If you are planning on selling or swapping your used Android mobile device it is very important that you remove the information stored on it properly, simply deleting the data doesn’t permanently destroy it. In most cases, this data can be easily restored. Below is the best-advised method for making sure your data is completely erased.
When deleting files from any device, be it your personal computer or mobile phone, you need to be aware that it isn’t actually permanently gone. The file still remains on your phone or computer even after being deleted. On deletion, a mark is placed in the position of the file you wish to remove and new data is placed on top of the old file. This happens in an endless cycle until data is eventually completely overwritten, subsequently destroyed. Something to remember though is that no method besides physically destroying your device is going to be 100 percent effective. Even after overwriting data dozens of times, forensics experts can sometimes still restore segments of files.
Important Steps to Take Before Beginning a Complete Phone Erase.
Before you begin the process of erasing your Android phone or tablet, there are a few things that you might want to do. Firstly backup all of the data you wish to save, including contacts, doubling checking the location they have been saved to, Sim card, Cloud, or Device. Also, don’t forget to remove the SIM card and any internal SD cards you may be using. Next make sure you log out of everything you are logged into on your device, email accounts, Google Play, Facebook and so on. If you wish to leave the SD card in the device you will need to follow the same erasure process as the main phone.
Note: Keep the serial number of the phone or tablet on file somewhere, in case you have any future issues.
Beginning the Erasure Process on Your Android Device.
The simplest and quickest way to wipe your Android device is to perform a Factory Reset. This is a very basic wipe and data such as SMS contacts and pictures can still be recovered quite easily, using standard and free online data recovery tools. The most secure method is to erase your Android phone or tablet by encrypting your device first, through the settings menu. This process doesn’t require you to download any special apps or tools and only requires a bit more of your time, however, the results are much more permanent.
Step One: Encrypting Your Android Device.
It is best to encrypt your device before wiping it, in order to scramble the data and ruin any patterns that might normally be detectable by recovery software. Even if the deletion process doesn't fully wipe your data, it will be near impossible to restore and is protected with a PIN or password. To begin the encryption process on a standard non-rooted Android device, go to Security Settings, which can be found under security in the main settings menu.
Note: This location may vary somewhat depending on your phone brand and model, for example on HTC devices, it is located in the phone storage menu. Some models will also only allow encryption from the base of a factory reset if you have this issue, reset the device first then encrypt it.
Step Two: Wiping the Data With a Factory Reset.
Once you have encrypted your data, you will need to perform a factory reset on your device. Factory reset can be found in various places, depending on the brand and model of your phone once again. Most commonly though factory reset is found under the Backup and Reset menu, just inside the main settings tab. Remember that performing a factory reset is going to erase all your data, so make sure you have created backup.
Step Three: Load Up on Junk Data.
When erasing data from your mobile device, generally steps one and two are going to provide plenty of protection for your data and ensure a very good level of removal. However, if you want to add an extra level of reassurance you can now fill the empty space on your newly reset phone with junk data. Random files, pictures, photos, anything you wish just to make any sort of recovery efforts much more confusing and complex. Once it's loaded, perform another factory reset. You can repeat this process as many times as you like to further bury and distort old information.
If you want to be 100% sure, it's best to just acid bath, burn, then smash your device with a large hammer, before burying the remains deep in the woods. But that may not be the most cost effective idea.