As new smartphones hit the market, people are looking to offload their outdated devices more frequently than ever before. When selling an old phone, the standard procedure is to restore the device to factory settings, wiping it clean of any personal data. This creates a new-phone feel for the new owner and offers protection for the original owner. However, a security firm has determined returning Android devices to factory settings doesn't actually wipe them clean.
Security firm Avast purchased twenty used Android phones on eBay. Through extraction methods, they were able to recover old emails, texts, and even photos. In their recovery, they found hundreds of nude selfies of one man, presumably the last owner. Even though they are a sophisticated security firm, Avast didn't have to work too hard to unlock this data. Avast used a digital forensics software, which they described to CNET as "fairly generic" and "publicly available."
So, in the event the future owner of your device happens to invest in this software, you should take extra measures to protect your data. Before you sell your device, here's a how to on really protecting your data by encrypting it before attempting the reset.
1. Plug in your phone to charge.
This is going to take at least an hour, and will fail if your battery dies during the process.
2. Open the Settings Icon on your Android device
3. Select Security within the Settings list
4. Select Encrypt Phone
Wait about an hour.
5. When the process is complete, restore to factory settings as you usually would.
Through this process, your data will be encrypted. It will be inaccessible to any future owner, protecting your information forever.