Yumi Sakemi
Fujitsu
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Publication
Featured researches published by Yumi Sakemi.
cryptology and network security | 2008
Yumi Sakemi; Yasuyuki Nogami; Katsuyuki Okeya; Hidehiro Kato; Yoshitaka Morikawa
This paper considers a new skew Frobenius endomorphism with pairing---friendly elliptic curve
public key cryptography | 2012
Yumi Sakemi; Goichiro Hanaoka; Tetsuya Izu; Masahiko Takenaka; Masaya Yasuda
E(\mathbb{F}{p}{})
international conference information security theory and practice | 2011
Yumi Sakemi; Tetsuya Izu; Masahiko Takenaka; Masaya Yasuda
defined over prime field
international conference on information security and cryptology | 2009
Yumi Sakemi; Shoichi Takeuchi; Yasuyuki Nogami; Yoshitaka Morikawa
\mathbb{F}{p}{}
advanced information networking and applications | 2014
Tetsuya Izu; Yumi Sakemi; Masahiko Takenaka; Naoya Torii
. Then, using the new skew Frobenius map, an efficient scalar multiplication method for pairing---friendly elliptic curve
international conference on hybrid information technology | 2008
Yumi Sakemi; Hidehiro Kato; Yasuyuki Nogami; Yoshitaka Morikawa
E(\mathbb{F}{p}{})
network-based information systems | 2013
Yumi Sakemi; Tetsuya Izu; Masaaki Shirase
is shown. According to the simulation result, a scalar multiplication by the proposed method with multi---exponentiation technique is about 40% faster than that by plain binary method.
network-based information systems | 2010
Yumi Sakemi; Kazushi Nishii; Tetsuya Izuta; Yasuyuki Nogami; Yoshitaka Morikawa
A discrete logarithm problem with auxiliary input (DLPwAI) is a problem to find α from G , αG , α d G in an additive cyclic group generated by an element G of prime order r , and a positive integer d satisfying d |(r −1). The infeasibility of this problem assures the security of some cryptographic schemes. In 2006, Cheon proposed a novel algorithm for solving DLPwAI (Cheons algorithm). This paper reports our experimental results of Cheons algorithm by implementing it with some speeding-up techniques. In fact, we have succeeded to solve DLPwAI on a pairing-friendly elliptic curve of 160-bit order in 1314 core days. Implications of our experiments on cryptographic schemes are also discussed.
international symposium on information theory | 2009
Yumi Sakemi; Yasuyuki Nogami; Hidehiro Kato; Yoshitaka Morikawa
The discrete logarithm problem with auxiliary input (DLPwAI) is a problem to find a from G, αG, αdG in an additive cyclic group generated by G of prime order r and a positive integer d dividing r - 1. The infeasibility of DLPwAI assures the security of some cryptographic schemes. In 2006, Cheon proposed a novel algorithm for solving DLP-wAI. This paper shows our experimental results of Cheons algorithm by implementing it with some speeding-up techniques. In fact, we succeeded to solve DLPwAI in a group with 128-bit order in 45 hours with a single PC on an elliptic curve defined over a prime finite field with 256-bit elements which is used in the TinyTate library.
network-based information systems | 2015
Yumi Sakemi; Masahiko Takenaka; Tetsuya Izu
In the case of Barreto-Naehrig pairing-friendly curves of embedding degree 12 of order r, recent efficient Ate pairings such as R-ate, optimal, and Xate pairings achieve Miller loop lengths of (1/4) ⌊log2r⌋. On the other hand, the twisted Ate pairing requires (3/4) ⌊log2r⌋ loop iterations, and thus is usually slower than the recent efficient Ate pairings. This paper proposes an improved twisted Ate pairing using Frobenius maps and a small scalar multiplication. The proposal splits the Millers algorithm calculation into several independent parts, for which multi-pairing techniques apply efficiently. The maximum number of loop iterations in Millers algorithm for the proposed twisted Ate pairing is equal to the (1/4) ⌊log2r⌋ attained by the most efficient Ate pairings.