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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

#31

Post by dcow »

josh2600 wrote: post #24
dcow wrote: 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 wrote zerocash, the protocol behind zcash, and he teaches cryptography at John Hopkins. When it comes to cryptography he knows enough to have opinions. It's hard to opine about black box systems, which is why open-source is so important. It's hard to trust what you can't verify.

I don't disagree but like if you want an open system why are you using an iPhone? Maybe Green is a little guilty of slurping up Apple's privacy marketing?...

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

#32

Post by notjesse »

nojs wrote: post #28
Jtsummers wrote: post #17

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…

Do you mean that every Apple device in the world acts as a proxy to forward Bluetooth requests from nearby (off) devices containing their location, automatically? E.g my laptop is pinging data to Apple about random nearby phones all the time that it sees with Bluetooth?

Yes, essentially.

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

#34

Post by trangus_1985 »

pininja wrote: 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…

If you're not familiar with it, their platform security team releases a whitepaper about the technical details of their security. Regardless of how you feel about Apple, these documents are incredibly well done and interesting to read. The Find My section may have more information, as will their contract tracing docs (which use a riff of the same technology)

https://covid19.apple.com/contacttracing

I highly recommend anyone interested in security or privacy to read this from start to finish:

https://manuals.info.apple.com/MANUALS/1000/MA1902/en_US/app...

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

#35

Post by sillysaurusx »

dcow wrote: post #27
dcow wrote: post #26

Earlier quoted context omitted.

FURTHER, unlike Google who would never let you turn this feature off, Apple does, but I have to GO INTO SETTINGS to find it OMG. And what a jokeshow marketing team Apple has because the name is a little confusing.

Somehow those bumbling buffoons over on HN found my tweet and half of them LIKE this feature. WTF! They're even discussing this thread like they like to do.

You're gonna get yourself rate limited. It's no fun.

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

#36

Post by saagarjha »

trangus_1985 wrote: post #34
pininja wrote: 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…

If you're not familiar with it, their platform security team releases a whitepaper about the technical details of their security. Regardless of how you feel about Apple, these documents are incredibly well done and interesting to read. The Find My section may have more information, as will their contract tracing docs (which use a riff of the same technology) https://covid19.apple.com/contacttracing I highly recommend…

Unfortunately that document mentions the AOP just once, only confirming its existence. It doesn't actually describe what it does.

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

#37

Post by m0zg »

Jtsummers wrote: post #25
m0zg wrote: post #12

Yep, that's not going to spark conspiracy theories and damage the brand at all, just like the backdoor they've recently put in. /s Again, why would $3T company damage its brand like that? It's not "for children" and certainly not to "find your phone". There's something going on there.

Apple has made it easier for users to locate lost (by being misplaced, forgotten, or stolen) devices with a feature that the user can opt out of on a temporary or permanent basis. What is controversial about this?

If there is such a capability (a rather technically involved one, I might add, all the way down to the silicon), do you really believe Apple can't turn it on at CIA/NSA's request without popping that dialog? And you wouldn't even know due to gag orders. And before you say this can't happen in the US, I can give you a few publicized examples of illegal spying on US citizens just in the past few years.

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

#38

Post by Gigachad »

nojs wrote: post #28
Jtsummers wrote: post #17

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…

Do you mean that every Apple device in the world acts as a proxy to forward Bluetooth requests from nearby (off) devices containing their location, automatically? E.g my laptop is pinging data to Apple about random nearby phones all the time that it sees with Bluetooth?

Not only a proxy. The other random devices use their known location to add to the data to show where the device was found. It’s all encrypted with the key of the lost device owner so apple can not read it.

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

#39

Post by normalocity »

nudpiedo wrote: post #5

I like a lot apple products and how they achieved popularizing many technologies, being the next one LIDAR but, for the first time ever I feel this is just going way too far. Sure I want to find my stolen phone even when it is off, but it is way too much loss of freedom having a permanent personal tracker even when the phone is off…

The ship has long since sailed on this point, powered on or not.

There's research that's talked about in the book, "Data and Goliath" that explains how the behavior of people specifically trying to avoid being tracked is sufficiently different from most other people that, even if you turn off your phone (sometimes ESPECIALLY if you turn off your phone) that act can be a behavioral marker used to correlate your activities with other people who do similarly, and your location can be largely deduced by process of elimination anyway.

It's a fascinating read.

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

#40

Post by backspace_ »

dcow wrote: post #31
josh2600 wrote: post #24

Earlier quoted context omitted.

Matthew Green wrote zerocash, the protocol behind zcash, and he teaches cryptography at John Hopkins. When it comes to cryptography he knows enough to have opinions. It's hard to opine about black box systems, which is why open-source is so important. It's hard to trust what you can't verify.

I don't disagree but like if you want an open system why are you using an iPhone? Maybe Green is a little guilty of slurping up Apple's privacy marketing?...

Everyone is quite an absolute word. How are non apple users slurping up Apple's privacy marketing?
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