Fingerprint Makes Computer Chips Counterfeit-Proof

Fraunhofer researchers will be presenting a prototype at the embedded world Exhibition& Conference in Nuremberg from March 1 to 3.

Product piracy long ago ceased to be limited exclusively to the consumer goods sector. Industry, too, is increasingly having to combat this problem. Cheap fakes cost business dear: The German mechanical and plant engineering sector alone lost 6.4 billion euros of revenue in 2010, according to a survey by the German Engineering Federation (VDMA). Sales losses aside, low-quality counterfeits can also damage a company's brand image. Worse, they can even put people's lives at risk if they are used in areas where safety is paramount, such as automobile or aircraft manufacture. Patent rights or organizational provisions such as confidentiality agreements are no longer sufficient to prevent product piracy. Today's commercially available anti-piracy technology provides a degree of protection, but it no longer constitutes an insurmountable obstacle for the product counterfeiters: Criminals are using scanning electron microscopes, focused ion beams or laser bolts to intercept security keys -- and adopting increasingly sophisticated methods.

No two chips are the same

At embedded world, researchers from the Fraunhofer Institute for Secure Information Technology SIT will be demonstrating how electronic components or chips can be made counterfeit-proof using physical unclonable functions (PUFs)."Every component has a kind of individual fingerprint since small differences inevitably arise between components during production," explains Dominik Merli, a scientist at Fraunhofer SIT in Garching near Munich. Printed circuits, for instance, end up with minimal variations in thickness or length during the manufacturing process. While these variations do not affect functionality, they can be used to generate a unique code.

Invasive attacks destroy the structure

A PUF module is integrated directly into a chip -- a setup that is feasible not only in a large number of programmable semiconductors known as FPGAs (field programmable gate arrays) but equally in hardware components such as microchips and smartcards."At its heart is a measuring circuit, for instance a ring oscillator. This oscillator generates a characteristic clock signal which allows the chip's precise material properties to be determined. Special electronic circuits then read these measurement data and generate the component-specific key from the data," explains Merli. Unlike conventional cryptographic processes, the secret key is not stored on the hardware but is regenerated as and when required. Since the code relates directly to the system properties at any given point in time, it is virtually impossible to extract and clone it. Invasive attacks on the chip would alter physical parameters, thus distorting or destroying the unique structure.

The Garching-based researchers have already developed two prototypes: A butterfly PUF and a ring oscillator PUF. At present, these modules are being optimized for practical applications. The experts will be at embedded world in Nuremberg (hall 11, stand 203) from March 1-3 to showcase FPGA boards that can generate an individual cryptographic key using a ring oscillator PUF. These allow attack-resistant security solutions to be rolled out in embedded systems.

Source

Clay-Armored Bubbles May Have Formed First Protocells: Minerals Could Have Played a Key Role in the Origins of Life

The research, published online in the journalSoft Matter,shows that clay vesicles provide an ideal container for the compartmentalization of complex organic molecules.

The authors say the discovery opens the possibility that primitive cells might have formed inside inorganic clay microcompartments.

"A lot of work, dating back several decades, explores the role of air bubbles in concentrating molecules and nanoparticles to allow interesting chemistry to occur," says lead author Anand Bala Subramaniam, a doctoral candidate at SEAS.

"We have now provided a complete physical mechanism for the transition from a two-phase clay-air bubble system, which precludes any aqueous-phase chemistry, to a single aqueous-phase clay vesicle system," Subramaniam says,"creating a semipermeable vesicle from materials that are readily available in the environment."

"Clay-armored bubbles" form naturally when platelike particles of montmorillonite collect on the outer surface of air bubbles under water.

When the clay bubbles come into contact with simple organic liquids like ethanol and methanol, which have a lower surface tension than water, the liquid wets the overlapping plates. As the inner surface of the clay shell becomes wet, the disturbed air bubble inside dissolves.

The resulting clay vesicle is a strong, spherical shell that creates a physical boundary between the water inside and the water outside. The translucent, cell-like vesicles are robust enough to protect their contents in a dynamic, aquatic environment such as the ocean.

Microscopic pores in the vesicle walls create a semipermeable membrane that allows chemical building blocks to enter the"cell," while preventing larger structures from leaving.

Scientists have studied montmorillonite, an abundant clay, for hundreds of years, and the mineral is known to serve as a chemical catalyst, encouraging lipids to form membranes and single nucleotides to join into strands of RNA.

