It's all over reddit to a tiresome degree, and increasing in Ask HNs as well, generally from new accounts (as of now, the OP account is green).
They all go like this:
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I've been doing this thing, and noticed stuff.
"The gap seems real"
"The use case seems obvious"
"So my question to the community is:"
- product/market fit bullets
Re-assertion of being just "curious".
"Happy to" [market to you more] "if you're interested".
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Who wrote the original structure? What is everyone using to generate this same form over and over?
(I could image it being one of those "$900 to learn this one cool trick" SEO influencers, maybe SaaS-ified into one of those custom GPTs? It is shockingly effective at driving engagement -- nerd sniping the genuinely helpful?)
Is there a way to filter these out?
2) Will drain your battery as it adds power to find a faraway cell tower (unless you are in airplane mode)
3) It actually does exist. It costs $1000: https://privoro.com/product-vault
I keep backup navigation tablets on my sailboat inside of those, with the idea being that if the boat is ever neutralized by lightning, at least I'll have some backups. (I also have paper charts for most everywhere I might be.)
If your answer is yes, then you don't need a faraday cage.
If your answer is no, you are facing advanced adversary. You probably don't want a phone on you at all, faraday caged or not.
If you for some reason do need one, it's important to know when you put a modern iPhone in airplane mode it disables cellular but leaves WiFi/Bluetooth enabled. When you disable WiFi/Bluetooth it just disconnects from the devices for a day, but doesn't actually fully disable these fully. You can verify by going into the settings app and seeing that the radios are still toggled on.
And even if you do _that_, I have no idea how the software actually disables the hardware, but it may not physically power off the chip.
But none of this helps with the "toggle-able" part of the requirements…
First, anyone truly concerned about this for actual use cases just isn’t going to bring their phone with them at sensitive times. Especially after the infamous chip bag Italian meta data incident.
Second, it’s conspicuous and kinda suspicious so its use is limited to primarily virtue signaling privacy advocates or crazy people and the latter aren’t usually big spenders.
Third: the engineering sounds challenging. All that metal in an undeployed fashion is going to reflect and interfere with reception. ( it isn’t an iron man suit, it has to get packed somewhere.). That may also interfere with RF safety approvals? Finally, avoiding RF leakage is surprisingly difficult in practice.
I’m not familiar with this one and search didn’t get me anything that seemed relevant. Got a link to something describing the incident?
Google/Apple can in the future announce a "safety" feature that periodically announce Airtag'ish Bluetooth beacons even when in Airplane or powered off mode.
It blocks nfc, bluetooth and wifi. The last time I checked, airplane mode left those on, and so did the toplevel “turn this radio off” buttons in iOS.
All of the bags and boxes others have posted make the phone unusable, so turning it off seems just as well. Plus, if you leave the phone on, without airplane mode, in a faraday cage, it’s going to die rather quickly while it searches for a signal.
Settings for WiFi, turn off; settings for Bluetooth, turn off; does turn them off.
This change was the result of years of supporting people meaning to turn it off in one place or one day, then confused it didn't work at home or the next day.
So now airplane mode is a conditional off (the state machine across cellular, wifi, and bluetooth is pretty decent at doing a reasonable set of toggles), while the settings are off off.
The near field stuff seems to remain available; full shutdown turns that off too.
A lot of planes have WiFi, and people are also using Bluetooth headphones. So when talking about being a passenger on an airplane, this seems like a rather practical choice.
Look in the digital forensics industry. Field forensic investigators can get bags or boxes (look like Pelican(r) cases), or inserts for Pelican cases (a 1615 fits just right into a sedan's trunk).
Long time ago when mobile forensics was in its infancy they were given out as swag.
The #1 problem is of course that if not in airplane mode, some not too smart phones keep increasing the power to the radio (smarter ones do this for a few minutes then power down radio, then cycle up again). Guess what happens with a bunch of juice dumped into electronics in a locked case inside a trunk in a hot car, with half dozen other phones doing the same thing (because it is never a single burner phone).
In a pinch, 3 to 5 layers of aluminum foil, stainless steel cocktail shaker, ammo can, or combination thereof works.
edit: Yes, if we are discussing this with physicists, RF cannot be blocked, it can be attenuated. The strength of the RF signal is reduced as it travels through different materials, and in theory it can never be completely eliminated. In practicality, the signal only needs to be attenuated until it cannot be picked up sufficiently even when very close by a receiver.
Also, I worked with clandestine people and for most of them had threat models more relaxed than a lot of people on HN. What are you all up to???
Or, even more free or cheap: Wrap it in aluminum foil.
[0] https://www.amazon.com/Nillkin-Samsung-Leather-Magnetic-Prot...
Edit: Oh, missed the "toggle on/off without removing the device." Nah, that's not a thing that's going to work. Even with the flap open you'll be attenuating enough RF through the back that either you won't have a decent connection, or your battery life will be crap.
Though as you suggest, relying that would be a bad idea.
For some reason manually turning off RF transmission seems to have been ruled out, so we are looking for an unusual solution to the problem.
(And this doesn't even require that the phone stay connected to the network after the wiretap-enable packet is received. Rather, while the phone is "powered off", the baseband modem might sit there passively acting as a bug, capturing conversation through the microphone onto a bit of NAND onboard the modem; and then, once the phone is powered on again, the baseband modem will take the opportunity to silently play back whatever it's recorded to the tower.)
