Tuesday, May 24, 2022

Diamond mirrors for high-powered lasers

Diamonds can withstand the heat from high-powered, continuous beam lasers

Peer-Reviewed Publication

HARVARD JOHN A. PAULSON SCHOOL OF ENGINEERING AND APPLIED SCIENCES

Diamond mirrors for high-powered lasers 

IMAGE: ILLUSTRATION OF A HIGH-POWERED CONTINUOUS LASER HITTING NANOSTRUCTURES ON A DIAMOND MIRROR. view more 

CREDIT: (CREDIT: LONCAR LAB/HARVARD SEAS)

Just about every car, train and plane that’s been built since 1970 has been manufactured using high-power lasers that shoot a continuous beam of light. These lasers are strong enough to cut steel, precise enough to perform surgery, and powerful enough to carry messages into deep space. They are so powerful, in fact, that it’s difficult to engineer resilient and long-lasting components that can control the powerful beams the lasers emit. 

Today, most mirrors used to direct the beam in high-power continuous wave (CW) lasers are made by layering thin coatings of materials with different optical properties. But if there is even one, tiny defect in any of the layers, the powerful laser beam will burn through, causing the whole device to fail. 

If you could make a mirror out of a single material, it would significantly reduce the likelihood of defects and increase the lifespan of the laser. But what material would be strong enough?

Now, researchers at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) have built a mirror out of one of the strongest materials on the planet: diamond. By etching nanostructures onto the surface of a thin sheet of diamond, the research team built a highly reflective mirror that withstood, without damage, experiments with a 10-kilowatt Navy laser. 

"Our one-material mirror approach eliminates the thermal stress issues that are detrimental to conventional mirrors, formed by multi-material stacks, when they are irradiated with large optical powers,” said Marko Loncar, the Tiantsai Lin Professor of Electrical Engineering at SEAS and senior author of the paper. “This approach has potential to improve or create new applications of high-power lasers.” 

The research is published in Nature Communications

Loncar’s Laboratory for Nanoscale Optics originally developed the technique to etch nanoscale structures into diamonds for applications in quantum optics and communications. 

“We thought, why not use what we developed for quantum applications and use it for something more classical,” said Haig Atikian, a former graduate student and postdoctoral fellow at SEAS and first author of the paper. 

Using this technique, which uses an ion beam to etch the diamond, the researchers sculpted an array of golf-tee shaped columns on the surface on a 3-milimeter by 3-milimeter diamond sheet. The shape of the golf tees, wide on top and skinny on the bottom, makes the surface of the diamond 98.9% reflective. 

“You can make reflectors that are 99.999% reflective but those have 10-20 layers, which is fine for low power laser but certainly wouldn’t be able to withstand high powers,” said Neil Sinclair, a research scientist at SEAS and co-author of the paper. 

To test the mirror with a high-power laser, the team turned to collaborators at the Pennsylvania State University Applied Research Laboratory, a Department of Defense designated U.S. Navy University Affiliated Research Center.

There, in a specially designed room that is locked to prevent dangerous levels of laser light from seeping out and blinding or burning those in the adjacent room, the researchers put their mirror in front of a 10-kilowatt laser, strong enough to burn through steel.  

The mirror emerged unscathed. 

“The selling point with this research is that we had a 10-kilowatt laser focused down into a 750-micron spot on a 3-by-3-millimeter diamond, which is a lot of energy focused down on a very small spot, and we didn’t burn it,” said Atikian. “This is important because as laser systems become more and more power hungry, you need to come up with creative ways to make the optical components more robust.”

In the future, the researchers envision these mirrors being used for defense applications, semiconductor manufacturing, industrial manufacturing, and deep space communications. The approach could also be used in less expensive materials, such as fused silica. 

Harvard OTD has protected the intellectual property associated with this project and is exploring the commercialization opportunities.

The research was co-authored by Pawel Latawiec, Xiao Xiong, Srujan Meesala, Scarlett Gauthier, Daniel Wintz, Joseph Randi, David Bernot, Sage DeFrances, Jeffrey Thomas, Michael Roman, Sean Durrant and Federico Capasso, the Robert L. Wallace Professor of Applied Physics and Vinton Hayes Senior Research Fellow in Electrical Engineering at SEAS. 

This research was performed in part at the Center for Nanoscale Systems (CNS), a member of the National Nanotechnology Coordinated Infrastructure Network (NNCI), which is supported by the National Science Foundation under NSF award no. 1541959. It was supported in part by the Air Force Office of Scientific Research (MURI, grant FA9550-14-1-0389), the Defense Advanced Research Projects Agency (DARPA, W31P4Q-15-1-0013), STC Center for Integrated Quantum Materials and NSF Grant No. DMR-1231319.