Because liposomes and RNA would have been essential precursors to primordial life, Subramaniam and his coauthors suggest that the pores in the clay vesicles could do double duty as both selective entry points and catalytic sites.

"The conclusion here is that small fatty acid molecules go in and self-assemble into larger structures, and then they can't come out," says principal investigator Howard A. Stone, the Dixon Professor in Mechanical and Aerospace Engineering at Princeton, and a former Harvard faculty member."If there is a benefit to being protected in a clay vesicle, this is a natural way to favor and select for molecules that can self-organize."

Future research will explore the physical interactions between the platelike clay particles, and between the liquids and the clay. The researchers are also interested to see whether these clay vesicles can, indeed, be found in the natural environment today.

"Whether clay vesicles could have played a significant role in the origins of life is of course unknown," says Subramaniam,"but the fact that they are so robust, along with the well-known catalytic properties of clay, suggests that they may have had some part to play."

Subramaniam and Stone's coauthors include Jiandi Wan, of Princeton University, and Arvind Gopinath, of Brandeis University.

The research was funded by the Harvard Materials Research Science and Engineering Center and supported by the Harvard Center for Brain Science Imaging Facility.

Source

How Safe Is Nano? Nanotoxicology: An Interdisciplinary Challenge

"Research into the safety of nanotechnology combines biology, chemistry, and physics with workplace hygiene, materials science, and engineering to create a truly interdisciplinary research field," explain Krug and Wick."There are several factors to take into account in the interaction of nano-objects with organisms," they add. The term nanotoxicology is fully justified."Nanoscale particles can enter into cells by other means of transport than larger particles."

Another critical feature is the large surface area of nano-objects relative to their volume. If a similar amount of substance is absorbed, an organism comes into contact with a significantly larger number of molecules with nanoparticles than with larger particles. Dose-effect relationships cannot therefore be assumed to be the same. Furthermore, chemical and physical effects that do not occur with larger particles may arise."Whether the larger or smaller particle is more toxic in any given case cannot be predicted," according to the authors."Clearly, the type of chemical compound involved and its conformation in a specific case can also not be ignored." Carbon in the form of diamond nanoparticles is harmless, whereas in the form of nanotubes -- depending on length and degree of aggregation -- it may cause health problems. It is also thus impossible to avoid considering each nanomaterial in turn.

For a risk assessment, it is also necessary to keep in mind what dosage would be considered realistic and that not every observed biological effect automatically equates to a health risk.

Krug and Wick indicate that a large amount of data about the biological effects of nanomaterials is available, but not all studies are reliable. Sometimes it is not possible to reproduce the specific material tested or the conditions."By pointing out methodological inadequacies and making concrete recommendations for avoiding them, we are hoping to contribute to a lasting improvement in the data," state Krug and Wick.

Source

GRIN Plasmonics: A Practical Path to Superfast Computing, Ultrapowerful Optical Microscopy and Invisibility Carpet-Cloaking Devices

Working with composites featuring a dielectric (non-conducting) material on a metal substrate, and"grey-scale" electron beam lithography, a standard method in the computer chip industry for patterning 3-D surface topographies, the researchers have fabricated highly efficient plasmonic versions of Luneburg and Eaton lenses. A Luneburg lens focuses light from all directions equally well, and an Eaton lens bends light 90 degrees from all incoming directions.

"This past year, we used computer simulations to demonstrate that with only moderate modifications of an isotropic dielectric material in a dielectric-metal composite, it would be possible to achieve practical transformation optics results," says Xiang Zhang, who led this research."Our GRIN plasmonics technique provides a practical way for routing light at very small scales and producing efficient functional plasmonic devices."

Zhang, a principal investigator with Berkeley Lab's Materials Sciences Division and director of UC Berkeley's Nano-scale Science and Engineering Center (SINAM), is the corresponding author of a paper in the journalNature Nanotechnology, describing this work titled,"Plasmonic Luneburg and Eaton Lenses." Co-authoring the paper were Thomas Zentgraf, Yongmin Liu, Maiken Mikkelsen and Jason Valentine.

GRIN plasmonics combines methodologies from transformation optics and plasmonics, two rising new fields of science that could revolutionize what we are able to do with light. In transformation optics, the physical space through which light travels is warped to control the light's trajectory, similar to the way in which outer space is warped by a massive object under Einstein's relativity theory. In plasmonics, light is confined in dimensions smaller than the wavelength of photons in free space, making it possible to match the different length-scales associated with photonics and electronics in a single nanoscale device.

