segunda-feira, 23 de junho de 2014

Cracks emerge in the cloud: Security weakness of cloud storage services

 

June 19, 2014

The Agency for Science, Technology and Research (A*STAR)

As individual computer users increasingly access the Internet from different smartphones, tablets and laptops, many are choosing to use online cloud services to store and synchronize their digital content. Cloud storage allows consumers to retrieve their data from any location using any device and can provide critical backups in the case of hard disk failure. But while people are usually vigilant about enacting security measures on personal computers, they often neglect to consider how safe their files are in the cloud.


Now, findings from a team led by Jianying Zhou of the A*STAR Institute for Infocomm Research in Singapore promise to improve the security of popular online services and better protect users by revealing hidden flaws associated with an important cloud storage feature -- the ability to share files with friends, co-workers or the public1.

Sharing content is an attractive way to let far-flung colleagues view and collaborate on projects without using email attachments, which often have strict file size limitations. Data sharing can be: public, with no access controls; private, in which the cloud service provider authenticates sharing through login controls; or 'secret' uniform resource locator (URL) sharing where people without an account on the cloud service can access data by following a specific web link.

The A*STAR-led researchers analyzed the security of three well-known cloud service providers -- Dropbox, Google Drive and Microsoft SkyDrive -- and found that all three had vulnerabilities many users might encounter. They uncovered several risks related to the sharing of secret URLs. Because URLs are saved in various network-based servers, browser histories and Internet bookmarks, frequent opportunities exist for third parties to access private data. Furthermore, the URL recipient may send the link to others without the data owner's consent.

Another danger lies in the practice of URL shortening -- reducing long web addresses to brief alphanumeric sequences for easier sharing on mobile devices. Although the original URL may point to a privately shared file, shortening changes this address into plain text unprotected by encryption. Zhou also notes that because short URLs have very limited lengths, they are susceptible to brute-force attacks that can dig out supposedly secret files.

Zhou explains that the root cause of cloud security problems lies in the need to balance usability with privacy protection. "Users should be careful when they share files in the cloud because no system is perfectly secure. The cloud industry, meanwhile, needs to constantly raise the bar against new attacks while keeping the service as functional as possible."

Protecting laptops on the move: Theoretical model for vibrations in laptops provides design strategies for reducing hard drive failures

 

June 19, 2014

The Agency for Science, Technology and Research (A*STAR)

Laptops have the advantages of being more versatile and portable than their desktop counterparts. But these attributes impose considerable demands on the electronic components in a laptop -- particularly the hard drive. The magnetic disk inside a hard drive rotates at a rate of several thousand revolutions a minute. At the same time, a read/write head moves only a few nanometers above the disk surface to access information on the disk. At such high speeds, large vibrations can permanently damage the hard drive.


Laptops have the advantages of being more versatile and portable than their desktop counterparts. But these attributes impose considerable demands on the electronic components in a laptop -- particularly the hard drive. The magnetic disk inside a hard drive rotates at a rate of several thousand revolutions a minute. At the same time, a read/write head moves only a few nanometers above the disk surface to access information on the disk. At such high speeds, large vibrations can permanently damage the hard drive.

To help reduce hard drive failures, Jianqiang Mou and colleagues from the A*STAR Data Storage Institute in Singapore have now developed a computer model that can predict and minimize the effects of vibrations on the hard drive and ultimately help to improve laptop design1.

Current designs of many laptops actually compound the problems caused by vibrations. For instance, to provide protection from external impact and accidents, laptops are often encased in special housings intended to absorb accidental drops and other shocks. Such laptop designs can actually be counterproductive if not done properly, explains Mou. "The commercial notebook computer industry rarely understands how chassis design can substantially affect the performance of the hard drive. Some notebook computers are designed with vibration sources, for example the loud speaker, located close to the hard drive."

To get back to the fundamentals of laptop design, the researchers developed a theoretical framework that models the propagation of vibrations from various components in a laptop, such as the speakers, to the hard drive. Underpinning this framework are mathematical equations that describe the transmission of vibrations in laptops, and these equations form the input for a computer model applied to specific laptop designs.

The results of the researchers' calculations can be used to inform general laptop design strategies. For example, often very stiff materials are used for laptop cases to provide enhanced mechanical strength. However, stiff materials tend to transmit high-frequency vibrations more strongly than flexible materials, and it is difficult for hard drives to compensate for these frequencies. Softer materials are preferable as they suppress higher frequency vibrations, leaving only slower vibrations which are easier for hard drives to compensate.

"Our study provides an effective approach for computer and hard drive makers to optimize the chassis design and component mounting," adds Mou. "Furthermore, the methodology presented in our paper can be applied for analysis and optimal design of other computer chassis, such as servers in data centers."

