Shinsaku Kiyomoto

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In this paper, we introduce the rakaposhi stream cipher. The algorithm is based on Dynamic Linear Feedback Shift Registers, with a simple and potentially scalable design, and is particularly suitable for hardware applications with restricted resources. The rakaposhi stream cipher offers 128-bit security, and aims to complement the current eSTREAM portfolio(More)
Abstract. In Shamir’s (k, n)-threshold secret sharing scheme (threshold scheme), a heavy computational cost is required to make n shares and recover the secret. As a solution to this problem, several fast threshold schemes have been proposed. This paper proposes a new (k, n)threshold scheme. For the purpose to realize high performance, the proposed scheme(More)
In this paper, we report that we have solved the SVP Challenge over a 128-dimensional lattice in Ideal Lattice Challenge from TU Darmstadt, which is currently the highest dimension in the challenge that has ever been solved. The security of lattice-based cryptography is based on the hardness of solving the shortest vector problem (SVP) in lattices. In 2010,(More)
The development of IEEE 802.16 was started by the IEEE in 2001. After that it was revised several times and ended in the final standard IEEE 802.16-2004 which corresponds to revision D and is often called Fixed WiMAX [1]. It defines Wireless Metropolitan Broadband access for stationary and nomadic use. This means end devices can not move between base(More)
Recent years have seen a dramatic increase in the number and importance of mobile devices. The security properties that these devices provide to their applications, however, are inadequate to protect against many undesired behaviors. A broad class of such behaviors is violations of simple informationflow properties. This paper proposes an enforcement system(More)
Recent years have seen a dramatic increase in the number and im-<lb>portance in daily life of mobile devices. The security properties that<lb>these devices provide to their applications, however, are inadequate<lb>to protect against many undesired behaviors. A broad class of such<lb>behaviors is violations of simple information-flow properties.<lb>This(More)
In this paper, we improve an analysis algorithm and apply it to cryptanalysis of Salsa and ChaCha. We constructed a distinguisher of double-bit differentials to improve Aumasson’s single-bit differential cryptanalysis. This method has potential to apply to a wide range of stream ciphers; a double-bit correlation would be found in case that no single-bit(More)