Apple reveals more about AirTag stalking protections

Nearly zero knowledge of the airtags protocol, but something like this would allow tracking a stalking tag without giving a trackable identifier.

• An AirTag which is seeing an owning device might only be reporting its presence to that device. We can ignore those. (I'm guessing AirTags listen in some limited way, this still works if they don't, it just is always in the separated state.)

• An AirTag which is separated from its owning device will be broadcasting a public key in an "I'm separated" message.

This public key is rotated periodically, but is used for a while. When my phone sees an "I'm separated" message it will send a hash of the public key and a location (encrypted with that key) to Apple central.

If I'm in motion, and continue to see the same public key crying out that it is separated, then it is traveling with me.

Of course everything is way more complicated…

• It probably doesn't just switch to a new public key and stop using the old one, that would let you correlate them, so there is probably some period of overlap to complicate that.

• How to decide when to tell the user about the tag is a complicated problem. If I'm on a train traveling with a tag I don't recognize, I probably don't care. If I change train cars (I'm still in motion, but 98% of the tags around me changed) I might care. If am walking after getting off the train and most of the other tags are gone, except this one, I might care. If it's still with me when I get home, I care.

"To find out if you're being stalked, buy an iPhone" wheww!

> The best GPS resolution available to civilians is about 8 meters (26 feet) - and that's under the best, most ideal situation using the best GPS receiver and a large antenna... things a small cell phone in a pocket or bag doesn't have.

I am not sure where you got this from but that is incorrect - the accuracy (or resolution) depends entirely on the number of satellites and/or augmentation systems you're tapped into, and how strong / clear those signals are. It can vary from a few kilometres down to a few centimetres.

Back in the 90's "Selective Availability" was a thing but it has since been removed.

See https://www.gps.gov/systems/gps/performance/accuracy/

Also - most modern phones can and do tap into the major providers (Galileo, Glonass, GPS etc), towers, WiFi spots, beacons and use all of these to give a a VERY accurate position of where the device is.

Edit: Might mention I worked first hand on indoor tracking of users, and a warehouse project for optimising worker picking - we were able to easily distinguish where a person was in a busy retail setting down to which section of a clothes rack they were selecting clothes from, and exactly where a worker was in a very interference-heavy (metals) warehouse floor using the above mentioned technologies.

Turn them off before traveling? Maybe Apple will prompt you?

Well, if it ridiculously easy to work around, they will probably get flak even earlier, harder, and be legislated to the ground more certainly than otherwise.

I spoke with Frank Wang on a few meetups in Shenzhen many years ago, back when DJI was still kind of a garage company.

Frank had big, nebulous ideas how he will be "engaging the civil society," "stakeholder negotiations," "industry wide self-governance body" blah blah blah to safeguard DJI from troubles.

I told him hiring lobbyists, and talking to officials, or even just making buzz about potential problems is a bad, bad idea.

Lawmakers can't ban things they don't know they can ban... unless you give them an idea.

Same thing with public reaction. People don't get outraged if they don't know why they should be.

In the end it came to that exact outcome, and drones are now in the process of being legislated to the ground, and effectively becoming unflyable by regular people without few kilograms of permits, and licenses.

He wanted to pride DJI on how government compliant, and safe his drones are, but instead just got them banned around every major city.