yeah, i seem to recall there was controversy about this at one time... another thing i know from android is it's possible to set it to this kind of "radio silence" mode but it passively listens and gathers signal data and beacon identifiers and logs it
Discussion
A lot of that was a foreign language to me. I probably wouldn't trust a device I bought, though. I want it as dumb as possible. Maybe like a little tag, and since it doesn't broadcast anything without hearing the password first, you'd never be able to listen for it with something like wireshark - which I've never used, but saw a video of a guy using that to find spycams. Well, imagine you're in a SHTF scenario and a thumb drive with Tails or a back up ID would be useful - you could put them all over the place and just memorize a password and a frequency.
yeah, that's what i'm saying, probably a lot of old mobile phones could do this if they have low enough sleep mode power draw (only the radio sitting running waiting
i'm sure you have spotted "connect to hidden hotspot" before, that's what i'm talking about... the SSID is a broadcast that advertises the hotspot, if you turn it off you can't connect if you don't know it's network name, and if encrypted, its key
and like you say, it's channel!
Hmm. I'll keep this in mind. Not reinventing the wheel is nice. But you hit the next problem - battery. Need those nifty diamond batteries
yeah that's why i mentioned bluetooth because it uses much less power
but let's say you pick a "rugged" phone like a Blackview, which has a massive battery, they are a bit big and chunky but they run recent versions of android and are decently configurable, the lifespan is gonna be pretty good alone
then there is also the possibility of having the device plug into a beefy battery bank, assuming you can find a device that will actually go into sleep mode with the power plugged in, should be able to
if you unlock developer mode, also, probably you can tweak some more things in the wireless network and sleep mode controls to even further reduce its idle power draw
if it's doing nothing but listening to the wifi, and it's got a 4000+mAh battery like a typical rugged phone, with all the dev mode tweaks on, i bet it would run for maybe 2-4 weeks between charges, possibly longer, kinda depends on how leaky the battery is, some batteries stay charged longer than others
Now I'm imagining things that last years. Like, no draw on battery at all, until a tiny charge makes it through an electrical lock on the antenna. If that makes sense. This might be mission creep.
well, probably some kind of NFC device can be used like this... it would need get enough power to actuate a hard switch, like, think of a very small solenoid attached to an antenna that you just need to send a signal at that frequency, then the hard switch closes and connects the device to the battery and it automatically powers up
years, i suppose a brand new fully charged lithium ion battery is gonna probably have enoughu charge to be useful for at least a year, maybe two, without anything connected to it... a lead acid battery has probably got a lower leak rate but much bigger
i don't know exactly how long the batteries hold charge without anything connected, but all the devices i've bought in the last few years have come charged and i believe they charge them 100% and typically they were around 60-80% on first power up, so i'd guess that's losing about 20% per 6 months, so yeah, a couple of years is feasible, if you can make an induction trigger to switch the power on
also, if you can make something a bit bigger, all this is easy to do with a raspberry pi and a few extra pieces, a fat battery
another thing too is if you can hide it within a relatively small range, like half a foot under ground, there are fully battery-free passive bluetooth tags and similar, NFC, that will respond within a short distance, but be hard to locate without knowing they are there, even with a metal detector
silent pocket(farraday) pull it out when one needs it?
I love the Faraday bag idea. Definitely has a place somewhere in my paranoid fantasies
got tired of being tracked & notified from it about my experience/ phone only, using cash & no account names
Those notifications are a runaway train... I'm having a better experience now with a pixel running grapheneOS
Yes! Which Pixel are you running?