Skydiving salamanders live in world's tallest trees

Salamander living in redwoods is able to maneuver in freefall, suggesting adaptation to living at heights

Peer-Reviewed Publication

UNIVERSITY OF CALIFORNIA - BERKELEY

Wandering salamander 

IMAGE: THE WANDERING SALAMANDER, ANEIDES VAGRANS, IS ABOUT 4 INCHES (10 CENTIMETERS) LONG AND LIVES ITS ENTIRE LIFE IN THE CROWNS OF REDWOOD TREES MORE THAN 150 FEET ABOVE THE GROUND. RESEARCHERS DISCOVERED THAT IT HAS ADAPTED TO ITS HIGH-RISE LIFESTYLE BY DEVELOPING THE ABILITY TO PARACHUTE AND GLIDE WHEN FALLING. view more 

CREDIT: CHRISTIAN BROWN

Salamanders that live their entire lives in the crowns of the world's tallest trees, California's coast redwoods, have evolved a behavior well-adapted to the dangers of falling from high places: the ability to parachute, glide and maneuver in mid-air.

Flying squirrels, not to mention numerous species of gliding frogs, geckos, and ants and other insects, are known to use similar aerial maneuvers when jumping from tree to tree or when falling, so as to remain in the trees and avoid landing on the ground.

Similarly, the researchers suspect that this salamander's skydiving skills are a way to steer back to a tree it’s fallen or jumped from, the better to avoid terrestrial predators.

"While they're parachuting, they have an exquisite amount of maneuverable control," said Christian Brown, a doctoral candidate at the University of South Florida (USF) in Tampa and first author of a paper about these behaviors. "They are able to turn. They are able to flip themselves over if they go upside down. They're able to maintain that skydiving posture and kind of pump their tail up and down to make horizontal maneuvers. The level of control is just impressive."

The aerial dexterity of the so-called wandering salamander (Aneides vagrans) was revealed by high-speed video footage taken in a wind tunnel at the University of California, Berkeley, where the salamanders were nudged off a perch into an upward moving column of air simulating free fall.

“What struck me when I first saw the videos is that they (the salamanders) are so smooth — there's no discontinuity or noise in their motions, they're just totally surfing in the air,” said Robert Dudley, UC Berkeley professor of integrative biology and an expert on animal flight. “That, to me, implies that this behavior is something deeply embedded in their motor response, that it (falling) must happen at reasonably high frequencies so as to effect selection on this behavior. And it's not just passive parachuting, they're not just skydiving downwards. They're also clearly doing the lateral motion, as well, which is what we would call gliding.”

The behavior is all the more surprising because the salamanders, aside from having slightly larger foot pads, look no different from other salamanders that aren’t aerially maneuverable. They have no skin flaps, for example, that would tip you off to their parachuting ability.

"Wandering salamanders have big feet, they have long legs, they have active tails. All of these things lend themselves to aerial behaviors. But everybody just assumed that was for climbing, because that's what they use those features for when we're looking at them," Brown said. "So, it's not really a dedicated aerodynamic control surface, but it functions as both. It helps them climb, and it seems to help them parachute and glide, as well."

Among the questions the researchers hope to answer in future research are how salamanders manage to parachute and maneuver without obvious anatomical adaptations to gliding and whether many other animals with similar aerial skills have never been noticed before.

"Salamanders are sluggish, you don't think of them as having particularly fast reflexes. It's life in the slow lane. And flight control is all about rapid response to dynamic visual cues and being able to target and orient and change your body position," Dudley said. "So, it's just kind of odd. How often can this be happening, anyway, and how would we know?"

A paper describing the behavior will be published May 23 in the journal Current Biology.

Life in the canopy

Using the wind tunnel, Brown and UC Berkeley graduate student Erik Sathe compared the gliding and parachuting behavior of A. vagrans — adults are about 4 inches (10 centimeters) from snout to tip of tail — with the abilities of three other salamander species native to Northern California, each with varying degrees of arboreality — that is, the propensity to climb or live in trees. The wandering salamander, which probably spends its entire life in a single tree, moving up and down but never touching the ground, was the most proficient skydiver. A related species, the so-called arboreal salamander, A. lugubris, which lives in shorter trees, such as oaks, was nearly as effective at parachuting and gliding.

