Deleting computer files is a process of removing files from a computers file system. This is normally done using the “Delete” or “Backspace” keys on the computer keyboard.
Basic Reasons of Deleting Computer Files
- Discarding unused or irrelevant data from the computer system.
- Creating free disk space.
- Getting rid of personal private information that you may not wish to expose to other people.
A person may however delete files accidentally or need some deleted files later. A “recycle bin” or “trash folder” is therefore important to help restore important files to your computer. One can also form a habit of backing up files regularly to be protected against such occurrences. There are rare applications like MS-DOS which provides the user with the ability to “undelete files”. Instead of the actual deleting of files, it only marks them as deleted while in real sense preserving them for future “undeleting”. You can also adopt a system of marking the files that are very important to you as read only.
Sensitive Data
Sensitive data normally poses a problem since the data you choose to delete is only virtually deleted and any interested individual or party can recover or restore it. What is actually deleted is only the link to the data but not the data itself. Even if you decide to format the hard disk or overwrite it with some other data, that will not be a sure guarantee of having completely discarded the sensitive data.
This process where data deleted by the user is retained by the system is called data remanence. It makes it possible, the discovery of very sensitive or important information. Nevertheless, the advent of sophisticated technology has made it possible the creation of smart data remanence countering techniques such as encryption, physical destruction, purging, overwriting and degaussing.
Encryption
This is a careful and strong method of countering data remanence where the data to be saved b y the system is countered before being stored in the medium therefore making it impossible to recover. It can be done collectively on the whole disk or from file to file.
Physical destruction
Although this method is very expensive, it is arguably the most effective way of countering remanence of data. It is also a very lengthy and complicated process. It may involve:
- Applying concentrated chemicals with the ability to cause corrosion for example acids to the surfaces used for recording.
- Over raising temperatures above the Curie point in the case of magnetic media.
- Vaporizing or liquidifying solid disks.
- Burning the disks.
- Breaking the disks physically for instance through grinding.
Purging
This method is also known as sanitizing and involves removing the sensitive data from the specific storage device in a way that no known method or technique can reconstruct it.
Overwriting
This technique is also referred to as file shredding or disk wiping and involves the overwriting of the storage device with some other data. It is a cheap method and is mostly implemented on software.
Degaussing
This refers to reducing or completely removing a magnetic field. It is a quick and effective method that makes use of a special device known as a degausser, hence the name degaussing. It erases the formatting on hard disks making them unusable.
There are therefore many techniques to choose from when deleting computer files. It is only a matter of selecting the most appropriate and effective method to suit individual needs.