Transistors, the building blocks of modern electronics, are typically made of silicon. Because it’s a semiconductor, this material can control the flow of electricity in a circuit. But silicon has fundamental physical limits that restrict how compact and energy-efficient a transistor can be.

MIT researchers have now replaced silicon with a magnetic semiconductor, creating a magnetic transistor that could enable smaller, faster, and more energy-efficient circuits. The material’s magnetism strongly influences its electronic behavior, leading to more efficient control of the flow of electricity. 

The team used a novel magnetic material and an optimization process that reduces the material’s defects, which boosts the transistor’s performance.

The material’s unique magnetic properties also allow for transistors with built-in memory, which would simplify circuit design and unlock new applications for high-performance electronics.

“People have known about magnets for thousands of years, but there are very limited ways to incorporate magnetism into electronics. We have shown a new way to efficiently utilize magnetism that opens up a lot of possibilities for future applications and research,” says Chung-Tao Chou, an MIT graduate student in the departments of Electrical Engineering and Computer Science (EECS) and Physics, and co-lead author of a paper on this advance.

Chou is joined on the paper by co-lead author Eugene Park, a graduate student in the Department of Materials Science and Engineering (DMSE); Julian Klein, a DMSE research scientist; Josep Ingla-Aynes, a postdoc in the MIT Plasma Science and Fusion Center; Jagadeesh S. Moodera, a senior research scientist in the Department of Physics; and senior authors Frances Ross, TDK Professor in DMSE; and Luqiao Liu, an associate professor in EECS, and a member of the Research Laboratory of Electronics; as well as others at the University of Chemistry and Technology in Prague. The paper appears today in Physical Review Letters.

Overcoming the limits

In an electronic device, silicon semiconductor transistors act like tiny light switches that turn a circuit on and off, or amplify weak signals in a communication system. They do this using a small input voltage.

But a fundamental physical limit of silicon semiconductors prevents a transistor from operating below a certain voltage, which hinders its energy efficiency.

To make more efficient electronics, researchers have spent decades working toward magnetic transistors that utilize electron spin to control the flow of electricity. Electron spin is a fundamental property that enables electrons to behave like tiny magnets.

So far, scientists have mostly been limited to using certain magnetic materials. These lack the favorable electronic properties of semiconductors, constraining device performance.

“In this work, we combine magnetism and semiconductor physics to realize useful spintronic devices,” Liu says.

The researchers replace the silicon in the surface layer of a transistor with chromium sulfur bromide, a two-dimensional material that acts as a magnetic semiconductor.

Due to the material’s structure, researchers can switch between two magnetic states very cleanly. This makes it ideal for use in a transistor that smoothly switches between “on” and “off.”

“One of the biggest challenges we faced was finding the right material. We tried many other materials that didn’t work,” Chou says.

They discovered that changing these magnetic states modifies the material’s electronic properties, enabling low-energy operation. And unlike many other 2D materials, chromium sulfur bromide remains stable in air.

To make a transistor, the researchers pattern electrodes onto a silicon substrate, then carefully align and transfer the 2D material on top. They use tape to pick up a tiny piece of material, only a few tens of nanometers thick, and place it onto the substrate.

“A lot of researchers will use solvents or glue to do the transfer, but transistors require a very clean surface. We eliminate all those risks by simplifying this step,” Chou says.

Leveraging magnetism

This lack of contamination enables their device to outperform existing magnetic transistors. Most others can only create a weak magnetic effect, changing the flow of current by a few percent or less. Their new transistor can switch or amplify the electric current by a factor of 10.

They use an external magnetic field to change the magnetic state of the material, switching the transistor using significantly less energy than would usually be required.

The material also allows them to control the magnetic states with electric current. This is important because engineers cannot apply magnetic fields to individual transistors in an electronic device. They need to control each one electrically.

The material’s magnetic properties could also enable transistors with built-in memory, simplifying the design of logic or memory circuits.

A typical memory device has a magnetic cell to store information and a transistor to read it out. Their method can combine both into one magnetic transistor.

“Now, not only are transistors turning on and off, they are also remembering information. And because we can switch the transistor with greater magnitude, the signal is much stronger so we can read out the information faster, and in a much more reliable way,” Liu says.

Building on this demonstration, the researchers plan to further study the use of electrical current to control the device. They are also working to make their method scalable so they can fabricate arrays of transistors.

This research was supported, in part, by the Semiconductor Research Corporation, the U.S. Defense Advanced Research Projects Agency (DARPA), the U.S. National Science Foundation (NSF), the U.S. Department of Energy, the U.S. Army Research Office, and the Czech Ministry of Education, Youth, and Sports. The work was partially carried out at the MIT.nano facilities.

