enhanced sensing (FES) looks beyond the steady-state values and extracts agent information from spectra and bispectra. As a result, it is possible to use a single sensor to perform multiple agent classification. This paper summarizes the application of some advanced algorithms that can classify and estimate concentrations of different chemical agents. Our tool involves two steps. First, spectral and bispectral features will be extracted from the sensor signals. The features contain unique agent characteristics. Second, the features are fed into a hyperspectral signal processing algorithm for agent classification and concentration estimation. The basic idea here is to use the spectral/bispectral shape information to perform agent classification. Extensive simulations have been performed by using simulated nanosensor data, as well as actual experimental data using commercial sensor (Taguchi). It was observed that our algorithms are able to accurately classify different agents, and also can estimate the concentration of the agents. Bispectra contain more information than spectra at the expense of high-computational costs. Specific nanostructured sensor model data yielded excellent performance because the agent responses are additive with this type of sensor. Moreover, for measured conventional sensor outputs, our algorithms also showed reasonable performance in terms of agent classification.
—Both selectivity and sensitivity of chemical sensors can be considerably improved by exploiting ... more —Both selectivity and sensitivity of chemical sensors can be considerably improved by exploiting the information contained in microfluctuations present in the sensor system. We call our collection of methods and algorithms to extract information from these microfluctuations, fluctuation enhanced sensing. In this paper, we present a short survey of results with Taguchi sensors, surface acoustic wave devices, MOSFET-based sensors, and nanosensors.
Microscopic fluctuations in a system can contain much more information about the system than the ... more Microscopic fluctuations in a system can contain much more information about the system than the average values of the corresponding physical quantities.
We present a short survey on fluctuation-enhanced gas sensing. We compare some of its main charac... more We present a short survey on fluctuation-enhanced gas sensing. We compare some of its main characteristics with those of classical sensing. We address the problem of linear response, information channel capacity, missed alarms and false alarms.
Microscopic fluctuations in a system can contain much more information about the system than the
... more Microscopic fluctuations in a system can contain much more information about the system than the average values of the corresponding physical quantities. • Often, the measurement of these fluctuations can serve with some unique information that cannot be assessed by other means or it causes the least perturbation to the system. • Fluctuation-Enhanced Sensing (2001, John Audia, SPAWAR, US Navy): sensing of physical, chemical or biological agents where fluctuations are utilized to gain sensory information.
• Fluctuation-enhanced sensing methods generate a fluctuation-fingerprint of the
stochastic compo... more • Fluctuation-enhanced sensing methods generate a fluctuation-fingerprint of the stochastic component of sensor signals which can be identified by pattern recognizers. • Typical FFT and bispectrum methods involved a large amount of data processing steps and therefore significant processing time and energy requirements. • Thus, for wireless, palmtop and similar low-power and low-processor-speed systems there is a need of a faster fingerprinting in an energy efficient way.
Signal separation at fluctuation-enhanced sensing improves speed,
selectivity and sensitivity.
• ... more Signal separation at fluctuation-enhanced sensing improves speed, selectivity and sensitivity. • We analyze a (symmetrical) two-sensor arrangement with a joint boundary line between an integrated sensor pair. • We show a way to separate the adsorption-desorption signal components from the diffusive signal component. • The method generates two independent output spectra which double the sensor information for pattern recognition.
The objective of this work is to investigate commercial
semiconductor gas sensors’ sensitivity an... more The objective of this work is to investigate commercial semiconductor gas sensors’ sensitivity and selectivity to odors generated by different types of bacteria which will then lead to detection and identification of bacteria by a simple, practical, rapid, and inexpensive way. • Electrical fluctuations of commercial semiconductor gas sensors during exposure to different biological agents via fluctuationenhanced sensing have been studied. • The normalized power spectra, zero-crossing patterns (ZCP) and a number of statistical features including first (mean, std) and high order statistics (skewness, kurtosis) and others are investigated for bacteria detection and identification.
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Papers by Laszlo B Kish
average values of the corresponding physical quantities.
• Often, the measurement of these fluctuations can serve with some unique information that cannot be
assessed by other means or it causes the least perturbation to the system.
• Fluctuation-Enhanced Sensing (2001, John Audia, SPAWAR, US Navy): sensing of physical, chemical
or biological agents where fluctuations are utilized to gain sensory information.
stochastic component of sensor signals which can be identified by pattern
recognizers.
• Typical FFT and bispectrum methods involved a large amount of data processing
steps and therefore significant processing time and energy requirements.
• Thus, for wireless, palmtop and similar low-power and low-processor-speed
systems there is a need of a faster fingerprinting in an energy efficient way.
selectivity and sensitivity.
• We analyze a (symmetrical) two-sensor arrangement with a joint
boundary line between an integrated sensor pair.
• We show a way to separate the adsorption-desorption signal
components from the diffusive signal component.
• The method generates two independent output spectra which double
the sensor information for pattern recognition.
semiconductor gas sensors’ sensitivity and selectivity to odors
generated by different types of bacteria which will then lead to
detection and identification of bacteria by a simple, practical,
rapid, and inexpensive way.
• Electrical fluctuations of commercial semiconductor gas sensors
during exposure to different biological agents via fluctuationenhanced
sensing have been studied.
• The normalized power spectra, zero-crossing patterns (ZCP) and
a number of statistical features including first (mean, std) and
high order statistics (skewness, kurtosis) and others are
investigated for bacteria detection and identification.