scholarly journals A Static-loop-current Attack Against the Kirchhoff-Law-Johnson-Noise (KLJN) Secure Key Exchange System

2019 ◽  
Vol 9 (4) ◽  
pp. 666 ◽  
Author(s):  
Mutaz Melhem ◽  
Laszlo Kish

In this study, a new attack against the Kirchhoff-Law-Johnson-Noise (KLJN) key distribution system is explored. The attack is based on utilizing a parasitic voltage-source in the loop. Relevant situations often exist in the low-frequency limit in practical systems, especially when the communication is over a distance, or between different units within an instrument, due to a ground loop and/or electromagnetic interference (EMI). Our present study investigates the DC ground loop situation when no AC or EMI effects are present. Surprisingly, the usual current/voltage comparison-based defense method that exposes active attacks or parasitic features (such as wire resistance allowing information leaks) does not function here. The attack is successfully demonstrated and proposed defense methods against the attack are shown.

2021 ◽  
pp. 2150050
Author(s):  
Mutaz Y. Melhem ◽  
Christiana Chamon ◽  
Shahriar Ferdous ◽  
Laszlo B. Kish

Recently, several passive and active attack methods have been proposed against the Kirchhoff–Law–Johnson–Noise (KLJN) secure key exchange scheme by utilizing direct (DC) loop currents. The DC current attacks are relatively easy, but their practical importance is low. On the other hand, parasitic alternating (AC) currents are virtually omnipresent in wire-based systems. Such situations exist due to AC ground loops and electromagnetic interference (EMI). However, utilizing AC currents for attacks is a harder problem. Here, we introduce and demonstrate AC current attacks in various frequency ranges. The attacks exploit a parasitic/periodic AC voltage-source at either Alice’s or Bob’s end. In the low-frequency case, the procedure is the generalized form of the former DC ground-loop-based attack. In the high-frequency case, the power density spectrum of the wire voltage is utilized. The attack is demonstrated in both the low and the high-frequency situations. Defense protocols against the attack are also discussed.


Author(s):  
Mutaz Y. Melhem ◽  
Laszlo B. Kish

A new attack against the Kirchhoff-Law-Johnson-Noise (KLJN) key distribution system is introduced. The attack is based on 1) Utilizing the dc-voltage-source - which we put at Alice’s end in our mathematical modeling of the attack-that could exist due to errors, imbalances, Electromagnetic interference and etc.2) On studying the number of samples per bit in the security key that the measured Alice/Bob voltages exceeds or falls below a threshold voltage, respectively. The threshold voltage is the average between dc voltages across low and high resistors- generated by a dc-voltage source. We count the number of samples the voltage at Bob’s end (containing both the noise and dc components) exceeds the threshold voltage and how many times it falls below the threshold to judge whether the resistor can be guessed as low or high for every cycle. Also for a pre-specified key-length we count the number of high resistance estimations per bit –at Bob’s end-according to the previous criterion and the non-successful estimations per bit to judge the final guessed resistor value at Alice’s end and Bob’s end, where if we have more bits with most of its measured samples are above the threshold voltage then we will predict Bob’s resistance as high resistance, otherwise we predict Bob’s resistance to be low resistance. The Simulation was conducted and the attack proved that it is successful unless the temperature increased dramatically to ranges more than a threshold temperature ~ Kelvin that increases when the number of samples per bit increases.


2019 ◽  
Vol 125 ◽  
pp. 14006
Author(s):  
Ahmed Jumui Sumoi Fomba ◽  
Hermawan Hermawan ◽  
Trias Andromeda ◽  
Mochammad Facta ◽  
Iwan Setiawan

This paper presents a simulation of a grid-connected photovoltaic power system. A complex model of power distribution system is developed in MATLAB Simulink, then it will be simulated to determine an amount of power delivered to the grid based on irradiance and temperature. Solar irradiance data collection is conducted using a solar irradiance meter. These weather data (solar irradiances and temperatures) are transformed into signal inputs and model through a grid-tied Photovoltaic (PV) model system which consists of PV, incremental conductance Maximum Power Point Tracking (MPPT) method, DC-DC boost converter, inverter, voltage source converter (VSC) control algorithms, and grid equipment. The output variables can be related to current, voltage or power. However, tracing of the current-voltage (I-V) characteristics or power-voltage (P-V) characteristics are the vital need to grid-tied PV system operation. Changes in solar irradiance and temperature imply changes in output variables. Detailed modelling of the effect of irradiance and temperature, on the parameters of the PV module and the output parameters will be discussed. With the aid of this model, one can have a feasible idea about the solar energy generation potential at given locations. This comprehensive model is simulated using MATLAB/Simulink software.