Last June during Pride, we launched a new initiative—LGBT Q&A—where we answered your most pressing queer-related digital rights questions on EFF’s Instagram and TikTok accounts. No question was too big or too small! You asked us things like what pictures to use on dating apps; how to remove your name from internet searches; why homophobic content doesn't get removed after you report it; and how to stay safe at Pride marches.

And this year, we’re doing it all again. 

Both online and offline, LGBTQ+ individuals and the fight for queer liberation are under threat; and the need for guidance and protection from prying eyes and oppressive structures is increasingly pertinent. This is particularly true for those of us who face consequences when intimate details around gender or sexual identities are revealed without consent. 

But we know that it can feel overwhelming to even start thinking about how you can protect yourself online in the face of these issues. That's why this Pride, we’re answering all your digital rights questions. 

How to submit your questions?

• If you would like to remain anonymous and away from social platforms, you can submit questions via this secure link. 
• Head to EFF’s Reddit or the r/LGBTQ subreddit and submit your questions underneath the posts. 
• Your questions can also be submitted under the linked posts on EFF’s Instagram and TikTok, as well as on our stories where you can submit questions directly. 
• If you prefer Mastodon and Bluesky, comment your questions under the linked posts. 

As always, we will not engage with comments that discriminate against marginalized groups, including the LGBTQ+ community.

We’re here to help build an online space where you get to decide what aspects of yourself you share with others, how you present to the world, and what things you keep private. Join us to make the internet private, safe, and full of pride.

The surveillance company Leonardo wants more data:

A surveillance company plans to add sensors to automatic license plate readers (ALPRs) that would mean the devices, as well as capture the license plate of passing vehicles, would also sweep up unique identifiers of mobile phones, wearables, and other Bluetooth-enabled devices in those cars, potentially letting law enforcement identify specific drivers or passengers.

The technology, called SignalTrace, would turn ALPR cameras from devices focused on tracking cars to ones that can more readily track the location of particular people. ALPR cameras have become a commonly deployed technology all across the U.S.; SignalTrace would make some of those cameras capable of collecting much more data...

An emerging field of research that can measure how much climate change has worsened individual disasters is under attack by friends of the fossil fuel industry. Billions of dollars are at stake.

Some progressive primary challengers to Democratic lawmakers are criticizing their opponents over the changes to the state’s climate law.

In a letter to state electricity officials, Gov. Greg Abbott asked for an outline of actions and recommendations by mid-July to help prevent a surge in residential electric costs.

The country's manufacturing investments in other countries fell short.

A top Democrat said Wednesday he wanted to see more movement on renewable energy approvals. A White House official didn’t appear willing to budge.

The modifications came in response to petitions from the oil and gas industry.

As Xavier Becerra and Steve Hilton prepare to face off, environmentalists lament the race that could have been.

A Prague-led coalition warned that Europe’s climate ambitions will become increasingly difficult to achieve if freight continues shifting from rail to road.

Any such move, which would increase costs for airlines, is likely to anger trading partners like the United States.

The effective closure of the Strait of Hormuz in early March has driven Asian buyers to look for alternative sources to replace disrupted Persian Gulf barrels.

Colombia is seeking to reverse decades of forest loss, much of it driven by the expansion of cattle ranching into previously forested areas.

When a friend buys you a cup of coffee, it’s likely that next time, you’ll return the gesture. This type of reciprocal generosity has been well-documented in behavioral economic studies.

However, anthropologists and other social scientists have known for decades that in the context of relationships where one person has more power, status, or influence, reciprocal generosity is usually not the norm. 

Researchers at MIT have now experimentally demonstrated, for the first time, that small changes to the relationship context can dramatically change people’s actions and expectations of reciprocal generosity. 

During interactions between people of different social status, people tend to expect that generosity will flow one way, and it can be either up or down. It may be that a professor always buys coffee for her students, or that a student always offers to help carry groceries for his resident advisor. Once the precedent is established, it is expected to continue.

One interpretation of the findings is that keeping track of whose turn it is to do a favor is the exception in social interactions, not the rule. That is, it is extra work that we do when we want to maintain equal relationships.

“In many intimate relationships, hierarchical relationships, or other kinds of role-based relationships, you don’t put in the work of trying to keep track of turns,” says Rebecca Saxe, the John W. Jarve Professor of Brain and Cognitive Sciences, a member of the McGovern Institute for Brain Research, and associate dean of science at MIT. “Under this interpretation, we just follow precedent because following a precedent is easier. We all know what to expect, and we don’t have to keep track of what happened last time.”

Saxe is the senior author of the study, which appears in the journal Open Mind. MIT graduate student Alicia Chen is the paper’s lead author.

Changing expectations

Most experimental studies of generosity have been done in the context of behavioral economics and game theory. In such experiments, people are usually paired with a stranger and asked to play games that require coordination. Such studies have found that people tend to use turn-taking and reciprocity as their default strategies. These scenarios, however, are stripped from any social context that might exist between people in the real world.

