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Changing the underlying find my network to break this would be challenging if not impossible while keeping the privacy protections in place. Apple can’t identif

Changing the underlying find my network to break this would be challenging if not impossible while keeping the privacy protections in place. Apple can’t identify devices sending data to find my, and doesn’t log requests. Short of changes that would break compatibility with older devices it should be relatively stable. OpenHaystack has been doing this for a few years now and Apple has made no efforts to restrict it.

gjsman-1000 2y ago
> Apple can’t identify devices sending data to find my, and doesn’t log requests. So what you're saying is that a decent firewall could still inspect the traffic, or the patterns thereof. Also, this doesn't make any sense, as if Apple doesn't know which AirTag belongs to who, Find My would be very useless; and law enforcement would be furious.
- stonegray 2y ago
  Airtags are associated with your apple ID for safety, but when you make a request for the location from Find My it doesn’t include any information about which airtag you’re asking about; just a CSPRNG-incremented public key that changes every 15 minutes. The location data itself is not available to Apple. Here is Apple’s docs on how they prevent themselves from inspecting traffic on Fmi: https://support.apple.com/guide/security/find-my-security-sec6cbc80fd0/web https://support.apple.com/guide/security/find-my-security-se...
  - wutwutwat 2y ago
    So Apple has no way to see anything even when developing the platform itself? They must have a way to decrypt payloads or otherwise get into the system they built and control. The fact that they let law enforcement know when someone is stalking someone with an AirTag shows that the data is available to them. It’s silly to think otherwise, paper or not.
    - future10se 2y ago
      > The fact that they let law enforcement know when someone is stalking someone with an AirTag shows that the data is available to them. Not technically correct. Apple devices (and Android phones with the appropriate app) detect if an unknown AirTag is moving with them and makes it home, possibly signalling a stalking attempt. The heuristics for this happen locally; Apple isn't "aware" of this happening. That said, when you first set-up an AirTag, the serial is tied to your account. Therefore, when you physically find an unknown AirTag and report it to law enforcement, they can then subpoena (or get a warrant?) Apple for information on the AirTag owner's identity. The serial itself, and any personal identifiers, are not used in the locating process, however. This is well documented in the paper above, in articles, as well as in reverse engineering efforts.
    - NavinF 2y ago
      > they let law enforcement know when someone is stalking someone Source? That's not a thing
      - refulgentis 2y ago
        +1
  - meindnoch 2y ago
    So how does Find My work on icloud.com then?
    - alphan0n 2y ago
      It’s explained pretty well in link provided in comment your replying to. The tl;dr is: The information is publicly available in an encrypted form that is only readable by the party with the key. Think of it like this, when you mark an item as lost you publish a hashed public identification key, if another device detects that key it creates a location report encrypted with your public key and posts it to a public list of encrypted reports, you decrypt the report with your private key.
      - meindnoch 2y ago
        >you decrypt the report with your private key Where would this private key be coming from when opening Find My on icloud.com (a website)?
        alphan0n 2y ago
        From your keychain. Decrypted locally. If you mean from another device other than one that your keychain is on, ie, a browser on a device you haven’t logged into before, you can’t. You can get an active location through iCloud if the device is powered on or its last location before power off if the setting is enabled. But you can’t decrypt find my location reports without the private key, which is only available in devices you’ve logged into.
        meindnoch 2y ago
        Websites can access my keychain? Since when?
        alphan0n 2y ago
        What’s your actual point here? You seem to be trying to build up to something by asking me questions instead of RTFM. You aren’t “sending” the key anywhere, you are downloading the report and decrypting it locally.
alphan0n 2y ago
I’ve been using FakeTag[0] and OpenHaystack[1] coupled with a vibration sensor to notify me when various things happen around my house. Inspired by this [2] article. It’s worked flawlessly for ~2 years. [0] https://github.com/dakhnod/FakeTag https://github.com/dakhnod/FakeTag [1] https://github.com/seemoo-lab/openhaystack https://github.com/seemoo-lab/openhaystack [2] https://hackaday.com/2022/05/30/check-your-mailbox-using-the-airtag-infrastructure/ https://hackaday.com/2022/05/30/check-your-mailbox-using-the...
malmeloo 2y ago
You're correct in saying that it would be challenging for them to overhaul the entire network, but this library directly makes API calls to Apple's servers to request location reports. So while the tags would likely keep working, they could totally block the library or your account if they really wanted to.

