5 research outputs found

    Quantum Neural Network based Distinguisher for Differential Cryptanalysis on Simplified Block Ciphers

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    Differential cryptanalysis is a block cipher analysis technology that infers a key by using the difference characteristics. Input differences can be distinguished using a good difference characteristic, and this distinguishing task can lead to key recovery. Artificial neural networks are a good solution for distinguishing tasks. For this reason, recently, neural distinguishers have been actively studied. We propose a distinguisher based on a quantum-classical hybrid neural network by utilizing the recently developed quantum neural network. To our knowledge, we are the first attempt to apply quantum neural networks for neural distinguisher. The target ciphers are simplified ciphers (S-DES, S-AES, S-PRESENT-[4]), and a quantum neural distinguisher that classifies the input difference from random data was constructed using the Pennylane library. Finally, we obtained quantum advantages in this work: improved accuracy and reduced number of parameters. Therefore, our work can be used as a quantum neural distinguisher with high reliability for simplified ciphers

    Quantum Implementation of AIM: Aiming for Low-Depth

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    Security vulnerabilities in the symmetric-key primitives of a cipher can undermine the overall security claims of the cipher. With the rapid advancement of quantum computing in recent years, there is an increasing effort to evaluate the security of symmetric-key cryptography against potential quantum attacks. This paper focuses on analyzing the quantum attack resistance of AIM, a symmetric-key primitive used in the AIMer digital signature scheme. We presents the first quantum circuit implementation of AIM and estimates its complexity (such as qubit count, gate count, and circuit depth) with respect to Grover\u27s search algorithm. For Grover\u27s key search, the most important optimization metric is the depth, especially when considering parallel search. Our implementation gathers multiple methods for a low-depth quantum circuit of AIM in order to reduce the Toffoli depth and full depth

    Seamless Grid Synchronization of a Proportional+Resonant Control-Based Voltage Controller Considering Non-Linear Loads under Islanded Mode

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    This paper proposes the grid synchronization method of inverter using a quasi Proportional+Multi Resonant (P+MR) control-based voltage controller a stationary reference frame. The inverter supplies a non-linear load under the islanded mode. In islanded mode, the inverter is defined as a voltage source to supply the full local load demand without a connection to the grid. On the other hand, if the grid is restored from a previous fault or the strategic islanding is unnecessary, the inverter needs to be synchronized with the phase of the grid before the transfer from islanded mode to grid-connected mode. When the system is modeled and controlled based on the stationary reference frame control, the AC reference voltage, which has a constant voltage and frequency in islanded mode, is substituted to the AC grid voltage. Significant error can occur due to the large phase differences between the phase of reference and that of the measured value. This error also can cause severe voltage dynamic problems. In addition, if any nonlinear local load is connected to the output of the inverter, it becomes more serious due to the harmonics generated from the loads. In this paper, the PR control under a stationary reference frame is used for voltage control under islanded mode considering the harmonic effects from the nonlinear load. The seamless grid synchronization method based on this PR control is proposed to solve the aforementioned problems. The validity of the proposed seamless grid synchronization method is verified through PSiM simulations and experimental results

    Galvanically Replaced, Single-Bodied Lithium-Ion Battery Fabric Electrodes

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    Despite extensive research on flexible/wearable power sources, their structural stability and electrochemical reliability upon mechanical deformation and charge/discharge cycling have not yet been completely achieved. A new class of galvanically replaced single-bodied lithium-ion battery (LIB) fabric electrodes is demonstrated. As a proof of concept, metallic tin (Sn) is chosen as an electrode active material. Mechanically compliable polyethyleneterephthalate (PET) fabrics are conformally coated with thin metallic nickel (Ni) layers via electroless plating to develop flexible current collectors. Driven by the electrochemical potential difference between Ni and Sn, the thin Ni layers are galvanically replaced with Sn, resulting in the fabrication of a single-bodied Sn@Ni fabric electrode (Sn is monolithically embedded in the Ni matrix on the PET fabric). Benefiting from the chemical/structural uniqueness and rationally designed bicontinuous ion/electron transport pathways, the single-bodied Sn@Ni fabric electrode provides exceptional redox reaction kinetics and omnidirectional deformability (notably, origami-folding boats), which lie far beyond those attainable with conventional LIB electrode technologies
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