We’ve all been there – you go to take a photo or download a new app on your phone, only to be confronted with the dreaded “Storage Almost Full” notification. So you head into your file manager and start deleting old pictures, videos, documents and apps to clear up space. But does deleting those files from your mobile device permanently remove the data? The reality is, that “deleted” file isn’t gone for good.
Understanding exactly what happens when you delete files from your smartphone or tablet is crucial from a data privacy and security perspective. Your personal information, pictures, communications and other sensitive data could potentially still exist on the device even after deleting files. This article will explore the process of deleting mobile files, how to permanently wipe data beyond recovery, and the implications of improper deletion hygiene.
Mobile File Systems Explained
In order to understand mobile file deletion, it is important to grasp the basics of how mobile operating systems like Android and iOS are currently managing the file storage on the hardware. Both make use of the file system structure in a logical way to map and display the physical location of all the data on the device’s internal storage chips or memory cards.
Android uses mostly file systems like EXT4, F2FS or EROFS. Apple’s iOS uses the Apple File System (APFS) which appeared in 2017. These file systems store intricate information about the files beyond just the raw data like each file’s size, location, timestamps, etc.
The actual file deletion process itself doesn’t start from the very beginning every time you click the delete button. The file is already located on the storage device and its virtual address is stored in the device’s file system index.
The Deletion Process
So what actually happens when you delete a file from your mobile device? Contrary to what the “delete” name implies, the file data itself is not actively erased or overwritten anywhere on the storage hardware. Instead, the file system simply removes the file’s virtual indexing information like its location and name.
Any actual data stored by that file remains entirely intact on the storage drive or memory card. The space that file occupied is just marked as freely available for new files to eventually overwrite it through regular usage. But until that free space is used, deleted file remnants still technically exist.
This is why it’s relatively trivial for file recovery tools to scan the raw storage blocks and undelete files – the tools can detect the data payloads of those “deleted” files and reconstruct them if they haven’t been overwritten yet.
Permanently Deleting Mobile Data
Removing the file from your mobile gallery or document app by just clicking on the delete button fails to securely wipe the data. The data can be recovered as long as it has not been overwritten by a new information until that specific storage space becomes full, which may take a very long time.
To thoroughly wipe deleted data beyond any possibility of recovery, more robust deletion methods are required:
Secure File Shredding Apps: This functionality will be carried out by the apps which will write the garbage character data instead of the deleted files and then remove the file pointer so that recovery is not possible.
Encryption: On the other hand, if the device’s entire storage is encrypted, then deleted files become scrambled data which will be useless without the decryption key.
Complete Device Wipe: Secure wipe tools can effectively reset the phone before selling it by utilizing cryptographic erase, signed code wiping or secure reformatting that provides 100% data erasure.
Although not being a new problem, the fear of personal data leaks and violations of the privacy of citizens have recently become a critical issue. Therefore, it is necessary to use the most sophisticated deletion methods rather than the standard file deletion that still leaves the ghosts.
Mobile Device Data Recovery
On the contrary, the fact that “deleted” files from mobile devices can be recovered is quite helpful in some cases, particularly in the legal field. A lot of data recovery tools and services are capable of retrieving the lost photos, videos, notes or other vital files that users mistakenly deleted from their phones.
Apart from that, mobile data recovery tools have major forensic and legal applications as well. Digital forensic experts often use these techniques to restore and analyze evidence that has been deleted from a suspect’s mobile phone during an investigation.
While these abilities can be leveraged for positive reasons, they are also used in a malicious way by the bad actors. Insufficiently wiped phones that are recycled, resold or otherwise passed on can lead to a huge breach of data privacy when data from the users is recovered.
The fact that this is always the case only highlights the importance of using such tools and strategies as secure data wiping or remote data wiping to avoid leakage of personal or corporate data from lost or stolen mobile devices.
Conclusion
Although hitting a delete button on your smartphone could remove a file from view, the data itself somehow is still there. Trash bin marketers that area as blank for future overwriting. Unlike the original file, the remaining file consists of data which keeps on staying in the system until a new data replaces it or until the system wipes it out.
On the other side, when no longer properly managed, archives can create data privacy and security issues. Implementing encryption, remote wiping of data and protocols suited for securing mobile devices is a must to guard against the regaining of sensitive data even after a mobile device is belatedly wiped.
Either you need to remove all your personal data, replace it with a non personal data or destroy the device before resale. Also, guard against the lost/stolen device or simply decrease the security threats by doing the basic digital hygiene practices. As we are all living in mobile-driven world now, the issue of eliminating data ghosts through secured deletion gets to be the highest priority.