Entries Tagged "eavesdropping"

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Backdoor in TETRA Police Radios

Seems that there is a deliberate backdoor in the twenty-year-old TErrestrial Trunked RAdio (TETRA) standard used by police forces around the world.

The European Telecommunications Standards Institute (ETSI), an organization that standardizes technologies across the industry, first created TETRA in 1995. Since then, TETRA has been used in products, including radios, sold by Motorola, Airbus, and more. Crucially, TETRA is not open-source. Instead, it relies on what the researchers describe in their presentation slides as “secret, proprietary cryptography,” meaning it is typically difficult for outside experts to verify how secure the standard really is.

The researchers said they worked around this limitation by purchasing a TETRA-powered radio from eBay. In order to then access the cryptographic component of the radio itself, Wetzels said the team found a vulnerability in an interface of the radio.

[…]

Most interestingly is the researchers’ findings of what they describe as the backdoor in TEA1. Ordinarily, radios using TEA1 used a key of 80-bits. But Wetzels said the team found a “secret reduction step” which dramatically lowers the amount of entropy the initial key offered. An attacker who followed this step would then be able to decrypt intercepted traffic with consumer-level hardware and a cheap software defined radio dongle.

Looks like the encryption algorithm was intentionally weakened by intelligence agencies to facilitate easy eavesdropping.

Specifically on the researchers’ claims of a backdoor in TEA1, Boyer added “At this time, we would like to point out that the research findings do not relate to any backdoors. The TETRA security standards have been specified together with national security agencies and are designed for and subject to export control regulations which determine the strength of the encryption.”

And I would like to point out that that’s the very definition of a backdoor.

Why aren’t we done with secret, proprietary cryptography? It’s just not a good idea.

Details of the security analysis. Another news article.

Posted on July 26, 2023 at 7:05 AM • View Comments

Recovering Smartphone Voice from the Accelerometer

Yet another smartphone side-channel attack: “EarSpy: Spying Caller Speech and Identity through Tiny Vibrations of Smartphone Ear Speakers“:

Abstract: Eavesdropping from the user’s smartphone is a well-known threat to the user’s safety and privacy. Existing studies show that loudspeaker reverberation can inject speech into motion sensor readings, leading to speech eavesdropping. While more devastating attacks on ear speakers, which produce much smaller scale vibrations, were believed impossible to eavesdrop with zero-permission motion sensors. In this work, we revisit this important line of reach. We explore recent trends in smartphone manufacturers that include extra/powerful speakers in place of small ear speakers, and demonstrate the feasibility of using motion sensors to capture such tiny speech vibrations. We investigate the impacts of these new ear speakers on built-in motion sensors and examine the potential to elicit private speech information from the minute vibrations. Our designed system EarSpy can successfully detect word regions, time, and frequency domain features and generate a spectrogram for each word region. We train and test the extracted data using classical machine learning algorithms and convolutional neural networks. We found up to 98.66% accuracy in gender detection, 92.6% detection in speaker detection, and 56.42% detection in digit detection (which is 5X more significant than the random selection (10%)). Our result unveils the potential threat of eavesdropping on phone conversations from ear speakers using motion sensors.

It’s not great, but it’s an impressive start.

Posted on December 30, 2022 at 7:18 AM • View Comments

Ukraine Intercepting Russian Soldiers’ Cell Phone Calls

They’re using commercial phones, which go through the Ukrainian telecom network:

“You still have a lot of soldiers bringing cellphones to the frontline who want to talk to their families and they are either being intercepted as they go through a Ukrainian telecommunications provider or intercepted over the air,” said Alperovitch. “That doesn’t pose too much difficulty for the Ukrainian security services.”

[…]

“Security has always been a mess, both in the army and among defence officials,” the source said. “For example, in 2013 they tried to get all the staff at the ministry of defence to replace our iPhones with Russian-made Yoto smartphones.

“But everyone just kept using the iPhone as a second mobile because it was much better. We would just keep the iPhone in the car’s glove compartment for when we got back from work. In the end, the ministry gave up and stopped caring. If the top doesn’t take security very seriously, how can you expect any discipline in the regular army?”

This isn’t a new problem and it isn’t a Russian problem. Here’s a more general article on the problem from 2020.

Posted on December 21, 2022 at 7:09 AM • View Comments

Eavesdropping on Phone Taps from Voice Assistants

The microphones on voice assistants are very sensitive, and can snoop on all sorts of data:

In Hey Alexa what did I just type? we show that when sitting up to half a meter away, a voice assistant can still hear the taps you make on your phone, even in presence of noise. Modern voice assistants have two to seven microphones, so they can do directional localisation, just as human ears do, but with greater sensitivity. We assess the risk and show that a lot more work is needed to understand the privacy implications of the always-on microphones that are increasingly infesting our work spaces and our homes.

