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Dec 14

Cryptographers chosen to duke it out in final fight.

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Reported by Celeste Biever in New Scientist, 13 December 2010.

A competition to find a replacement for one of the gold-standard computer security algorithms used in almost all secure, online transactions just heated up.

The list of possibilities for Secure Hash Algorithm-3, or SHA-3, has been narrowed down to five finalists. They now face the onslaught of an international community of “cryptanalysts” – who will analyse the algorithms for weaknesses – before just one is due to be selected as the winner in 2012.

The competition, which is being run by the US National Institute of Standards and Technology in Gaithersburg, Maryland, is a huge deal for cryptographers and cryptanalysts alike. “These are incredibly competitive people. They just love this,” says William Burr of NIST. “It’s almost too much fun. For us, it’s a lot of work.”

The need for the competition dates back to 2004 and 2005, when Chinese cryptanalyst Xiaoyun Wang shocked cryptographers by revealing flaws in the algorithm SHA-1, the current gold-standard “hash algorithm”, which is relied upon for almost all online banking transactions, digital signatures, and the secure storage of some passwords, such as those used to grant access to email accounts.

Diversity of designs

Hash algorithms turn files of almost any length into a fixed-length string of bits called a hash. Under SHA-1, it was believed that the only way to find two files that produce the same hash would require millions of years’ worth of computing power, but Wang found a shortcut, raising the possibility that online transactions could one day be rendered insecure.

So in 2007, NIST launched a competition to find a replacement.

Submissions closed in 2008, by which time NIST had received 64 entries “of widely varying quality”, says Burr. In July 2009, NIST pruned the list to 14 that warranted further consideration.

Then, on 9 December, he announced that NIST had settled on just five finalists (pdf).

“We picked five finalists that seemed to have the best combination of confidence in the security of the algorithm and their performance on a wide range of platforms” such as desktop computers and servers, Burr told New Scientist.

“We also gave some consideration to design diversity,” he says. “We wanted a set of finalists that were different internally, so that a new attack would be less likely to damage all of them, just as biological diversity makes it less likely that a single disease can wipe out all the members of a species.”

Sponge construction

The finalists include BLAKE, devised by a team led by Jean-Philippe Aumasson of the company Nagravision in Cheseaux, Switzerland; and Skein, the brainchild of a team led by famous computer security expert and blogger Bruce Schneier of Mountain View, California.

All of the finalists incorporate new design ideas that have arisen over the last few years, says Burr.

Hash algorithms start by turning a document into a string of 1s and 0s. Then over multiple cycles these bits are shuffled around, manipulated and either condensed down or expanded out to produce the final string, or hash.

One novel idea, called the “sponge hash construction”, does this by “sucking up” the original document and then later entering a “squeezing state” in which bits are “wrung out” to produce a final hash, Burr says. One of the finalists, an algorithm called Keccak devised by a team led by Guido Bertoni of STMicroelectronics, makes a particular point of using this method .

‘Brilliant woman’

The five teams have until 16 January 2011 to tweak their algorithms. Then there will be a year in which cryptanalysts are expected to attempt to break these algorithms. On the basis of these, and its own analyses, NIST will then choose the winner in 2012.

So will Wang, the cryptanalyst who attacked the initial SHA, be among those attempting to break the algorithms that are left? “We assume she may,” says Burr. “She is certainly a brilliant woman. But we hope to pick something that is good enough that she will fail this time.”

As well as finding a gold-standard algorithm, Burr is excited about the ability of such competitions to further cryptographic knowledge. The idea to use a competition to select the algorithm was inspired by the competition that led to the Advanced Encryption Standard (AES) used by the US government.

“There is a general sense that the AES competition really improved what the research community knew about block ciphers,” says Burr. “I think the same sense here is that we are really learning a lot about hash functions.”

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Dec 14

Five Contests That Recognize The Science Achievements of the Everyman

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Reported by Rebecca Boyle in Popular Science, 12.13.2010.

You Won’t Get Merit Badges For Winning These Contests, But You Will Get Money

There’s a long tradition of offering big cash prizes to entice talented and creative individuals to solve problems that have stymied industry and governments for decades. For example, in 1810, French cook Nicolas Appert won a 12,000-franc government prize for a food preservation method to help feed Napoleon’s army. His demonstration of putting food in airtight glass jars and sterilizing them with heat led to canning techniques that are still used today. Recently, such contests have blossomed, with many geared toward particle physicists and backyard tinkerers alike. Each year now, innovators are awarded some 30,000 prizes, worth in total about $1 billion. Here are our picks for the five most accessible.

