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Always-on Processor magic: How Find My works while iPhone is powered off

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Re: Always-on Processor magic: How Find My works while iPhone is powered off

#81
post #76

Earlier quoted context omitted.

Sure you can power off your device! Just take out the batt-- oh...

Swappable battery is a trend that should return- to both phones and electric vehicles.

As long as the timeframe scales with the size of the battery. A phone battery should be swappable in a few minutes. A car battery should be swappable in a day or two. They have to be heavily shielded in case of an accident.

Re: Always-on Processor magic: How Find My works while iPhone is powered off

#82
In some way this feature reminded me of Android's song detection functionality which is also on by default and is constantly listening in the background [1].

So now tech companies normalized that:

- the mic is always on.

- the phone is always on, even when it's off. (thanks to AOP)

- devices are always online even when they are offline.(thanks to company-operated p2p networks like Find My or Sidewalk)

What could possibly go wrong?

https://support.google.com/pixelphone/answer/7535326?hl=en

Re: Always-on Processor magic: How Find My works while iPhone is powered off

#83
post #11

Maybe I missed it in the article but how does it work with Bluetooth exactly — how does that help my find my phone over a long distance? What’s the Bluetooth connecting to and how does the phone get the request?

The Find My Network is, basically, every Apple device out in the world. Using bluetooth in this fashion, all the other devices participating in the network and in the area of the phone (or AirTags, they work similarly) will receive the bluetooth broadcast. They'll then communicate that to Apple's system. So when you go to find your device, its most recent known location can be provided to you. They've got some crypto…

Did not know that’s how Find My worked - very interesting

Re: Always-on Processor magic: How Find My works while iPhone is powered off

#84
post #49

So according to the post iphones now have an AOP (Always on Processor) running a proprietary operating system with access to other phone components. Do we know if other manufacturers also include such a processor? A quick google search showed a relevant apple patent [0] and a similar qualcomm processor product for wearables [1] which suggests to me this (always on processors on consumer electronics) "is out there ...…

> now have an AOP (Always on Processor) They've long had this. It's how they turn on when picked up (by tracking the motion sensor) or when touching the screen (tracking capacitive sensor)

This seems different to those examples because it works when the phone is powered off. AFAIK neither pick up nor touching the screen have ever done anything when the phone is powered off, only when it’s asleep.

Re: Always-on Processor magic: How Find My works while iPhone is powered off

#85
post #83

Earlier quoted context omitted.

The Find My Network is, basically, every Apple device out in the world. Using bluetooth in this fashion, all the other devices participating in the network and in the area of the phone (or AirTags, they work similarly) will receive the bluetooth broadcast. They'll then communicate that to Apple's system. So when you go to find your device, its most recent known location can be provided to you. They've got some crypto…

Did not know that’s how Find My worked - very interesting

It is how the new feature works. The old feature did not work this way.

Re: Always-on Processor magic: How Find My works while iPhone is powered off

#86
post #15

Very interesting read. This seems to be implemented as a Bluetooth LE app running on the ultra-low power “always on processor” used for a variety of features, like “wake-up on motion.” Much like an Tile or AirTag is implemented. No comment on what this is capable in the future.. but for now this shows power usage / signal strength / proximity of other “actually on” devices are a limitations of this feature. What’s im…

> I’ll be pretty shocked if I’m “spied on” with this style of device. Why? There's plenty of devices in the wild constantly looking for wifi connection attempts, BLE Scans. Even cellular provider track locations in real-time by logging what cell towers you're using and associated signal strength. Just search for a place in google maps, and note the "Popular Times". How do you think they got that data :D

Um they get that data from being a monopoly and knowing when most people are looking up directions to or information about a location.

Sure, they might do some other stuff to expand the data but there's much more relevant data right in their first-party domain.

Re: Always-on Processor magic: How Find My works while iPhone is powered off

#87
post #82

In some way this feature reminded me of Android's song detection functionality which is also on by default and is constantly listening in the background [1]. So now tech companies normalized that: - the mic is always on. - the phone is always on, even when it's off. (thanks to AOP) - devices are always online even when they are offline.(thanks to company-operated p2p networks like Find My or Sidewalk) What could poss…

It’s a feature of Pixel phones, not Android.

I’m not sure how this will change in the future, but currently at least it’s probably not possible to transcribe and communicate speech this way (the power and bandwidth requirements would be too high).

But we’re damn close.

Edit: It seems like throughput isn’t even an issue in the case of Amazon’s Sidewalk. Now it’s just transcription in low power modes. Heck, you might even be able to send raw audio.

This is feasible.

Re: Always-on Processor magic: How Find My works while iPhone is powered off

#88
post #66

Earlier quoted context omitted.

Unless they opt out of it, yes. Which is pretty easy to do, pretty sure it's an option during initial device configuration, but regardless it's in the system settings. Which is pretty easy to navigate. There's even a search option at the top to help you find it instead of navigating to the setting.

If you know about it.

you have to opt in when setting up a new device, and I think when updating to the OS version that enabled it

Re: Always-on Processor magic: How Find My works while iPhone is powered off

#89
post #82

In some way this feature reminded me of Android's song detection functionality which is also on by default and is constantly listening in the background [1]. So now tech companies normalized that: - the mic is always on. - the phone is always on, even when it's off. (thanks to AOP) - devices are always online even when they are offline.(thanks to company-operated p2p networks like Find My or Sidewalk) What could poss…

Yes which supports all kinds of functionality that people like. Just because you have a processor on or mic listening for wake words doesn’t mean everything is always being transmitted or evil is being done.

State actors could do this selectively regardless even before these features. There have been attacks on Motorola razrs, etc for spying. Long before the smartphone, they just implanted microphones, shine lasers on windows, etc.

Re: Always-on Processor magic: How Find My works while iPhone is powered off

#90
post #14

Is Matthew Green some industry security personality that people respect? I appreciate this write up, it's interesting. But it seems motivated by his little Twitter rant the other day. Who is he beyond some Twitizen in a Guy Fawkes mask who hates HN? I don't particularly like his demeanor, at least from his rather naively uninformed tantrum the other day. Didn't seem very professional or respectable so I just wrote hi…

Matthew Green is a well known Cryptography professional and has a ton of write ups on his also well known blog. https://blog.cryptographyengineering.com/ You seem a little judgemental and obviously unaware.

Because he posted a bunch of admittedly pretty annoying Tweets based on angsty presumptions about stuff that someone who put in the effort to do their research and submit a real teardown and writeup rips apart. Being some crypto associate professor doesn't absolve you of the responsibility of doing your research before spewing off on Twitter. At least he's seemed to handle things with some amount of humility since then so I'll chalk this one up to having a bad day or something. I've actually read some of his stuff before I just didn't know him by name which is why I asked.
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