From the paper:

Abstract: Voice assistants are now ubiquitous and listen in on our everyday lives. Ever since they became commercially available, privacy advocates worried that the data they collect can be abused: might private conversations be extracted by third parties? In this paper we show that privacy threats go beyond spoken conversations and include sensitive data typed on nearby smartphones. Using two different smartphones and a tablet we demonstrate that the attacker can extract PIN codes and text messages from recordings collected by a voice assistant located up to half a meter away. This shows that remote keyboard-inference attacks are not limited to physical keyboards but extend to virtual keyboards too. As our homes become full of always-on microphones, we need to work through the implications.

Posted on December 22, 2020 at 10:21 AM • View Comments

Copying a Key by Listening to It in Action

Researchers are using recordings of keys being used in locks to create copies.

Once they have a key-insertion audio file, SpiKey’s inference software gets to work filtering the signal to reveal the strong, metallic clicks as key ridges hit the lock’s pins [and you can hear those filtered clicks online here]. These clicks are vital to the inference analysis: the time between them allows the SpiKey software to compute the key’s inter-ridge distances and what locksmiths call the “bitting depth” of those ridges: basically, how deeply they cut into the key shaft, or where they plateau out. If a key is inserted at a nonconstant speed, the analysis can be ruined, but the software can compensate for small speed variations.

The result of all this is that SpiKey software outputs the three most likely key designs that will fit the lock used in the audio file, reducing the potential search space from 330,000 keys to just three. “Given that the profile of the key is publicly available for commonly used [pin-tumbler lock] keys, we can 3D-print the keys for the inferred bitting codes, one of which will unlock the door,” says Ramesh.

Posted on August 20, 2020 at 6:22 AM • View Comments

iPhone Apps Stealing Clipboard Data

iOS apps are repeatedly reading clipboard data, which can include all sorts of sensitive information.

While Haj Bakry and Mysk published their research in March, the invasive apps made headlines again this week with the developer beta release of iOS 14. A novel feature Apple added provides a banner warning every time an app reads clipboard contents. As large numbers of people began testing the beta release, they quickly came to appreciate just how many apps engage in the practice and just how often they do it.

This YouTube video, which has racked up more than 87,000 views since it was posted on Tuesday, shows a small sample of the apps triggering the new warning.

EDITED TO ADD (7/6): LinkedIn and Reddit are doing this.

Posted on June 29, 2020 at 10:24 AM • View Comments

Eavesdropping on Sound Using Variations in Light Bulbs

New research is able to recover sound waves in a room by observing minute changes in the room’s light bulbs. This technique works from a distance, even from a building across the street through a window.

Details:

In an experiment using three different telescopes with different lens diameters from a distance of 25 meters (a little over 82 feet) the researchers were successfully able to capture sound being played in a remote room, including The Beatles’ Let It Be, which was distinguishable enough for Shazam to recognize it, and a speech from President Trump that Google’s speech recognition API could successfully transcribe. With more powerful telescopes and a more sensitive analog-to-digital converter, the researchers believe the eavesdropping distances could be even greater.

It’s not expensive: less than $1,000 worth of equipment is required. And unlike other techniques like bouncing a laser off the window and measuring the vibrations, it’s completely passive.

News articles.

Posted on June 16, 2020 at 10:20 AM • View Comments

How Did Facebook Beat a Federal Wiretap Demand?

This is interesting:

Facebook Inc. in 2018 beat back federal prosecutors seeking to wiretap its encrypted Messenger app. Now the American Civil Liberties Union is seeking to find out how.

The entire proceeding was confidential, with only the result leaking to the press. Lawyers for the ACLU and the Washington Post on Tuesday asked a San Francisco-based federal court of appeals to unseal the judge’s decision, arguing the public has a right to know how the law is being applied, particularly in the area of privacy.

[…]

The Facebook case stems from a federal investigation of members of the violent MS-13 criminal gang. Prosecutors tried to hold Facebook in contempt after the company refused to help investigators wiretap its Messenger app, but the judge ruled against them. If the decision is unsealed, other tech companies will likely try to use its reasoning to ward off similar government requests in the future.

Here’s the 2018 story. Slashdot thread.

Posted on April 29, 2020 at 12:29 PM • View Comments

Russia Is Trying to Tap Transatlantic Cables

The Times of London is reporting that Russian agents are in Ireland probing transatlantic communications cables.

Ireland is the landing point for undersea cables which carry internet traffic between America, Britain and Europe. The cables enable millions of people to communicate and allow financial transactions to take place seamlessly.

Garda and military sources believe the agents were sent by the GRU, the military intelligence branch of the Russian armed forces which was blamed for the nerve agent attack in Britain on Sergei Skripal, a former Russian intelligence officer.

This is nothing new. The NSA and GCHQ have been doing this for decades.

Boing Boing post.

Posted on February 24, 2020 at 6:27 AM • View Comments

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Sidebar photo of Bruce Schneier by Joe MacInnis.