Ryuichi Harasawa
Nagasaki University
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Publication
Featured researches published by Ryuichi Harasawa.
field programmable logic and applications | 2014
Aiko Iwasaki; Keisuke Dohi; Yuichiro Shibata; Kiyoshi Oguri; Ryuichi Harasawa
This paper presents implementation and evaluation of an accelerator architecture for soft-cores to speed up reduction process for the arithmetic on GF(2m) used in Elliptic Curve Cryptography (ECC) systems. In this architecture, the word size of the accelerator can be customized when the architecture is configured on an FPGA. Focusing on the fact that the number of the reduction processing operations on GF(2m) is affected by the irreducible polynomial and the word size, we propose to employ an unconventional word size for the accelerator depending on a given irreducible polynomial and implement a MIPS-based soft-core processor coupled with a variable-word size accelerator. As a result of evaluation with several polynomials, it was shown that the performance improvement of up to 10.2 times was obtained compared to the 32-bit word size, even taking into account the maximum frequency degradation of 20.4% caused by changing the word size. The advantage of using unconventional word sizes was also shown, suggesting the promise of this approach for low-power ECC systems.
2015 IEEE Symposium in Low-Power and High-Speed Chips (COOL CHIPS XVIII) | 2015
Aiko Iwasaki; Yuichiro Shibata; Kiyoshi Oguri; Ryuichi Harasawa
This paper proposes an FPGA-based soft core processor architecture equipped with a configurable accelerator to speed up GF(2m) arithmetic for elliptic curve cryptography (ECC) systems. Focusing on the fact the number of operations required for GF(2m) arithmetic is influenced by the relationship between the irreducible polynomial and the machine word size, we propose an approach where the word size of the accelerator is tailored to a given irreducible polynomial. The evaluation results reveal that the performance and the energy efficiency of GF(2m) multiplication including reduction can be improved by up to 6.67 times and 5.24 times, respectively.
international conference on arithmetic of finite fields | 2012
Ryuichi Harasawa; Yutaka Sueyoshi; Aichi Kudo
In this paper, we describe an improvement of the Berlekamp algorithm, a method for factoring univariate polynomials over finite fields, for binomials xn−a over finite fields
Japan Journal of Industrial and Applied Mathematics | 2007
Ryuichi Harasawa; Yutaka Sueyoshi; Aichi Kudo
\mathbb{F}_{q}
IACR Cryptology ePrint Archive | 2009
Nozomu Nishihara; Ryuichi Harasawa; Yutaka Sueyoshi; Aichi Kudo
. More precisely, we give a deterministic algorithm for solving the equation
IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences | 2013
Ryuichi Harasawa; Yutaka Sueyoshi; Aichi Kudo
h(x)^{q} \equiv h(x) \ ({\rm mod}\ x^{n} -a)
Far east journal of applied mathematics | 2011
Yutaka Sueyoshi; Ryuichi Harasawa; Aichi Kudo
directly without applying the sweeping-out method to the corresponding coefficient matrix. We show that the factorization of binomials using the proposed method is performed in
IACR Cryptology ePrint Archive | 2006
Ryuichi Harasawa; Yutaka Sueyoshi; Aichi Kudo
O \, \tilde{}\, (n \log q)
IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences | 2016
Ryuichi Harasawa; Heiwa Ryuto; Yutaka Sueyoshi
operations in
IEICE technical report. Speech | 2014
Aiko Iwasaki; Yuichiro Shibata; Kiyoshi Oguri; Ryuichi Harasawa
\mathbb{F}_{q}