Two of the least arboreal salamanders — Ensatina eschscholtzii, a forest floor-dwelling salamander, and A. flavipunctatus, the speckled black salamander, which occasionally climbs trees — essentially flailed ineffectively for the few seconds they were airborne in the wind tunnel. All four species are plethodontid, or lungless, salamanders, the largest family of salamanders and mostly found in the Western Hemisphere.

"The two least arboreal species flail around a lot. We call it ineffective, undulating motion because they don't glide, they don't move horizontally, they just kind of hover in the wind tunnel freaking out," Brown said. "The two most arboreal species never actually flailed."

Brown encountered these salamanders while working in California's Humboldt and Del Norte counties with nonprofit and university conservation groups that mark and track the animals that live in the redwood canopy, primarily in old growth forest some 150 feet off the ground. Using ropes and ascenders, the biologists regularly climb the redwoods — the tallest of which rise to a height of 380 feet — to capture and mark wandering salamanders. Over the past 20 years, as part of a project led by James Campbell-Spickler, now director of the Sequoia Park Zoo in Eureka, the researchers discovered that most of their marked salamanders could be found in the same tree year after year, although at different heights. They live primarily in fern mats growing in the duff, the decaying vegetable matter that collects in the junctions of large branches. Brown said that few marked wandering salamanders from the redwood canopy have been found on the ground, and most of those were found dead.

Brown noticed, when picking them up to mark them, that the salamanders were quick to leap out of his hands. Even a light tap on a branch or a shadow passing nearby were enough to get them to jump from the redwood canopy. Given their location high above the forest floor, their nonchalant leaps into thin air were surprising.

"They jump, and before they've even finished toeing off, they've got their forelimbs splayed out, and they're ready to go," he said. "So, the jump and the parachute are very closely tied together. They assume the position immediately."

When he approached Dudley, who has studied such behavior in other animals, he invited Brown to bring some of the salamanders into his wind tunnel to record their behavior. Using a high-speed video camera shooting at 400 frames per second, Brown and Sathe filmed the salamanders for as long as they floated on the column of air, sometimes up to 10 seconds.

They then analyzed the frames to determine the animals’ midair posture and to deduce how they used their legs, bodies and tails to maneuver. They typically fell at a steep angle, only 5 degrees from vertical, but based on the distances between branches in the crowns of redwoods, this would usually be sufficient for them to reach a branch or trunk before they hit the ground. Parachuting reduced their free-fall speed by about 10%.

Brown suspects that their aerial skills evolved to deal with falls, but have become part of their behavioral repertoire and perhaps their default method of descent. He and USF undergraduate Jessalyn Aretz found, for example, that walking downward was much harder for the salamander than walking on a horizontal branch or up a trunk.

"That suggests that when they're wandering, they're likely walking on flat surfaces, or they're walking upward. And when they run out of habitat, as the upper canopy becomes drier and drier, and there's nothing else for them up there, they could just drop back down to those better habitats," he said. "Why walk back down? You're already probably exhausted. You've burned all your energy, you're a little 5 gram salamander, and you've just climbed the tallest tree on Earth. You're not going to turn around and walk down — you're going to take the gravity elevator."

Brown sees A. vagrans as another poster child for old growth forests that is akin to the spotted owl because it is found primarily in the crowns of the tallest and oldest redwoods, although also in Douglas fir and Sitka spruce.

“This salamander is a poster child for the part of the redwoods that was almost completely lost to logging — the canopy world. It is not there in these new-growth forests created by logging companies,” he said. “Perhaps it would help not just efforts in conserving redwoods, but restoring redwoods, so that we could actually get canopy ecosystems. Restoring redwoods to the point of fern mats, to the point of salamanders in the canopy — that would be a new bar for conservation.”

In the meantime, this denizen of old growth forests has a lot to tell us about evolution and perhaps the origin of flight, said Dudley.

"It (gliding) is a novelty, something unexpected in an otherwise well-studied group of animals, but it illustrates the urgency with which animals that are living in trees must evolve aerial capacity, even if they don't have wings," Dudley said. "Flight, in the sense of controlled aerial behavior, is very common. They're controlling their body posture, and they're moving laterally. This predisposes many, many things that are living in trees to ultimately evolve flapping flight, which is probably hard to evolve and why it has only turned up three times on the planet today."

Co-authors of the paper with Brown and Dudley are Sathe and Stephen Deban, professor of integrative biology at the University of South Florida.