Materials for the building industry: A shape-conscious alloy

 

June 20, 2014

Empa Swiss Federal Laboratories for Materials Science and Technology

When the frame of a pair of glasses is bent out of shape, it's not that easy to return it to its original form. If, however, your spectacles are made of a shape memory alloy then you don't have a problem. Just place the frame in hot water and bingo! – they're as good as new again. Empa researchers have now shown that these materials can also find applications in the building industry. For example in the reinforcement of bridges.


Forging an iron-based shape memory alloy (SMA) cast block: To shape the block, it is heated to around 1,150 degrees Celsius.

Shape memory alloys, or SMAs, possess the ability to return to their original shape after being severely deformed, either spontaneously or following the application of heat. This makes them useful materials, not just for making spectacle frames but also for technical applications such as thermostats, stents and micro-actuators. Other applications in the construction industry are conceivable too, for example in the reinforcement of bridges.

If a concrete beam is cast with reinforcing rods made of an SMA material, these can then be "activated" through the application of heat. They attempt to return to their original shape, but because of their concrete sheath they cannot do so, thus exerting a pre-stressing force on the beam. This effect can be used, for example, to pre-stress a complete bridge span. In order to generate the necessary force the SMA rods must simply be heated by passing an electric current through them. This obviates the need for using elaborate tensioning systems and jacket tubes, as used in conventional pre-stressing techniques.

The nickel titanium alloys used to make spectacle frames or stents are not very suitable for use in the construction industry. Iron-based SMA products are much more attractive, since both the raw materials and the processing costs are far cheaper. However, to date one problem has remained a stumbling block: to activate the memory effect the materials currently used must be heated up to 400° C, which for applications involving concrete or mortar, or other heat sensitive materials, is too high. Empa researchers led by Christian Leinenbach of the Joining Technology and Corrosion Laboratory have now succeeded in developing a novel iron-manganese-silicon SMA alloy which is activated at just 160° C, a temperature much more suitable for use with concrete. The material science researchers "designed" a range of virtual alloys using thermodynamic simulations, and then selected the most promising combinations. These were then manufactured in the laboratory and their shape memory characteristics tested, with great success. Several of the new materials met the construction engineers' requirements, an important milestone on the path to providing economic shape memory steel alloys for industrial applications -- in other words, manufacturing them by the ton.

The long road from laboratory to finished product

Christoph Czaderski, of Empa's Engineering Structures Laboratory, believes that iron-based SMA materials have a promising future in the building industry since the process of pre-stressing is simpler and therefore cheaper than in conventional techniques. In addition they may allow engineers to create pre-stressed structures which are impossible or very difficult to achieve using conventional techniques. These include the use of short fibre concrete, near surface mounted laminates, column wrapping and ribbed armouring steel. A feasibility study financed by the Commission for Technology and Innovation (CTI) recently showed that it is possible to produce the new alloys on an industrial scale, not just a few kilos for laboratory use. The manufacturing process has been developed in collaboration with Leoben University (Austria), the Technical University Bergakademie Freiberg (Germany), and the German company G. Rau GmbH.

The working of cast ingots, each about 100 kg in weight, into thin strips around 2 mm thick or ribbed armouring steel rods at temperatures over 1000° calls for high degree of technical knowledge, and the appropriate infrastructure. The working process also needs to be adapted for use with the novel alloys. The metal strips produced in this way demonstrated their capabilities in the tests which followed, during which they were inserted into slits cut in the surface of concrete beams and fixed with adhesive. To carry forward the developments made at Empa, a start-up company, re-Fer AG, has been set up. This will in future produce and distribute iron-based SMA for the construction industry. The cost of the new products is expected to be about the same order of magnitude as that for stainless steel based materials.

Major step forward for the world's largest optical/infrared telescope


Today a groundbreaking ceremony took place to mark the next major milestone towards ESO’s European Extremely Large Telescope (E-ELT). Part of the 3000-metre peak of Cerro Armazones was blasted away as a step towards levelling the summit in preparation for the construction of the largest optical/infrared telescope in the world.

Today a groundbreaking ceremony took place to mark the next major milestone towards ESO's European Extremely Large Telescope (E-ELT). Part of the 3000-metre peak of Cerro Armazones was blasted away as a step towards levelling the summit in preparation for the construction of the largest optical/infrared telescope in the world.

The groundbreaking ceremony at Paranal Observatory, 20 kilometres away from the blasting, was attended by distinguished guests from both Chile and the ESO Member States, as well as representatives of the local communities, senior officials from the project and ESO staff. The event was also streamed live online and a recording of the event can now be viewed.

The order to proceed with the blasting was given by the Chilean Vice Minister of National Assets, Jorge Maldonado.