Postcode Lottery Green Challenge

Postcode Lottery Green Challenge: Develop a marketable technology to reduce greenhouse gas emissions.

The Challenge:

Create a marketable, user-friendly technology to reduce greenhouse-gas emissions. To win the Dutch lottery’s prize, your invention should be refined enough to implement within two years. Judges favor creativity, sustainability and entrepreneurship.

The Payoff:

First place: about $700,000; second: about $275,000

The Competition:

A 25-year-old engineer, Scot Frank, won this year for a portable solar concentrator. The runner-up, rainforest researcher Jason Aramburu, also 25, submitted a kiln for people in developing nations to turn waste into carbon-capturing charcoal.


N-Prize: Create a small, inexpensive satellite that can be launched into orbit, circling the Earth at least nine times.

The Challenge:

Launch a satellite weighing between 0.35 and 0.70 ounces into low-Earth orbit by September 19, 2011. According to the prize’s sponsor, biologist Paul Dear, the launch must cost less than $1,600 and the satellite must circle the planet nine times.

The Payoff:

One-shot launching system: about $16,000; reusable one: about $16,000.

The Competition:

This prize is geared toward basement engineers around the world. The 26 teams that have signed up so far include both professional aerospace engineers and amateurs with no rocket-science background at all.

Sikorsky Human-Powered Helicopter Competition

Sikorsky Human-Powered Helicopter Competition: Power a chopper with only your own muscles and hover higher and longer than anyone before.

The Challenge:

Hover at least 9.8 feet off the ground for 60 seconds, using only human power and no energy-storage devices. The Sikorsky Aircraft and American Helicopter Society’s contest rules stipulate that lighter-than-air gases such as helium are not allowed.

The Payoff:

$250,000 (and a serious cardio workout).

The Competition:

Only two human-powered copters have ever flown. California State Polytechnic students hovered at eight inches for about eight seconds in 1989. A team from Nihon University in Japan set the current world record in 1994, at the same height for nearly 20 seconds.

Wendy Schmidt Oil Cleanup X Challenge

Wendy Schmidt Oil Cleanup X Challenge: Save the world's oceans from destruction with a more efficient, environmentally-friendly way to clean up after oil spills.

The Challenge:

Clean up oil spills better than current methods, and without any negative environmental effects. Teams selected by the X Prize Foundation will compete head-to-head for the quickest and most efficient cleanup on a test spill next summer.

The Payoff:

First place: $1 million; second: $300,000; third: $100,000

The Competition:

The X Prize Foundation hasn’t yet announced teams, but the Deepwater Horizon disaster has already proved that great ideas can come from anyone, such as the oil-tanker captain who invented a mesh sieve that snags tar balls from the ocean.

Rolex Awards For Enterprise

Rolex Awards For Enterprise: Construct an innovative prototype of "world-changing technology" in one of many categories.

The Challenge:

Build a working prototype of a “world-changing technology.” Categories include Science and Health, Environment, Exploration and Discovery, and Applied Technology. Representatives for the watch company judge entries on originality, impact and feasibility.

The Payoff:

First place: $100,000 and a gold Rolex; runners-up: $50,000 and a steel-and-gold Rolex.

The Competition:

Past winning projects were an acoustic whale-detector to protect the animals from ships, and a stove powered by discarded rice husks. Winners have included academics, professionals, entrepreneurs and students.

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Dec 10

A 3-D Tour of All the Known Galaxies, In 90 Seconds!

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Reported by Dan Nosowitz in Popular Science, December 6, 2010.

This little video, brought to us by NASA Goddard, shows off all of the galaxies we’re currently aware of, in one swirling, fluid shot. It’s like the visualizer your freshman college roommate used to stare at on his laptop while listening to Sigur Ros, under the influence of who knows what–but for real.

Apparently the video was created by taking images from the Hubble telescope and several other sources and placing them in a virtual 3-D space, corresponding to our viewing vantage point. Basically, it’s a 3-D video tour of the universe as we know it at the moment. You can check out the full-sized video here. Enjoy!

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Dec 10

Infrared add-on could let standard cameras see cancer.

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Reported by by Kate McAlpine in New Scientist, 09 December 2010

Doctors could one day instantly detect cancers by photographing patients with a digital camera.

