Activate this 'Bracelet of Silence,' and Alexa Can't Eavesdrop (nytimes.com) 129
Ben Zhao and his wife, Heather Zheng, computer science professors at the University of Chicago, designed what they are calling a "bracelet of silence" that will jam the Echo or any other microphones in the vicinity from listening in on the wearer's conversations. The New York Times reports: The bracelet is like an anti-smartwatch, both in its cyberpunk aesthetic and in its purpose of defeating technology. A large, somewhat ungainly white cuff with spiky transducers, the bracelet has 24 speakers that emit ultrasonic signals when the wearer turns it on. The sound is imperceptible to most ears, with the possible exception of young people and dogs, but nearby microphones will detect the high-frequency sound instead of other noises. "It's so easy to record these days," Mr. Lopes said. "This is a useful defense. When you have something private to say, you can activate it in real time. When they play back the recording, the sound is going to be gone." During a phone interview, Mr. Lopes turned on the bracelet, resulting in static-like white noise for the listener on the other end. At this point, the bracelet is just a prototype. The researchers say that they could manufacture it for as little as $20, and that a handful of investors have asked them about commercializing it. "The 'bracelet of silence' is not the first device invented by researchers to stuff up digital assistants' ears," the report notes. "In 2018, two designers created Project Alias, an appendage that can be placed over a smart speaker to deafen it. But Ms. Zheng argues that a jammer should be portable to protect people as they move through different environments, given that you don't always know where a microphone is lurking."
"Other precursors to the bracelet include a 'jammer coat' designed by an Austrian architecture firm in 2014 to block radio waves that could collect information from a person's phone or credit cards," reports The New York Times. "In 2012, the artist Adam Harvey created silver-plated stealth wear garments that masked people's heat signature to protect them from the eyes of drones, as well as a line of makeup and hairstyles, called CV Dazzle, to thwart facial recognition cameras."
"Other precursors to the bracelet include a 'jammer coat' designed by an Austrian architecture firm in 2014 to block radio waves that could collect information from a person's phone or credit cards," reports The New York Times. "In 2012, the artist Adam Harvey created silver-plated stealth wear garments that masked people's heat signature to protect them from the eyes of drones, as well as a line of makeup and hairstyles, called CV Dazzle, to thwart facial recognition cameras."
Cheap alternative (Score:4, Insightful)
Or... you could just not own an Alexa.
It's possible!
Re:Cheap alternative (Score:4, Informative)
But my common sense tells me that most people who are interested in such technology wouldn't buy a device like Alexa in the first place.
The concern is that devices of other people can listen and record you, without your consent.
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Good point.
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The Cube has eight microphones in it and I keep Alexa turned off. But is it really off? It doesn't respond when you speak, but it could still be listening.
There's the simple "don't buy a fire" answer, but there's another simple answer. Open the box, cut all wires connected to microphones (e.g. identify one mic, work out where it connects to, use that to trace all the others; cut the wires and/or circuit board traces). No mics connected - no possibility that the box is listening. If you have never done that before, now is the time to start learning.
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Thats why they put 8 mics in there, you just connected the dots for some people! Some are probably soldered to the board, and you can surely bet there arent 8 nice motherboard style connectors in a row with "M1, M2" etc printed on the board next to them, heck some motherboards are like that with nothing printed next to the power / reset / usb pin block!
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Or chewing gum.
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In my case I'd be too paranoid to trust such a jamming device's efficacy without having extensively tested it under controlled lab conditions.
Amazon will attempt to bypass whatever the device does with digital filters or most likely let a neural network learn how to bypass it. They have the resources to do that.
If you want to be sure you'd probably have to disable those microphones on the hardware level (certainly voiding any warranty you might have had for it) yourself
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Or just put a low-pass filter between the microphone and the input to the computer. Most of the content of speech is in the low-end frequencies, which is why phones worked perfectly well over lines (and intermediate amplifiers) with a peak response at about 5kHz and a cut-off at about 8kHz.
That is why your fax modems and so on in the early 90s used frequencies of 4800Hz, an
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The insane ISPs here call "fibre DSL".