During the groundbreaking ceremony the Chilean company ICAFAL Ingenieria y Construccion S.A. blasted part of the top of Cerro Armazones and loosened about 5000 cubic metres of rock. This is just one part of an elaborate levelling process which will help landscape the mountain, so that it can accommodate the 39-metre telescope and its huge dome. A grand total of 220 000 cubic metres will need to be removed to make room for the 150 metre by 300 metre E-ELT platform.

The Cerro Armazones civil works started in March 2014 and are expected to take 16 months. These include the laying and maintenance of a paved road, the construction of the summit platform and the construction of a service trench to the summit .

The E-ELT first light is planned for 2024, when it will begin to tackle the biggest astronomical challenges of our time. The giant telescope is expected to allow the exploration of completely unknown realms of the Universe -- it will be: "the world's biggest eye on the sky."

Safe water for the people in Tanzania


Inhabitants of the village of Mdori in the region of Manyara taste the freshly filtered water.

Hydraulic engineer Andrea Schäfer and photovoltaics expert Bryce Richards have developed a solar filtration system to produce high-quality drinking water from polluted brackish water and tested it successfully in Tanzania. The test results are currently being analyzed at the KIT. The filter effectively separates undesired substances, bacteria, and viruses. Fluoride concentration that often is extremely high in Tanzania is reduced below the limit given by the World Health Organization (WHO). The system combines two membrane techniques for the separation of smallest particles and dissolved contaminants. As it is robust and autonomously mobile, it is suited well for water supply in poor and rural areas.

Outside of the rainy season, the area of Mdori which is located in the north of Tanzania in the region of Manyara is extremely hot and dry. Water is scarce, the lake located nearby has an extremely high salt concentration. A well drilled to extract water from a natural spring supplies water with a high salt concentration and 60 µg of fluoride per liter -- 40 times the concentration limit given by the WHO -. This water is not potable. At this spring, Professor Andrea Schäfer and Professor Bryce Richards, who are now working at the KIT, tested their water filtration system ROSI (Reverse Osmosis Solar Installation).

The system can be operated with solar and/or wind power. It combines ultrafiltration membranes of about 50 nm in pore size to retain macromolecular substances, particles, bacteria, and viruses with membranes for nanofiltration and reverse osmosis with pore sizes below 1 nm to remove dissolved molecules from the water. Andrea Schäfer and Bryce Richards conceived ROSI in Australia and developed it further in Scotland before they started to plan their field tests at the Nelson Mandela African Institution of Science and Technology in Tanzania. In February and March this year, they tested the system at places like Mdori. Presently, Schäfer and Richards are evaluating the test results at the KIT. In the next phase, the systems will be installed at the locations selected.

As the system is run directly by solar power without batteries, the behavior of the filter changes as a function of the light conditions: Under full solar irradiation, the filtration system reduces the fluoride concentration of the water below the WHO limit of 1.5 mg/l. As a result of the change between day and night and strong temporary cloud formation in the region of Mdori, however, energy supply varies considerably. It is interrupted, if solar irradiation is insufficient. Influence of such fluctuations on water quality was one of the aspects covered by the tests of the researchers. "If less power is available, pressure decreases. As a result, less water passes the membranes. The fluoride concentration increases for a short term," Professor Andrea Schäfer explains. She heads the Membrane Technology Division of the Institute of Functional Interfaces (IFG) of KIT. "The concentration of fluoride and other pollutants, however, is balanced as soon as more water passes the filter again. Hence, the water is completely safe."

Andrea Schäfer and Bryce Richards, Professor of Nanophotonics for Energy at the KIT, are now looking for companies to support system manufacture and installation and operation in rural regions of Tanzania. One system can supply about 50 people with high-quality drinking water and water for household use. "At the moment, no other system removes pollutants, such as fluoride, as reliably and sustainably as ours," Schäfer says. High fluoride concentrations may cause tooth discolorations and severe skeletal deformities in children. It is also important to remove bacteria and viruses from the water. In many areas of Africa, diseases that actually can be treated well, such as diarrheal diseases, are often fatal especially for children due to malnutrition and lacking medical care. Supply with safe drinking water will play a key role for the future of the people in Africa.

No such thing as a 'finished article': The truth behind online news


News delivery and consumption has rapidly changed in the digital era. No longer print-bound, the BBC, Guardian, Daily Mail and FT use blog format online news delivery, giving live commentary and many edited versions. Powerful news sources such as Twitter also abound, challenging the more conventional channels to beat to a faster pace.

Whilst such a fluid news production process allows instant access to news as it happens, does it risk the integrity and clarity of reporting? Is it too easy to conceal mistakes, misrepresentation and bias? Most news is remodelled for delivery via print, tweet, web-stream, SMS and online text, but does such a variety of channel comes at the expense of hard fact, proper investigation, credibility and truth?