Saxe and Chen wanted to see if they could measure the effects of social context by incorporating relationships into the type of experiments used to evaluate people’s expectations regarding generosity.

“Where generosity becomes hard and complicated is when it starts to occur in the context of existing relationships, because it changes the terms of the relationships,” Saxe says. “What’s expected of you is very different within a relationship than outside of one.”

To study these effects, the researchers designed experiments in which participants read stories about different types of interactions. In some of the scenarios, the subjects of the stories were described as having either symmetric or asymmetric relationships. In others, they were given specific social relationships such as aunt-niece or manager-employee.

Each story described interactions that might be seen in typical daily life, such as buying coffee for a co-worker or preparing a meal for one’s family. Participants were then asked to predict what would happen the next time the interaction occurred.

In all of these scenarios, the researchers found that people expected that generous acts would be reciprocated when they occurred between individuals in symmetric relationships such as friends, cousins, or co-workers of equal rank. However, their expectations changed for asymmetric relationships, where each person has a different social status. In those cases, people expected that any precedent that was set would continue in the future.

One possible explanation for this is that reciprocity is not the norm but an exception that only occurs in the interactions between equals or strangers, the researchers say. Many of our interactions are with people with whom we have asymmetric relationship, and to maintain those relationships, it’s simply easier to follow precedent.

“If there’s no need to keep track of our equal status, then in some ways it’s the default to fall back on following precedents,” Saxe says.

Maintaining relationships

The study showed that in asymmetric relationships, generosity could flow in either direction. Once that direction was established, it was expected to continue. For example, after an older brother bought concert tickets for a much younger brother, the study participants expected that the older brother would also buy the tickets for the next concert. 

“We found that when people know the relationship is asymmetric, they don’t expect reciprocity; they expect the same action to keep on going,” Chen says. “If the lower-rank person acts generously, people expect that to continue, and if the higher-rank person acts generously, people expect that to continue.”

Following precedents is not only easier, but keeping up these actions may help solidify and define existing relationships. For example, anthropologists have long known that gift-giving helps to construct and maintain social relationships. 

“Following a precedent can be a way of actively maintaining relationships and hierarchies, when the asymmetry of the exchange truly reflects the asymmetry of the relationship,” Saxe says. 

The researchers are now working on creating computational models that could be used to analyze different factors that people take into account when they’re considering whether someone might reciprocate a generous act. In addition to the factors examined in this study, others could include how much each person will benefit, what type of relationship they’re in, and culturally specific expectations of how people should act in different situations.

“One really powerful thing about these models is that we can build in existing theories, add things to the models, and then compare how much these extra factors, like considerations related to social relationships, matter in terms of explaining what people are doing,” Chen says. “This allows us to quantitatively compare the different theories to each other.”

The research was funded by the Simons Foundation Autism Research Initiative and the Patrick J. McGovern Foundation.

For remotely operated underwater vehicles, cloudy and turbulent waters are often a no-go. When vehicles settle on the seafloor or dig through a sandbed, they can kick up clouds of sediment that make it tough for onboard cameras to see through. Often, the only thing to do is to wait until the marine dust settles before a vehicle can safely proceed. 

But a new underwater mapping technique developed by engineers at MIT and the Woods Hole Oceanographic Institution (WHOI) may allow vehicles to see through murky, low-visibility waters. 

The method fuses visual images from optical cameras with acoustic data from sonar sensors. The combination enables a vehicle to quickly map the general shape of its surroundings using sonar, even in low-visibility waters. A vehicle can move toward certain shapes in the sonar-mapped environment, coming close enough for optical cameras to visually resolve specific objects in detail. 

The technique is akin to pairing a dolphin’s echolocation with a sea turtle’s close-range vision to see and navigate through murky water, in real-time. 

The researchers tested the method in tank experiments where they could control the water’s degree of visibility. Even in the cloudiest conditions, the system was able to see through the sediment to map the tank’s environment and visualize centimeter-scale details of objects in the tank. 

The team is further improving the technique, which they’ve named Sonar-MASt3R. They envision that the mapping method could safely guide underwater vehicles through murky environments for a range of applications, including scientific exploration, underwater construction and maintenance, and deep-sea recovery. 

“We hope that this work enables us to do more operations in those challenging, low-visibility environments, and helps provide more coverage in areas that are difficult to operate in today,” says Amy Phung, a graduate student in MIT’s Department of Aeronautics and Astronautics, who led the work. 

Phung presented a paper detailing Sonar-MASt3R this week at the IEEE International Conference on Robotics and Automation (ICRA). The paper’s co-author is Richard Camilli, senior scientist of applied ocean physics and engineering at WHOI. 

