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A researcher holds their thumb to the fingerprint sensor of a smartphone and touches a door handle at the same time.

Sending Passwords Through Your Body Could Be More Secure Than Transmitting Them Over The Air

Another day, another cybersecurity threat to worry about. Earlier this week, Johnson and Johnson told patients that it had discovered a security flaw in its insulin pumps, which left the pumps vulnerable to hacking—though the company said the risk of such a hack actually occurring is “extremely low.”

Meanwhile, a group of researchers at the University of Washington in Seattle is offering an alternative to wireless data transmission that could make medical devices and wearables more secure: transmitting the data through our bodies rather than broadcasting them over the air. Their premise is that it’s much harder to surveil a human body without someone noticing than it is to surreptitiously pluck a password from wireless signals in the air.

In tests with 10 subjects, the group showed that it’s possible to transmit passwords at speeds of up to 50 bits per second (bps) through the human body, using off-the-shelf products such as fingerprint scanners and iPhone fingerprint sensors. For comparison, a standard Internet package in the U.S. offers download speeds of 15 megabits-per-second, or 15 million bits per second.

“You can hold a phone in your hand and you can have a receiver on your leg, and you can actually receive signals very strongly,” says Shyamnath Gollakota, a wireless researcher at the University of Washington and collaborator on the project.

The experiments were led by graduate students Mehrdad Hessar and Vikram Iyer with the guidance of Gollakota. The group recently presented its work at the 2016 ACM International Joint Conference on Pervasive and Ubiquitous Computing in Germany.

If the technique were ever to catch on, it would be limited to applications such as wearables, medical implants, and digital door locks because it requires users to simultaneously touch both the device that is sending the password and the one that is receiving it.

And the low bit rate means it would work best for transferring short strings of numbers such as a passcode rather than full sentences, or high-definition films. As an example, the group says sending a four-digit numerical code to a digital door lock would require fewer than 16 bits, which could be transmitted through the body in less than a second. A 256-bit serial number could be sent to a medical device in under 15 seconds.

Jeffrey Walling, an assistant professor at the University of Utah who has studied capacitive touch, says even this method of on-body password transferral wouldn’t be hackproof. “Certainly, any time you’re transmitting any type of signal, you can't make it 100 percent secure,” he says. But it could be an improvement over the wireless channels used today. 

In the past, other researchers have successfully demonstrated on-body communications but those projects often required users to add custom hardware onto their devices in order to pull it off. To see whether it was possible to do this with existing technology, the University of Washington group selected several commercial devices to test: an iPhone 5s; an iPhone 6s; a Lenovo touchpad; an Adafruit touchpad; and a Verifi P5100 fingerprint scanner.

The touchpad or fingerprint sensor on all of these devices use a concept called capacitive coupling—they connect to a 2-D grid of electrodes that measure capacitance, or the ability to store energy as an electric charge. When the device sends a voltage signal through either the row or column, it creates an electric field at the intersections. When a finger touches the screen, it affects the electric field and thereby changes the capacitance at that point. The device can use this change to detect the presence of a finger as well as characterize the peculiar patterns of swirls and ridges in a fingerprint.

When a finger touches the screen or scanner, it also offers a path for these signals to travel through the body. Skin isn’t a great conductor, so the signals travel instead through extracellular fluid found in blood vessels and muscles. The signals emitted by fingerprint sensors fall below 10 megahertz, which is important because higher-frequency signals would be absorbed by these same fluids. It’s an added bonus that sub–10 MHz signals do not travel well through the air. They degrade and become hard to detect after traveling just 6 centimeters from a fingerprint sensor or 20 centimeters from a touchpad.

For their demonstration, the researchers wanted to not only transmit a signal from a fingerprint sensor through the body, but also alter it in order to send a message. But due to security concerns, many device manufacturers don’t allow users to access the software or hardware that directly controls these signals.

So, the group had to improvise. They wrote software that initiated power cycling, which means it quickly turned the devices on and off, in effect sending a digital code with “on”  equaling a 1 and “off” meaning a 0. By using this technique, they could transmit messages using the signals that commercial devices were already generating.

To receive those messages, the group developed a bracelet wrapped in conductive copper tape that they attached to a subject’s arm, leg, or chest. This bracelet was connected to a receiver built from a USB TV tuner, an upconverter that could boost the low frequency signal to make it readable to the receiver, and a software-defined radio platform housed on a laptop.