Author(s):  
Niraj Kumar Choudhary ◽  
Soumya Ranjan Mohanty ◽  
Ravindra Kumar Singh

This paper presents an investigation about the impact of integrating renewable energy based generation sources on the existing distribution system in terms of load sharing. The study of load sharing among various distributed generators (DGs) and utility grid has been performed for two cases: (a) when equivalent source based DG is connected and (b) when real PV/Fuel cell based DG is properly integrated to the distribution system. The real photovoltaic and fuel cell based DG do not behave as stiff current/voltage source due to disturbances happening either internally in system known as parametric uncertainties or due to external disturbances like weather conditions, load change etc. Further it has been observed with extensive analysis using simulation result, that even though all DGs are of equal capacity in their generation but when the load is either increased or decreased this doesn’t essentially guarantee that all DGs will equally share the active and reactive power demand


Author(s):  
Niraj Kumar Choudhary ◽  
Soumya Ranjan Mohanty ◽  
Ravindra Kumar Singh

This paper presents an investigation about the impact of integrating renewable energy based generation sources on the existing distribution system in terms of load sharing. The study of load sharing among various distributed generators (DGs) and utility grid has been performed for two cases: (a) when equivalent source based DG is connected and (b) when real PV/Fuel cell based DG is properly integrated to the distribution system. The real photovoltaic and fuel cell based DG do not behave as stiff current/voltage source due to disturbances happening either internally in system known as parametric uncertainties or due to external disturbances like weather conditions, load change etc. Further it has been observed with extensive analysis using simulation result, that even though all DGs are of equal capacity in their generation but when the load is either increased or decreased this doesn’t essentially guarantee that all DGs will equally share the active and reactive power demand.


Electronics ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 60
Author(s):  
Mario Ponce-Silva ◽  
Daniel Salazar-Pérez ◽  
Oscar Miguel Rodríguez-Benítez ◽  
Luis Gerardo Vela-Valdés ◽  
Abraham Claudio-Sánchez ◽  
...  

The main contribution of this paper is to show a new AC/DC converter based on the rearrangement of the flyback converter. The proposed circuit only manages part of the energy and the rest is delivered directly from the source to the load. Therefore, with the new topology, the efficiency is increased, and the stress of the components is reduced. The rearrangement consist of the secondary of the flyback is placed in parallel with the load, and this arrangement is connected in series with the primary side and the rectified voltage source. The re-arranged flyback is only a reductive topology and with no magnetic isolation. It was studied as a power supply for LEDs. A low frequency averaged analysis (LFAA) was used to determine the behavior of the proposed circuit and an equivalent circuit much easier to analyze was obtained. To validate the theoretical analysis, a design methodology was developed for the re-arranged flyback converter. The designed circuit was implemented in a 10 W prototype. Experimental results showed that the converter has a THDi = 21.7% and a PF = 0.9686.


Author(s):  
Akram Qashou ◽  
Sufian Yousef ◽  
Abdallah A. Smadi ◽  
Amani A. AlOmari

AbstractThe purpose of this paper is to describe the design of a Hybrid Series Active Power Filter (HSeAPF) system to improve the quality of power on three-phase power distribution grids. The system controls are comprise of Pulse Width Modulation (PWM) based on the Synchronous Reference Frame (SRF) theory, and supported by Phase Locked Loop (PLL) for generating the switching pulses to control a Voltage Source Converter (VSC). The DC link voltage is controlled by Non-Linear Sliding Mode Control (SMC) for faster response and to ensure that it is maintained at a constant value. When this voltage is compared with Proportional Integral (PI), then the improvements made can be shown. The function of HSeAPF control is to eliminate voltage fluctuations, voltage swell/sag, and prevent voltage/current harmonics are produced by both non-linear loads and small inverters connected to the distribution network. A digital Phase Locked Loop that generates frequencies and an oscillating phase-locked output signal controls the voltage. The results from the simulation indicate that the HSeAPF can effectively suppress the dynamic and harmonic reactive power compensation system. Also, the distribution network has a low Total Harmonic Distortion (< 5%), demonstrating that the designed system is efficient, which is an essential requirement when it comes to the IEEE-519 and IEC 61,000–3-6 standards.


2021 ◽  
Vol 22 (1) ◽  
pp. 113-127
Author(s):  
Mulualem Tesfaye ◽  
Baseem Khan ◽  
Om Prakash Mahela ◽  
Hassan Haes Alhelou ◽  
Neeraj Gupta ◽  
...  

Abstract Generation of renewable energy sources and their interfacing to the main system has turn out to be most fascinating challenge. Renewable energy generation requires stable and reliable incorporation of energy to the low or medium voltage networks. This paper presents the microgrid modeling as an alternative and feasible power supply for Institute of Technology, Hawassa University, Ethiopia. This microgrid consists of a 60 kW photo voltaic (PV) and a 20 kW wind turbine (WT) system; that is linked to the electrical distribution system of the campus by a 3-phase pulse width modulation scheme based voltage source inverters (VSI) and supplying power to the university buildings. The main challenge in this work is related to the interconnection of microgrid with utility grid, using 3-phase VSI controller. The PV and WT of the microgrid are controlled in active and reactive power (PQ) control mode during grid connected operation and in voltage/frequency (V/F) control mode, when the microgrid is switched to the stand-alone operation. To demonstrate the feasibility of proposed microgrid model, MATLAB/Simulink software has been employed. The performance of fully functioning microgrid is analyzed and simulated for a number of operating conditions. Simulation results supported the usefulness of developed microgrid in both mode of operation.


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