The best of both

To see underwater, scientists have generally taken an either/or approach, using either optical cameras or sonar sensors to guide the way. Optical cameras can provide detailed visual imagery of a scene, but only in waters that are relatively clear and well-lit. In contrast, sonar sensors perform just as well in clear and murky water; by emitting acoustic waves and measuring the time and angle at which they return, sonar sensors can determine the exact shape, distance, and depth of objects in the environment, though a sonar map lacks any visual detail. 

To get the best of both modes, scientists have looked to combine the two in a new approach known as “opti-acoustic fusion.” In a handful of prior works, research groups have merged sonar and optical data in mapping techniques that are mostly geared toward object recognition and reconstructing workplace environments. Most techniques require time to sync and process the data and therefore do not work in real-time, while only a few can map an environment in 3D. None have been applied to high-resolution mapping underwater in murky, turbid conditions. 

Phung, who is a student in the MIT-WHOI Joint Program, and Camilli, her advisor, aimed to develop an opti-acoustic fusion technique that would generate detailed 3D maps of underwater environments in real time and in low-visibility conditions. The team was motivated, in part, by challenges in safely recovering unexploded underwater mines.

“There can be old explosives in areas that make it unsafe for ships to be in, and the ability to get rid of those safely is best done by robotics,” Camilli says. “But a lot of these explosives are set in surf zone environments where visibility adds to the challenge of doing this safely. That’s one of many applications that our technique can be used for.”

Cloudy, with a chance of mapping

The new method, Sonar-MASt3R, builds on an existing technique, MASt3R, that was developed by researchers in France. MASt3R is an image matching algorithm that is trained to take in visual images of the same scene and quickly estimate the relative depth of each pixel in the scene. In this way, MASt3R can generate a 3D map of the environment in real-time, based on a camera’s 2D images. 

“The downside is that there is no sense of scale,” Phung says. “It will say ‘this pixel is five units closer than this pixel,’ but it can’t say whether that’s 5 meters or 5 feet.”

Luckily, sonar provides absolute measurements of scale. The timing of sonar reflections can be translated directly into a specific depth and distance of objects that the signals bounced off, as well as their shape and contour. 

In their new work, Phung and Camilli used sonar data to correct MASt3R’s scaling and generate precise 3D maps of underwater environments. Even in murky water, the method’s sonar-corrected map would enable a vehicle to know the precise location of objects, and therefore how far to safely move in for a closer inspection, which the vehicle could then do using conventional optical cameras.

The team tested Sonar-MASt3R in experiments with a tank that they filled with water, sediment, and a variety of objects such as a small boulder, a coffee mug, and a packing crate. Inside the tank, they also set up a robotic arm, onto which they mounted an underwater camera, and a sonar sensor. 

For each experimental run, they first carried out a sweep trajectory, in which the robotic arm slowly swept from one side of the tank to the other to capture sonar and visual data. With this first sweep, Sonar-MASt3R quickly creates a coarse sonar-based map of the shapes and contours of the tank and its objects. The coarse map is then used to record close-up camera images of the objects, which are used to improve the map resolution. A “keyframe” approach quickly compares each new image frame to the last keyframe. If a frame provides new information not contained in the last keyframe, the image is added as a new keyframe to the map. If it is similar, it is immediately discarded. In this way, the approach can quickly fill in the map with relevant visual detail, in real-time. 

The researchers tested their new approach underwater, testing eight different levels of turbidity, which they created by stirring up the tank’s sediment. Compared with other opti-acoustic fusion approaches, Sonar-MASt3R generated more accurate 3D maps and resolved smaller, centimeter-scale details, and in cloudier conditions. In the cloudiest condition, which the robotic arm’s cameras could not see through, its sonar sensors were able to generate a rough map of the tank’s hidden objects. This initial map enabled the arm to move safely through the murk and closer to specific objects, which its underwater camera could then visualize in more detail. 

“An analogy would be if you were to go into a china shop in the dark, and try to pick your way around to find a specific coffee mug without knocking things over,” Camilli offers. “This would allow you to do that.”

The team plans to test the approach in natural underwater conditions, where they suspect that the mapping task should be more straightforward. 

“In a tank, it’s like an echo chamber,” Camilli says. “It’s like trying to do this in a funhouse mirror setting where you get all these distortions and reverberations and ghost images that really complicates the processing. If you put it in the real world, it should be easier.”

Then, they say, Sonar-MASt3R could help scientists safely explore in cloudy, turbid, and murky underwater regions.

“The real value in this effort is so we can use this technology in mission scenarios that are untractable right now,” Phung says. “And there are plenty of untractable missions because we don’t have the observational or perception capabilities.”

This research was supported, in part, by NASA, and the National Science Foundation.

