Privacy General

Hardware/Software Privacy General https://invidious.snopyta.org/watch?v=e0elNU0iOMY >Title: The hidden background noise that can catch criminals Interesting topic. It talks about ENF Analysis (Electrical Network Frequency), and mains hum that could be extracted from audio recordings. It requires long uncut recordings for it to be matched to an existing database with high accuracy. I've theorized these long ago and finding out it's in the works is not surprising. >AC hum leaks into audio recording device. It doesn't matter even if you're on DC, as long as a microphone picks up EMF on working electronics or wires in vicinity, it will pick it up. There's a reason why room recording studio mic have a metal mesh around them. This is why audiophiles need all that cable lifting and proper wire separation and management, to avoid the hum but it's not at all surprising it could be used as a geo locator, even the hum harmonics (50/60/100/120hz) can tell a lot about the region where the sound came from. It's also still possible for a microphone to pick up EMF as a noise even if the microphone is battery powered. Another similarity is how a light bulb would flicker, usually it's either multiple of 50/60hz but on certain places like malls I've tried taking pics or a video on some shop before and either the shutter speed options would still show a strobing effect, it already occured to me that it could theoretically also be used to ID/geolocate the place where the video took place. And there's already apps that do track people's location inside a store through an app with camera access (or maybe some disguised sensor API, android, never change..). Usually this "hum" also happens to be what electronics would give off as a noise (either multiple of 50/60hz) on occasions (wash machines, refrigerators). I've already thought of these being used for (or in future) over computers or portable ones. Most computers have built-in microphone, heck even a HDD has one used for haptics and vibration detection. And let's not forget smartphones having multiple microphones up to seven (even ANC earphones have up to 3 microphones PER side these days). So it's not impossible that they're already abusing this and use the "four horsemen" excuse all over again. Just be wary as awlays, Lain.

[cont.]OP Note: Privacy in IMO is probably more of a DIY thing, as setting up privacy protections are more of a daunting manual task which may include extra physical removal or modification. Not sure whether to post this on sec or tech, definitely not sec while tech is way fast enough for that and I don't want to limit "privacy" into something that can be solved by "software tools and OS (which /Ω/ seems to be focused on)" Modern anti-privacy and location/tracking/id uses mainly hardware and clever methods like street/zone lighting or city frequencies https:// cityfreqs.com.au/pilfer.php Another topic about "audio" >This hidden method is the broadcast of inaudible sounds from IoT devices and services using near-ultra high frequency (NUHF) audio between 18 kHz to 24 Khz. The purpose of using such hidden sounds is to identify the person and their phone without our awareness. If not coincidental, maybe it's the reason why Opus has become the web standard and also mobile devices are locked to 48000Hz to accomodate for the extra high frequencies headroom for NUHF content, maybe coincidentally, also the reason pipewire is 48kHz by default? Coincidence or not, it's probably worth noting. There's also certain things I've found out long ago. Using certain time zone on a certain android phone would change its colors. I found this when I was experimenting with the new feature on android called "night mode" (like f.lux) and a certain time zone would give a different warmer temperature but what actually happened was the color profile setting for display changed completely (but not the colors/screen data). So I'm guessing they can somehow use and track phones origin based off that. And then, certain electronics have their certain colors. Lets say Japanese electronics, trees appear more greenish on videos or photos, on Hong Kong/SG, it is somewhat reddish, and so on. It's like certain regions have their own unique color profile (or maybe it's just the atmosphere is different) that sometimes you can even tell a photo was captured from Japan based off the colors but then the time zone experiment I did with a phone had proven it to otherwise may not be the case but it could be that some device use a unique color profile depending on the locale.

a. Why would a criminal make any sort of audio recording? If it's voice, I believe this person's voice is already recorded somewhere, but yeah, locating exact place through mains hum is next gen stuff. About time to go off-grid and stop using air conditioners. b. There's like a 3 billion devices global spyware network called Android. It sends coordinates of every wireless access point to central server, what else could it do, probably record these background harmonics and map them to real places as well. Oh, and this latest Apple thingie, AirTag beacon, it's existence basically confirms that every iPhone actively scans surroundings for it's presence and sends data to central server upon encountering one, there's a separate radio module for such occasion.

Couldn't someone just make a metal mesh to cover built in microphones? I don't know enough about electronics but wouldn't flicker of a light depend on what kind of lightbulb is used and it's wattage plus this will depend on the frame rate the camera is set to use and how visible it will be also may vary by camera?

>>7986 Most decent enough microphones already have metal mesh (but ungrounded). I don't have perfect pitch but I usually tinker with my calibrated microphone, suprisingly it is still way too sensitive to sounds even though I have blocked the microphone's entrances and using my audizr pro app (fft analyzer) from what I can tell, microphones are still capable of picking up frequencies in the form of sound waves (not electro/radio) which appliances may have "harmonized" with the mains hum (60/120hz) so they appear as a spike on the app or with other spectrometers, they will also show the said frequencies. > flicker of a light depend on what kind of lightbulb is used they have specialized light bulbs now, I don't remember what they are called but they are probably like a location-aware bulb that emit unique frequencies which is a tech that already exist on some shopping malls or grocery stores. >frame rate the camera I don't even know at this point, they can use whatever proprietary sensor is bundled with your phone with proprietary kernel/os, I was even surprised that most phones have multiple microphones inside them lately, one at the top, bottom, rear camera-facing, and for voice recognition (and another in 3.5mm trrs) but it's not documented anywhere and there's even bogus info that multiple mic streams only worked in android 11 or something but multi-microphones existed since forever.

>>8023 Wouldn't the mesh on a phone speaker only cover the side the noise comes out of so it's not really effective as a shielding. I looked it up a while back and halogen lights don't really flicker too bad because they are slow to react. Compact fluorescent doesn't flicker too noticeably either because they dont react to fluctuations quickly as well but there is some more dim flicker. Though I question about CFLs and tube fluorescent because on older bulbs with my bare eyes I can actually see waves travelling across it. LED bulbs can flicker really bad to point you can even visually notice it sometimes (due to a broken circuit usually from a failing capacitor) but there also are flicker free LED bulbs. The flicker free LEDs just use some circuitry to normalize the current or something along those lines. Might be worth making a sensor that gives you readings of flicker rates if you dont want to buy a dedicated tool or use some app on a phone/tablet. The effect flicker has on cameras can be used to advantage in some situations though. Using a flickering IR light source at right frequency in dimly lit areas you can cause distortion on video and photos. I've read before that some concerts and similar events flicker their lights to try to stop people filming.

>>7983 >uses mainly hardware and clever methods like street/zone lighting or city frequencies hmm? How are they getting that information? From your tracking device, perhaps?