Need for Secure Data Wiping for Data privacy

 

Need for Secure Data Wiping for Data privacy

 

If you were trying to delete confidential data from your hard drive or SSD, a malicious person could recover your files using data recovery software or Windows file history. So what to do to permanently delete a file from your hard drive? Follow our elaborate guide to stay calm.

Let's imagine that you want to permanent Data Wipe that contains confidential data such as business documents, your bank details, administrative information, financial documents, a private conversation or something else. In short, the things that you want to eliminate forever and that no one finds.

 

Data Wiping Process

Normally, you send the file to the Recycle Bin, and then empty it completely. Faster, you can also select the file from Windows Explorer and press Ctrl + Del to delete it without going through the Trash.

 

Using this method, you get the impression that your file is permanently deleted. However, it still physically exists on the HDD or SSD.

 

A file occupies a specific space on the disk, so when you delete a file from the Recycle Bin, the file system (the library that organizes and stores files on the disk) simply tells Windows that the space occupied by that file was left free and can be used to store another file in its place. The file system only deletes the reference in the file table, but not the file itself.

 

An "X" file will remain on the HDD or SSD until another "Y" file is created and placed in the space occupied by this old "X" file. And even after that, it is still possible to recover the data from the old file by studying the magnetic fields on the surface of the hard drive tray.

 

In short, when you delete a file from the Recycle Bin, the data in the file is not removed from the disk, but simply waits to be replaced. The solution is to write random data to the disk space where the old file was located. Therefore, nobody will be able to recover your file because only the random data written on that file will be visible.

 

What happens to a file when it is deleted?

We leave you the two most common cases:

 

Hard disk drives (HDD)

When you delete a file on an HDD, it goes to the Recycle Bin. This gives the opportunity to recover it in case it was accidentally deleted and needed again.

But what happens when it is removed from the Recycle Bin? Not much really. The file is not moving or going anywhere. In fact, when you moved it to the Recycle Bin, it didn't physically go there either. All that happened was an index was updated to say that the file is in the Recycle Bin, not the Documents folder. The index is called the Master File Table (MFT) for hard drives. Until the operating system puts data there, the data in the deleted file will remain recoverable. It may take minutes, days, weeks, or months for the data to be overwritten.

 

Solid State Drives (SSD)

It is not exactly the same for solid state drives. SSDs are always randomly moving files. Therefore, figuratively speaking, if you delete a file from location 2781, the deleted information can sooner or later be moved to another random location, until at some point the SSD finally decides to overwrite that file.

 

So how do you select old file to be safely deleted on SSD drive?

Well, you really can't. A group of engineers from the University of California studied how difficult it is to erase data from an SSD drive. What you can do is make sure that you encrypted your SSD and that you have a TRIM capable SSD. This is not a problem for most people, but you may be concerned that people can still access that deleted information.

 

The least secure Data Wiping method

Just delete the file in Windows Explorer and empty the Recycle Bin. Unless you think someone will come up with data recovery software and search for that file at some point, this will probably be pretty safe for most people.

However, this is the easiest way to leave the deleted files on your disk so that they can be found through specialized software. We already made this clear at the beginning of the article, right? 

 

Software to delete files on an HDD

To do this, you must use file shredding software. There are several, but if I recommended one to permanently erase your files, it would be Eraser. By default, Eraser uses the Guttmann algorithm, which writes patterns several times in the space containing the data to be destroyed. This algorithm ensures that your data cannot be recovered.

We leave you a small tutorial on how to permanently delete a file or folder, with the free Eraser software. Here we go!

 

Simple erase with Eraser

Simple removal from Windows Explorer: removal starts immediately or when Windows restarts, using the default removal method and the right mouse button, selecting “Erase” and “Options”.

An information bubble will appear in the notification bar once the file has been permanently removed from the hard drive.

 

Advanced erasure with Eraser

Advanced erasing by creating a task from the Eraser interface. This method offers more possibilities: choose the delete method, schedule the Data Wiping at a specific date and time, choose the type of items you want to delete (file, folder, trash, unused disk space, and more).

Before you start deleting a file and whatever method you choose, go to the Eraser settings to define the delete method.

 

In the default Data Wiping method, choose the default delete method for your files and folders. Erasure methods are ranked from top to bottom, from the most efficient (Gutmann - 35 passes) to the most superficial 

 

With the Gutmann method, you have the assurance that your data will be completely erased from the hard drive, making it impossible to recover it. However, this method takes a long time, since 35 passes are made in the area to be erased. On the contrary, the Pseudorandom Data method is very fast, but it does not guarantee a permanent Data Wiping.

 

In the default unused space erase method, choose the default erase method to be applied to unused disk space (feature available with advanced erase).

 

Open Eraser, click on the arrow to the right of the "Erase Schedule" option and select "New Task" (shortcut: Ctrl + N).

 

·         You must define the following properties:

·         Task name (optional): this is the name you want to give your task, and it is optional.

·     Task Type: when you want to execute the task, being able to choose between manual, immediate, restarting or recurring.

·         Data to erase: data to be permanently erased.

·     If you select “Recurring” to delete files on a schedule, go to the “Schedule” tab to configure the schedule settings and select when to start deleting: Daily (every day), Weekly (every week) or Monthly (every month).

In the "Task" tab, click on the "Add data" button to select the items you want to remove:

·        File: a specific file.

·        Files in folder: all files in a folder. Check the Delete folder if empty box to delete the folder as well and not just its contents.