The authors of "Revealing the news: How online news changes without you noticing," published in Digital Journalism, discuss a means of tracking changes to news: enabling readers to distinguish the original content from the hidden edits. The 'News Inspector' could potentially be the latest cutting-edge tool, providing an easy and low cost way to reveal these undeclared edits to news reports. They analysed a BBC story published online which was 65% rewritten over the course of a few hours for reasons and by persons unknown.

The 'News Inspector' intends to allow readers to probe a 'moral dimension', give greater transparency to stories and glean underlying conclusions from the more meaningful edits. The product will analyse word counts, time and sequence changes and variations of names and headlines to track alterations. The aim is for the reader to have access to when and who changed the content by a simple roll-over or pop-up.

The authors report "a growing public distrust of online sources of information"; will The News Inspector reinstate confidence?

Super-stretchable yarn is made of graphene


Strong, stretchable fibers made of graphene oxide can be knotted like yarn.

Researchers at Penn State and Shinshu University in Japan have developed a simple, scalable method of making graphene oxide (GO) fibers that are strong, stretchable and can be easily scrolled into yarns with strengths approaching that of Kevlar.

The researchers made a thin film of graphene oxide by chemically exfoliating graphite into graphene flakes, which were then mixed with water and concentrated by centrifugation into a thick slurry. The slurry was then spread by bar coating -- something like a squeegee -- across a large plate. When the slurry dries, it becomes a large-area transparent film that can be carefully lifted off without tearing. The film is then cut into narrow strips and wound on itself with an automatic fiber scroller, resulting in a fiber that can be knotted and stretched without fracturing.

"We found this graphene oxide fiber was very strong, much better than other carbon fibers. We believe that pockets of air inside the fiber keep it from being brittle," says Mauricio Terrones, professor of physics, chemistry and materials science and engineering at Penn State.

Terrones and colleagues believe this method opens up multiple possibilities for useful products. For instance, removing oxygen from the GO fiber results in a graphene fiber with high electrical conductivity. Adding silver nanorods to the graphene film would increase the conductivity to the same as copper, which could make it a much lighter weight replacement for copper transmission lines. Many kinds of highly sensitive sensors are imaginable.

"The importance is that we can do almost any material, and that could open up many avenues -- it's a lightweight material with multifunctional properties," Terrones remarks. And the main ingredient, graphite, is mined and sold by the ton.

Their discovery was reported online in a recent issue of ACS Nano and titled "Super-stretchable Graphene Oxide Macroscopic Fibers with Outstanding Knotability Fabricated by Dry Film Scrolling."

The researchers received support from the Research Center for Exotic Nanocarbons, Japan, and the Center for Nanoscale Science, Penn State.

Time to think big: A call for a giant space telescope


An artist’s concept of the ATLAST telescope under construction in space. This design has a segmented mirror 20 metres across.

In the nearly 25 years since the launch of the Hubble Space Telescope (HST), astronomers and the public alike have enjoyed ground-breaking views of the cosmos and the suite of scientific discoveries that followed. The successor to HST, the James Webb Telescope should launch in 2018 but will have a comparatively short lifetime.

Now Prof Martin Barstow of the University of Leicester is looking to the future. In his talk at the National Astronomy Meeting (NAM 2014) in Portsmouth on Tuesday 24 June, he calls for governments and space agencies around the world to back the Advanced Technologies Large Aperture Space Telescope (ATLAST), an instrument that would give scientists a good chance of detecting hints of life on planets around other stars.

ATLAST is currently a concept under development in the USA and Europe. Scientists and engineers envisage a telescope with a mirror as large as 20 m across that like HST would detect visible light and also operate from the far-ultraviolet to the infrared parts of the spectrum. It would be capable of analysing the light from planets the size of the Earth in orbit around other nearby stars, searching for features in their spectra such as molecular oxygen, ozone, water and methane that could suggest the presence of life. It might also be able to see how the surfaces of planets change with the seasons.

Within the vision "Cosmic birth to living Earths," ATLAST would study star and galaxy formation in high definition, constructing the history of star birth in detail and establishing how intergalactic matter was and is assembled into galaxies over billions of years.

If it goes ahead, ATLAST could be launched around 2030. Before this can happen, there are technical challenges to overcome such as enhancing the sensitivities of detectors and increasing the efficiencies of the coatings on the mirror segments. Such a large structure may also need to be assembled in space before deployment rather than launching on a single rocket. All of this means that a decision to construct the telescope needs to happen soon for it to go ahead.

Prof Barstow is the President of the Royal Astronomical Society, but is speaking in a personal capacity. He sees ATLAST as an ambitious but extraordinary project. He commented:

"Since antiquity human beings have wondered whether we really are alone in the universe or whether there are other oases of life. This question is one of the fundamental goals of modern science and ATLAST could finally allow us to answer it.

'The time is right for scientific and space agencies around the world, including those in the UK, to take a bold step forward and to commit to this project."