"Applying transformation optics to plasmonics allows for precise control of strongly confined light waves in the context of two-dimensional optics," Zhang says."Our technique is analogous to the well-known GRIN optics technique, whereas previous plasmonic techniques were realized by discrete structuring of the metal surface in a metal-dielectric composite."

Like all plasmonic technologies, GRIN plasmonics starts with an electronic surface wave that rolls through the conduction electrons on a metal. Just as the energy in a wave of light is carried in a quantized particle-like unit called a photon, so, too, is plasmonic energy carried in a quasi-particle called a plasmon. Plasmons will interact with photons at the interface of a metal and dielectric to form yet another quasi-particle, a surface plasmon polariton (SPP).

The Luneburg and Eaton lenses fabricated by Zhang and his co-authors interacted with SPPs rather than photons. To make these lenses, the researchers worked with a thin dielectric film (a thermplastic called PMMA) on top of a gold surface. When applying grey-scale electron beam lithography, the researchers exposed the dielectric film to an electron beam that was varied in dosage (charge per unit area) as it moved across the film's surface. This resulted in highly controlled differences in film thickness across the length of the dielectric that altered the local propagation of SPPs. In turn, the"mode index," which determines how fast the SPPs will propagate, is altered so that the direction of the SPPs can be influenced.

"By adiabatically tailoring the topology of the dielectric layer adjacent to the metal surface, we're able to continuously modify the mode index of SPPs," says Zentgraf."As a result, we can manipulate the flow of SPPs with a greater degree of freedom in the context of two-dimensional optics."

Says Liu,"The practicality of working only with the purely dielectric material to transform SPPs is a big selling point for GRIN plasmonics. Controlling the physical properties of metals on the nanometer length-scale, which is the penetration depth of electromagnetic waves associated with SPPs extending below the metal surfaces, is beyond the reach of existing nanofabrication techniques."

Adds Zentgraf,"Our approach has the potential to achieve low-loss functional plasmonic elements with a standard fabrication technology that is fully compatible with active plasmonics."

In theNature Nanotechnologypaper, the researchers say that inefficiencies in plasmonic devices due to SPPs lost through scattering could be reduced even further by incorporating various SPP gain materials, such as fluorescent dye molecules, directly into the dielectric. This, they say, would lead to an increased propagation distance that is highly desired for optical and plasmonic devices. It should also enable the realization of two-dimensional plasmonic elements beyond the Luneburg and Eaton lenses.

Says Mikkelsen,"GRIN plasmonics can be immediately applied to the design and production of various plasmonic elements, such as waveguides and beam splitters, to improve the performance of integrated plasmonics. Currently we are working on more complex, transformational plasmonic devices, such as plasmonic collimators, single plasmonic elements with multiple functions, and plasmonic lenses with enhanced performance."

This research was supported by the U.S. Army Research Office and the National Science Foundation's Nano-scale Science and Engineering Center.

Source

Future Surgeons May Use Robotic Nurse, 'Gesture Recognition'

Both the hand-gesture recognition and robotic nurse innovations might help to reduce the length of surgeries and the potential for infection, said Juan Pablo Wachs, an assistant professor of industrial engineering at Purdue University.

The"vision-based hand gesture recognition" technology could have other applications, including the coordination of emergency response activities during disasters.

"It's a concept Tom Cruise demonstrated vividly in the film 'Minority Report,'" Wachs said.

Surgeons routinely need to review medical images and records during surgery, but stepping away from the operating table and touching a keyboard and mouse can delay the surgery and increase the risk of spreading infection-causing bacteria.

The new approach is a system that uses a camera and specialized algorithms to recognize hand gestures as commands to instruct a computer or robot.

At the same time, a robotic scrub nurse represents a potential new tool that might improve operating-room efficiency, Wachs said.

Findings from the research will be detailed in a paper appearing in the February issue of Communications of the ACM, the flagship publication of the Association for Computing Machinery. The paper was written by researchers at Purdue, the Naval Postgraduate School in Monterey, Calif., and Ben-Gurion University of the Negev, Israel.

Research into hand-gesture recognition began several years ago in work led by the Washington Hospital Center and Ben-Gurion University, where Wachs was a research fellow and doctoral student, respectively.