But I remember using a discrete splitter back when i had aDSL. In most modern cases around here those splitters are integrated components in routers/gateways which you simply plug into the phone connection sockets, like the popular Fritz!Box products.
Splitters also aren't going to be needed in the future around here as POTS and I
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Honestly, unless you have Frank's 2000-inch TV, I really don't see the point to 4k.
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Mine's 65 inch, and the difference between 1080P and 4K content is clear as night and day.
Now, is there a point to it? Na, I can live just fine with 1080P on it. But the 4K is damn gorgeous.
Re: Cheap alternative (Score:3, Insightful)
Yeah...if you just wanted to stay home all the time, this device would be a piece of furniture and not mobile, like a piece of jewelry.
As for the rest of us, we sometimes find ourselves in environments that we donâ(TM)t control.
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Good point, although the summary says "When you have something private to say, you can activate it in real time" so I assumed crimin^W citizens might be thinking on turning it on/off at home.
I'm sure they can send out a firmware update to low pass filter the input though. If this becomes a problem.
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That's just not an option these days. Last year my extended family went to a vacation house together, and one person was cooking and said, "Alexa, set a timer for 10 minutes." It didn't work because there was no Alexa spying on the house. He was annoyed because he couldn't use his Alexa.
When I said, maybe not being able to set a timer by voice was a poor tradeoff for a spy microphone in your house listening 24/7, he said it's the modern age and everyone has one these days, and since he has nothing to h
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...and since he has nothing to hide why should he worry?
Does anybody have a good, snappy, soundbite response to this? I spent an hour trying to explain to somebody the other day and they just shrugged it off (failing to see the connection between what their phone does and having curtains on their windows, not wearing a t-shirt with all their personal details on it, etc).
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...and since he has nothing to hide why should he worry?
Does anybody have a good, snappy, soundbite response to this?
"What's your social security number?" "What's your mother's maiden name?"
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"Fuck you, asshole."
I do have some prototypes: (Score:2)
There's *always* an asshole,
that wants to "find" something on you!
[Points at Alexa]
So keep fucking yelling at him!
More rope to hang you with.
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How long do you think you could hang around a cop, a criminal and a religious fundamentalist, before doing something that displeases them?
[Points at Alexa] They're listening.
Give me all the naivity you got!
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It's not about what you have to hide, but about what they want to *find*.
"If one gave me six lines, written by the hand of the most honest man, I'd FIN
Re:Cheap alternative (Score:5, Interesting)
"What's your password?" "What's your credit card number?"
Those are easy. Anything you'd keep private is something to hide.
If they're married, you can ask even more personal questions, like "What does your spouse like to do for sex?" (Yes, this works even in the LGTBQ+ couples). Or "What's your kink? What's your spouse's kink?"
Or at the very least "How much money do you make?"
If they object, remind them they have no qualms about telling some stranger that information because they have nothing to hide, so why the sudden concern just because you're friends/relatives/etc?
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"Let me just post your photo and basic info on 4Chan... Theeere we go."
It's a bit of a brick-response, but boy when those bricks start flying...
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...and since he has nothing to hide why should he worry?
Does anybody have a good, snappy, soundbite response to this?
Yes: the correct response is "That's not what privacy is about. It's about WHO gets to choose when to reveal personal facts."
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People either wise up on their own or they don't. Sometimes it takes a shock to their system to get them to wake the hell up, something like having their identity stolen, or having evidence right in their face of their Most Very Private Thing violated by some faceless corporation or government agency. Sadly most people just drif
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I worry because I'm above the age of two, when humans learn other people can't hear their thoughts, and they begin hiding things for the rest of their lives, trivial or not.
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Try this. [xkcd.com]
Re: Cheap alternative (Score:2)
"alexa, how do I make an IED"
"alexa, what kind of security does the president have when travelling"
"alexa, look up Trump's speaking schedule"
"alexa, what kind of forensic evidence is left on explosives"
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You don't have nothing to hide? So you wouldn't mind me installing a video camera in your bedroom and broadcasting it to the world?
Why not? Got something to hide?
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Basically all of those that have one of the smart-tvs with a built-in camera and microphone in their bedroom.
