Computers Math

Security gaps exist not only in software, but also directly in hardware. Attackers might deliberately have them built in in order to attack technical applications on a large scale. Researchers at Ruhr University Bochum, Germany, and the Max Planck Institute for Security and Privacy (MPI-SP) in Bochum are exploring methods of detecting such so-called hardware Trojans. They compared construction plans for chips with electron microscope images of real chips and had an algorithm search for differences. This is how they detected deviations in 37 out of 40 cases.
The team at the CASA Cluster of Excellence (short for Cyber Security in the Age of Large-Scale Adversaries), headed by Dr. Steffen Becker, and the MPI-SP team headed by Endres Puschner, will present their findings at the IEEE Symposium on Security and Privacy, which will take place in San Francisco from 22 to 25 May 2023. The research was conducted in collaboration with Thorben Moos from the Université catholique de Louvain (Belgium) and the Federal Criminal Police Office in Germany.
The researchers released all images of the chips, the design data as well as the analysis algorithms online for free so that other research groups can use the data to conduct further studies.
Manufacturing plants as a gateway for hardware Trojans
These days, electronic chips are integrated into countless objects. They are more often than not designed by companies that don’t operate their own production facilities. The construction plans are therefore sent to highly specialised chip factories for production. “It’s conceivable that tiny changes might be inserted into the designs in the factories shortly before production that could override the security of the chips,” explains Steffen Becker and gives an example for the possible consequences: “In extreme cases, such hardware Trojans could allow an attacker to paralyse parts of the telecommunications infrastructure at the push of a button.”
Identifying differences between chips and construction plans
Becker and Puschner’s team analysed chips produced in the four modern technology sizes of 28, 40, 65 and 90 nanometres. For this purpose, they collaborated with Dr. Thorben Moos, who had designed several chips as part of his PhD research at Ruhr University Bochum and had them manufactured. Thus, the researchers had both the design files and the manufactured chips at their disposal. They obviously couldn’t modify the chips after the fact and build in hardware Trojans. And so they employed a trick: rather than manipulating the chips, Thorben Moos changed his designs retroactively in order to create minimal deviations between the construction plans and the chips. Then, the Bochum researchers tested if they could detect these changes without knowing what exactly they had to look for and where.

In the first step, the team at Ruhr University Bochum and MPI-SP had to prepare the chips using complex chemical and mechanical methods in order to take several thousand images of the lowest chip layers with a scanning electron microscope. These layers contain several hundred thousand of the so-called standard cells that carry out logical operations.
“Comparing the chip images and the construction plans turned out to be quite a challenge, because we first had to precisely superimpose the data,” says Endres Puschner. In addition, every little impurity on the chip could block the view of certain sections of the image. “On the smallest chip, which is 28 nanometres in size, a single speck of dust or a hair can obscure a whole row of standard cells,” stresses the IT security expert.
Almost all manipulations detected
The researchers used image processing methods to carefully match standard cell for standard cell and looked for deviations between the construction plans and the microscopic images of the chips. “The results give cause for cautious optimism,” as Puschner sums up the findings. For chip sizes of 90, 65 and 40 nanometres, the team successfully identified all modifications. The number of false-positive results totalled 500, i.e. standard cells were flagged as having been modified, although they were in fact untouched. “With more than 1.5 million standard cells examined, this is a very good rate,” says Puschner. It was only with the smallest chip of 28 nanometres that the researchers failed to detect three subtle changes.
Higher detection rate through clean room and optimised algorithms
A better recording quality could remedy this problem in the future. “Scanning electron microscopes do exist that are specifically designed to take chip images,” points out Becker. Moreover, using them in a clean room where contamination can be prevented would increase the detection rate even further.
“We also hope that other groups will use our data for follow-up studies,” as Steffen Becker outlines potential future developments. “Machine learning could probably improve the detection algorithm to such an extent that it would also detect the changes on the smallest chips that we missed.” More