In a voice vote earlier this week, the House of Representatives passed H.R. 6028, the “Legislative Branch Agencies Clarification Act.” The legislation is presented as a technical reorganization of some government agencies, but it’s much more than that. 

H.R. 6028 would fundamentally change the U.S. Copyright Office, and not in a good way. The bill removes the Library of Congress’ current supervisory role over the Copyright Office, transfers several powers directly to the Register of Copyrights, and makes the Register a presidential appointee, confirmed by the Senate. 

These changes would make an office that’s already hugely influential in copyright and tech policy much more political. EFF first explained why that’s a terrible idea when it came up nearly a decade ago. This bill, like the older one, weakens the few public-interest checks and balances that do exist.  We hope the Senate promptly rejects this bill. 

The Copyright Office Doesn’t Need More Politics—Or More Power

The Copyright Office's main responsibilities are administrative and advisory. It registers copyrights, maintains records, grows the Library of Congress’s collections, and provides expertise to Congress on copyright law. But over the past two decades, the Office has also become increasingly influential in copyright policy debates that affect free expression, libraries, educators, competition—and everyday internet users. Unfortunately, it has not been a neutral advocate. The office’s recent report on the role of AI severely bungled the issue of fair use, prioritizing private licensing market “solutions” over user rights. 

Going further back, the Copyright Office supported one of the most infamous anti-internet proposals of all time—the Stop Online Piracy Act (SOPA), a disastrous internet censorship proposal that sparked one of the largest online protests in history. The Office has repeatedly advanced positions that favored large entertainment-industry interests over the public interest.

The Office also plays a major role in the Digital Millennium Copyright Act (DMCA) Section 1201 rulemaking process, which determines when the public may lawfully bypass digital locks for activities such as security research, repair, preservation, or accessibility. EFF has used this process repeatedly to mitigate some of the worst harms of the DMCA. H.R. 6028 would move rulemaking authority over 1201 from the Librarian of Congress to the Register of Copyrights, further consolidating power within the Copyright Office itself.

The bill also makes the Register of Copyrights a presidential appointee confirmed by the Senate. Each administration will be pressured to pick nominees aligned with their own policy preferences, and the powerful copyright owning industries will invest even more heavily in lobbying to get their way, and influence the selection. This position should be focused on administrative ability and actual expertise, not lobbying and politics. 

The Copyright Office Should Stay Connected To The Library of Congress

H.R. 6028 would do more than change who appoints the Register of Copyrights. It would sever the Copyright Office from Library of Congress supervision and transfer many Librarian powers directly to the Register. 

The supervisory relationship exists for good reason, as the nation’s libraries have pointed out for years. The Library, while far from perfect, at least has the mission of preserving and providing access to knowledge. That should be an important public-interest counterweight in copyright debates. Congress has not explained how weakening the ties between the Library and the Copyright Office would serve the public better, or even seriously inquired about it. 

This Bill Was Rushed Through

Back in March, EFF joined Public Knowledge, the Center for Democracy and Technology, library organizations and tech groups, urging Congress not to fast-track this legislation. We told them changes to the Copyright Office will have major consequences for the “speech rights, educational opportunities, and creative freedoms of all Americans.” 

Yet Congress moved forward without any hearings on the bill, and without meaningful examination. H.R. 6028 creates a years-long separation of the Copyright Office from the Library of Congress, transfers significant legal authority, and restructures the appointment process for the nation’s top copyright official. Changes like that deserve hearings, debate, and public scrutiny. H.R. 6028 got none of that. 

The Senate Should Stop This Bill

Copyright law exists to serve the public and “promote the progress” of science and learning. The institutions that administer copyright law should do the same. 

H.R. 6028 would move the Copyright Office further away from that goal. Congress should be strengthening public-interest oversight of copyright policymaking, not looking for ways to concentrate more authority in a single presidentially appointed official. 

The Senate should reject H.R. 6028. The Copyright Office should serve the public—not presidential administrations, and not industry lobbyists. 

For months now, Congress has been kicking the ball down the road—temporarily postponing the expiration of the mass surveillance authority Section 702 of FISA in hopes that some consensus could be reached. Now, with the deadline looming, the stakes have never been higher. Nearly every time the statute has come up for renewal, the people demanding privacy and civil liberties have had to compromise, but with current negotiations seemingly at  an impasse, it’s time for surveillance maximalist lawmakers to come to the table. 

We say to the Intelligence Community crowd: Section 702 should require a warrant before the Federal Bureau of Investigation can look at digital communications collected from Americans. If not, we should let the whole thing expire.

This is a serious proposition. The intelligence community can keep a useful national security surveillance tool if and only if they make FBI agents get a warrant signed by a judge before they sift through and read out private communications. A warrant requirement is not the only demand EFF has been making for changing Section 702, but it is the most important reform and it should happen before there is any more reauthorization of the policy. 