With this system and their on-off code, the team transmitted password data at a maximum of 25 bps with the Verifi scanner, but managed 50 bps with the Adafruit touchpad. They found that the signal’s strength remained steady as it traveled throughout the entire body instead of degrading, as it would over air. Transmission was not significantly impacted by the height, weight, or posture of users, and when the group tested their system in the presence of other electronic devices, they found virtually no interference.

Gert Cauwenberghs, a biomedical researcher who has studied similar methods at the University of California, San Diego, thinks the group could achieve even higher data rates—potentially hundreds of bits per second—by gaining direct access to the fingerprint sensors.

For now, the group says that even the relative snail’s pace of 50 bps is sufficient to send a passcode that could unlock a door if a user were to touch their smartphone’s fingerprint sensor and the door handle at the same time. But Cauwenberghs points out that the convenience of this method only increases with speed. At the present low rates, “you'd probably have to hold your finger on that patch for a few seconds for this to authenticate,” he says.  

Before entrusting any such system with the passcodes to his own front door, Walling of the University of Utah says he’d like to see more statistical analysis about how often this technique generates false positive and negatives. “If they really can transmit a strong enough signal and do this repeatedly, I really do think it's something of potential,” he says.  

Cauwenberghs would also like to learn more about the biological impact of such transmissions before people start making a habit of using their bodies as communication links. The low frequencies used in this study have no known health impacts, but he says it would be best to study the effects of repeatedly sending such signals through the body in this manner before ruling it safe.

The Nvidia Titan X is one of the latest examples of GPU chips used in deep learning.

Fujitsu Memory Tech Speeds Up Deep-Learning AI

Artificial intelligence driven by deep learning often runs on many computer chips working together in parallel. But the deep-learning algorithms, called neural networks, can run only so fast in this parallel computing setup because of the limited speed with which data flows between the different chips. The Japan-based multinational Fujitsu has come up with a novel solution that sidesteps this limitation by enabling larger neural networks to exist on a single chip.

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The Google Translate icon on the screen of a smartphone

Google Translate Gets a Deep-Learning Upgrade

Google Translate has become a quick-and-dirty translation solution for millions of people worldwide since it debuted a decade ago. But Google’s engineers have been quietly tweaking their machine translation service’s algorithms behind the scenes. They recently delivered a huge Google Translate upgrade that harnesses the popular artificial intelligence technique known as deep learning.

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Brain inspired computing

IBM's Brain-Inspired Chip Tested for Deep Learning

The deep-learning software driving the modern artificial intelligence revolution has mostly run on fairly standard computer hardware. Some tech giants such as Google and Intel have focused some of their considerable resources on creating more specialized computer chips designed for deep learning. But IBM has taken a more unusual approach: It is testing its brain-inspired TrueNorth computer chip as a hardware platform for deep learning.

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Arial photo of China's FAST telescope

China Unveils World's Largest Single-Dish Radio Telescope

Move over, Arecibo. The title of “world’s largest single-dish radio telescope” now belongs to China’s Five-hundred-meter Aperture Spherical Telescope (FAST).

The telescope, which had its official launch on Sunday, has already received astrophysical signals, China’s press agency, Xinhua, reports. The almost 1.2-billion-yuan (US $180 million) project was spearheaded by the Chinese Academy of Sciences. 

Like the 305-meter-wide dish of the Arecibo Observatory in Puerto Rico, FAST consists of a spherical reflector dish that collects radio signals and focuses them onto the receiver system suspended above it. But FAST, which was built in a natural hollow in southern Guizhou province, also boasts an active reflector surface: Triangular panels that make up its dish can be moved to form a smaller, transient reflector, in order to focus and target different locations on the sky.

According to the FAST site, the telescope will have double the raw sensitivity of the Arecibo Observatory. Among other things, it is expected to be able to hunt for the universe’s first stars, search for signals from an extraterrestrial intelligence, and enable the detection of new pulsars—the spinning remnants of dead stars—in our galaxy and others.

For more of a visual feel for the telescope, Rebecca Morelle of the BBC did a nice video tour, published in May. 

Follow Rachel Courtland on Twitter at @rcourt.