Mammograms take time (Image: Image Source/Getty)

Jeppe Seidelin Dam and colleagues at the Technical University of Denmark in Roskilde are developing a device that can convert infrared radiation into visible light. Attached to a digital camera fitted with an infrared flash, it could detect tumours by recording the telltale pattern of infrared light they reflect.

“This would allow a surgeon to quickly determine if the entire tumour has been removed before finishing an operation,” he says.

At the heart of the system is a multilayered crystal of potassium titanium oxide phosphate in which the infrared photons from the object to be imaged interfere with photons from an infrared laser, also fired into the crystal. The interaction shifts the wavelength into the visible spectrum while preserving the image information, allowing it to be captured by a normal camera.

Mirror amplifiers

The idea was first explored in the 1970s, but improvements to methods for growing crystals since then have improved the resolution of the device 300-fold. By placing a pair of mirrors on either side of the crystal so that the laser light reflects back and forth, the team increased the odds of its photons interfering with infrared photons from the object.

“We pass the same photons through the crystal up to 100 times,” says Dam. The crystal was able to capture an infrared panorama with a resolution of 200 by 1000 pixels, the team says.

The device could be placed in front of a digital camera lens like a filter, and be used to take thermal photographs or video. Shrinking it down to a size suitable for everyday use should not be difficult, says Dam. “These are basically the same components that are in green laser pointers.”

While current infrared colour imagers need to run at -200°C and cost around $100,000, Dam says that an upconversion imager would run at room temperature and cost about $10,000.

Stefano Bonora of the University of Padua, Italy, calls the upconversion technique “really interesting” for its potential to generate infrared images at room temperature. Such detectors are lacking at the moment, he says.

Journal reference: Optics Letters, DOI: 10.1364/OL.35.003796

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Dec 07

IEEE Signal Processing Society offers free educational content via Connexions.

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Reported in EurekAlert! December 01, 2010.

Partnership assures quality of open-access educational materials

HOUSTON — (Dec. 1, 2010) — Rice University’s Connexions and the IEEE Signal Processing Society (IEEE-SPS) today announced the release of a broad collection of free, high-quality lessons that practicing engineers can use for their own education and career growth and that engineering instructors can mix and match to build customized courses, textbooks and study guides. The free material, all of it peer-reviewed to ensure high quality, is available online via the popular education site Connexions (, which attracts more than 2 million visits per month.

A novel aspect of the collaboration is the rigorous peer review of the quality of the materials by experts identified by the IEEE-SPS. Materials found to be of high quality are certified and collected in the IEEE-SPS “lens,” which is available at

“Connexions’ lenses adapt the time-tested peer-review process to open-access educational content, thus erasing a major concern for academic authors,” said Joel Thierstein, executive director of Connexions.

While the open-education movement has grown rapidly in recent years, critics have questioned how open-access publishers can ensure the quality of freely authored and edited materials. An oft-proposed option is adapting peer review — the process academic researchers have used for centuries to vet and certify research papers and books.

Founded more than a decade ago, Connexions is among the world’s most popular open- education sites. Connexions’ repository of free educational content can be employed, adapted and modified by anyone. The number of people using Connexions has grown exponentially in recent years.

“All materials must pass thorough a rigorous quality evaluation before they appear on the IEEE Signal Processing Society’s branded portal in Connexions,” said Roxana Saint-Nom, chair of the society’s Connexions Lens Subcommittee.

“While quality assurance of content was a key issue for us, Connexions offers other tangible benefits for our members,” said SPS President Mos Kaveh. “Compared with traditional publishing, Connexions is much faster, has global reach and is perfectly suited for the rapid pace of change in our field.”

In Connexions, anyone can create modules or “learning objects.” Like Lego blocks, these modules can be assembled and reassembled by users to create an almost endless variety of customized Web courses, textbooks, study guides and curricula.

While Connexions welcomes contributions from anyone, anywhere, it also features filtering layers called lenses. These lenses are what IEEE-SPS and other groups use to certify content. While Connexions supplies the tools, each organization develops its own processes for certifying contributed materials. In the case of the IEEE-SPS, the society developed a lens with social software features like a keyword tag cloud, discussion areas and tools that allow authors to track the worldwide impact of their contributions. The society’s lens can also single out exemplary signal processing-related content.

“Lenses are a key feature that differentiates Connexions from other open-education projects,” said Rice engineering professor and Connexions founder Richard Baraniuk, an IEEE-SPS member. “We’re glad to see the IEEE Signal Processing Society taking leadership both in establishing peer review for the open-access environment and in encouraging their members to contribute open-access materials to Connexions.”

