Auch wenn der Begriff Kryptographie nicht viel ~ilter als 350 Jahre ist, wird die Kunst des geheimen Schreibens seit mehr als dreitausend Jahren geª Ihre Entwicklung ging nicht stetig vor sich. Auch sind ihre Wurzeln an mehreren Stellen der Welt feststellbar. Die Entwicklung der Kryptographie beschleunigte sich im letzten Jahrhundert jedoch mit nahezu exponentiellem Anstieg. Heute betrifft Kryptographie weitaus mehr als Geheimschriften, sie ist zum vielseitigen Instrument der Sicherheit in der Informationstechnik, kurz als IT-Sicherheit bezeichnet, geworden. Ziel dieser Arbeit ist, die Entwicklung der Kryptographie von der ehemals empirischen Kunst zur abstrakten Wissenschaft der Gegenwart darzustellen. Die einzelnen Entwicklungsschritte werden mit Hilfe von Abstraktion transparent gemacht. Im ersten Abschnitt wird dazu dargelegt, was in diesem Zusammenhang unter Abstraktion zu verstehen ist. Der zweite Abschnitt gibt Auskunft ª die spezifischen Fachbegriffe. Die folgenden Abschnitte zeigen die einzelnen Schritte, mit denen die ersten zwei von insgesamt drei definierten Abstraktionsstufen erreicht werden. Ein Blick auf den gegenw~Lrtigen Stand und m6g-liche Zukunftsperspektiven beschliel~t den Artikel. SchlªKryptographie; Geschichte; Entwicklung; Kryptosysteme; IT-Sicherheit; Kryptopolitik From empirical to abstract cryptography. Cryptography has been employed for more than three thousand of years to get privacy in communications. But purpose and application of cryptography grew with nearly exponentially speed of development. Now it is an important tool for overall security in information technology. The aim of this paper is to show this development which started empirically and lead to the "abstract cryptography" of today. To make transparent what cryptography is and how it has been grown to its present state abstraction helps to find out the single steps of development. In the first section a brief overview shows what is meant under the term "abstraction". The second section contains explanations of the specific terms used. The following sections show the steps which lead to the first two of totally three possible levels of abstraction. A look at the state of the art and future directions closes the article.
Schopnost poskytnout zásadní informace o události ještě předtím, než nastane, staví zpravodajské analytiky do první řady boje s hrozbami terorismu, extre mismu, šíření zbraní hromadného ničení či aktivitami cizích zpravodajských slu žeb. Příspěvek ukazuje aspekty zpravodajské analýzy, které mají velmi často vliv na kvalitu výsledné zpravodajské informace zpracovávané pro uživatele. Rozebírá problematiku zpravodajské analýzy ve spojení s uživatelem informací a současně se zabývá i úvahami v souvislosti s problematikou indikace příznaků a metodami varování před překvapivými útoky protivníka. Cílem příspěvku je zvýšit pozornost čtenářů a podnítit diskuzi k problematice predikcí budoucích hrozeb v souvislosti s činností analytických týmů, protože jejich výsledky nejsou vždy dostatečně uži vateli uznávány.
Geoinformation technologies require fast processing of high and quickly increasing volumes of all types of spatial data. Parallel computational approach and distributed systems represent technologies which are able to provide required services, with reasonable costs. MapReduce is one example of such approach. It has been successfully implemented in large clusters in several instances. The applications include spatial and imagery data processing. The contribution deals with its implementation and operational performance using only a very small cluster (consisting of a few commodity personal computers) to process large-volume spatial data. Open-source implementation of MapReduce, named, Apache Hadoop, is used. The contribution is focused on a low-price solution and it deals with speed of processing and distribution of processed files. Authors run several experiments to evaluate the benefit of distributed data processing in a small-sized cluster and to find possible limitations. Size of processed files and number of processed values is used as the most important criteria for performance evaluation. Point elevation data were used during the experiments.
This paper describes the design of a technique used to extract harmonic spectrum characteristics of human voice. The voice characteristic can be used for a speaker identification process. The cepstral analysis is the most popular method, which uses a Mel-Frequency Cepstral Coefficient vector as unique characteristics of given speaker voice. This method provides only limited reliability. The harmonic spectrum based on fundamental frequency of speaker's voice can extend the characteristic vector by more values. The extended characteristics can provide better reliability of the speaker identification.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
334 Leonard St
Brooklyn, NY 11211
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.