Electrostatic Glider Could Maneuver Around Asteroids Without Expending Fuel

One of the biggest constraints on exploration of the solar system is fuel. Spacecraft need fuel to get where they're going, and they need even more fuel in order to do what they're supposed to do once they arrive. Though energy (electricity) can be replenished for years (or even decades) with solar panels or RTGs, once you run out of reaction mass, your spacecraft is through. (If you're smart, you'll have suicided it into something well before then.)

Propulsion systems like ion engines and electrospray engines can use small amounts of fuel very efficiently, but only postpones the problem of limited reaction mass as opposed to solving it. Fortunately, some very smart people are working on alternative means of fuel-free propulsion; one of the least crazy ones has been funded NASA as part of its Innovative Advanced Concepts Program. It’s called E-Glider, and it uses electrostatic fields to surf through the charged dust found around asteroids, comets, and moons.

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A underwater acoustic hologram projects a pair of rings onto the water's surface

3D-Printed Plastic Blocks Generate Complex Acoustic Holograms

The closest thing we have right now to a Star Trek–style tractor beam is a technology based on moving small objects with sound. Last year, researchers from the Public University of Navarre, in Spain, demonstrated how ultrasonic acoustic holograms can be used to manipulate things in midair, using arrays of ultrasonic transducers and some reasonably complicated modeling and programming. The overall complexity of the acoustic hologram—a 3D structure made of sound—that you can create in this way (and consequently what you can do with it) is limited primarily by the characteristics of your transducer array, and because transducers can only get so small, this is a significant limitation.

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Project RAMA

Project RAMA: Turning Asteroids Into Catapult-Powered Analog Spacecraft

Given how expensive it is to lift anything into space from the surface of the Earth, the future of efficient and affordable space travel may be dependent on using the resources that are already up there. Space may seem big and empty, and it mostly is, but there's enough raw material floating around out there in the form of asteroids and comets to keep us going for eons. The trick is going to be rounding these asteroids up and bringing them somewhere they can be of use without spending so much fuel on the process that the effort is rendered pointless. 

Made In Space is a company that develops technology for, you guessed it, making stuff in space. For example, they've got 3-D printers aboard the International Space Station that make tools, and they've experimented with turning simulated regolith (Moon dust) into a material that can be 3-D printed into useful things. With funding from NASA's Innovative Advanced Concept Program, Made in Space has been exploring a fairly wild idea: To gather the raw material for all of our making-in-space needs, Made in Space wants to send small “seed craft” to near-Earth asteroids with the aim of turning them into giant spacecraft that will fly themselves back to Earth to be mined.

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New York Mayor Bill de Blasio (R) and New York Governor Andrew Cuomo (C) stand in front of a mangled dumpster while touring the site of an explosion that occurred on Saturday night on September 18, 2016 in the Chelsea neighborhood of New York City.

Lessons From the New York Bombing

Late in the evening of Saturday, Sept. 17, New York City residents living in Manhattan’s Chelsea district received some unsettling news via their cellphones. After hearing an emergency alert, they were informed that there had been a bomb blast in their neighborhood, and that they should stay inside and away from their windows until further notice.

An attack based on an Improvised Explosive Device, or IED—a hallmark of the wars in Iraq and Afghanistan—had once again wreaked havoc in a major U.S. city. The Chelsea explosion, which injured 29 people, was one of a series of attacks and related events that ended with the arrest of a 28-year-old suspect in Linden, New Jersey on Monday morning. The events began with a pipe-bomb explosion near the seashore in New Jersey, on Saturday morning, and continued on Saturday night with the Chelsea bombing, on West 23rd Street in Manhattan and the discovery of another bomb near the Chelsea site. On Sunday night, five other bombs were found in a backpack in Elizabeth, New Jersey. All of the bombs are believed to be the work of a single person.

For Col. Barry Shoop, head of the Department of Electrical Engineering and Computer Science at the U.S. Military Academy at West Point, the attacks were a grim confirmation of a long-held belief. “If we can’t solve this problem outside of the United States, we are going to see them [IEDs] inside the borders of the United States,” he said in an interview shortly after the arrest of the suspect. In a podcast interview with IEEE Spectrum in 2013, after an IED killed 3 and wounded 264 in Boston, Shoop pointed out that every month there were 400 to 500 IED “events” around the world, not including Afghanistan. (Shoop is also the current president of the IEEE.)

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A silver tower lined with antennas against a clear blue sky broadcasts cellular signals.

