I'm no EM expert, but is it possible to have a transparent Faraday cage material that lets a capacitive touch screen register touches and be seen without any leak of radiation/data? As I understand it a big conductive finger crossing a Faraday cage breaks it quite completely, but I'm not certain of this.
The Faraday effect can't really be toggled except by physically compromising the enclosure, i.e. opening the Faraday cage/pouch and removing the device. Your "Faraday case" wouldn't be meaningfully more convenient than a pouch or other enclosure.
I think that the engineering is very challenging and the market for this is nonexistent.
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.
Maybe this is a dumb comment, but couldn’t you just turn the phone off? You’d have to trust that the setting to disable Bluetooth when powered down is reliable and configured correctly, but if your use case is that sensitive even carrying a smartphone seems questionable.
I'm curious how you'd plan the toggling to work. It'd have to be foldable at minimum to be able to wrap around and over the screen. But I'd imagine just having a folded back faraday shield on the back of the phone would tank network performance no?
Just electroless plate the interior of something like this [0]? Or use conductive paint if the polyurethane doesn't take an electroless well. Don't know what OEM Nillkin uses but I'm sure the factory has iPhone cases as well.
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.
> Faraday bags exist (SLNT, Mission Darkness, etc.) - they block all RF signals
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?
There are plenty of Faraday bags readily available for cell phones.
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.
You don't need a form fitting faraday cage. Want a free one? Find a food delivery bag that is insulated with foil. I believe some of the meal prep delivery services package their groceries in this. Stick your phone in there and wrap it up. All signals gone as far as I can tell.
Or, even more free or cheap: Wrap it in aluminum foil.
> Camera slider cases exist (Spy-Fy, etc.) - they block physical camera access
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.
And camera slider cases are privacy theater. If somehow someone activated your camera remotely, don’t you think they could also activate your microphone, and your GPS?
Where is this karma-farming marketing template from?
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:
---
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".
---
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?)
26 comments
[ 3.0 ms ] story [ 44.9 ms ] threadFirst, 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.
[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.
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
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?
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.
Or, even more free or cheap: Wrap it in aluminum foil.
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.
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.
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:
---
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".
---
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?
Just use grapheneOS or calyxOS or postmarketOS or whatever.