gjsman-1000 2y ago

> Apple can’t identify devices sending data to find my, and doesn’t log requests. So what you're saying is that a decent firewall could still inspect the traffic, or the patterns thereof. Also, this doesn't make any sense, as if Apple doesn't know which AirTag belongs to who, Find My would be very useless; and law enforcement would be furious.

stonegray 2y ago
Airtags are associated with your apple ID for safety, but when you make a request for the location from Find My it doesn’t include any information about which airtag you’re asking about; just a CSPRNG-incremented public key that changes every 15 minutes. The location data itself is not available to Apple. Here is Apple’s docs on how they prevent themselves from inspecting traffic on Fmi: https://support.apple.com/guide/security/find-my-security-sec6cbc80fd0/web https://support.apple.com/guide/security/find-my-security-se...
- wutwutwat 2y ago
  So Apple has no way to see anything even when developing the platform itself? They must have a way to decrypt payloads or otherwise get into the system they built and control. The fact that they let law enforcement know when someone is stalking someone with an AirTag shows that the data is available to them. It’s silly to think otherwise, paper or not.
  - future10se 2y ago
    > The fact that they let law enforcement know when someone is stalking someone with an AirTag shows that the data is available to them. Not technically correct. Apple devices (and Android phones with the appropriate app) detect if an unknown AirTag is moving with them and makes it home, possibly signalling a stalking attempt. The heuristics for this happen locally; Apple isn't "aware" of this happening. That said, when you first set-up an AirTag, the serial is tied to your account. Therefore, when you physically find an unknown AirTag and report it to law enforcement, they can then subpoena (or get a warrant?) Apple for information on the AirTag owner's identity. The serial itself, and any personal identifiers, are not used in the locating process, however. This is well documented in the paper above, in articles, as well as in reverse engineering efforts.
  - NavinF 2y ago
    > they let law enforcement know when someone is stalking someone Source? That's not a thing
    - refulgentis 2y ago
      +1
- meindnoch 2y ago
  So how does Find My work on icloud.com then?
  - alphan0n 2y ago
    It’s explained pretty well in link provided in comment your replying to. The tl;dr is: The information is publicly available in an encrypted form that is only readable by the party with the key. Think of it like this, when you mark an item as lost you publish a hashed public identification key, if another device detects that key it creates a location report encrypted with your public key and posts it to a public list of encrypted reports, you decrypt the report with your private key.
    - meindnoch 2y ago
      >you decrypt the report with your private key Where would this private key be coming from when opening Find My on icloud.com (a website)?
      - alphan0n 2y ago
        From your keychain. Decrypted locally. If you mean from another device other than one that your keychain is on, ie, a browser on a device you haven’t logged into before, you can’t. You can get an active location through iCloud if the device is powered on or its last location before power off if the setting is enabled. But you can’t decrypt find my location reports without the private key, which is only available in devices you’ve logged into.
        meindnoch 2y ago
        Websites can access my keychain? Since when?
        alphan0n 2y ago
        What’s your actual point here? You seem to be trying to build up to something by asking me questions instead of RTFM. You aren’t “sending” the key anywhere, you are downloading the report and decrypting it locally.

alphan0n 2y ago

I’ve been using FakeTag[0] and OpenHaystack[1] coupled with a vibration sensor to notify me when various things happen around my house. Inspired by this [2] article. It’s worked flawlessly for ~2 years. [0] https://github.com/dakhnod/FakeTag https://github.com/dakhnod/FakeTag [1] https://github.com/seemoo-lab/openhaystack https://github.com/seemoo-lab/openhaystack [2] https://hackaday.com/2022/05/30/check-your-mailbox-using-the-airtag-infrastructure/ https://hackaday.com/2022/05/30/check-your-mailbox-using-the...

malmeloo 2y ago

You're correct in saying that it would be challenging for them to overhaul the entire network, but this library directly makes API calls to Apple's servers to request location reports. So while the tags would likely keep working, they could totally block the library or your account if they really wanted to.