1

I have a rooted phone I'm willing to sell, but I had Personally Identifiable Information (PII) on it and I am questioning whether filling the internal storage with null bytes using dd would be sufficient to prevent data recovery by possible third parties.

I'm not fully familiar with the inner workings of the Android system and the differences it shares with the core Linux.

Improve this question
6
  • 1
    If you have encryption on a factory reset should be sufficient for removing all data securely. Commented Jul 25, 2023 at 16:47
  • 1
    What is the threat and what is the risk? If you are a casual user and sell the phone to another casual user, a factory reset is enough. If your phone really contains life critical secrets and you want to be protected against governmental agencies level forensics, just do not sell it but physically destroy it. Commented Jul 26, 2023 at 6:59
  • @SergeBallesta I had a photo of my personal ID on there. I've used the traditional rm -rf afterwards via ADB Shell. The question is what's the probability of that information being still available if somebody tried to recover "hidden" data? Commented Jul 26, 2023 at 7:06
  • @EsaJokinen I am running Android 12; I've read that Android 10 and upwards enforces this rule by default? Commented Jul 26, 2023 at 7:07
  • 3
    rm -rf never destroys the data itself but just removes the links to it from the file system. That means that it is still possible to identify removed files by searching well known patterns on the disk device. dd is of course more secure because it overwrites the data but: 1/ if you overwrite system data, you phone will not be useable any longer 2/ unless you know the specifics of the implementation of your phone you cannot be sure that there are no hidden partitions. BTW and IMHO, an ID card is personal data but not secret data Commented Jul 26, 2023 at 7:14

0

Reset to default

You must log in to answer this question.