著者

Nasratullah GHAFOORI Atsuko MIYAJI Ryoma ITO Shotaro MIYASHITA

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE Transactions on Information and Systems (ISSN:09168532)

巻号頁・発行日

vol.E106.D, no.9, pp.1407-1422, 2023-09-01 (Released:2023-09-01)

参考文献数

30

被引用文献数

2

---

This paper introduces significant improvements over the existing cryptanalysis approaches on Salsa20 and ChaCha stream ciphers. For the first time, we reduced the attack complexity on Salsa20/8 to the lowest possible margin. We introduced an attack on ChaCha7.25. It is the first attack of its type on ChaCha7.25/20. In our approach, we studied differential cryptanalysis of the Salsa20 and ChaCha stream ciphers based on a comprehensive analysis of probabilistic neutral bits (PNBs). The existing differential cryptanalysis approaches on Salsa20 and ChaCha stream ciphers first study the differential bias at specific input and output differential positions and then search for probabilistic neutral bits. However, the differential bias and the set of PNBs obtained in this method are not always the ideal combination to conduct the attack against the ciphers. The researchers have not focused on the comprehensive analysis of the probabilistic neutrality measure of all key bits concerning all possible output difference positions at all possible internal rounds of Salsa20 and ChaCha stream ciphers. Moreover, the relationship between the neutrality measure and the number of inverse quarter rounds has not been scrutinized yet. To address these study gaps, we study the differential cryptanalysis based on the comprehensive analysis of probabilistic neutral bits on the reduced-round Salsa20 and ChaCha. At first, we comprehensively analyze the neutrality measure of 256 key bits positions. Afterward, we select the output difference bit position with the best average neutrality measure and look for the corresponding input differential with the best differential bias. Considering all aspects, we present an attack on Salsa20/8 with a time complexity of 2241.62 and data complexity of 231.5, which is the best-known single bit differential attack on Salsa20/8 and then, we introduced an attack on ChaCha7.25 rounds with a time complexity of 2254.011 and data complexity of 251.81.

著者

Nasratullah GHAFOORI Atsuko MIYAJI Ryoma ITO Shotaro MIYASHITA

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE TRANSACTIONS on Information and Systems (ISSN:09168532)

巻号頁・発行日

vol.E106-D, no.9, pp.1407-1422, 2023-09-01

被引用文献数

2

---

This paper introduces significant improvements over the existing cryptanalysis approaches on Salsa20 and ChaCha stream ciphers. For the first time, we reduced the attack complexity on Salsa20/8 to the lowest possible margin. We introduced an attack on ChaCha7.25. It is the first attack of its type on ChaCha7.25/20. In our approach, we studied differential cryptanalysis of the Salsa20 and ChaCha stream ciphers based on a comprehensive analysis of probabilistic neutral bits (PNBs). The existing differential cryptanalysis approaches on Salsa20 and ChaCha stream ciphers first study the differential bias at specific input and output differential positions and then search for probabilistic neutral bits. However, the differential bias and the set of PNBs obtained in this method are not always the ideal combination to conduct the attack against the ciphers. The researchers have not focused on the comprehensive analysis of the probabilistic neutrality measure of all key bits concerning all possible output difference positions at all possible internal rounds of Salsa20 and ChaCha stream ciphers. Moreover, the relationship between the neutrality measure and the number of inverse quarter rounds has not been scrutinized yet. To address these study gaps, we study the differential cryptanalysis based on the comprehensive analysis of probabilistic neutral bits on the reduced-round Salsa20 and ChaCha. At first, we comprehensively analyze the neutrality measure of 256 key bits positions. Afterward, we select the output difference bit position with the best average neutrality measure and look for the corresponding input differential with the best differential bias. Considering all aspects, we present an attack on Salsa20/8 with a time complexity of 2241.62 and data complexity of 231.5, which is the best-known single bit differential attack on Salsa20/8 and then, we introduced an attack on ChaCha7.25 rounds with a time complexity of 2254.011 and data complexity of 251.81.