For too long, the FBI has been able to piggyback on a major national security tool as an unconstitutional backdoor way of reading Americans’ communications. 702 collects communications going to, from, or between people in other countries—including when they are contacted by people in the United States. Mass surveillance is just that—mass. It’s lacking any of the individualized suspicion that our legal system is based on. 

Take action

TELL congress: 702 Needs Reform

So, what’s been happening?

On one side are surveillance hawks and intelligence community-devotees who think the mass surveillance of Americans is an acceptable, even valuable, product of this authority. This bipartisan coalition of privacy deniers think that 702 should be extended without any change, and they seem to be willing to let the authority expire rather than compromise with the lawmakers and public that are demanding common-sense reforms. They’ve been given a number of chances to pass bills that would implement some key incremental reforms, but those opportunities have not moved the needle. 

On the other side of the debate is a bipartisan coalition of people who understand that this authority can no longer operate as is. Section 702 is rife with problems, loopholes, and compliance issues that need fixing. The National Security Agency collects full conversations being conducted by and with overseas targets—including conversations by and with Americans in the U.S.—and stores them in massive databases. The NSA then allows other agencies, specifically the FBI, to access untold amounts of that information. In turn, the FBI takes a “finders keepers” approach to this data: they reason that since it's already collected under one law, it’s OK for them to see it. If the FBI wanted to get that data on their own, it would require them to get a warrant signed by a judge certifying that there is probable cause. Instead, under current practice, the FBI can query and even read the U.S. side of that communication without a warrant. What’s more, victims of this surveillance won’t know and have very few ways of finding out that their communications have been surveilled.

Complicating this matter more is that the Trump administration has announced Bill Pulte as the new Director of National Intelligence, whose job it will be to oversee and direct U.S. intelligence agencies. This is particularly concerning because of Pulte’s history of using private information held by the government as a political weapon. In his FHFA role, he has accused several of the President’s political foes and targets—including New York State Attorney General Letitia James, U.S. Sen. Adam Schiff, D-Calif., and Federal Reserve governor Lisa Cook—of mortgage fraud based on private data held by his agency. Because of his looming appointment, many Democrats have vowed not to reauthorize Section 702 unless he is removed from the position. They shouldn’t stop there—they should use that leverage to demand a warrant requirement. The integrity of the people in charge of a program should not be the only thing that stands between Americans and violations of their civil liberties. 

What happens if 702 expires? 

As the New York Times reports, “The law, however, has a built-in safety net for a temporary lapse that allows the surveillance program to endure until annual certifications issued by the nation’s intelligence court expire, though such a scenario could invite legal challenges. The court recertified the program in March, meaning the N.S.A. could continue to operate the program through March 2027 even if the statute were to expire.” 

If Section 702 does stay expired past March 2027, the United States government will likely revert to using other programs and authorities to justify the surveillance of overseas national security targets, namely 12333, a shadowy executive order from the 1980s that gives the U.S. government nearly unlimited power to spy on people overseas.  Even if this does come to pass, standing our ground on warrant requirements and allowing Section 702 to expire  is important for several reasons. First, just because the government continues surveillance under a different authority does not mean it is legally justified in doing so—this was the lesson of the post 9/11 Presidential Surveillance Program, which was only retroactively immunized by Congress. Second, seeing how the government responds to the end of Section 702 might give us opportunities to push for transparency in other parts of information collection and better understand how the inner workings of the intelligence apparatus pivot and adapt as new legal authorities take precedence. 

Where do we go from here? 

Every few years, for almost two decades now, we’ve been fighting to reform Section 702 so that it will no longer enable the warrantless mass surveillance of Americans. A bipartisan coalition in Congress supports this goal, but the White House and Congressional leadership won’t listen. It’s past time we make at least one serious reform to a mass surveillance law that has been abused for decades. Tell your elected official: Put a warrant requirement in Section 702 or let it expire.

Take action

TELL congress: 702 Needs Reform

Myriam Heiman, the John and Dorothy Wilson Professor of Neuroscience at MIT, will become the director of MIT’s Picower Institute for Learning and Memory, effective July 1. She succeeds Picower Professor Li-Huei Tsai, who is stepping down after leading the institute for 16 years.

Heiman, a molecular neurobiologist and geneticist, studies the neurodegenerative diseases of the brain’s basal ganglia, including Huntington’s disease and Parkinson’s disease. Using cutting-edge techniques, including single-cell genomics and a powerful transcriptomic technique she helped invent, called translating ribosome affinity purification, she aims to understand the molecular changes that eventually lead to cell death in these diseases. 

