Your phone consist of the same components as a traditional computer. It has a screen, memory, storage, a processor and a (virtual) keyboard. Just like a computer, your phone hold hundreds of files such as documents, email, videos and photos. More importantly, your phone also runs a filesystem which decide what to do when you delete files.
Files Are Hidden and Not Permanently Deleted
Whenever you delete a file on your phone, that file is marked as deleted and hidden. However, the file itself is still stored inside your phone’s memory. And can easily be recovered if your device is not wiped or protected with encryption. Deleted files are only erased when you fill your storage with new files, such as music, so that your device is forced to free up old space.
A typical file such as a photo consist of two parts. The first part is the photo itself. The second part is the metadata which is information about the photo. Metadata include the name of the file, its size, the date and time the photo was taken, GPS coordinates where the photo was taken. And information about the device that was used to capture the photo. Files also has fingerprints, a long random and unique string of text, which is assigned to each file when created.
As you can imagine this information is very valuable for governments and tech companies (and probably your friends and employer too). This is because metadata can be used to connect the pieces together. Companies throw away old multi-function printers, scanners and color copiers and other devices. And people collect them to recover the documents stored in memory.
You should always wipe your phone before selling it, giving it away or leaving it somewhere. If you have an old phone or you work in law enforcement, health care or similar profession, destroying the phone is the best option. And it will give you peace of mind.
Make sure that you backup your data and store it safely before wiping your device.
How To Wipe Your iPhone, iPad, or iPod
- Tap Settings > General > Reset and tap Erase All Content and Settings
- Enter your passcode or Apple ID (if asked)
- Depending on device’s age and performance, it will be wiped after a minute or two
How To Wipe Your Android Device
Samsung
Go to Settings > General Management > Reset > Factory data reset and then tap Reset device.
Huawei
Go to Settings > System > Reset > Factory data reset and then tap Reset Phone.
Google Pixel
Go to Settings > System > Advanced > Reset options > Erase all data (factory reset) and then tap Reset phone.
Data Destruction Software Tools
As mentioned earlier, files are not permanently deleted until that old storage space is needed to fit new files on your phone. For your safety you should also use an data destruction, or file shredder, app to completely erase your device. These tools will fill up your storage with random dummy data and use military grade techniques to wipe your device so that it cannot be recovered by any means.
There are many free data destruction apps available on Google Play and iStore. Now that you have reset your device to factory settings, just create a new dummy profile for Google Play or iStore and search for “delete data” and you will find many options to completely wipe your device. Here are some suggested alternatives actively being reviewed.
Secure Erase with iShredder 6
This app securely wipes your data in three simple steps using patented security standards, making it impossible to recover any deleted files. You choose a secure deletion method and simply start the erasure process.
Shreddit – Data Eraser
A fast tool that uses chip smartly for data shredding which quickly wipes your devices in seconds. Recommended if you have an device with a lot of storage space.