"Real 5G" Will Broadcast Above 6 Gigahertz, Says Analyst

Brace yourself—the debate over what should and shouldn’t count as 5G has only begun. Defining the next generation of wireless networks is complicated, partly because engineers are developing so many exciting technologies at once and have yet to agree on the standards by which they will operate.

Within that murkiness is plenty of room for disagreement over how and where 5G will emerge. Stéphane Téral, an analyst at IHS Markit, recently weighed in by criticizing the use of “5G” to describe sub-6 gigahertz developments in a research note.

Radio waves in the sub-6 GHz range are considered the most desirable among carriers for delivering cellular signals because they can penetrate materials such as concrete and glass. Two ranges in particular—frequencies around 800 megahertz and 1.9 GHz—have long dominated the U.S. cellular landscape.

But these frequencies are becoming crowded as more users consume more data on more devices. And a bevy of other consumer technologies including Wi-Fi, Bluetooth, microwave ovens, and satellite radio operate at frequencies between 1.9 GHz and 6 GHz. So carriers have begun to browse higher frequencies for open bands that they can co-opt for cellular use.

Many have set their sights on much shorter millimeter waves that fall between 30 and 300 GHz. There are plenty of frequencies available in the millimeter-wave range, because they’ve been used only for specialized applications such as remote sensing and military radar. But waves at these frequencies can’t travel as far or make it through as many obstacles, so companies and researchers are still figuring out what it would mean to integrate them into future 5G networks.  

“Obviously, the low latency and high bandwidth stuff like AR and VR will definitely benefit from millimeter wave,” says Anshel Sag, a 5G analyst for Moor Insight & Strategy. “But the way the technology works right now, it’s still pretty power hungry and requires a complicated array of antennas.”

Given the situation, Téral says it’s not surprising that carriers are also focused on finding more efficient ways to deliver data on lower sub-6 GHz frequencies. They’re improving their networks through technologies such as multiple input and multiple output (MIMO), in which carriers add antennas to existing 4G base stations to handle more traffic from more users at once.

In fact, some companies have begun to concentrate their 5G efforts on these kinds of sub-6 GHz improvements. Chinese smartphone manufacturer Huawei has said that sub-6GHz bands will be “the primary working frequency” for 5G, and Qualcomm recently announced a new 5G radio prototype focused on the same batch of frequencies.

But Téral is irked by companies who dub these developments 5G. He says only advancements at higher frequencies (those above 6 GHz) should count as “real 5G,” because they would represent a paradigm shift for improving data rates and latency on future wireless networks. He argues that sub-6 GHz improvements incorporated into existing 4G and 4G LTE networks are simply business as usual.

“The cellular guys want to use that spectrum to make a 5G claim, but this is not a dramatic move from where cellular is, from 700 MHz to 2.6 GHz,” he says. “You really want to call that 5G? It doesn't justify a generational jump.”

However, other experts say the importance of millimeter waves to 5G has been overstated, and key developments at lower frequencies, including the repurposing of TV white space, will play a significant role in enabling faster mobile connections, connected cars, and the Internet of Things.

Sag thinks it’s a mistake to rule out anything other than millimeter waves as true 5G. He says 5G New Radio, a wireless standard defined by the global wireless standards group 3GPP, should count as 5G no matter which frequencies it handles. Many others also envision future 5G networks as a blend of millimeter waves and sub-6 GHz technologies.

“I'm in the camp that doesn't believe that millimeter wave is the only way to do 5G,” Sag says. “In fact, I think it's the wrong way of doing 5G if you think of it as the only way of doing it.” Instead, Sag believes 5G will permeate every swatch of spectrum from the low frequencies used for NarrowBand IoT all the way up to high-frequency millimeter waves.

Téral admits progress in the sub-6 GHz range is an important first step in the “pre-5G” evolution of wireless. He also acknowledges that many of the potential uses that experts have dreamt up for 5G can and will be achieved through incremental improvements to 4G LTE networks. But he says he’d prefer to call those improvements “transitional 4G” instead. “There’s nothing new, and that’s the whole point,” he says.

To Sag, the matter of what counts as 5G is not just a theoretical debate: It could have a real impact on the trust that consumers place in carriers. “My biggest concern is kind of the same concern with 4G, in that the definitions get muddled and the consumers get confused,” he says.


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