·      Unused Disk Space - Unused disk space on the hard drive. We have seen before that a free space does not mean that there are no files on the hard drive, just that these files are waiting to be replaced by later files.

·        Recycling Bin: the Recycling Bin itself.

·       Secure move: move the file to another location without leaving a trace.

·       Drive / Partition: select the partition you want to delete.

 

You can also select the erasing method in “Erasure Method”.

Double click on OK to confirm the final Data Wiping, depending on the options you just defined. Eraser tells you in its interface when the tasks will be executed next time (in the Next Execution column).

 

If you have decided to manually delete a file or folder, you should start deleting by right-clicking on the task and selecting Run now.

The status of the task changes to Completed when the files are deleted.

 

Other applications for Data Wiping

With their hard drives, some people try to recover deleted data, for example with software like Recuva. Others point to the exact opposite: ensuring that deleted files are no longer recoverable at all. For this, there is nothing better than resorting to secure erasure software.

Thanks to the kind of software, not only are files and folders that are basically deleted no longer recoverable, but formatted and partitioned disks also lose all traces of your old data. At least that's what the developers promise.

 

Clean Disk Security

It is a shareware (the license costs $ 19) whose interface (in English) makes it easy to carry out a set of secure erasure tasks. Simply check the desired options (out of a total of ten), choose the method and click the "Clean" button.

As in Eraser, there is a "Clean standard free space" function, but apparently no function to safely delete existing files. For security reasons, the developer has chosen to install this option in the Windows context menu, by right-clicking on a file or folder.

Clean Disk Security also provides a tool to view the content of each sector of the disk from the "View" button, a slightly more technical option that may be useful.

 

Prevent Restore

 

It's the free version of the Prevent Restore Pro software, which costs about $ 14.95. In this lighter version, only one deletion algorithm is proposed, which consists of replacing the deleted data with spaces.

 

The software is easier to use than Clean Disk Security, and even easier than Eraser, since you only need to answer a wizard's questions to start a safe removal procedure.

Note that here you can only permanently delete what has already been deleted: if necessary, you will need to delete the content you want to delete before starting the software.

 

Despite its limited functions and erasure methods , Prevent Restore is an interesting option that can be sufficient within a company, for example to clean a reconditioned workstation to move it from one department to another.

 

C-Cleaner

 

If you know CCleaner, you probably know that it is not secure erasure software, but a Windows optimization tool. It is used in particular to remove (in a traditional way) temporary files from browsers and to optimize the Windows Registry.

 

CCleaner is nevertheless an interesting option here, as it is equipped with a disk erasure module. Which may be enough for your needs?

Everything is very simple here: you choose what to erase (free space or all), how (with a simple to very complex algorithm, from 1 to 35 passes) and where (in which drive). And that's it.

 

The advantage of choosing CCleaner to secure your hard drives is that the software is available in a portable version. You can copy CCleaner Portable to a USB stick and thus have a ready-to-use eraser tool in your pocket and just one click away.

Also, the interface is in Spanish.

 

Data Wiping on solid state drives

 

Solid State Drives (SSDs) are becoming increasingly popular and it seems like it's only a matter of time until they replace conventional hard drives in computer systems.

SSD drives work differently from hard drives, especially when it comes to drive read and write processes. The most efficient way to safely remove hard drives (overwrite space with data) becomes unusable on SSD drives due to their design.

 

Data on hard drives can be erased by overwriting them. This ensures that the data is not recoverable by data recovery tools. This method does not work on SSD drives as it is not possible to specify the location to overwrite. This is very problematic for computer users who want to give away their computer or sell it to a third party, as the data on the SSD can be recovered by the new owner.

 

But for SSDs there are also erasure methods:

·         Official manufacturer utilities

·         PartedMagic

·         Delete files

·         Format the SSD drive

 

Official manufacturer utilities

Erasing any trace of an SSD is more complicated. However, also in this case we can use different methods. The first is to use the SSD manufacturer's utilities. Each manufacturer of SSDs includes software with their products to be able to manage the data and functions of the disk. These are the main utilities that SSD manufacturers include:

·         Solid State Toolbox

·         Corsair SSD Toolbox

·         SanDisk SSD Toolbox

·         Samsung Magician Software

·         OCZ Toolbox

 

Using Parted Magic

Another way to delete data on an SSD is Parted Magic. This is very effective software that costs around $ 12.

 

Delete files

This is a direct way to delete files on the solid state drive from the operating system. It is the only option that can be used to selectively delete files and folders. Deleting the files directly in Windows Explorer is not enough to protect data from recovery software, as software like Recuva can find almost 100% of the files that have been deleted in Windows Explorer.

 

Deleting files directly in the operating system is therefore not an option to permanently delete sensitive data on solid state drives.

 

Formatting the Solid State Drive

This is the easiest option, as it can be run directly without the need for additional software. Windows users should locate the SSD drive in Windows Explorer, right-click on it, and select "Format" from the available options. It is important to uncheck the "Quick Format" option to make sure that all data on the drive is formatted. Windows Explorer does not display any files on the drive after the full format is complete.

 

Recommended method to erase data on SSD

Many recommend formatting the solid state drive as it is the easiest method of all. Generally, it is not necessary to encrypt the data on the drive before formatting it, as it produces the same results as doing a standard format. It is highly recommended to test the result with a file recovery software to make sure that the excess data cannot be recovered.

 

Conclusion

In this tutorial we saw several methods that allow you to permanently delete a file or folder from an HDD or SSD.