Epidemiologist and health security expert says clinicians should prepare for monkeypox

‘Unusual’ outbreak larger and more widespread than previous outbreaks outside of Africa

Peer-Reviewed Publication

AMERICAN COLLEGE OF PHYSICIANS

Epidemiologist and health security expert says clinicians should prepare for monkeypox

‘Unusual’ outbreak larger and more widespread than previous outbreaks outside of Africa

Significant number of cases have occurred among men who have sex with men, though cause is unclear

 

FREE full text:  https:// www.acpjournals.org/doi/10.7326/M22-1581

URLs go live when the embargo lifts

The current monkeypox outbreak is more widespread than previous outbreaks outside of Africa and should prompt all clinicians to be attuned to the possibility that patients presenting with febrile illness and rash may be infected, according to the authors of a new commentary from the Johns Hopkins Center for Health Security at the Bloomberg School of Public Health. The authors also note that a significant number of these new cases have occurred among men who have sex with men (MSM), though the cause is unclear. These and other important facts about the current monkeypox outbreak are explained in a new commentary published in Annals of Internal Medicine.

 

Currently, several dozen monkeypox cases have been reported in Europe, the UK and North America, concerning epidemiologists and public health experts around the world. What distinguishes these cases — all occurring outside of the endemic region of the virus — is that person-to-person transmission is occurring, with the majority of the cases seemingly unlinked to travel from an endemic country, with the appearance of multiple, so far unlinked clusters.  In addition, a significant proportion, though not all, of the cases are occurring in MSM, and many of these cases are being diagnosed at sexually transmitted infection (STI) clinics. The authors emphasize that this does not necessarily mean that monkeypox is sexually transmitted.

 

As a member of the orthopox viral family, of which smallpox is also a member, it is possible that the rise in monkeypox outbreaks in recent years is related to diminished population immunity to smallpox over time. Smallpox vaccination could prevent cases and smallpox antivirals may treat monkeypox cases, as well.

 

Monkeypox typically presents with fever and rash that starts in the mouth, then moves to the face, followed by the extremities, including palms and soles in a tell-tale centrifugal pattern. Primary care physicians, urgent care physicians, emergency medicine physicians, dermatologists, and those working in STI clinics may be the most likely to identify new monkeypox patients should they continue to appear. Clinicians who suspect monkeypox should alert state health officials to initiate testing, as commercially available test for monkeypox.

Media contacts: For an embargoed copy, please contact Angela Collom at acollom@acponline.org. To speak with an author, please contact Margaret Miller at margaret.miller@jhu.edu.

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Worldwide shortage of health workers threatens effective health coverage


Peer-Reviewed Publication

INSTITUTE FOR HEALTH METRICS AND EVALUATION

SEATTLE—More than 43 million additional health workers are needed to meet targets for universal health coverage around the world, according to a new peer-reviewed study by the Institute for Health Metrics and Evaluation (IHME) at the University of Washington’s School of Medicine that was published today in The Lancet. The largest gaps were observed in sub-Saharan Africa, South Asia, and North Africa and the Middle East.

“These are the most comprehensive estimates to date of the global health care workforce,” said senior author Dr. Rafael Lozano, Director of Health Systems at IHME. “Health care workers are essential to the functioning of health systems, and it’s very important to have these data available so that countries can make informed decisions and plan for the future.”

The researchers looked at shortages in four categories: physicians, nurses and midwives, dental personnel, and pharmaceutical personnel. In 2019, they estimated that more than 130 countries had shortages of physicians and more than 150 had shortages of nurse and midwives. When comparing current levels of health care workers to the minimum levels needed to meet a target score of 80 on the universal health coverage (UHC) effective service coverage index, researchers estimated a shortage of more than 43 million health care workers, including 30.6 million nurses and midwives and 6.4 million physicians.

“We found that the density of health care workers is strongly related to a nation’s level of social and economic development,” said lead author Dr. Annie Haakenstad, Assistant Professor of Health Metrics Sciences at IHME. “There are different strategies and policy approaches that may help with addressing worker shortages, and these should be tailored to the individual situation in each country. We hope that these estimates can be used to help prioritize policy interventions and inform future planning.”

The study revealed more than a 10-fold difference in the density of health care workers across and within regions in 2019. Densities ranged from 2.9 physicians for every 10,000 people in sub-Saharan Africa to 38.3 per 10,000 in Central Europe, Eastern Europe, and Central Asia. Cuba also stood out, with a density of 84.4 per 10,000 compared to 2.1 in Haiti.

