NEC

About: NEC is a company organization based out in Tokyo, Japan. It is known for research contribution in the topics: Signal & Layer (electronics). The organization has 33269 authors who have published 57670 publications receiving 835952 citations. The organization is also known as: NEC Corporation & NEC Electronics Corporation.

Ab Initio Investigation of Physisorption of Molecular Hydrogen on Planar and Curved Graphenes

Abstract: Ab initio molecular orbital theory was used to examine the physisorption of a hydrogen molecule on planar and curved graphene clusters. The repulsive nature of a H2−H2 interaction and the small dependence of physisorption energies on physisorption sites favor a close-packed structure for molecular hydrogen physisorption on a planar graphene. It was also found that the physisorption energies are significantly increased on curved graphenes.

A nonvolatile programmable solid electrolyte nanometer switch

Abstract: A reconfigurable LSI employing a nonvolatile nanometer-scale switch, NanoBridge, is proposed, and its basic operations are demonstrated. The switch, composed of solid electrolyte copper sulfide, has a <30-nm contact diameter and <100-/spl Omega/ on-resistance. Because of its small size, it can be used to create extremely dense field-programmable logic arrays. A 4 /spl times/ 4 crossbar switch and a 2-input look-up-table circuit are fabricated with 0.18-/spl mu/m CMOS technology, and operational tests with them have confirmed the switch's potential for use in programmable logic arrays. A 1-kb nonvolatile memory is also presented, and its potential for use as a low-voltage memory device is demonstrated.

Cryptanalysis of DES Implemented on Computers with Cache

Abstract: This paper presents the results of applying an attack against the Data Encryption Standard (DES) implemented in some applications, using side-channel information based on CPU delay as proposed in (11). This cryptanalysis technique uses side-channel information on encryption processing to select and collect effective plaintexts for cryptanalysis, and infers the information on the expanded key from the collected plaintexts. On applying this attack, we found that the cipher can be broken with 2 23 known plaintexts and 2 24 calculations at a success rate > 90%, using a personal computer with 600-MHz Pentium III. We discuss the feasibility of cache attack on ciphers that need many S-box look-ups, through reviewing the results of our experimental attacks on the block ciphers excluding DES, such as AES.

Linear amplification technique for digital mobile communications

Abstract: The author proposes a novel predistortion linearizer which can meet the power-amplification requirements of digital mobile radio systems with high power efficiency and low out-of-band emission. This method can be used for narrowband mobile radio systems. It has been shown that the linearizer can achieve low-out-of-band emission under frequent changes of the amplifier nonlinearity. It is indicated that the hardware volume and the power consumption can be reduced sufficiently to make this predistortion linearizer applicable to mobile station transmitters. Nearly -60dB out-of-band emission and 33% power efficiency were obtained, which is comparable to corresponding results for a class C amplifier. >

An Efficient Scheme for Proving a Shuffle

Abstract: In this paper, we propose a novel and efficient protocol for proving the correctness of a shuffle, without leaking how the shuffle was performed. Using this protocol, we can prove the correctness of a shuffle of n data with roughly 18n exponentiations, where as the protocol of Sako-Kilian[SK95] required 642n and that of Abe[Ab99] required 22n log n. The length of proof will be only 211n bits in our protocol, opposed to 218n bits and 214 n log n bits required by Sako-Kilian and Abe, respectively. The proposed protocol will be a building block of an efficient, universally verifiable mix-net, whose application to voting system is prominent.