著者

Tianliang Xu Shanqiang Yang Xin Wang Chenxu Wang Zhiquan Zhou Tian Rong

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE Electronics Express (ISSN:13492543)

巻号頁・発行日

vol.20, no.16, pp.20230242, 2023-08-25 (Released:2023-08-25)

参考文献数

31

---

With the continuous deepening of ocean exploration and the growth of emergency rescue needs, the hydroacoustic transducer, as an important component of sonar, has become more and more demanding. To improve the reception performance of the piezoelectric transducer, we developed a high-frequency, high-sensitivity planar piezoelectric transducer. A variant 1-3-2 type piezoelectric material is used to improve the effective electromechanical coupling coefficient, the upper surface of the material is covered with a brass plate to amplify the reception stress, and two variant 1-3-2 type piezoelectric materials with different dimensional parameters are arranged vertically to expand the bandwidth. We investigated the material properties and determined the material dimensions actually used to fabricate a planar hydroacoustic transducer utilizing electromechanical equivalent circuit analysis methods and finite element simulations. A prototype planar hydroacoustic transducer was fabricated and tested for resonant frequency, receiver sensitivity, bandwidth, and horizontal directivity then. The results show that the transducer’s resonant frequency is about 218.7kHz, the maximum receiving sensitivity is -178.7dB, the 3dB loss receiving bandwidth is about 45kHz, and the horizontal directivity is about 17°. The test results all indicate that the developed hydroacoustic transducer has great potential for application in marine exploration and underwater emergency rescue.

著者

Hiroki MAYUMI Keigo TAKEUCHI

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences (ISSN:09168508)

巻号頁・発行日

vol.E103-A, no.12, pp.1666-1669, 2020-12-01

被引用文献数

1

---

Expectation propagation (EP) decoding is proposed for sparse superposition coding in orthogonal frequency division multiplexing (OFDM) systems. When a randomized discrete Fourier transform (DFT) dictionary matrix is used, the EP decoding has the same complexity as approximate message-passing (AMP) decoding, which is a low-complexity and powerful decoding algorithm for the additive white Gaussian noise (AWGN) channel. Numerical simulations show that the EP decoding achieves comparable performance to AMP decoding for the AWGN channel. For OFDM systems, on the other hand, the EP decoding is much superior to the AMP decoding while the AMP decoding has an error-floor in high signal-to-noise ratio regime.

著者

内藤 喜之 水本 哲弥

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

電子情報通信学会論文誌 C (ISSN:03736113)

巻号頁・発行日

vol.J69-C, no.3, pp.257-261, 1986-03-25

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強磁性材料フェライトは,焼結フェライト,ゴムフェライトといった形で電波吸収体として用いられている.しかし,これらフェライトを用いた場合,電波吸収体の厚さを薄くするのにはある一定の限界がある.そこで,ゴムフェライト電波吸収体の厚さを薄くする目的でこれにカーボンを添加し,その電波吸収特性を検討した.その結果,カーボンをフェライトの数%~10数%(体積比)添加することによって吸収体厚を約30%薄くできることがわかった.吸収体の厚さを薄くすることはその重量を軽減することにつながる.さらに,フェライトに比べてカーボンの方が比重が小さいので,カーボン混入によって吸収体が薄層化されることは吸収体の軽量化に大きな効果をもつ.本論文はこれらカーボン添加ゴムフェライトの電波吸収特性をまとめたものである.

著者

中井 大貴 河南 壮太 田原 映理 山本 有貴 福山 尚 五味 文 角所 考 岡留 剛

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

電子情報通信学会論文誌 D (ISSN:18804535)

巻号頁・発行日

vol.J106-D, no.8, pp.419-430, 2023-08-01

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非侵襲な検査を可能にする光干渉断層計(OCT: Optical Coherence Tomography)によるスキャン画像において,網膜の層の厚みと,視力や病状との関係性を捉えるためには,画像における網膜の層を抽出する必要がある.本研究では,網膜剥離を伴う眼科疾患におけるOCTスキャン画像で網膜の層を抽出する手法を提案する.その手法では,各層に対し,それぞれの特徴を反映したコスト関数の最小化により層の境界を決定し,とりわけ,治療後視力と相関があると考えられる厚みを求めるために必要な網膜剥離領域の輪郭線と内境界膜・外境界膜が抽出できる.その応用として,得られた境界から層の厚みに関する特徴量を算出し,中心性漿液性脈絡網膜症の治療後視力を予測するARDガウス過程回帰を構築し,予測に有意な特徴量が,中心窩における内境界膜から外境界膜までの長さと,外境界膜から網膜色素上皮までの長さの剥離前後での変化度であることを明らかにした.

著者

宮崎 龍一 須賀 良介

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

電子情報通信学会論文誌 C (ISSN:13452827)

巻号頁・発行日

vol.J106-C, no.8, pp.334-335, 2023-08-01

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電子レンジのグリル機能ではグリル皿に貼付したフェライトをマイクロ波により加熱することで食品を下面から焼くが,そのフェライトに生じる定在波による食品の焼成ムラが懸念される.本研究では,1/4波長共振器を用いてフェライト内部の磁界分布を均一化する手法について電磁界解析により検討した.