Similar disparities were observed in measuring numbers of nurses and midwives, with a density of 152.3 per 10,000 in Australasia compared to 37.4 per 10,000 in Southern Latin America. Despite steady increases in the health care workforce between 1990 and 2019, substantial gaps persisted.

The researchers cited existing literature that highlights factors that contribute to worker shortages, including out-migration of health workers, war and political unrest, violence against health care workers, and insufficient incentives for training and retention. They noted that high-income locations should follow WHO guidelines on responsible recruitment of health personnel to avoid contributing to workforce gaps in lower-income regions.

These findings show how ill-prepared the world was when the COVID-19 pandemic swept across the world, taxing health systems that already were short of crucial frontline workers. Having these estimates today will help policymakers, hospitals, and medical clinics prepare for future pandemics by turning their attention to training and recruitment. The authors also note that there is still much to learn about the impact of the pandemic on the health workforce. This includes gender dynamics in human resources for health (HRH) and how the departure of women from formal employment for care-taking duties at home may have depleted the health workforce, among other stressors on HRH during the pandemic.

The full dataset from the study is available at the Global Health Data Exchange.

video news release that is embargoed until May 23 6:30 p.m. EDT/23:30 UK time is available for download and viewing. A transcript of the video news release is available for download, as well.

For media interviews, contact media@healthdata.org.

An independent population health research organization based at the University of Washington School of Medicine, the Institute for Health Metrics and Evaluation (IHME) works with collaborators around the world to develop timely, relevant, and scientifically valid evidence that illuminates the state of health everywhere. In making our research available and approachable, we aim to inform health policy and practice in pursuit of our vision: all people living long lives in full health.

North East experts chosen to work with Arctic communities on new climate change technology

Grant and Award Announcement

NORTHUMBRIA UNIVERSITY

Professor Mike Lim undertaking research in Canada’s Inuit Nunangat 

IMAGE: PROFESSOR MIKE LIM UNDERTAKING RESEARCH IN CANADA’S INUIT NUNANGAT. view more 

CREDIT: IMAGE CREDIT WERONIKA MURRAY

Northumbria University researchers are part of a unique team working on a new £1m project to better equip Indigenous communities in the Arctic against the disproportionate impacts of climate change.

The study, involving local community researchers and action groups, government agencies and decision-makers, Inuit knowledge-holders, and leading UK and Canadian academics, will investigate changing ground conditions and assess their wider implications in coastal regions of Canada’s Inuit homeland that are under threat from thawing permafrost, disappearing sea ice and high rates of erosion.

Nearly a third of Canada’s landmass and 50 per cent of its coastline is within the area of Inuit Nunangat, home to approximately 65,000 Inuit people. The researchers will work with affected local communities to co-develop appropriate new tools and solutions to the landscape changes that threaten critical infrastructure, navigation routes, food and water security, and impact physical and mental health and wellbeing. Some areas are under such threat that they may be lost in as little as 20 years.

The project, which is named Nuna, taken from the word for ‘land’, ‘country’ and ‘soil’ in the Inuvialuktun language, brings together experts from Northumbria’s Departments of Mechanical and Construction EngineeringGeography and Environmental Sciences and Maths, Physics and Electrical Engineering, alongside their Canadian counterparts from McGill and Wilfred Laurier Universities.

They will join Arctic community initiatives and researchers from Natural Resources Canada, the National Research Council of CanadaEnvironment CanadaParks Canada, and the Government of Northwest Territories to drive unique solutions-based research.

Professor Mike Lim, who will lead the project alongside Tuktoyaktuk Community Senior Administrative Officer Shawn Stuckey, explained: “Coastal communities have demonstrated exceptional resilience to the challenges of Arctic living but are having to make increasingly difficult decisions over how to respond to the complex nature of more intense and disruptive environmental changes.

“Through Nuna we’ll combine a wealth of existing data and Indigenous knowledge with exciting technological developments, empowering communities to better identify and avoid emerging hazards related to the rapidly changing landscape.”

Changes to the Arctic environment are occurring faster than elsewhere on the planet and leading to many varied and interconnected impacts. Project Nuna will provide new data on when relocation will be needed in critical areas, develop early warning for ground subsidence, issue clear guidance on harmful dust exposure levels, and water-based threats such as driftwood or contaminants released during storms will also be addressed through new accessible community monitoring and citizen science data.

One of only 13 successful applicants to the Canada-Inuit Nunangat-United Kingdom Arctic Research Programme (CINUK), funding will be split between the team at Northumbria and researchers based in Canada, with the UK award provided by UK Research and Innovation (UKRI).

