Information Security and data termination

Added: (Fri Mar 05 2010)

Pressbox (Press Release) - How Does File Deletion Work

Data maintenance and security is an area where even the most experienced computer user is caught wanting for information. Most people believe that computers strictly stick to the 0-1 (true or false) binary system in which either there's data there, or there's not. Actually it works quite a bit differently.

Data is stored in the hard-disk on magnetic discs. And every time data is modified, stored or deleted there's a physical effect and a magnetic residue which records the operations. So even if you delete a file from the hard disk, and over-write it, there's still a possibility that some of the data can be recovered.

This is what the computer experts in government organizations rely on when they investigate a computer. They are potentially able to retrieve almost all of the data the data that has been stored or recorded on the hard disk using specialized tools.

In fact the truth is that the normal file deletion of your operating system does not even delete the file at all. All it does is mark the clusters available for use, while your data still lies there in all its glory. Anyone with a simple undelete or a recovery application can retrieve this data.

There are specialized applications that attempt to delete data permanently from the hard disk drive. There are many approaches to doing this and different applications handle things differently. The most relied upon algorithm writes upon the deleted data several times to ensure that the chances of recovery are minimized.

Unfortunately permanent deletion of data is a time-consuming affair that's why doing it while your other operations are suspended can be really irritating. That's why not many people utilize the hard deletion options available to them.

The number of iterations of writing the random data over the deleted data decide how difficult recovering the deleted data is going to be. The more random the data and more the number of iterations the harder it is to recover deleted data. Data deletion in this manner is performed in a sector-by-sector basis so implementation defers from file system to file system.

The most popular Windows based file systems are NTFS and FAT32. NTFS is used in Windows XP, Vista and Windows Server products while FAT32 was used in Windows 98. Generally a permanent file deletion utility has to support at least these file systems.

Most permanent file deletion programs do not work in an un-obtrusive or stealthy manner, so the security they provide is only effective if the owner is around to manually delete the files. This is not very helpful if your computer is stolen and your sensitive files are there.