著者

山極 大葵 萓野 良樹 上 芳夫 肖 鳳超 井上 浩

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

電子情報通信学会論文誌 B (ISSN:13444697)

巻号頁・発行日

vol.J106-B, no.8, pp.509-518, 2023-08-01

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電子機器の小型・軽量化に伴い,伝送線路から発生する電磁ノイズ対策の一つとして,薄い導体シールドが採用されている.本論文は,薄い導体シールドを伝送線路に実装した際に生じる周波数分散の物理現象の解明及び定量的表現に基づく特性の予測を目的としている.差動線路間隔よりも近傍に薄い導体シールドを実装した際に一次定数に生じる周波数分散の導体シールド厚み依存性及び近傍磁界シールド効果との対応関係について電磁界解析により検討し,周波数分散を予測するための定量的表現方法について提案した.検討周波数は高速伝送線路を想定した20 MHz ~10 GHzである.一般的なマイクロストリップやストリップ構造の伝送線路とは異なり,周波数分散は物理現象をもとに四つのシンプルな周波数帯域に区分でき,特に近傍磁界シールド効果に起因した帯域区分では,シグモイド関数により定量的に表現できることを示した.更に,定量的表現のフィッティング定数及び近傍磁界シールド効果の導体厚み依存性評価により,周波数分散が生じる帯域と導体シールドの厚みは反比例の関係があることを明らかにした.この周波数分散の定量的表現と導体シールド材料の厚み等の条件から,周波数特性が定量的に予測可能となることも示した.

著者

Amr Amrallah Ehab Mahmoud Mohamed Gia Khanh Tran Kei Sakaguchi

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE Communications Express (ISSN:21870136)

巻号頁・発行日

vol.12, no.8, pp.403-408, 2023-08-01 (Released:2023-08-01)

参考文献数

3

被引用文献数

2

---

In a post-disaster area, Unmanned Aerial Vehicles (UAVs) are considered one of the most effective ways to provide emergency wireless communication services. In this letter, we investigate the UAV-based emergency wireless communication network for a post-disaster area. Our optimization problem aims to optimize the UAV 3D flight trajectory to maximize the number of visited ground users during the flight round. Then, a dual-cost-aware multi-armed bandit algorithm is adopted to tackle this problem under the limited available energy for both the UAV and ground users. Finally, simulation results show that the proposed algorithm could solve the optimization problem and maximize the achievable throughput under these constraints.

著者

園田 潤 國岡 達也 高橋 信 細川 寿樹

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

電子情報通信学会論文誌 B (ISSN:13444697)

巻号頁・発行日

vol.J104-B, no.5, pp.414-416, 2021-05-01

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アスファルト舗装下の深さ1.0 mと2.0 mの比誘電率をTDR (Time Domain Reflectometry)で1年間測定し,比誘電率の変動を調べた.この結果からアスファルト舗装下の比誘電率と,埋設管探査における深さ推定の誤差を定量化した.

著者

Jungwoo KWON Gyeonghwan KIM

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE TRANSACTIONS on Information and Systems (ISSN:09168532)

巻号頁・発行日

vol.E106-D, no.8, pp.1287-1291, 2023-08-01

被引用文献数

1

---

In this letter, we propose a feature-based knowledge distillation scheme which transfers knowledge between intermediate blocks of teacher and student with flow-based architecture, specifically Normalizing flow in our implementation. In addition to the knowledge transfer scheme, we examine how configuration of the distillation positions impacts on the knowledge transfer performance. To evaluate the proposed ideas, we choose two knowledge distillation baseline models which are based on Normalizing flow on different domains: CS-Flow for anomaly detection and SRFlow-DA for super-resolution. A set of performance comparison to the baseline models with popular benchmark datasets shows promising results along with improved inference speed. The comparison includes performance analysis based on various configurations of the distillation positions in the proposed scheme.

著者

Yuanzhong XU Tao KE Wenjun CAO Yao FU Zhangqing HE

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE TRANSACTIONS on Electronics (ISSN:09168516)

巻号頁・発行日

vol.E106-C, no.8, pp.432-441, 2023-08-01

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Physical Unclonable Function (PUF) is a promising lightweight hardware security primitive that can extract device fingerprints for encryption or authentication. However, extracting fingerprints from either the chip or the board individually has security flaws and cannot provide hardware system-level security. This paper proposes a new Chip-PCB hybrid PUF(CPR PUF) in which Weak PUF on PCB is combined with Strong PUF inside the chip to generate massive responses under the control of challenges of on-chip Strong PUF. This structure tightly couples the chip and PCB into an inseparable and unclonable unit thus can verify the authenticity of chip as well as the board. To improve the uniformity and reliability of Chip-PCB hybrid PUF, we propose a lightweight key generator based on a reliability self-test and debiasing algorithm to extract massive stable and secure keys from unreliable and biased PUF responses, which eliminates expensive error correction processes. The FPGA-based test results show that the PUF responses after robust extraction and debiasing achieve high uniqueness, reliability, uniformity and anti-counterfeiting features. Moreover, the key generator greatly reduces the execution cost and the bit error rate of the keys is less than 10-9, the overall security of the key is also improved by eliminating the entropy leakage of helper data.