Professor Christopher Smith, UKRI International Champion and Executive Chair at the Arts and Humanities Research Council said: “The need to understand and respond to the deep and interlinked impacts of climate change in the Arctic has never been greater. 

“We recognise and embrace the value and importance of doing so in genuine and mutually respectful and empowering partnership with Inuit researchers and communities. I look forward to seeing how the projects develop over the next three years and hearing the results of both their work and their partnerships.”

Chief Scientist of Québec, Rémi Quirion, added: “More than ever, the climate crisis demands strong and immediate action from all levels of decision-making and sectors of civil society. The scientific community is no exception. It must join forces to develop innovative, sustainable, and socially acceptable solutions to reduce the environmental impacts of climate changes.

“The 13 research projects co-developed by scientists and Inuit community representatives will have very concrete impacts and sow the seeds of hope that it is possible to change the course of things.”

The study is just one example of Northumbria University’s world-leading environmental research into extreme, cold and palaeo environments. The University is ranked second in the UK for its research power in Geography and Environmental Studies and is top 25 in Engineering in the 2021 Research Excellence Framework, with 90 per cent of its research in these disciplines rated as being either world-leading or internationally excellent.

Find out more about some of the world-leading research Northumbria University is undertaking in all aspects of climate change.

CAPTION

Professor Mike Lim undertaking research in Canada’s Inuit Nunangat

CREDIT

Image credit: Weronika Murray


CAPTION

Professor Mike Lim undertaking research in Canada’s Inuit Nunangat.

CREDIT

Image credit Weronika Murray

Towards having your privacy, security and exchanging crypto too

New paper outlines better privacy and security protections when swapping cryptocurrencies

Reports and Proceedings

CARNEGIE MELLON UNIVERSITY

Privacy and security and control of those things are paramount in the world of cryptocurrencies.

“The whole cryptocurrency decentralized business is about giving control of the digital coins to you,” says Aravinda Thyagarajan, a postdoctoral researcher in the computer science department advised by CyLab’s Elaine Shi. “You should control your coins, and you don’t want to leak any information about them.”

This week, Thyagarajan will be presenting a new paper outlining a new protocol towards better privacy and security protections when swapping cryptocurrencies. The paper, “Universal Atomic Swaps: Secure Exchange of Coins Across All Blockchains,” is being presented at the 2022 IEEE Symposium on Security and Privacy.

Right now, if two people or entities want to swap one cryptocurrency for another—say, 1 Bitcoin for 1 Ethereum—they can swap directly between themselves, but there’s always a chance one of the two parties will be dishonest and not hold up their end of the deal. Another option, then, is to have a third-party exchange service mediate the deal. But what if the exchange service is an adversary and steals both parties’ coins?

“In the wild west of cryptocurrency, no one should be trusted,” says Thyagarajan.

There’s also an issue of privacy. If an e-commerce website only accepts one specific cryptocurrency, and you only have coins in a different cryptocurrency, you must perform an exchange into the compatible currency before purchasing from the website. That exchange can reveal sensitive information.

“You lose a bit of your privacy,” says Thyagarajan. “Using sophisticated mechanisms, people can learn to some probability information about your assets.”

Thyagarajan’s paper outlines a protocol that addresses these security and privacy concerns. First, the protocol is universal—it allows for exchanges across all current and future cryptocurrencies. Second, the swap protocol ensures that the swap will happen honestly or it won’t happen at all, meaning no one will maliciously lose coins, without relying on third parties. And lastly, the protocol supports the exchange of multiple types of coins—e.g. Bitcoin, Ethereum, Dogecoin, etc.—in a single swap.

“With this protocol, you can shop on that e-commerce website using a coin that is not the coin that they accept, and keep your privacy,” says Thyagarajan. “You're able to do that because you're not relying on third-party services, and also because it doesn't rely on any special features of the underlying currency.”

All of this requires an enormous amount of computing power, Thyagarajan says, so one currently can’t do this on a laptop or phone, presenting an opportunity for future work. However, for major currencies currently, like Bitcoin, Ethereum, etc., Thyagarajan’s paper presents an efficient solution for the exchange that can be run now even on low-end devices.

Paper reference

Universal Atomic Swaps: Secure Exchange of Coins Across All Blockchains

  • Sri AravindaKrishnan Thyagarajan, Carnegie Mellon University
  • Giulio Malavolta, Max Planck Institute for Security and Privacy
  • Petro Moreno-Sanchez, IMDEA Software Institute