Why you need to securely delete files from your device

Information is crucial in our contemporary technical society, community and environment. People use it every day while companies are constantly striving to obtain it, due to its ability to improve their products and services. However, while incredibly useful, it can also be quite dangerous if it happens to end up in the wrong hands. Information exists in many forms on all of our devices, applications and gadgets, meaning that there are a plethora of different ways in which it can be stolen, collected, sold or leaked.

Issues related to user privacy and online security have been becoming increasingly more prevalent, which has resulted in many such cases of personal data leaks and information breaches. While there are quite a number of actions that you can perform to protect your privacy and security, you might forget to look in one particular place - your device’s storage system.

Storing different files on your device for an extended period of time can lead to potential damage to you and your device in the long run. This, of course, refers to random files or files that you have downloaded from an untrusted source (including those generated by divergent applications). Furthemore, unused apps can also pose a secret threat to your security due to the fact that less usage almost always guarantees that the given app has not been updated in quite some time, not to mention any sensitive files that you might have deleted previously.

Ultimately, it is crucial to take out data from your device, but you also need to know how to do so efficiently and permanently. This is because some files do not get removed forever, but are rather moved to your trash, kept in the register memory or transferred to another local folder on a pc, laptop, table or mobile. So, keeping that in mind, let us dive right into it!

Why do I need to make sure to delete my unused files?

Before we can get into the nitty-gritty of permanently getting rid of anything on your machine, you need to consider what can happen if you decide not to do so. First off, unused files take up extra space that you can otherwise use to accommodate new applications and other files. However, this is not the primary reason behind removing your files. As a matter of fact, it is due to the security and privacy aspect, which we already highlighted before.

Downloading random files such as executables (.exe), images or textual documents can be quite problematic if they are executed or opened on your device. Avoiding downloading anything from a random source is the best remedy to avoid potential issues in the future. However, if you happen to find yourself downloading and actively storing such files on your system, you have to be sure to remove them immediately. This is because such files can act as a tracker to your device, passively collecting information about your device, location and everyday activities.

Additionally, they can also track your calls, serve as an overlay that can collect sensitive information such as your private data, card numbers, passwords, emails and accounts in general. Moreover, with the rise of cryptocurrencies, you never know when a mining software will find itself onto your device. 

Finally, if you delete a file that contains usernames, passwords or other login/account credentials, it is quite possible for someone to recover it if they gain access to your device, meaning that they can potentially obtain sensitive information. Because of this, the bottom line is that you should never store anything suspicious or personal on your device and you should actively strive to remove anything that you do not use or do not intend to do so.

How to securely delete a file depending on your operating system

There are many different variations of operating systems that are utilized on a global scale. However, regardless of the system that your device has, in most cases you will need to use a ‘shredder’ application. But why is that? 

When you delete a given file, what your operating system does is to simply remove the pointer that is currently attached to it. Then, when new data is funneled into the storage system, it gets routed to that same address, essentially overriding the data that was in a way ‘left’ or ‘stuck’ on the drive. This means that until the old data gets overridden, it is still possible to recover these files, which we will go into more detail on in the following sections. Additionally, for the sake of this article, we are going to be looking into the most used operating systems worldwide.

Deleting files on Windows

When you take out a file on Windows, you are generally prompted with a message of whether you would like to move the given file to the trash bin. However, doing this will only result in the file’s location being changed, making it possible to be recovered if you have accidentally made a mistake when initially disposing of the file. But while you would think that once you have emptied your trash you cannot possibly bring a file back, you would be quite surprised to know that this is not always true.

Even when you hard delete a file such as using Shift + Delete from your keyboard, a portion of the file’s data still remains on your device’s memory. Windows and other operating systems do this in order to save time. It is a lot easier and substantially quicker to remove the pointer and its reference to the particular memory deposit on the storage system rather than removing the information or file entirely. Most of you have probably noticed that it can take only a few seconds (in most cases it is even instantaneous) to dispose of a substantially large bunch of files of let’s say around 50GB, while installing a 5GB application or downloading a 10GB file can take ages. This is because when any new data is being added to the system, it is overriding the previously stored information, resulting in the whole process taking longer.

Because of this, if you want to permanently delete a file from your system, you are advised to utilize a shredder application that we mentioned previously as it can completely remove anything from your device in addition to changing and overwriting any previous file data. This will guarantee that everything will be permanently removed from your system without you having to worry about it being recovered or stored somewhere else.

Some shredder applications that you can look into using are:

• Eraser
• WipeFile
• BitKiller
• File Shredder
• Freeraser
• PC Shredder
• SecureDelete
• And many more

These applications are all more than capable of securely deleting your files, however, as with everything else, some have additional features that others do not. We are not going to be comparing them in this article, but you can do some further independent research to get to know about the features, advantages and drawbacks of each one. The main point here is to use any shredder to permanently remove files from your Windows device.

Removing files on Linux

Securely deleting files on Linux happens with the use of some command line tools that can perform different functions. Similarly to removing files on Windows, these tools can allow you to permanently dispose of the contents of a given file, including its data and references in terms of the storage system. Just remember that these are all tools and you need to download and install before you can start using them.

The following tools all perform different functions but here is a basic rundown of what each has to offer:

• Wipe - when using ‘wipe’ you will be getting rid of all specified files from the magnetic memory of your device, making it impossible for them to be recovered
• Shred - ‘shred’ allows you to either override a given file or to completely take it out in general
• Sfill - ‘sfill’ takes your ‘free’ data, which is waiting to be overridden and fills it up with information from ‘/dev/urandom’, which will guarantee that even if these not yet overridden sections of memory were to be accessed, they will contain data which will be completely random

Disposing of data on Android and iOS

Deleting files securely on Android or iOS, similarly to Windows, involves using a shredder application. There are plenty of available options on the playstore that you can get for absolutely free and there are also some premium ones that have additional features for you to utilize. Some of the more famous ones for Android in particular include:

• Shreddit
• Fshred
• SDelete

While some suggestions for iOS are:

• Stellar iPhone
• PanFone
• PhoneClean
• iShredder
• iMyFone

Again, as we previously mentioned, we will not be covering each one in detail as the primary goal here is to learn how to securely dispose of information from your device and each one of those apps can help you do so.

Another thing that you can do in order to bin files from your phone is to connect your Android/iOS device to your desktop or laptop and then manually browse through your device’s file system, which will allow you to delete information from your system.

Alternatively, you can also do a full-system reset by returning your phone to its factory settings. However, this will result in all of your data being lost so only consider it in extreme cases.

That’s it! Remember that removing files from your system is crucial in order to guarantee that your privacy is protected.