“Myriam is an extraordinary scientist, a proven leader within MIT, and a deeply caring and generous mentor. Her research to determine why specific brain cell types are particularly vulnerable to diseases such as Huntington’s has produced studies that are both deep in their insight and sweeping in their scope,” says Nergis Mavalvala, dean of the MIT School of Science and the Curtis and Kathleen Marble Professor of Astrophysics. “I firmly believe that Myriam will be an excellent leader during the Picower Institute’s next chapter.”

“I am honored to take on this role to support the institute’s exceptional scientists and trainees as they pursue discoveries that deepen our understanding of the brain and improve human health,” says Heiman, a professor in MIT’s Department of Brain and Cognitive Sciences (BCS). 

The Picower Institute is a community of 16 neuroscience labs dedicated to understanding the mechanisms that drive learning and memory and related functions such as cognition, emotion, perception, behavior, and consciousness. Institute neuroscientists explore the brain and nervous system at multiple scales, from genes and molecules to cells and synapses to circuits and systems, producing novel insights into how disruptions in these mechanisms can lead to developmental, psychiatric, or neurodegenerative disease. 

Picower Professor Susumu Tonegawa founded the institute as a center in 1994 before a transformative gift from Barbara and Jeffry Picower enabled it to become an institute in 2002. Li-Huei Tsai has served as director since 2009, but announced in March that she would step down after more than 16 years to focus on her research.

Heiman joined the Picower Institute, BCS, and the Broad Institute of Harvard and MIT in 2011, after completing her postdoctoral training at The Rockefeller University. She holds a PhD from Johns Hopkins University and a BA from Princeton University. 

“Ever since joining the institute, Heiman’s research has been guided by the principle that fundamental understanding can lead to breakthroughs in addressing disease,” Tsai says. “Myriam has made it her mission to address these kinds of urgent questions in neuroscience.”

Heiman employs sophisticated DNA and RNA analysis technologies to gain detailed insights into how brain cell states change amid disease, revealing molecular pathways that contribute to the particular vulnerability of different cell types. In 2020, Heiman published the results of an innovative in vivo screening of every mouse gene’s impact on the survival of neurons in the brain, identifying hundreds necessary for sustaining neurons and highlighting a specific gene that promoted their resilience in the context of Huntington’s disease. 

Other studies, both in mice and in postmortem human brain samples, have revealed errant immune responses in neurons and in the brain’s blood vessels that contribute to the disease’s progression. The latter finding arose in a 2022 paper, published with MIT Computer Science and Artificial Intelligence Laboratory colleague Manolis Kellis, that also provided the field one of the first cellular atlases of the brain’s vasculature.  

Her research has also produced insights into other neurodegenerative and psychiatric disorders, including ALS and frontotemporal dementia. In 2024, together with Kellis, Heiman published a paper in Cell showing the diseases have remarkable overlaps at the cellular and molecular levels, revealing potential targets that could yield therapies applicable to both disorders. Heiman’s latest research is also producing new insights into substance use disorders and schizophrenia.

Her research program has garnered many awards. In 2021, Heiman became co-recipient of a National Institutes of Health Transformative Research Award, which “promotes cross-cutting, interdisciplinary approaches that could potentially create or challenge existing paradigms” as part of the NIH’s High-Risk, High-Reward Research program. The next year she also received a prestigious NIH R35 grant to find early triggers of disease progression.

Heiman is also a dedicated teacher and mentor. In 2017, she earned the Department of BCS award for excellence in graduate mentoring; and in 2020, she received the department’s award for excellence in undergraduate teaching. In 2024, she was named one of 23 faculty across MIT who are “committed to caring” — an award given out by MIT’s Office of Graduate Education to faculty members who have served as exceptional mentors to graduate students.

Beyond MIT, Heiman serves on editorial boards and the scientific advisory board of the nonprofit Huntington’s Disease Foundation, an organization that supports research aimed at finding treatments and a cure for Huntington’s and related disorders.. 

Heiman says she is looking forward to her new role in service to MIT by leading the Picower Institute.

“I approach this role with humility and enormous enthusiasm,” Heiman says. “The Picower Institute has an extraordinary legacy, and I’m eager to do everything I can to help support the next generation of transformative research.”

A new kernel, or core program within an operating system, gives researchers a cleaner view of what’s happening inside a processor. Called Fractal and developed at MIT, the kernel has already surfaced previously unknown behavior in Apple’s M1.

When security researchers want to understand what a modern processor is really doing with the kind of detail that determines whether attacks like Spectre and Meltdown are possible, they usually run their experiments on top of an operating system that was never built for the job. They open up macOS or Linux, patch the kernel by hand, and hope the modifications hold. The approach is unstable, hard to reproduce, and on Apple’s platforms, slated for deprecation.