著者

Yixuan ZHANG Meiting XUE Huan ZHANG Shubiao LIU Bei ZHAO

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences (ISSN:09168508)

巻号頁・発行日

vol.E106-A, no.8, pp.1037-1042, 2023-08-01

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Network traffic control and classification have become increasingly dependent on deep packet inspection (DPI) approaches, which are the most precise techniques for intrusion detection and prevention. However, the increasing traffic volumes and link speed exert considerable pressure on DPI techniques to process packets with high performance in restricted available memory. To overcome this problem, we proposed dual cuckoo filter (DCF) as a data structure based on cuckoo filter (CF). The CF can be extended to the parallel mode called parallel Cuckoo Filter (PCF). The proposed data structure employs an extra hash function to obtain two potential indices of entries. The DCF magnifies the superiority of the CF with no additional memory. Moreover, it can be extended to the parallel mode, resulting in a data structure referred to as parallel Dual Cuckoo filter (PDCF). The implementation results show that using the DCF and PDCF as identification tools in a DPI system results in time improvements of up to 2% and 30% over the CF and PCF, respectively.

著者

Jin Chen Minghui You Guohua Liu Zhiqun Cheng

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE Electronics Express (ISSN:13492543)

巻号頁・発行日

vol.20, no.14, pp.20230206, 2023-07-25 (Released:2023-07-25)

参考文献数

30

---

A method for designing a broadband high-efficiency power amplifier (PA) based on a novel loop-shaped filter matching structure is proposed in this paper. By combining a power amplifier matching circuit and a loop-shaped filter structure, a broadband high-efficiency PA based on a new harmonic matching structure is realized. The novel loop-shaped filter can control the second and third harmonics in a wide frequency range and has a specific control effect on higher-order harmonics, which can further expand the bandwidth of class-F PA and improve efficiency. To verify its feasibility, a power amplifier with a bandwidth of 1.6GHz-3.4GHz, a saturated output power greater than 41dBm, a drain efficiency of 65%-72% with a gain greater than 10dB is designed and fabricated using GaN HEMT CGH40010F transistor.

著者

Masato Kawaguchi Hideyuki Kato

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

Nonlinear Theory and Its Applications, IEICE (ISSN:21854106)

巻号頁・発行日

vol.14, no.3, pp.590-608, 2023 (Released:2023-07-01)

参考文献数

32

---

Some studies started analyzing time series via complex networks in the noughties. A study reported that time series, which were transformed into networks via recurrence plots (RPs), especially k-nearest neighbor RP, exhibited superfamily phenomena resulting from the network motif analysis. However, it is not hard to imagine that the transformation properties drastically change the results of the motif analysis. In this study, we examine that by introducing another type of RP.As a result, the RP employed in this study works better for the superfamily phenomena among the time series than the previously used RP.

著者

吉川 諒 落合 秀也 矢谷 浩司

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

電子情報通信学会論文誌 D (ISSN:18804535)

巻号頁・発行日

vol.J106-D, no.7, pp.409-418, 2023-07-01

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情報セキュリティ・倫理に関する知識を学ぶ必要性がますます高まる中,全てのユーザが最新の知識を定期的に手に入れられているとは言い難い.そこで我々は先行研究において,一般人に対して定期的に学習機会を提供するためのシステムの設計を目指した.そして,情報倫理・セキュリティに関するマイクロラーニングをボット判定に統合するシステム,DualCheckを提案した.DualCheckはreCAPTCHA-v2等と同様にチェックボックスをクリックする挙動でボット判定を実施するが,同時にインターネットの適切な利用を促すクイズを出題する.先行研究ではDualCheckを利用することが知識の定着に役立ち,またユーザビリティが高いことが示されたが,定着した知識がどの程度持続するかは不明であった.そこで本研究では,DualCheck利用後4ヶ月程度が経過した参加者を対象に,知識の定着を測定するテストを行った.結果として,DualCheckの利用前に比べて,テストの正答率が有意に高いことが明らかとなった.更に,DualCheck利用直後の知識の多くが持続していることも判明した.

