Android’s “Factory reset” option is perfect for use when you are having issues with your phone or just want a completely clean phone to start with again. However, one of its main uses is to delete all data before getting rid of your phone, whether to sell it, give it to someone or just throw it away.
Factory Reset does NOT delete all data
One would think that all the personal information is completely deleted and safe from other peoples’ eyes. But that’s not the case, some of the data, including personal information, still remains accessible on the local storage, even after Factory reset!
When you factory reset your Android phone, even though your phone system becomes factory new, but some of the old Personal information is not deleted. This information is actually “marked as deleted” and hidden so you can’t see it at a glance. That including your Photos, emails, Texts and contacts, etc.
But all the data is present in your phone memory and can be easily recovered using a free data-recovery tool such as FKT Imager. If you just do a simple Factory reset and someone gets their hands on your phone, they can easily recover most of your personal information with the use of such a data-recovery tool.
In a research by Avast! a popular Anti-Virus company, 20 used Android phones were bought from eBay and with the help of Data-recovery tools, they managed to recover, above 40,000 photos, 250 contacts, 750 Texts and emails and other such personal data. This means, it is actually quite easy to gain all this personal information just by using a simple tool.
Why does a Factory Reset leave data?
Now, you must be thinking that WHY this is happening? Actually, it does take space in your memory, but it is not shown to you and when you start using the phone again, this data is overwritten.
In a time when hard drives were very slow, OS makers found that it was much better to mark the space as free instead of actually (physically) deleting the content. Eventually, new content would be written, so it seemed superfluous to write zeros or random numbers on top of it. This also avoids the wear of Flash Memory, which has a limited number of writes in their lifespan. It’s a good practice, but it assumed that you are still in control of your device. Also, this gives you a chance to recover deleted data.
However, if you want to completely wipe your android phone then the answer to this problem is actually simple, all you need to do is encrypt your phone data before factory resetting it. By following these simple steps, you will easily be able to protect your personal data and have peace of mind before giving away your phone.
Encrypt your phone before deleting the data
Step 1: Encrypt your phone
When you encrypt all your phone data before factory resetting your phone, all your data will be scrambled. Even if anyone wants to recover data using any of the Data-recovery tools, they will have to provide a specific key to unscramble the data first.
To encrypt data just go to:
Settings and tap on Security
In Security, you will see the option of Encrypt device (in some phones it is Encrypt Phone) tap on it and in the next page you can just tap on Set screen lock type to set the lock.
The whole process can take up to an hour, so make sure your phone is charged enough and you don’t need to use your phone for at least an hour.
Step 2: Factory Reset your Phone
After encrypting your phone data, you can safely Factory reset your phone. However, it should be noted that all data will be deleted so if you would like to save any data make a backup of it first. To Factory Reset your phone go to:
Settings and tap on Backup and reset under the heading “PERSONAL”.
At the end, you will see the option of Factory data reset, tap on it and in the next page tap on Reset phone at the end of the screen.
Your phone will restart and take about 2-5min to reset. Make sure you have enough battery to handle the process and battery is not pulled off during the process. This can lead to corrupting your data.
Step 3: Load fake Data and Factory Reset your Phone
This step is not necessary, the above process should be enough to give you the peace of mind that your personal information is safe. However, if you are not satisfied and want to go even further with protection, then you can add some extra steps.
Load fake data on your phone, you can connect your phone to a PC and copy/paste things that are big enough to fill all the space (although it is not necessary to fill all the space, more is just better).
After loading all fake data, do another factory reset just like in the Step 2. Now, how this extra step adds more protection? When you load fake data and delete it using the Factory reset option, all your personal data will be buried under all the fake data, making it even harder to reach.
If you are still not satisfied, then repeat this step as many times you like until you are completely satisfied.
Filed in Cellphones. Read more about Android, Data and Security.
