I advice you to read the official blog of the best practice of google to see what the use case match with your specification : https://developer.android.com/training/articles/user-data-ids.html
For me i occcured the same problem about the unicity of android identifiers and i found the only solution is to use the MediaDrm API ( https://android.googlesource.com/platform/frameworks/base/+/android-cts-4.4_r1/media/java/android/media/MediaDrm.java#539 )
which contains a unique device id and can survive even on the factory reset and doesn’t need any additional permission on your manifest file.
Here is the couple of code how can we retreive the unique identifier on Android 10 :
import android.media.MediaDrm
import java.security.MessageDigest
import java.util.*
object UniqueDeviceID {
/**
* UUID for the Widevine DRM scheme.
* <p>
* Widevine is supported on Android devices running Android 4.3 (API Level 18) and up.
*/
fun getUniqueId(): String? {
val WIDEVINE_UUID = UUID(-0x121074568629b532L, -0x5c37d8232ae2de13L)
var wvDrm: MediaDrm? = null
try {
wvDrm = MediaDrm(WIDEVINE_UUID)
val widevineId = wvDrm.getPropertyByteArray(MediaDrm.PROPERTY_DEVICE_UNIQUE_ID)
val md = MessageDigest.getInstance("SHA-256")
md.update(widevineId)
return md.digest().toHexString()
} catch (e: Exception) {
//WIDEVINE is not available
return null
} finally {
if (AndroidPlatformUtils.isAndroidTargetPieAndHigher()) {
wvDrm?.close()
} else {
wvDrm?.release()
}
}
}
fun ByteArray.toHexString() = joinToString("") { "%02x".format(it) }
}