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Give me six lines written by the most honest man in the world, and I will find enough in them to hang him.
You think this only worked in Richelieu's time? In a world of terrorism and public outrage when someone wants to interpret something you said as "offensive"?
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When I said, maybe not being able to set a timer by voice was a poor tradeoff for a spy microphone in your house listening 24/7, he said it's the modern age and everyone has one these days, and since he has nothing to hide why should he worry?
Oh look, I found a picture of your 'friend'! [wikimedia.org]
I think you need a new friend, that one's horribly, horribly broken, thanks to all the 'programming' courtesy of social media (and perhaps government propaganda). Either that or he's just naturally a fool.
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That's just not an option these days. Last year my extended family went to a vacation house together, and one person was cooking and said, "Alexa, set a timer for 10 minutes." It didn't work because there was no Alexa spying on the house. He was annoyed because he couldn't use his Alexa.
I met a woman with a young daughter named Alexa, who also has an Alexa; she says confusion sometimes ensues.
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I don't. That doesn't mean I haven't had an Alexa interrupt a conversation I had with someone else and start playing music no one asked for.
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The problem isn't being home, the problem is rather not being home and not knowing whether the person who invited you owns an eavesdropping device. My strategy so far is something I bummed from xkcd [xkcd.com], because it usually quickly made people get hectic if they own something like that, but it also led to me not being a welcome guest anymore.
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In the basement.
Re:Unplug (Score:5, Insightful)
Come on, be serious.
This is meant for jamming other people's devices, not your own.
I do not let Amazon, Google, etc. install microphones in my house... as far as I know. But I have plenty of acquaintances who have the damn things. This would help when I want to say something I do not want recorded and stored on someone's servers.
By the way, how do the owners of Alexa and Co get around the laws forbidding recording people without their consent? Or does entering an Alexa infested house qualify as consent?
Re:Unplug (Score:4, Insightful)
By the way, how do the owners of Alexa and Co get around the laws forbidding recording people without their consent? Or does entering an Alexa infested house qualify as consent?
Palm-greasing.
Re: Very easy workaround. (Score:3)
Nah, but im your pocket! (Score:3)
What do you think your smartphone is?
XKCD to the rescue (Score:3)
Re:Unplug (Score:5, Insightful)
Oh and by the way all it'd take is someone 'open sourcing' the schematics and/or code for a device like this, or just publishing to the Internet the details of how it works, and the technology proliferates, much in the same way that quadcopter drone technology proliferated: the genie is already out of the bottle, Pandoras' Box is already opened, you can't put it back in, and people who want it will eat it with a spoon. Hell, my first thought was to mass-produce little solar-powered versions of this and hide them all over in public places to fight at least some of the surveillance that's being done to everyone with smartphones that everyone is carrying (I'm pretty sure this would defeat a smartphone too). Build them into standard electrical outlets and covertly replace them in public places. Install one in your car so everywhere you drive it you have a zone of privacy. 'Technologies' like this pop up spontaneously because there is a need for it.
So-called 'law enforcement' ('so-called' because they seem to be more about serving their own agenda and gathering more and more power over everyone else, instead of serving actual law and order and serving the public) can seethe and yell about this sort of thing all they want but they're not going to stop it. There are enough people in the world who don't want to be treated like convicts in a prison 24/7 that things like this will exist.
Re:Unplug (Score:5, Insightful)
Blanketing public places with ultrasonic screamers that deny peace to youth, dogs and animals sounds like a bad idea.
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There are easier ways of temporarily disabling such a device than unplugging it or taking out the batteries - just knit a muffler for it, for one.
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There are easier ways of temporarily disabling such a device than unplugging it or taking out the batteries - just knit a muffler for it, for one.
Even easier, buy one from an auto-parts store. :-)
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has a switch to turn off the microphone.
Are you sure the switch actually disables the microphone? It could just inhibit the device from responding to its activation word/phrase.
The next step versions will use cameras (Score:2)
and an AI back-end to read lips when sound is being jammed.
It will be even worse at translating what someone doesn't want captured.