著者

久保田 繁 有馬 ボシールアハンマド 廣瀬 文彦

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

電子情報通信学会論文誌 C (ISSN:13452827)

巻号頁・発行日

vol.J106-C, no.7, pp.267-276, 2023-07-01

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有機薄膜太陽電池は低コスト,高デザイン性,軽量,フレキシブル,無毒性といった優れた特徴を併せもつ次世代の太陽電池であるが,薄い(~100 nm)発電層に光を十分に吸収するのが困難であるという技術的な課題が存在する.このため,波長と同程度の空間スケールを有するナノ構造を用いて光の流れを制御することで,発電層内の電界を局所的に強化することにより光吸収を促進する光閉じ込め技術の開発が,今後特に重要になると考えられる.本論文では,筆者等がこれまで行ってきた,表面ナノ構造による有機薄膜太陽電池の光閉じ込めに関する研究について,薄膜太陽電池特有の光制御技術に関する知見と合わせて紹介する.

著者

Jiayi Wang Yuepeng Yan

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE Electronics Express (ISSN:13492543)

巻号頁・発行日

vol.20, no.13, pp.20230179, 2023-07-10 (Released:2023-07-10)

参考文献数

33

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In this study, a mechanical movable device is used to achieve a mechanical tuning phase shifter with adjustable substrate, which has a huge potentiality of tuning range. The main body of phase shifter is microstrip structure. The substrate has two layers with one movable layer. By moving the movable layer, the equivalent relative permittivity of component is changed and tunability is realized. The phase is -128.2° to 96.1° at 6GHz while the transmission coefficient S21 is from -2.09dB to -2.70dB throughout the entire tuning process. The movable layer is better to be with high relative permittivity and relative permeability to reach a wider tuning range.

著者

Shuang WANG Hui CHEN Lei DING He SUI Jianli DING

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE TRANSACTIONS on Information and Systems (ISSN:09168532)

巻号頁・発行日

vol.E106-D, no.7, pp.1209-1218, 2023-07-01

被引用文献数

1

---

The issue of a low minority class identification rate caused by data imbalance in anomaly detection tasks is addressed by the proposal of a GAN-SR-based intrusion detection model for industrial control systems. First, to correct the imbalance of minority classes in the dataset, a generative adversarial network (GAN) processes the dataset to reconstruct new minority class training samples accordingly. Second, high-dimensional feature extraction is completed using stacked asymmetric depth self-encoder to address the issues of low reconstruction error and lengthy training times. After that, a random forest (RF) decision tree is built, and intrusion detection is carried out using the features that SNDAE retrieved. According to experimental validation on the UNSW-NB15, SWaT and Gas Pipeline datasets, the GAN-SR model outperforms SNDAE-SVM and SNDAE-KNN in terms of detection performance and stability.

著者

Ming NI Yan HAN Ray C. C. CHEUNG Xuemeng ZHOU

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE TRANSACTIONS on Electronics (ISSN:09168516)

巻号頁・発行日

vol.E106-C, no.7, pp.417-426, 2023-07-01

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This paper presents a hippocampal cognitive prosthesis chip designed for restoring the ability to form new long-term memories due to hippocampal system damage. The system-on-chip (SOC) consists of a 16-channel micro-power low-noise amplifier (LNA), high-pass filters, analog-digital converters (ADCs), a 16-channel spike-sorter, a generalized Laguerre-Volterra model multi-input, multi-output (GLVM-MIMO) hippocampal processor, an 8-channel neural stimulator and peripheral circuits. The proposed LNA achieved a voltage gain of 50dB, input-referred noise of 3.95µVrms, and noise efficiency factor (NEF) of 3.45 with the power consumption of 3.3µW. High-pass filters with a 300-Hz bandwidth are used to filter out the unwanted local field potential (LFP). 4 12-bit successive approximation register (SAR) ADCs with a signal-to-noise-and-distortion ratio (SNDR) of 63.37dB are designed for the digitization of the neural signals. A 16-channel spike-sorter has been integrated in the chip enabling a detection accuracy of 98.3% and a classification accuracy of 93.4% with power consumption of 19µW/ch. The MIMO hippocampal model processor predict output spatio-temporal patterns in CA1 according to the recorded input spatio-temporal patterns in CA3. The neural stimulator performs bipolar, symmetrical charge-balanced stimulation with a maximum current of 310µA, triggered by the processor output. The chip has been fabricated in 40nm standard CMOS technology, occupying a silicon area of 3mm2.