Researchers from the University of Technology Sydney (UTS) have developed biosensor technology that will allow you to operate devices, such as robots and machines, solely through thought control.
The advanced brain-computer interface was developed by Distinguished Professor Chin-Teng Lin and Professor Francesca Iacopi, from the UTS Faculty of Engineering and IT, in collaboration with the Australian Army and Defence Innovation Hub.
As well as defence applications, the technology has significant potential in fields such as advanced manufacturing, aerospace and healthcare — for example allowing people with a disability to control a wheelchair or operate prosthetics.
“The hands-free, voice-free technology works outside laboratory settings, anytime, anywhere. It makes interfaces such as consoles, keyboards, touchscreens and hand-gesture recognition redundant,” said Professor Iacopi.
“By using cutting edge graphene material, combined with silicon, we were able to overcome issues of corrosion, durability and skin contact resistance, to develop the wearable dry sensors,” she said.
A new study outlining the technology has just been published in the peer-reviewed journal ACS Applied Nano Materials. It shows that the graphene sensors developed at UTS are very conductive, easy to use and robust.
The hexagon patterned sensors are positioned over the back of the scalp, to detect brainwaves from the visual cortex. The sensors are resilient to harsh conditions so they can be used in extreme operating environments.
The user wears a head-mounted augmented reality lens which displays white flickering squares. By concentrating on a particular square, the brainwaves of the operator are picked up by the biosensor, and a decoder translates the signal into commands.
The technology was recently demonstrated by the Australian Army, where soldiers operated a Ghost Robotics quadruped robot using the brain-machine interface. The device allowed hands-free command of the robotic dog with up to 94% accuracy.
“Our technology can issue at least nine commands in two seconds. This means we have nine different kinds of commands and the operator can select one from those nine within that time period,” Professor Lin said.
“We have also explored how to minimise noise from the body and environment to get a clearer signal from an operator’s brain,” he said.
The researchers believe the technology will be of interest to the scientific community, industry and government, and hope to continue making advances in brain-computer interface systems. More

Researchers have devised a new concept of superconducting microwave low-noise amplifiers for use in radio wave detectors for radio astronomy observations, and successfully demonstrated a high-performance cooled amplifier with power consumption three orders of magnitude lower than that of conventional cooled semiconductor amplifiers. This result is expected to contribute to the realization of large-scale multi-element radio cameras and error-tolerant quantum computers, both of which require a large number of low-noise microwave amplifiers.
The devise they used is called an SIS mixer. The SIS mixer is named after its structure, a very thin film of insulator material sandwiched between two layers of superconductors (S-I-S). In a radio telescope, cosmic radio waves collected by an antenna are fed into an SIS mixer, and the output signal is amplified by low-noise semiconductor amplifiers. An SIS mixer operates in a very low temperature environment, as low as 4 Kelvin (-269 degrees Celsius), and the amplifiers are also operated at that temperature.
To improve the performance of radio telescopes, researchers are developing a large-format radio camera equipped with 2D arrays of SIS mixers and amplifiers. However, the power consumption is a limiting factor. The typical power consumption of a semiconductor amplifier is about 10 mW, and by assembling 100 sets of detectors, the total power consumption reaches the maximum cooling capability of a 4 Kelvin refrigerator.
The research team led by Takafumi Kojima, an associate professor at the National Astronomical Observatory of Japan (NAOJ), has come up with a simple but innovative idea to realize a superconductor amplifier by connecting two SIS mixers. The team exploits the basic functions of the SIS mixer: frequency conversion and signal amplification. “The most important point is that the power consumption of an SIS mixer is, in principle, as low as microwatts,” says Kojima. “This is three orders of magnitude less than that of a cooled semiconductor amplifier.”
After obtaining successful preliminary results in 2018, the team advanced both the theoretical studies of the system and the physical implementation of its various components. In the end, the research team optimized the system and realized an “SIS amplifier” with 5 — 8 dB (three to six times) gain below the frequency of 5 GHz and a typical noise temperature of 10 K, which is comparable to the current cooled semiconductor amplifiers such as HEMT and HBT, but with much lower power consumption.
“By changing the configuration of the components, we can further improve the gain and low-noise performance of an SIS amplifier,” explains Kojima. “The idea of connecting two SIS mixers has broader applications for making various electronics that have functions other than amplification.”
Interestingly, this low-noise, low-power-consumption amplifier is also highly anticipated for large-scale error-tolerant quantum computers. Currently available quantum computers are small-scale with less than 100 qubits, but larger-scale, error-tolerant general-purpose quantum computers will require more than 1 million qubits. To handle a large number of qubits, a large number of amplifiers must also be installed, and dramatic reductions in amplifier power consumption are needed.
NAOJ has experience in the development of superconducting receivers for a number of radio telescopes, including NAOJ’s Nobeyama 45-meter Radio Telescope, which started operation in 1982. NAOJ is also currently working to upgrade the superconducting receivers to improve the performance of the Atacama Large Millimeter/submillimeter Array (ALMA), which is operated in the Republic of Chile in cooperation with East Asia, Europe, and North America. Of the 10 types of receivers (corresponding to 10 different frequency bands) currently installed on ALMA, three were developed by NAOJ, and the SIS chips at the heart of these receivers were also developed and produced in the cleanroom of the NAOJ Advanced Technology Center (ATC). The NAOJ ATC continues to promote research on the miniaturization and integration of superconducting circuits, not only for the realization of more powerful radio telescopes, but also for their potential as the basis of various technologies that will support society in the new era, such as quantum computing. More