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Dec 05

Lighting up chips gives computers a brain boost

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Reported in New Scientist in 01 December 2010 by Duncan Graham-Rowe

Computers could soon be rivalling the human brain for speed of thought.

A look at IBM's new chip architecture. (Image: IBM)

The computer giant IBM today unveiled a new type of computer chip that integrates both electrical and optical nano-devices on the same piece of silicon. This could soon make it possible for supercomputers to perform one million trillion calculations – or an exaflop – in a single second.

Such supercomputers would not only be a thousand times faster than today’s most powerful petaflop machines, but for the first time would have the same processing power as the human brain, says William Green, a researcher at IBM’s silicon integrated nanophotonics group at Yorktown Heights, in New York.

One of the main challenges in making super-fast computers lies in the ability to quickly transmit large amounts of data between chips, he says. But while optical fibres are much better at doing this than copper wires, components that convert electrical data into photons tend to only exist in separate off-chip devices. This means that data still has to flow through wires to reach them, which creates a bottleneck.

Light speed

But over the last four years IBM has developed a range of tiny photonic switches, waveguides, detectors and modulators, all of which are made out of silicon. And now for the first time these have been integrated into chips, so that the same silicon that makes up the electrical circuitry and transistors of the chip is also used to convey and convert photons, and channel them off the chip through thousands of waveguides, each just 500 nanometres wide.

Announcing the technology – called CMOS Integrated Silicon Nanophotonics – at the SEMICON conference in Tokyo, IBM says that a single chip can transmit terabits per second of data from a single processing core. And since these photonic devices are made out of silicon they can be made using the same fabrication processes used to make the transistors.

Switching to silicon nanophotonics could greatly improve the speed and power consumption of computer chips, says Hiroshi Mizuta, head of the University of Southampton’s Nano Research Group in the UK. “(Computing) performance is heavily limited by the interconnections,” he says.

Shrinking chips

The nanotechnology will also allow the optical and electrical components to be integrated into an area occupying ten times less silicon than conventional components, says Green.

IBM hopes to use the technology to create powerful exaflop supercomputers within the next five years. But further into the future the technology could also find its way into high performance games consoles, to increase the flow of data between graphics cards and processors, he says.

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Dec 03

Proteins, like people, act differently when crowded together.

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This story is available at

People in a jetliner act and feel one way when crammed together like sardines in a can. But they have quite a different mindset when the middle seat is empty and they have more personal space. Scientists are pursuing a remarkable parallel that exists among the proteins involved in health and disease inside living cells. The cover story in the current issue of Chemical & Engineering News (C&EN), ACS’ weekly newsmagazine, focuses on how the study of proteins crowded together inside cells is opening new doors to the prevention, diagnosis, and treatment of disease.

C&EN Senior Editor Celia Henry Arnaud notes that much of the scientific knowledge about proteins comes from research done in watered-down solutions, as if they had much of an airplane or cell to themselves. But cells are packed with proteins, which fill about 30 percent of a cell’s volume. In order to understand proteins’ actual role, scientists must study proteins under these jam-packed conditions.

The article describes how scientists are forging ahead with research that mimics the real-world conditions under which proteins function in cells. One discovery, for example, indicates that under crowded conditions, a protein involved in Lyme disease changes shape in a way that reveals a potential new target for diagnosing and treating the disease.

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Dec 03

Short, on-chip light pulses for ultrafast data transfer within computers.

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Reported in PhysOrg, November 24, 2010.

Electrical engineers generated short, powerful light pulses on a chip — an important step toward the optical interconnects that will likely replace the copper wires that carry information between chips within today’s computers. University of California, San Diego electrical engineers recently developed the first ultra compact, low power pulse compressor on a silicon chip to be described in the scientific literature. Details appeared online in the journal Nature Communications on November 16.

Scanning electron micrograph of dispersive grating before deposition of SiO2 overcladding. (Decorative red filter added to image.) Image credit: UC San Diego / Dawn Tan

This miniaturized short pulse generator eliminates a roadblock on the way to optical interconnects for use in PCs, data centers, imaging applications and beyond. These optical interconnects, which will aggregate slower data channels with pulse compression, will have far higher data rates and generate less heat than the copper wires they will replace. Such aggregation devices will be critical for future optical connections within and between high speed digital electronic processors in future digital information systems.