A team at MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL) decided to build something different. Fractal, an operating system kernel written from the ground up, treats the hardware itself as the object of study. Its first major use, a deep look at branch predictors — a CPU’s way of guessing what code to run next, before it knows for certain, so it doesn’t have to waste time waiting to find out — inside Apple’s M1 processor, has already turned up findings that prior work missed, including the first evidence that a class of speculative attack known as “Phantom” affects Apple Silicon.

“We’re using hardware in ways it wasn’t designed for,” says Joseph Ravichandran, the MIT PhD student in electrical engineering and computer science (EECS) who led the project. “It’s not even obvious that this is a possible thing you could do with the hardware. But we found a way to pull all these different primitives off. It’s like a microscope. If you’ve got a hand magnifying glass, you can see a little bit. But if you had an electron microscope, now we’re really talking. That’s what Fractal is. The electron microscope of operating systems.”

A clean room for chip research

The core problem Fractal solves is one that researchers have worked around for years. Modern processors keep state in many internal structures: branch predictors, caches, translation lookaside buffers, and more. To study how those structures behave across the boundary between user code and kernel code, two domains the chip is supposed to keep isolated, researchers need to run nearly identical experiments on each side of that boundary. On a general-purpose operating system, that is very difficult. The system itself manages privilege levels, address spaces, and scheduling, and it injects its own activity into every measurement.

Fractal inverts the model. It boots directly on bare metal, with no other software running, and exposes primitives that let a single experiment switch privilege levels at runtime while executing the same instructions in the same address space. The team calls the underlying technique multi-privilege concurrency, and it relies on a new construct they introduced: the outer kernel thread, which sits inside a user process’s memory but executes with kernel privileges.

The result is an experimental setup with almost no background noise. Where measurements taken under macOS or Linux are blurred by interrupts, scheduler activity, and address-space management, Fractal produces flat baselines and clean signals.

What Fractal found on the M1

Apple’s M1 implements an ARM specification called CSV2, which is supposed to prevent code running in one privilege level from steering speculation in another. Using Fractal, the MIT team confirmed that the protection works for the execute stage of indirect branch prediction: a user-mode program cannot make the kernel speculatively execute a chosen target through the indirect branch predictor.

But the team also found something the chip’s designers may not have intended. The CPU still fetches the target into the instruction cache before the protection kicks in. That fetch is observable through a side channel, which means user code can still influence what the kernel pulls into its caches across the privilege boundary. The same pattern appeared between processes assigned different address space identifiers.

The team also produced the first evidence that Apple Silicon exhibits Phantom speculation, a class of misprediction previously demonstrated only on AMD and Intel processors. In Phantom, ordinary instructions, including a no-op, can be misinterpreted by the CPU as branches, triggering speculative behavior the program never asked for. On the M1, Fractal showed that Phantom fetches succeed across both privilege levels and address spaces, though the execute phase remains blocked.

A separate Fractal experiment overturned a finding from earlier work on the M1’s conditional branch predictor, which had reported that cross-privilege training worked on Apple’s performance cores, but not its efficiency cores. The Fractal team showed that the conditional branch predictor has no privilege isolation at all, on either core type, and that the earlier result was likely an artifact of macOS quietly migrating threads between cores during system calls.

“For us, it is a true independent variable,” Ravichandran says. “You change the privilege level, nothing else changes. The only thing that could explain whether the attack succeeds or not is the privilege level.”

A tool, not a one-off

Fractal supports x86_64, ARM64, and RISC-V, and consists of more than 31,000 lines of code. The team designed it as infrastructure rather than as a single experiment, with familiar POSIX system calls, a C library, and ports of standard tools like vim, GCC, and the dash shell, so that researchers can move existing experiment code over with minimal friction.

The MIT team disclosed its M1 findings to Apple’s product security team. In an unusual reversal, Apple’s engineers also examined Fractal. 

The longer-term ambition is bigger than any single result. Ravichandran wants Fractal to become to microarchitecture research what tools like QEMU and FFmpeg are to their fields: shared infrastructure that the whole community builds on. 

“My hope is that our results as a community get significantly more reliable, significantly more accurate,” says Ravichadran. “With this reduced noise, this clarity, and this guarantee that you’re running on the right core, on the right system.”

“Fractal is a strong architecture contribution because it turns an often ad hoc microarchitectural reverse-engineering workflow into reusable research infrastructure,” says University of Southern California assistant professor Mengyuan Li, who wasn’t involved in the paper. “By reducing software noise and giving researchers tighter control across privilege boundaries, it makes difficult hardware experiments much easier to interpret.”

Ravichandran worked with Mengjia Yan, an MIT associate professor of EECS and CSAIL principal investigator, on the paper. Their work was supported, in part, by the National Science Foundation, the U.S. Air Force Office of Scientific Research, and ACE, which is part of a program sponsored by the U.S. Defense Advanced Research Projects Agency. They presented their work at the IEEE Symposium on Security and Privacy in San Francisco, California.