He is now working to extend the system's capabilities in research with Purdue's School of Veterinary Medicine and the Department of Speech, Language, and Hearing Sciences.

"One challenge will be to develop the proper shapes of hand poses and the proper hand trajectory movements to reflect and express certain medical functions," Wachs said."You want to use intuitive and natural gestures for the surgeon, to express medical image navigation activities, but you also need to consider cultural and physical differences between surgeons. They may have different preferences regarding what gestures they may want to use."

Other challenges include providing computers with the ability to understand the context in which gestures are made and to discriminate between intended gestures versus unintended gestures.

"Say the surgeon starts talking to another person in the operating room and makes conversational gestures," Wachs said."You don't want the robot handing the surgeon a hemostat."

A scrub nurse assists the surgeon and hands the proper surgical instruments to the doctor when needed.

"While it will be very difficult using a robot to achieve the same level of performance as an experienced nurse who has been working with the same surgeon for years, often scrub nurses have had very limited experience with a particular surgeon, maximizing the chances for misunderstandings, delays and sometimes mistakes in the operating room," Wachs said."In that case, a robotic scrub nurse could be better."

The Purdue researcher has developed a prototype robotic scrub nurse, in work with faculty in the university's School of Veterinary Medicine.

Researchers at other institutions developing robotic scrub nurses have focused on voice recognition. However, little work has been done in the area of gesture recognition, Wachs said.

"Another big difference between our focus and the others is that we are also working on prediction, to anticipate what images the surgeon will need to see next and what instruments will be needed," he said.

Wachs is developing advanced algorithms that isolate the hands and apply"anthropometry," or predicting the position of the hands based on knowledge of where the surgeon's head is. The tracking is achieved through a camera mounted over the screen used for visualization of images.

"Another contribution is that by tracking a surgical instrument inside the patient's body, we can predict the most likely area that the surgeon may want to inspect using the electronic image medical record, and therefore saving browsing time between the images," Wachs said."This is done using a different sensor mounted over the surgical lights."

The hand-gesture recognition system uses a new type of camera developed by Microsoft, called Kinect, which senses three-dimensional space. The camera is found in new consumer electronics games that can track a person's hands without the use of a wand.

"You just step into the operating room, and automatically your body is mapped in 3-D," he said.

Accuracy and gesture-recognition speed depend on advanced software algorithms.

"Even if you have the best camera, you have to know how to program the camera, how to use the images," Wachs said."Otherwise, the system will work very slowly."

The research paper defines a set of requirements, including recommendations that the system should:

• Use a small vocabulary of simple, easily recognizable gestures.
• Not require the user to wear special virtual reality gloves or certain types of clothing.
• Be as low-cost as possible.
• Be responsive and able to keep up with the speed of a surgeon's hand gestures.
• Let the user know whether it understands the hand gestures by providing feedback, perhaps just a simple"OK."
• Use gestures that are easy for surgeons to learn, remember and carry out with little physical exertion.
• Be highly accurate in recognizing hand gestures.
• Use intuitive gestures, such as two fingers held apart to mimic a pair of scissors.
• Be able to disregard unintended gestures by the surgeon, perhaps made in conversation with colleagues in the operating room.
• Be able to quickly configure itself to work properly in different operating rooms, under various lighting conditions and other criteria.

"Eventually we also want to integrate voice recognition, but the biggest challenges are in gesture recognition," Wachs said."Much is already known about voice recognition."

The work is funded by the U.S. Agency for Healthcare Research and Quality.

Source

An Ice-Bar Made from Pure Ice

Building structures from ice and snow is probably something everyone has tried in their youth. Today, using ice as a building material is also something which is being discussed by scientists. The research group supervised by Prof. Kollegger of the Institute of Structural Engineering is looking into ways of building large-scale, stable domes made of ice. Following a thorough preparatory and research phase, a new ice dome construction method is now being put to the test in Obergurgl -- a world first. This structure, showing more than 10 metres free span, is now home to a bar -- for as long as the temperatures are low enough.

Using ice as a building material has actually been done before: entire ice hotels have been built in e.g. Scandinavia."In most cases though the spans of the structures are small or the ice is not a load-bearing component and merely acts as cladding for the actual construction," explains Prof. Kollegger. The team of Vienna University of Technology has developed an ice dome which presents a stable and free-standing safe structure, and does not require additional support using other building materials. Theoretical calculations and several experiments have been carried out in this area over the past few years and, thanks to the latest technology, ice structures which are large and stable enough to actually be used as serviceable buildings can now be built.