The development of new information and communication technologies poses new challenges to scientists and industry. Designing new quantum materials — whose exceptional properties stem from quantum physics — is the most promising way to meet these challenges. An international team led by the University of Geneva (UNIGE) and including researchers from the universities of Salerno, Utrecht and Delft, has designed a material in which the dynamics of electrons can be controlled by curving the fabric of space in which they evolve. These properties are of interest for next-generation electronic devices, including the optoelectronics of the future. These results can be found in the journal Nature Materials.
The telecommunications of the future will require new, extremely powerful electronic devices. These must be capable of processing electromagnetic signals at unprecedented speeds, in the picosecond range, i.e. one thousandth of a billionth of a second. This is unthinkable with current semiconductor materials, such as silicon, which is widely used in the electronic components of our telephones, computers and game consoles. To achieve this, scientists and industry are focusing on the design of new quantum materials.
Thanks to their unique properties — especially the collective reactions of the electrons that compose them — these quantum materials could be used to capture, manipulate and transmit information-carrying signals (for example photons, in the case of quantum telecommunications) within new electronic devices. Moreover, they can operate in electromagnetic frequency ranges that have not yet been explored and would thus open the way to very high-speed communication systems.
A warp drive
”One of the most fascinating properties of quantum matter is that electrons can evolve in a curved space. The force fields, due to this distortion of the space inhabited by the electrons, generate dynamics totally absent in conventional materials. This is an outstanding application of the principle of quantum superposition,” explains Andrea Caviglia, full professor at the Department of Quantum Matter Physics in the Faculty of Science of the UNIGE and last author of the study.
After an initial theoretical study, the international team of researchers from the Universities of Geneva, Salerno, Utrecht and Delft designed a material in which the curvature of the space fabric is controllable. ”We have designed an interface hosting an extremely thin layer of free electrons. It is sandwiched between strontium titanate and lanthanum aluminate, which are two insulating oxides,” says Carmine Ortix, professor at the University of Salerno and coordinator of the theoretical study. This combination allows us to obtain particular electronic geometrical configurations which can be controlled on-demand.
One atom at a time
To achieve this, the research team used an advanced system for fabricating materials on an atomic scale. Using laser pulses, each layer of atoms was stacked one after another. ”This method allowed us to create special combinations of atoms in space that affect the behavior of the material,” the researchers detail.
While the prospect of technological use is still far off, this new material opens up new avenues in the exploration of very high-speed electromagnetic signal manipulation. These results can also be used to develop new sensors. The next step for the research team will be to further observe how this material reacts to high electromagnetic frequencies to determine more precisely its potential applications. More

