Information Systems: Secure Access and Storage in the Age of Cloud Computing

Given that cloud computing is a remotely accessed service, the connection between provider and customer needs to be adequately protected against all known security risks. In order to ensure this, an open and clear specification of all standards, algorithms and security protocols adopted by the cloud provider is required. In this paper, we review current issues concerned with security threats to cloud computing and present a solution based on our unique patented compression-encryption method. The method provides highly efficient data compression where a unique symmetric key is generated as part of the compression process and is dependent on the characteristics of the data. Without the key, the data cannot be decompressed. We focus on threat prevention by cryptography that, if properly implemented, is virtually impossible to break directly. Our security by design is based on two principles: first, defence in depth, where our proposed design is such that more than one subsystem needs to be violated to get both the data and their key. Second, the principle of least privilege, where the attacker may gain access to only part of a system. The paper highlights the benefits of the solution that include high compression ratios, less bandwidth requirements, faster data transmission and response times, less storage space, and less energy consumption among others

A novel Hexa data encoding method for 2D image crypto-compression

Abstract: We proposed a novel method for 2D image compression-encryption whose quality is demonstrated through accurate 2D image reconstruction at higher compression ratios. The method is based on the DWT-Discrete Wavelet Transform where high frequency sub-bands are connected with a novel Hexadata crypto-compression algorithm at compression stage and a new fast matching search algorithm at decoding stage. The novel crypto-compression method consists of four main steps: 1) A five-level DWT is applied to an image to zoom out the low frequency sub-band and increase the number of high frequency sub-bands to facilitate the compression process; 2) The Hexa data compression algorithm is applied to each high frequency sub-band independently by using five different keys to reduce each sub-band to1/6of its original size; 3) Build a look up table of probability data to enable decoding of the original high frequency sub-bands, and 4) Apply arithmetic coding to the outputs of steps (2) and (3). At decompression stage a fast matching search algorithm is used to reconstruct all high frequency sub-bands. We have tested the technique on 2D images including streaming from videos (YouTube). Results show that the proposed crypto-compression method yields high compression ratios up to 99% with high perceptual quality images

SALVADOR, MAKING OF: uma cidade através das câmeras do poder

O artigo investiga a tentativa de construção de uma imagem pública para a cidade de Salvador, a partir das ações governamentais. Para tanto, foram investigadas produções audiovisuais que, em épocas diferentes, promoveram a cidade para uma audiência externa ao estado. Para as análises, foram utilizadas categorias operacionais da Análise do Discurso francesa (AD)

Cylindrical black bounces and their field sources

We apply the Simpson-Visser phenomenological regularization method to a cylindrically symmetric solution of the Einstein-Maxwell equations known as an inverted black hole. In addition to analyzing some properties of thus regularized space-time, including the Carter-Penrose diagrams, we show that this solution can be obtained from the Einstein equations with a source combining a phantom scalar field with a nonzero self-interaction potential and a nonlinear magnetic field. A similar kind of source is obtained for the cylindrical black bounce solution proposed by Lima et al. as a regularized version of Lemos's black string solution. Such sources are shown to be possible for a certain class of cylindrically, planarly and toroidally symmetric metrics that includes the regularized solutions under consideration.Comment: 14 pages, 9 figures. V2: Fixed misprints, some references added. Published in the PR

Saturnus: Um Simulador Discreto Baseado em Eventos para Sistemas de Arquivos Paralelos

The focus of this work is to study parallel file systems, their elements and present Saturnus, a simulator under development for systems like these. The proposal is to use it to extract data and generate information, focusing on load balancing through the studied environment, showing experiments and possible uses for the tool. (O foco desse trabalho e ́ estudar sistemas de arquivos paralelos, seus elementos e apresentar o Saturnus, um simulador em desenvolvimento para sistemas como esses. A proposta consiste em utilizar o mesmo para extrair dados e gerar informacoes, com foco no balanceamento de carga atrave ́s do ambiente estudado, mostrando experimentos e poss ́ıveis usos para a ferramenta.

Use of Drugs that Act on the Cytochrome P450 System in the Elderly

OBJECTIVES: The objective of this study was to analyze medications that act on the cytochrome P450 (CYP450) enzymatic system and are used daily by non-institutionalized elderly individuals. METHODS: A cross-sectional population-based study of elderly individuals (> 60 years old) was conducted. All continuously used medications with hepatic metabolism via CYP450 that are classified as substrates, inducers or inhibitors were considered. For the analysis, elderly individuals were stratified according to age groups, and hepatic metabolism activity due to daily alcohol consumption and smoking were considered. RESULTS: Elderly individuals (396 in total: 222 women and 174 men) between 60 and 95 years of age (mean: 72.1) were assessed. Use of drugs that act on CYP450 was identified in 61.6% of the subjects. Drug use was observed among 16.2% of the subjects: three drugs among 9.8% and four or more among 6.3% of the subjects. The metabolic activities of the drugs used were classified as substrates (58.8%), inhibitors (14.9%), and inducers (4.3%). The main drugs used were beta-blockers and statins (as substrates), proton pump inhibitors and fluoxetine (as inhibitors), and prednisone and carbamazepine (as inducers). CONCLUSIONS: The results demonstrate that the elderly use high levels of medications that act on CYP450, thereby increasing the risk of drug interactions in a group that is already vulnerable to adverse drug effects

Low temperature photoluminescence in ultra-thin germanium quantum wells

We measured the photoluminescence (PL) spectra of a series of Gen quantum wells as a function of temperature, from 2K to 50K. The PL spectra at 2.1K are dominated by broad emission lines, which can be interpreted as recombination across the indirect gap of the Si/Ge microstructure and are strongly inuenced by the interface morphology of each sample. Beyond T & 15K, all samples show identical spectra in which the broad structures are replaced by thin, strong lines. We interpret these changes as a quenching of the recpmbination across the gap PL of the microstructure and the appearance of defect-related peaks from the Si substrate