Slow deformation process - like a glacier

First, a 20 cm-thick plate of ice is cut into 16 segments. These two-dimensional segments have then to be transformed into a three-dimensional structure. The University research team takes advantage of one property of ice, known as"creep behaviour." If pressure is applied to the ice, it can slowly change its shape without breaking. Glacial creep functions similarly."The segments of ice are placed on stacks of wood. Then, under the load of its own weight, the ice begins to change shape all by itself, resulting in a curved dome segment," explains Sonja Dallinger, research assistant at the Institute of Structural Engineering and on-site manager of the Obergurgl construction experiment.

The greatest challenge that had to be faced was the prevention of any breakage of the individually curved segments when assembling the dome. To solve this issue, a wooden tower was erected and the dome segments were held together by means of steel chains. The wooden tower could only be removed once all the segments had been positioned correctly and the ice dome stood on its own.

Austria's coolest bar

The ice dome was constructed in front of the spa area of the Hotel Alpina in Obergurgl and is presently being used as an ice bar. The drinks are definitely pretty cool -- and of course it's up to you whether or not to wear a cocktail dress!

Source

Metamaterials Approach Makes Better Satellite Antennas

"Existing horn antennas have adequate performance, but have undergone little change over several decades except for advances in more accurate modeling techniques," said Erik Lier, technical Fellow, Lockheed Martin Space Systems Co."Modifications enabled by metamaterials can either enhance performance, or they can lower the mass and thus lower the cost of putting the antenna in space."

Lighter antennas cost less to boost into space and more energy-efficient antennas can reduce the size of storage batteries and solar cells, which also reduces the mass.

Metamaterials derive their unusual properties from structure rather than composition and possess exotic properties not usually found in nature.

"Working with Penn State, we decided that the first year we were going focus on applications for radio frequency antennas, where we thought we had a reasonable chance to succeed," said Lier.

According to Douglas H. Werner, professor of electrical engineering, Penn State, this is one of the first practical implementations of electromagnetic metamaterials that makes a real world device better.

"These results also help lay to rest the widely held viewpoint that metamaterials are primarily an academic curiosity and, due to their narrow bandwidth and relatively high loss, will never find their way into real-world devices," the researchers report in the current issue ofNature Materials.

They specifically designed their electromagnetic metamaterials to avoid previous limitations of narrow bandwidth and high intrinsic material loss, which results in signal loss. Their aim was not to design theoretical metamaterial-enhanced antennas, but to build a working prototype.

"We have developed design optimization tools that can be employed to meet real device requirements," said Werner."We can optimize the metamaterial to get the best device performance by tailoring its properties across a desired bandwidth to meet the specific needs of the horn antenna."

The researchers wanted an antenna that could work over a broad band of frequencies -- at least an octave -- and improve upon existing antennas. An octave in the radio frequency spectrum is a stretch of bandwidth where the upper frequency is twice the lower frequency -- 3.5 to 7 gigahertz for example, which is wider than the standard C-band.

Horn antennas are part of communications satellites that relay television and radio signals, telephone calls and data around the world. Two commonly used microwave bands on satellites are C-band -- used for long-distance radio and telecommunications -- and Ku-band -- used for broadcast television and remote television uplinks.

The researchers, who also included Qi Wu and Jeremy A. Bossard, postdoctoral fellows in electrical engineering, and Clinton P. Scarborough, graduate student, electrical engineering, all from Penn State, designed horn antenna liners from metamaterials with special low-index electromagnetic properties -- effective refractive index between zero and one -- which do not physically exist in natural materials. To increase bandwidth and decrease loss, the antenna liners needed to have repetitive structure considerably smaller than the wavelengths the antenna is designed to transmit.

Ku-band -- 12 to 18 gigahertz -- antennas require small structural intervals that are easily fabricated using conventional printed circuit board manufacturing techniques, while super extended C-band -- 3.4 to 6.725 gigahertz -- could be achieved with a simple wire grid structure that is easily manufactured with an interval of about a quarter of an inch between wires. The researchers chose to convert the C-band application into a prototype.

"This is just an example of what we can do," said Lier."It opens up the way for a broader range of other applications and is proof of the new metamaterial technology and an example of how it can be used."

The Lockheed Martin University Research Initiative program funded this project.

Source