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Open the pod bay doors, HAL
Hearing aids (Score:3, Insightful)
This would also jam hearing aids which use the same kinds of microphones and audio processing.
I'm not sure about that (Score:2)
Hearing aids amplify a narrow band of frequencies. Any half decently designed aid will have low and high pass filters on the input.
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The filters are irrelevant. The ultrasound sets up mechanical resonance in the speaker element causing it to react the same way it would to a loud sound in the audible range. The device takes advantage of the difference in mechanical properties of the human ear and the microphone.
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This would also jam hearing aids which use the same kinds of microphones and audio processing.
"... the sound is imperceptible to most ears, with the possible exception of young people and dogs..."
... cats, mice, anopheles mosquitoes, government listening devices, bats and Brian Eno."
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Yes, it targets the microphones, or more specifically the electronics that amplify them, so will screw with hearing aids as well as smart speakers.
filtered (Score:5, Informative)
this would get filtered by a firmware update the day after they hit the shops.
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Yep, so this bracelet actually makes the problem much worse.
If you believe you're magically immune to microphones then you'll say all sorts of things you might not say if you believe people are listening.
(I expect this bracelet will appear on the Amazon "hot products" page the day after the firmware update ships....)
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Aren't mute people magically immune to microphones?
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>"this would get filtered by a firmware update the day after they hit the shops."
+1
Yep, I came to post the same thing. Sure the mics can hear it, but filtering it out will be a simple code change, similar to taking an EQ and turning down a few knobs. Such devices don't depend on sounds above the human voice, so filtering them even much lower than ultrasonic would be fine.
Meanwhile, such a device could be terribly distressful for our pets. I know my cats would not appreciate being around such a thing,
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Play the video so you can hear the noise you'll be attempting to filter out. Filters have limits. In real life you can't fix it by saying "enhance" to the computer over and over.
Re:filtered (Score:4, Informative)
They may not be able to. By the time the firmware gets a crack at it, the input is already polluted with aliased noise all over the spectrum. Filter it all out and there's nothing left.
From a legal standpoint, the amount of effort it would take to even have a hope of eking out any information would make a claim of casually overhearing impossible to support. It might even be so much processing that arguably you could have gotten the "filter" to output any arbitrary signal you wanted. Kinda like back before TVs squelched static, you could almost hear music or voices in the static if you were sleepy enough.
Too bulky (Score:2)
I'll wait for the encoder ring.
Lowpass filter? (Score:4, Informative)
Implemented by a simple software update for the signal processor?
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Yup. Absolutely trivial to bypass.
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Depends. If you can emit noise at a volume that causes the ADC to clip, there's no possible fix other than turning down the input gain before the ADC. That, in turn, may mean low to negative SNR, assuming it's even possible to do via software.
So, depends how close to full scale these devices are operating and how much spare dynamic range they have.
Proper aesthetic (Score:2)
It looks like some futuristic maximum security jail handcuffs. As our private is being held hostage by these spying technologies it is a good fit.
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Filter The Recording (Score:2)
Is this fancy watch going to be totally defeated the first time someone at google or amazon notices they are getting a number of recordings with weird high frequency static and decides to filter out the high frequencies before passing it on to be analyzed?
Sure sounds like it unless they've done something super clever which somehow generates lower frequency sound at the receiving microphone but I doubt that's possible without being generally audible.
Source to noise... (Score:5, Informative)
The original article http://sandlab.cs.uchicago.edu... [uchicago.edu] has some interesting graphs showing efficacy under certain situations. Looks like sometimes it can be fairly effective. What's missing are the frequency (ies) and sound energy the bracelet (transducers) puts out. Normal conversation is about 60 dB in amplitude. If you can get an SPL out of the transducers exceeding this, then the source (conversation) to noise (jamming) ratio will be low enough that the level will swamp the input of the listening device. The signal has to go through an A/D converter on the front end, and if you can get enough volume out of the jammer, that's all it will pick up. No amount of post filtering will make the signal intelligible.
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The signal does not have to go through an A/D converter at all. Most competently designed microphone systems have a low-pass filter before the A/D, to prevent aliasing and artifacts, and no signal whatsoever will reach the A/D.