A new way of describing the connections in real-world systems such as food webs or social networks could lead to better methods for predicting and controlling them.
According to research published in the journal PNAS, by mathematicians at the University of Birmingham, mapping the hierarchies and also the incoherence within a system will enable us to predict the system’s strong and weak points.
Understanding how these connections work is crucial in many different ways — for example knowing how a disease will spread through a population, or whether every point in a communications network is ‘in the loop’.
Real-world systems like these are referred to as ‘directed networks’ by mathematicians because the connections usually flow in a specific direction. In food webs, for example, biomass will generally move upwards from plants, through herbivores and on towards apex predators. Networks are strongly connected if it’s possible to move around the network without ignoring the directionality.
If a network is perfectly “coherent,” with distinct trophic levels like plants, herbivores and carnivores, it can’t be strongly connected. However, most real-world systems are neither perfectly coherent nor completely incoherent, but lie somewhere in between. In a food web, for instance, this might occur because of omnivorous animals that will eat both plants and other animals.
The researchers found that it was possible to use this trophic incoherence to estimate the point at which a network becomes strongly connected. They demonstrated that the method works for any type of network, including those of neurons, people, species, metabolites, genes and words, among others.
Niall Rodgers, lead author on the paper, said: “Our approach opens up news possibilities for understanding all sorts of different networks that are regularly encountered in society. A disease outbreak, for example, could be thought of as a network connected by the spread of bacteria through a population. Understanding where you are in that network and whether the connectivity is strong or weak could be crucial to making decisions about infection control.”
Samuel Johnson, senior author on the paper, added: “This modelling approach could be used to disrupt networks as well, because the points at which connectivity becomes strong can be targeted. Neurologists, for example, might find new ways to treat epilepsy by pinpointing specific connections responsible for maintaining seizures.” More

Synecoculture is a new agricultural method advocated by Dr. Masatoshi Funabashi, senior researcher at Sony Computer Science Laboratories, Inc. (Sony CSL), in which various kinds of plants are mixed and grown in high density, establishing rich biodiversity while benefiting from the self-organizing ability of the ecosystem. However, such dense vegetation requires frequent upkeep — seeds need to be sown, weeds need to be pruned, and crops need to be harvested. Synecoculture thus requires a high level of ecological literacy and complex decision-making. And while the operational issues present with Synecoculture can be addressed by using an agricultural robot, most existing robots can only automate one of the above three tasks in a simple farmland environment, thus falling short of the literacy and decision-making skills required of them to perform Synecoculture. Moreover, the robots may make unnecessary contact with the plants and damage them, affecting their growth and the harvest.
With the rising awareness of environmental issues, such a gap between the performance of humans versus that of conventional robots has spurred innovation to improve the latter. A group of researchers led by Takuya Otani, an Assistant Professor at Waseda University, in collaboration with Sustainergy Company and Sony CSL, have designed a new robot that can perform Synecoculture effectively. The robot is called SynRobo, with “syn” conveying the meaning of “together with” humans. It manages a variety of mixed plants grown in the shade of solar panels, an otherwise unutilized space. An article describing their research was published in Volume 13, Issue 1 of Agriculture, on 21 December 2022. This article has been co-authored by Professor Atsuo Takanishi, also from Waseda University, other researchers of Sony CSL, and students from Waseda University.
Otani briefly explains the novel robot’s design. “It has a four-wheel mechanism that enables movement on uneven land and a robotic arm that expands and contracts to help overcome obstacles. The robot can move on slopes and avoid small steps. The system also utilizes a 360o camera to recognize and maneuver its surroundings. In addition, it is loaded with various farming tools — anchors (for punching holes), pruning scissors, and harvesting setups. The robot adjusts its position using the robotic arm and an orthogonal axes table that can move horizontally.”
Besides these inherent features, the researchers also invented techniques for efficient seeding. They coated seeds from different plants with soil to make equally-sized balls. These made their shape and size consistent, so that the robot could easily sow seeds from multiple plants. Furthermore, an easy-to-use, human-controlled maneuvering system was developed to facilitate the robot’s functionality. The system helps it operate tools, implement automatic sowing, and switch tasks.
The new robot could successfully sow, prune, and harvest in dense vegetation, making minimal contact with the environment during the tasks because of its small and flexible body. In addition, the new maneuvering system enabled the robot to avoid obstacles 50% better while reducing its operating time by 49%, compared to a simple controller.
“This research has developed an agricultural robot that works in environments where multiple species of plants grow in dense mixtures,” Otani tells us. “It can be widely used in general agriculture as well as Synecoculture — only the tools need to be changed when working with different plants. This robot will contribute to improving the yield per unit area and increase farming efficiency. Moreover, its agricultural operation data will help automate the maneuvering system. As a result, robots could assist agriculture in a plethora of environments. In fact, Sustainergy Company is currently preparing to commercialize this innovation in abandoned fields in Japan and desertified areas in Kenya, among other places.”
Such advancements will promote Synecoculture farming, with the combination of renewable energy, and help solve various pressing problems, including climate change and the energy crisis. The present research is a crucial step toward achieving sustainable agriculture and carbon neutrality. Here’s hoping for a smart and skillful robot that efficiently supports large-scale Synecoculture! More