> if your use case is that sensitive even carrying a smartphone seems questionable.
The issue is that, if you're an actual honest-to-god spy (or investigative journalist...) trying to poke their nose into the goings-on of some government, then you want to draw as little suspicion to yourself as possible; and it's much more suspicious to be going around without the subject government's favorite citizen-surveillance tool on your person. In fact, to blend in, you need to be constantly using your state-surveillance-device to communicate with (decoy) friends and coworkers, doom-scroll, etc.
This is why spies are fans of the few remaining Android phone brands that offer designs with removable batteries. When meeting with a contact, they'll still slip their could-be-bugged-phone into a faraday bag, to cut off its network connectivity; but they'll also remove the phone's battery before putting the phone into the faraday bag, to inhibit this class of "powered-off" record-to-NAND-style baseband wiretap attacks.
(Of course, these are just ways to secure a phone you own + can determine wasn't subject to a supply-chain attack. If two people are meeting who aren't within the same security envelope, then either of them might be trying to surreptitiously record the conversation, and so their phones (or anything else on them) might contain a tiny bug with its own power source, that would stay active even if the macro-scale device's battery was removed. For such meetings, you therefore want to leave all electronic devices in a soundproof safe, in another room. Which will also implicitly act as a faraday cage.)
Could you link to such a law?
Documentation is insufficient for protection.
Stuxnet happened, despite correct documentation of Siemens PLCs.
That said, I do see merit to flagging these. Related surprises are usually e.g. speakers being possible to use as microphones, and accelerometer data being possible to use for location tracking in lieu of GPS / any kind of radio, just not remotely & live ofc.
And if anyone wanted to look at my 51 year old body I think I would take that as complement.
Like held in your hand? Quickly checking something mid-dressing? Or on the toilet?
My approach is; how do avoid the snitch? I just leave my phone in the car or at home.
Realistically, if your adversaries are capable of communicating with your phone while it's turned off or in airplane mode, your best solution is probably just to hit your phone with a five dollar wrench until it breaks.
They really don’t. “Blocking” RF really isn’t a thing. RF can be attenuated, but it is quite a complicated problem to solve. Have you tried any of these bags?
I didn't mind that they knew where I was when I was being paid, but I had issues with abuse by one particular manager (who was more my equal than my boss, but nevermind that).
This tracking software could be disabled with a couple of button pushes, or the phone simply turned off, but these action generated alerts that were sent home to the mothership. I did not like this aspect at all.
So I bought a little Faraday bag from somewhere in China -- back then, probably from DealExtreme. It fit the phone so well that it seemed like it must have been made for that specific model (even though it almost certainly was not). Inside, it had two compartments: One that encapsulated the device well-enough with conductive fabric, and another that was outside of (and adjacent to) that envelope, which just protected the phone from things like incidental abrasions.
I used it as an every-day phone case. When I wanted the phone to work, I used the non-shielded part. If I wanted the phone to not work, then I used the shielded compartment instead.
In imprecise practical terms, this bag blocked successful RF communications. (And I knew this to be true, because I also had access to the mothership's web interface and could review the tracking data for myself and my coworkers.)
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I can accept that "blocked" is not the most-precise term. In a way that is similar to many other things, a valid and accurate technical description of what was achieved would require additional precision.
But such precision is not always necessary in order to succinctly have words convey their desired intent, and I don't think it's required here for OP's intent to be understood.
My old Nokia would smash the whole range of AM/FM and UHF bands.
I don't know about higher frequencies that could escape one of these cages intended to block WiFi/5G/GPS but it is possible in theory and then it would be likely a backdoor that only becomes active when no signal can be detected.
That is impossible to know without knowing the characteristics of the signal, noise, attenuation performance, sensitivity of the receiver, and other environmental conditions.
> Or they don’t block all RF?
They definitely don’t.
If you want to attenuate an RF signal, you need to do RF engineering. There are products to help people do this (eg RF test enclosure), but they aren’t marketed as “blocking RF” because that is nonsensical. The products that advertise as “blocking RF” without any real specifications are unsuitable for serious RF engineering, they are primarily sold to conspiracy theorists, hypochondriacs, etc.
> That is impossible to know without knowing the characteristics of the signal
Do you dispute that de facto these products work?
You can cut off GPS and high frequency cell spectrum pretty easily. Most cell spectrum is effectively attenuated by good quality professional RF enclosures designed for those frequencies. 2.4 ghz signals like wifi (with good quality radios) are hard to attenuate to the point where they can’t connect to other radios nearby, even with very expensive RF test enclosures.
If you’re trying to block against an unknown threat you are fucked. If someone wanted to back door a baseband they’d probably make it transmit at low speeds and low frequencies to be resistant to attenuation.
Go put a phone in a filing cabinet and call it. It will ring.
Just use grapheneOS or calyxOS or postmarketOS or whatever.
Do they block the front camera? I’ve only seen one case that even attempted to block it, and it was kind of flimsy and would uncover the front camera when you took it out of your pocket.
Plus you can’t block the front camera very well without impacting facial recognition.
(puts on tin-foil hat) and you’ll notice that all new models only support facial recognition and no longer offer fingerprint unlock.