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The mic picks up frequencies above 22.05 kilohertz because energy in those bands causes energy in their harmonic bands as well. So you can pump out ultrasound with the effect of messing with electronic reception of man-hearable frequencies, but not that of humans.
Can't filter this out either, because there's enough ultrasound frequencies to fuck with the whole breadth of regular sound.
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>Unless the harmonics are caused by a resonance in the microphone assembly itself (or I suppose the case right next to the microphone),
That's the idea: that it'd show up in the signal the microphone produces (before filters and ADCs come into play), and is therefore unavoidable. Whether it'd be heard by people is a matter of whether the human ear (and nerve bits behind it) behave the same way is another question, and anyway the actual device described in the article works on a different principle. I'm mo
I accidentally made one of these (Score:2)
I have an old ultrasonic cleaning tank down in my workshop and I noticed that when it is running, it completely jams my phone's audio pickup within an eight foot or so radius. The phone uses a MEMS based microphone and I was actually concerned that it might damage the cantilever so I have been keeping it away from that area when it is running.
XKCD about Alexa I saw a while ago (Score:4, Funny)
https://xkcd.com/1807/ [xkcd.com]
Re: XKCD about Alexa I saw a while ago (Score:2)
I heard Amazon blocked that specific purchase. But I haven't tried it myself.
Animal torture devices. (Score:2)
Use that thing around my animals (or babies), and I'll treat you exactly tha same as an Alexa usee.
Especially because Amazon will have this patched in software in no time.
Funny, how often supposedly smart people don't evrn think twice before they run with it.
The dog thing would be an obvious no-go for me as an inventory in any case!
Next Alexa version... (Score:2)
Convenience! (Score:2)
The sound is imperceptible to most ears, with the possible exception of young people...
Imagine never having to yell "Get off my lawn!" ever again.
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https://en.wikipedia.org/wiki/... [wikipedia.org]
Cone of Silence (Score:2)
Perfect to wear around audiophiles. (Score:2)
It would shut down I can hear 30K nonsense real quick.
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Technically, you're not an audiophile. You're a mutant.
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Just tape a bag of those magic rocks [machinadynamica.com] to your forehead. That should clear it right up.
You'll also probably get a seat to yourself when you ride the light rail (YMMV if you're in New York).
Why does it need to be listening 24/7 (Score:2)
A low pass filter will recover the conversation (Score:2)
Especially not if you don't buy one ;) (Score:2)
I Define Insanity... (Score:2)
Every old sci-fi idea is new again (Score:2)
It's interesting that we're rapidly reaching back into the types of science fiction in the 1940s and 50s that focused heavily on countering the oppressive uses of certain additional technological changes.
Arthur C. Clarke's "Silence Please [wikipedia.org], and even the psychological blockers used to counter the Second Foundation in Asimov's work are all basically dealing with the same idea as this device.
Student work, not an effective strategy (Score:2)
This assumes that the device with the microphone is sensitive to frequencies above the hearing range. Most devices have a low-pass filter for the purpose of avoiding any input above 1/2 the sample rate of the DAC, since these will create artifacts, aliasing, and distortion. Even in the case that current devices have left out the low-pass filter, it costs pennies to add.
Cone of Silence (Score:2)
but is it legal (Score:2)
there are laws in the US that prevents jamming. I am not sure this jamming bracelet would be legal here. It could also prevent mobile payments at stores. could even affect some medical devices people wear. and what about home security security that listens and records?
Cool Proof of concept but... (Score:2)
Being invited somewhere and torturing their and/or their neighbors pets, Is to many undesireable.
I was thinking of making or getting one until I read that line. It's completely impractical for the purpose it is made for, unless I'm reading this wrong.
Anybody else (Score:2)
envisioning this as the successor to the Cone of Silence, and still never goddamn working right?
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Because their objective was to research the effectiveness of the technique rather than to make a fashion statement. Why wast a bunch of time making it look sleek when you don't yet know if it'll actually work.
Welcome to the world of prototyping.
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https://www.youtube.com/watch?... [youtube.com]