Mathematical Theory of Probability and Statistics

In past few years, as security ciphers in the Internet of Things (IoT), the research of lightweight block cipher has attracted tremendous attention in cryptography. The SPN structure has been widely used in the design of block cipher. However, the encryption and decryption processes of ciphers based on the SPN structure are different. We design a new SPN structure, which is perfect for lightweight block cipher. The new SPN structure makes that the encryption process is the same as decryption. Moreover, input and output data directions are the same for encryption and decryption processes. Thus, the same process can absolutely be shared in decryption and encryption both for software and hardware implementation. Further, we propose a family of involutional lightweight block cipher, called Loong, based on the proposed SPN structure and components. Rigorous analysis indicates that Loong is of high security against cryptanalysis, especially the differential attack and linear attack. As shown by our experiments and comparisons, Loong is compact in hardware environment and is suitable for the IoT.

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Loong: A Family of Involutional Lightweight Block Cipher Based on SPN Structure

Differential and linear cryptanalysis are two of the most effective attacks on block ciphers. Searching for (near) optimal differential or linear trails is not only useful for the security evaluation of block ciphers against these attacks, but also indispensable to the cryptanalysts who want to attack a cipher with these techniques. In recent years, searching for trails automatically with Mixed-Integer Linear Programming (MILP) gets a lot of attention. At first, Mouha et al. translated the problem of counting the minimum number of differentially active S-boxes into an MILP problem for word-oriented block ciphers. Subsequently, in Asiacrypt 2014, Sun et al. extended Mouha et al.’s method, and presented a technique which can find actual differential or linear characteristics of a block cipher in both the single-key and related-key models. In this paper, we refine the constraints of the 2-XOR operation in order to reduce the overall number of variables and constraints. Experimental results show that MILP models with the refined constraints can be solved more efficiently. We apply our method to HIGHT (an ISO standard), and we find differential (covering 11 rounds) or linear trails (covering 10 rounds) with higher probability or correlation. Moreover, we find so far the longest differential and linear distinguishers of HIGHT.

Improved Cryptanalysis of an ISO Standard Lightweight Block Cipher with Refined MILP Modelling

A unique PMN-PT electro-optic type VOA configuration is proposed The VOA includes a Peltier element that enables a 100-ns range operation speed and an integrated PD that acts as a quasi-loss-less input tap-monitor

High-speed opto-electronic VOA with an integrated quasi-loss-less photo-diode and a temperature control module

A novel thermal-optical phase modulation structure based on polymer/silica hybrid waveguide is proposed. Patterned graphene strip is introduced as electric nanoheater in the structure. Finite element method simulation is performed on both thermal and optical field analysis. Results show that response speed is improved by a factor of three and power consumption is reduced by half, in comparison with conventional state-of-art polymer-based phase shifter. This proposed structure is compatible with current complementary metal-oxide-semiconductor power supply standard and has very large design robustness. It shows great application potential on low-power optical switch, modulator and polymer thermal-optical phase arrays.

/pdf/design-and-analysis-of-a-novel-graphene-assisted-silica-optr2bclqe.pdf

Design and Analysis of a Novel Graphene-Assisted Silica/Polymer Hybrid Waveguide With Thermal–Optical Phase Modulation Structure

Because of mission extensions, a cube satellite uses several frequencies and its earth station suffers from cabling around antennas. We report an earth station employing an electro-absorption modulator integrated laser in a RoF system.

Electro-absorption modulator integrated laser application to a cube satellite earth station

We show a meet-in-the-middle (MITM) attack with Splice-and-Cut technique (SCT) on the 19-round variant of the block cipher HIGHT. The original HIGHT having 32-round iteration was proposed by Hong et al. in 2006, which applies the 8-branch Type-2 generalized Feistel network (GFN) with 64-bit data block and 128-bit secret key. MITM attack was proposed by Diffie and Hellman in 1977 as a generic method to analyze symmetric-key cryptographic algorithms. SCT was proposed by Aoki and Sasaki to improve MITM attack in 2009. In this paper we show that 19-round HIGHT can be attacked with 28 bytes of memory, 28 + 2 pairs of chosen plain and cipher texts, and 2120.7 times of the encryption operation by using MITM attack with SCT.

Meet-in-the-middle Attack with Splice-and-Cut Technique on the 19-round Variant of Block Cipher HIGHT

Damage of electric power facilities caused by typhoons is one of the most common meteorological disasters in Japan. The electric power supply is sometimes cut off in wide areas for a long time by typhoons, which brings an undesirable effect on society. To ensure the speedy restoration of the electric power supply, it is important to predict the amount of damage accurately for an approaching typhoon. This paper presents an improvement of Gaussian process (GP)-based predictor of electric power damage caused by typhoons. The electric power facilities have been maintained so that they are robust to the disasters, and the robustness changes with time. Therefore, the proposed predictor uses the information of the arrival date of typhoons as well as the typhoon weather information. Simulation results based on actual data show that the proposed predictor improves the accuracy of prediction compared with the conventional GP-based predictor.

Improvement of Gaussian Process Predictor of Electric Power Damage Caused by Typhoons Considering Time-Varying Characteristics

Variable Optical Attenuator Employing a Dye-Doped (Polymer/Liquid Crystal) Composite Film

Doping metal complex into polymer liquid-crystal composite film improves extinction ratio at visible wavelength and extends applicable wavelength to 1.5-μm optical fiber communication band. A polarization dependent loss was measured as 0.32 dB or lower.

Yasutaka Igarashi

Papers

Electro-absorption modulator integrated laser application to a cube satellite earth station

Meet-in-the-middle Attack with Splice-and-Cut Technique on the 19-round Variant of Block Cipher HIGHT

Improvement of Gaussian Process Predictor of Electric Power Damage Caused by Typhoons Considering Time-Varying Characteristics

Variable Optical Attenuator Employing a Dye-Doped (Polymer/Liquid Crystal) Composite Film

Metal-complex-doped polymer/liquid-crystal composite film operating at wide wavelength range