“Our pulse compressor is implemented on a chip, so we can easily integrate it with computer processors,” said Dawn Tan, the Ph.D. candidate in the Department of Electrical and Computer Engineering at UC San Diego Jacobs School of Engineering who led development of the pulse compressor.

“Next generation computer networks and computer architectures will likely replace copper interconnects with their optical counterparts, and these have to be complementary metal oxide semiconductor (CMOS) compatible. This is why we created our pulse compressor on silicon,” said Tan, an electrical engineering graduate student researcher at UC San Diego, and part of the National Science Foundation funded Center for Integrated Access Networks.

The pulse compressor will also provide a cost effective method to derive short pulses for a variety of imaging technologies such as time resolved spectroscopy – which can be used to study lasers and electron behavior, and optical coherence tomography – which can capture biological tissues in three dimensions.
In addition to increasing data transfer rates, switching from copper wires to optical interconnects will reduce power consumption caused by heat dissipation, switching and transmission of electrical signals.

“At UC San Diego, we recognized the enabling power of nanophotonics for integration of information systems close to 20 years ago when we first started to use nano-scale lithographic tools to create new optical functionalities of materials and devices – and most importantly, to enable their integration with electronics on a chip. This Nature Communications paper demonstrates such integration of a few optical signal processing device functionalities on a CMOS compatible silicon-on-insulator material platform,” said Yeshaiahu Fainman, a professor in the Department of Electrical and Computer Engineering in the UC San Diego Jacobs School of Engineering. Fainman acknowledged DARPA support in developing silicon photonics technologies which helped to enable this work, through programs such as Silicon-based Photonic Analog Signal Processing Engines with Reconfigurability (Si-PhASER) and Ultraperformance Nanophotonic Intrachip Communications (UNIC).

  • Pulse Compression for On-Chip Optical Interconnects

The compressed pulses are seven times shorter than the original — the largest compression demonstrated to date on a chip.
Until now, pulse compression featuring such high compression factors was only possible using bulk optics or fiber-based systems, both of which are bulky and not practical for optical interconnects for computers and other electronics.

The combination of high compression and miniaturization are possible due to a nanoscale, light-guiding tool called an “integrated dispersive element” developed and designed primarily by electrical engineering Ph.D. candidate Dawn Tan.

The new dispersive element offers a much needed component to the on-chip nanophotonics tool kit.

The pulse compressor works in two steps. In step one, the spectrum of incoming laser light is broadened. For example, if green laser light were the input, the output would be red, green and blue laser light. In step two, the new integrated dispersive element developed by the electrical engineers manipulates the light so each spectrum in the pulse is travelling at the same speed. This speed synchronization is where pulse compression occurs.

Imagine the laser light as a series of cars. Looking down from above, the cars are initially in a long caravan. This is analogous to a long pulse of laser light. After stage one of pulse compression, the cars are no longer in a single line and they are moving at different speeds. Next, the cars move through the new dispersive grating where some cars are sped up and others are slowed down until each car is moving at the same speed. Viewed from above, the cars are all lined up and pass the finish line at the same moment.

This example illustrates how the on-chip pulse compressor transforms a long pulse of light into a spectrally broader and temporally shorter pulse of light. This temporally compressed pulse will enable multiplexing of data to achieve much higher data speeds.

“In communications, there is this technique called optical time division multiplexing or OTDM, where different signals are interleaved in time to produce a single data stream with higher data rates, on the order of terabytes per second. We’ve created a compression component that is essential for OTDM,” said Tan.
The UC San Diego electrical engineers say they are the first to report a pulse compressor on a CMOS-compatible integrated platform that is strong enough for OTDM.

“In the future, this work will enable integrating multiple ‘slow’ bandwidth channels with pulse compression into a single ultra-high-bandwidth OTDM channel on a chip. Such aggregation devices will be critical for future inter- and intra-high speed digital electronic processors interconnections for numerous applications such as data centers, field-programmable gate arrays, high performance computing and more,” said Fainman, holder of the Cymer Inc. Endowed Chair in Advanced Optical Technologies at the UC San Diego Jacobs School of Engineering and Deputy Director of the NSF-funded Center for Integrated Access Networks.

More information: “Monolithic nonlinear pulse compressor on a silicon chip,” by Dawn T.H. Tan, Pang C. Sun and Yeshaiahu Fainman from the Department of Electrical and Computer Engineering at the UC San Diego Jacobs School of Engineering. Published online by the journal Nature Communications on November 16, 2010.

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