Storing Authentication Files Securely

For storing files, if you were to store authentication files then you’d have to do so in a secure manner. i.e. KeyChain on iOS and KeyStore on Android. flutter_secure_storage pub encapsulates this for you.

Persisting information and surviving app uninstallation

As per your second point, your stored authentication files cannot survive uninstallation. You have to use DeviceCheck for iOS and SafetyNet for Android. Which offers storing bare minimum information (two bits on iOS!) and associating them with the device.

KeyChain may support this for now, but this is not guaranteed to be future-proof. KeyStore certainly does not support this.

You can also check out the following articles for more insights:

• What Role do DeviceCheck and SafetyNet play in App Authentication?
• The Travelled iOS Developer — Device Check
• DeviceCheck API Unique Identifier for the iOS Devices
• Device Check Tutorial

I am looking for a solution to get the external path for the IOS platform to store some authentication files which should not be deleted even though my application is being uninstalled. Is there any way to achieve this with the solution I am looking for or any other technique could be used.
All suggestions are welcomed,
Thanks for help.