One main reason many Android users go for a factory reset is to take care of bugs that arise from updates, be it the stock Android OS or apps installed on the phone.
At times, the process is also carried out when one wants to maintain a top-performing device or maybe when s/he wants to wipe complete data from the device and make it as good as new. While many go for the inbuilt factory reset that comes with Android OS, this method can easily expose your data even after resetting the phone. If your goal is to get completely rid of all data stored on your device and at the same time prevent any attempts to recover the data, there is a better way of doing this rather than the usual factory reset.
Before carrying out a factory reset, Google will usually warn you that all of your data including passwords to signed-in accounts and installed apps will be lost. However, this is usually not the case, as it turns out.
Why factory reset doesn’t work
It has been found that Android devices – even after fully performing a factory reset – still keep some files behind. Researchers from Cambridge University found out that account tokens can be recovered. These are what Google, WhatsApp, Facebook and other services use to authenticate users once they provide a password for the first time. In more than 80% of the tests, it was possible to recover the master tokens that can essentially be used to recover everything about the said account. It means that your accounts can still be synced to the device and access the data stored in your emails, contacts, cloud storage services and other accounts.
How to wipe all data on Android devices
In case you want to get rid of everything from your Android device before maybe moving onto another, here is what you should do.
The first thing is to use a strong and hard to decrypt password that makes use of a mixture of characters. Even though it is quite awkward, it will keep you and your data safe as anyone trying to decrypt the device after a factory reset has to work on it maybe for days. On the other hand, you can choose to refill the flash storage with unnecessary data so as to overwrite the stored tokens or even crypto keys that may be lagging behind in the device’s flash storage.
You will have to download the app for filling the phone from a source outside the Play Store so as to avoid getting the tokens stored on the device as well. According to the researchers, the only best solution is to destroy the device or maybe, you could simply take great care of the hands your second-hand device ends in just in case you want to get rid of it.