Yasutaka Igarashi

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

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.

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

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.

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

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.

The 12th-Order Differential Attack on the 10-Round Variants of Midori64 Block Cipher

Midori64 proposed by Banik et al. in 2015 is an SPN-type block cipher with 128-bit secret key. The designers have evaluated the security of Midori64 against differential attack, linear attack, boomerang-type attack, impossible differential attacks, and meet-in-the-middle attack by themselves. In this paper, we discuss higher-order differential attack on Midori64, which has not been analyzed yet. Higher-order differential attack proposed by Lai is one of the generic cryptanalysis technique focusing on degree of boolean polynomial of encryption function. As a result, we show the 12th-order differential attack on the 10-round variant of Midori64 where we exploit partial-sum technique proposed by Ferguson and the first-round key assumption called a round-elimination technique. The original Midori64 is secure against our attack because it consists of 16 round functions.

A Practical-time Attack on Reduced-round MISTY1.

MISTY1 is a symmetric key algorithm which has been standardized by ISO and that its modified version is used in GSM and 3G mobile networks. MISTY1 is a 64-bit block cipher supporting key length of 128 bits. In this paper, we focused on evaluating the security of MISTY1 against higher order differential attack. We show 6-round MISTY1 with 4 FL layers is attackable with 243 blocks of chosen plaintexts and 243.31 times of data encryption. This is the best practical-time attack on reduced-round MISTY1.

The Improved 16th-Order Differential Attack on 10- Round Variant of Block Cipher PRESENT

We study the improved 16th-order differential attack on 10-round variant of PRESENT that is a 64-bit block cipher supporting 80-bit and 128-bit secret keys proposed by Bogdanov et al. in 2007. Higher-order differential attack is one of the cryptanalytic techniques exploiting a low algebraic degree of an encryption/decryption function. In 2013 Wu et al. reported the 16th-order differential attack on 10-round variant of PRESENT, which requires 222.4 pairs of plaintext and ciphertext, and 299.3 times of encryption operation. In this article we adopt partial sum technique to solve an attack equation, which leads to low computational complexity. As a result we show that 10-round variant of PRESENT can be attacked with 222.3 pairs of plaintext and ciphertext, and 281.3 times of encryption operation.

Variable optical attenuator employing a dye-doped (polymer/liquid crystal) composite film

To clarify extinction mechanism of a dye-doped (polymer/liquid crystal) composite film variable optical attenuator, we evaluated its scattering intensity dependencies on the wavelength and scattering angle. We have obtained some experimental data that suggest Rayleigh scattering is a primary mechanism of extinction.