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.

Improving the generalized Feistel

Abstract: The generalized Feistel structure (GFS) is a generalized form of the classical Feistel cipher A popular version of GFS, called Type-II, divides a message into k > 2 sub blocks and applies a (classical) Feistel transformation for every two sub blocks, and then performs a cyclic shift of k sub blocks Type-II GFS has many desirable features for implementation A drawback, however, is its low diffusion property with a large k This weakness can be exploited by some attacks, such as impossible differential attack To protect from them, Type-II GFS generally needs a large number of rounds In this paper, we improve the Type-II GFS's diffusion property by replacing the cyclic shift with a different permutation Our proposal enables to reduce the number of rounds to attain a sufficient level of security Thus, we improve the security-efficiency treading off of Type-II GFS In particular, when k is a power of two, we obtain a significant improvement using a highly effective permutation based on the de Bruijn graph

Dynamic random access memory device having addressing section and/or data transferring path arranged in pipeline architecture

Abstract: A dynamic random access memory device is responsive to a row address signal and a column address signal supplied in synchronism with a system clock signal for providing a data path from a data input/output port and a memory cell selected from the memory cell array, and latch circuits are provided in the addressing section and the data transferring path for temporarily storing address decoded signal and write-in and read-out data bits in response to latch control signals higher in frequency than the system clock signal, thereby controlling the data stream in a pipeline fashion.

System and method of eliminating quotation codes from an electronic mail message before synthesis

Abstract: In order to provide a practical E-mail reader for reading out E-mails phonetically enabling easy grasping of their contents by a user with its vocal output even when quotation codes or header information are included in the E-mails, a phonetic E-mail reader of the invention comprises a speech synthesizer (102) for converting text data into vocal data, quotation code storing means (105) for storing quotation codes used for indicating a quotation line inserted at a top of the quotation line, and quotation code elimination means (106) for detecting and eliminating a quotation code inserted at tops of quotation lines referring to the quotation code storing means (105) before supplying the quotation lines to the speech synthesizer (102).

Combining strengths of circuit-based and CNF-based algorithms for a high-performance SAT solver

Abstract: We propose satisfiability checking (SAT) techniques that lead to a consistent performance improvement of up to 3/spl times/ over state-of-the-art SAT solvers like Chaff on important problem domains in VLSI CAD. We observe that in circuit oriented applications like ATPG and verification, different software engineering techniques are required for the portions of the formula corresponding to learnt clauses compared to the original formula. We demonstrate that by employing the same innovations as in advanced CNF-based SAT solvers, but in a hybrid approach where these two portions of the formula are represented differently and processed separately, it is possible to obtain the consistently highest performing SAT solver for circuit oriented problem domains. We also present controlled experiments to highlight where these gains come from. Once it is established that the hybrid approach is faster, it becomes possible to apply low overhead circuit-based heuristics that would be unavailable in the CNF domain for greater speedup.

Chemical mechanical polishing slurry

Abstract: This invention provides a chemical mechanical polishing slurry for polishing a copper-based metal film formed on an insulating film comprising a concave on a substrate, comprising a polishing material, an oxidizing agent and water as well as a benzotriazole compound and a triazole compound. The polishing slurry may be used in CMP to form a reliable damascene electric connection with excellent electric properties at a higher polishing rate, i.e., a higher throughput while preventing dishing.