Integrating sensors into rotational mechanisms could make it possible for engineers to build smart hinges that know when a door has been opened, or gears inside a motor that tell a mechanic how fast they are rotating. MIT engineers have now developed a way to easily integrate sensors into these types of mechanisms, with 3D printing.
Even though advances in 3D printing enable rapid fabrication of rotational mechanisms, integrating sensors into the designs is still notoriously difficult. Due to the complexity of the rotating parts, sensors are typically embedded manually, after the device has already been produced.
However, manually integrating sensors is no easy task. Embed them inside a device and wires might get tangled in the rotating parts or obstruct their rotations, but mounting external sensors would increase the size of a mechanism and potentially limit its motion.
Instead, the new system the MIT researchers developed enables a maker to 3D print sensors directly into a mechanism’s moving parts using conductive 3D printing filament. This gives devices the ability to sense their angular position, rotation speed, and direction of rotation.
With their system, called MechSense, a maker can manufacture rotational mechanisms with integrated sensors in just one pass using a multi-material 3D printer. These types of printers utilize multiple materials at the same time to fabricate a device.
To streamline the fabrication process, the researchers built a plugin for the computer-aided design software SolidWorks that automatically integrates sensors into a model of the mechanism, which could then be sent directly to the 3D printer for fabrication.

MechSense could enable engineers to rapidly prototype devices with rotating parts, like turbines or motors, while incorporating sensing directly into the designs. It could be especially useful in creating tangible user interfaces for augmented reality environments, where sensing is critical for tracking a user’s movements and interaction with objects.
“A lot of the research that we do in our lab involves taking fabrication methods that factories or specialized institutions create and then making then accessible for people. 3D printing is a tool that a lot of people can afford to have in their homes. So how can we provide the average maker with the tools necessary to develop these types of interactive mechanisms? At the end of the day, this research all revolves around that goal,” says Marwa AlAlawi, a mechanical engineering graduate student and lead author of a paper on MechSense.
AlAlawi’s co-authors include Michael Wessely, a former postdoc in the MIT Computer Science and Artificial Intelligence Laboratory (CSAIL) who is now an assistant professor at Aarhus University; and senior author Stefanie Mueller, an associate professor in the MIT departments of Electrical Engineering and Computer Science and Mechanical Engineering, and a member CSAIL; as well as others at MIT and collaborators from Accenture Labs. The research will be presented at the ACM CHI Conference on Human Factors in Computing Systems.
Built-in sensing
To incorporate sensors into a rotational mechanism in a way that would not disrupt the device’s movement, the researchers leveraged capacitive sensing.

