Specific Control
The studies have shown that people don't securely delete data from drives before selling them. By deleting files from operating system, an entry is deleted in the index of files that tells where the data is stored. A new data have to overwrite the old data, for the data not to be visible. Otherwise, the files can be easily recovered.
Knoppix is a very useful tool for securely deleting the files on the system because it provides a shred utility. Shred utility overwrites the data multiple times with random data, that way any real data that is on there is scrambled with random data that will likely actually overwrite its place on the drive. When you shred a file, shred not only unlinks it, but it also overwrites the sectors on the drive 25 times with random data. After shredding the file the risk of recovering the data is greatly reduced.
To shred the data Knoppix must be booted and you will need to find the appropriate partition to wipe. Open a console window and type in the following:
sudo shred �n 2 �z �v /dev/hda1
-n 2 � it tells shred to overwrite the partition 2 times. By default it set to 25 times but each pass can take some time. You can choose the number by the amount of time you have.
-z - it tells shred to write zeros into the drive
-v - it shows user the progress
hda1 � the name of the chosen partition from which the data will be deleted or shredded
To the companies a LiveCD provides an easy way to shred data. Especially in cases where the sensitive data is stored on the hard drive it is important to securely delete the data. After shredding the files the hard drive can be sold or thrown away without the worries of data being recovered.