Device-unique data on Android

On Android devices, two device-specific keys are computed to ensure uniqueness. One is generated from the ANDROID_ID or (exclusive) the SERIAL, depending on the deviceIdentificationMethod configuration. The other is generated from the ANDROID_ID, and may also include the SERIAL depending on the deviceIdentificationMethod configuration. For more information, refer to https://developer.android.com/reference/android/provider/Settings.Secure#ANDROID_ID.

Since Android 8.0, the SERIAL value is not accessible anymore. Devices activated using the SERIAL will keep using this value stored securely inside the application. If the SERIAL is not available at activation, a random value is used instead, and is securely stored for future operations.