A capacitor consists of two plates of conductive material that have an insulating material sandwiched between them. If the overlapping area or distance between the conductive plates is changed, perhaps by rotating the mechanism, a capacitive sensor can detect resulting changes in the electric field between the plates. That information could then be used to calculate speed, for instance.
“In capacitive sensing, you don’t necessarily need to have contact between the two opposing conductive plates to monitor changes in that specific sensor. We took advantage of that for our sensor design,” AlAlawi says.
Rotational mechanisms typically consist of a rotational element located above, below, or next to a stationary element, like a gear spinning on a static shaft above a flat surface. The spinning gear is the rotational element and the flat surface beneath it is the stationary element.
The MechSense sensor includes three patches made from conductive material that are printed into the stationary plate, with each patch separated from its neighbors by nonconductive material. A fourth patch of conductive material, which has the same area as the other three patches, is printed into the rotating plate.
As the device spins, the patch on the rotating plate, called a floating capacitor, overlaps each of the patches on the stationary plate in turn. As the overlap between the rotating patch and each stationary patch changes (from completely covered, to half covered, to not covered at all), each patch individually detects the resulting change in capacitance.
The floating capacitor is not connected to any circuitry, so wires won’t get tangled with rotating components.
Rather, the stationary patches are wired to electronics that use software the researchers developed to convert raw sensor data into estimations of angular position, direction of rotation, and rotation speed.
Enabling rapid prototyping
To simplify the sensor integration process for a user, the researchers built a SolidWorks extension. A maker specifies the rotating and stationary parts of their mechanism, as well as the center of rotation, and then the system automatically adds sensor patches to the model.
“It doesn’t change the design at all. It just replaces part of the device with a different material, in this case conductive material,” AlAlawi says.
The researchers used their system to prototype several devices, including a smart desk lamp that changes the color and brightness of its light depending on how the user rotates the bottom or middle of the lamp. They also produced a planetary gearbox, like those that are used in robotic arms, and a wheel that measures distance as it rolls across a surface.
As they prototyped, the team also conducted technical experiments to fine-tune their sensor design. They found that, as they reduced the size of the patches, the amount of error in the sensor data increased.
“In an effort to generate electronic devices with very little e-waste, we want devices with smaller footprints that can still perform well. If we take our same approach and perhaps use a different material or manufacturing process, I think we can scale down while accumulating less error using the same geometry,” she says.
In addition to testing different materials, AlAlawi and her collaborators plan to explore how they could increase the robustness of their sensor design to external noise, and also develop printable sensors for other types of moving mechanisms.
This research was funded, in part, by Accenture Labs. More

A study in the Journal of The National Cancer Institute Cancer Spectrum looked at chatbots and artificial intelligence (AI), as they become popular resources for cancer information. They found these resources give accurate information when asked about common cancer myths and misconceptions. In the first study of its kind, Skyler Johnson, MD, physician-scientist at Huntsman Cancer Institute and assistant professor in the department of radiation oncology at the University of Utah (the U), evaluated the reliability and accuracy of ChatGPT’s cancer information.
Using the National Cancer Institute’s (NCI) common myths and misconceptions about cancer, Johnson and his team found that 97% of the answers were correct. However, this finding comes with some important caveats, including a concern amongst the team that some of the ChatGPT answers could be interpreted incorrectly. “This could lead to some bad decisions by cancer patients. The team suggested caution when advising patients about whether they should use chatbots for information about cancer,” says Johnson.
The study found reviewers were blinded, meaning they didn’t know whether the answers came from the chatbot or the NCI. Though the answers were accurate, reviewers found ChatGPT’s language was indirect, vague, and in some cases, unclear.
“I recognize and understand how difficult it can feel for cancer patients and caregivers to access accurate information,” says Johnson. “These sources need to be studied so that we can help cancer patients navigate the murky waters that exist in the online information environment as they try to seek answers about their diagnoses.”
Incorrect information can harm cancer patients. In a previous study by Johnson and his team published in the Journal of the National Cancer Institute, they found that misinformation was common on social media and had the potential to harm cancer patients.
The next steps are to evaluate how often patients are using chatbots to seek out information about cancer, what questions they are asking, and whether AI chatbots provide accurate answers to uncommon or unusual questions about cancer.
The study was supported by the National Institutes of Health/National Cancer Institute including P30 CA042014 and Huntsman Cancer Foundation. More