Question Fingerprinting

rvbfan

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The IMEI would be one way. Never changes no matter how many times it is reset. That's how stolen or lost phones can be black listed. Also people that skip out on paying off loans for phones.
As for apps? Not all apps require that sort of identification except probably banking or government apps. Most apps would do it by registration info, Google backup for one.
 
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B. Diddy

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Maybe it's the unique MAC address. Also, some apps will backup data to their own cloud server, and Google can also backup data to your Google account, so when you reinstall an app, it may still restore the previous data.
 

mustang7757

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Hello. I'm asking how they identify my device even after factory reset.
Factory reset through the device settings removes application to identity your application because you would use Google on most devices or cloud services from that manufacturer, if you factory reset through recovery will delete applications and pictures some features but your Google account is Link this way still if you do it through recovery and will ask for Google credentials.

If you have no Google account then your device doesn't have an account to go by and will be like how you got it need not associated with anything
 

VidJunky

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Sorry for being late to the party on this one. Can you, without giving up too much personal info, give us an example of an app that still recognized your device after a factory reset?

Will you also describe the steps you take, or took, that brought you to this conclusion? Was it actually a factory reset or some other action?

For instance, I know you say that you do not have a Google account on the device, but how then are you getting apps? A linked Google account is needed to access apps from the Play Store. It used to be that a Google account was needed to activate an Android device without being limited to the very basic of uses.

Are you also saying that none of your apps require a log-in of any kind? If they do not have any log in what information are they providing that causes you to believe they remember you/your device?

Barring the need for a Google account to download and install apps, if only from the Play Store, I've had phones that pull up previously saved data after uninstalling and installing the same app again because uninstalls are not as complete as many make them seem. Often there are folders left on the device which could include some saved or archived data from a previous install. How strong or weak this is depends on the device and the OS version as newer, more recent versions of the OS, have many more securities built in.

What device do you have and what OS version are you using?

Let's not forget your SIM card, carrier account. Both of which are accessible when granting Phone permission to an app. This falls under reading the phone state, I believe. If not it is accessible in other ways through permissions.

These devices are mini data recorders and we literally feed them everything about our selves in ways we can't even count. In fact doing a factory reset with app recovery literally requires the device to record every app on the device so that it can reinstall them once the reset is complete. How can an app remember you, the question should be what are you doing to make the phone forget your apps.
 

nanotomi

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I'm using adb to install apps. And using fingerprint.com to check if device is known to them.
Changing drm id works to confuse their demo app but it still somehow knows when device was factory reset.
 

VidJunky

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Well it sounds like you're more versed in this than I am. I had to look up fingerprint and DRM. I'm not sure how DRM plays into this since it appears to be related to signing copy righted materials, but your device IP wouldn't change, which I'm sure is part of how FP.com IDs devices. And honestly as far as demo trials and such go they may not care too much about that stuff if they're trying to get eyes and minds on their product.

When you say it knows when your device was FR the phone records these events. It may keep records of FR activity for life since these are probably rare events but I'm sure it keeps track of power off events and installation events as well. These records are in places not accessible to most users, and probably duplicated in different locations on the device as well, so only people with in-depth knowledge of Android OS, and the MFR's software twist would be able to identify or locate them all. And I'm sure at least some of these records are retained even after a FR. Resets are more to remove personal information, settings, and other odd things but doesn't just wipe the whole device like one might think.
 
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VidJunky

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You would need to root the device to access all areas of the OS. These are not things you can just use a file manager to access or simply find by randomly going through some folders. It's part of the OS which users are locked out of. Even after rooting you would need a depth of understanding about Android. Rooting around in the OS is not something that you can just trial and error your way through. We've seen countless instances of users saying, I just deleted this packet, or changed this value, making what they thought was a small innocuous change and that having a profound effect, damaging or disabling the device.

If you want to know more about rooting. Check in at XDA Developers. They do more with rooting and custom ROMs.
 
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