Data erasure

Unlike degaussing and physical destruction, which render the storage media unusable, data erasure removes all information while leaving the disk operable.

[1] Software-based overwriting uses a software application to write a stream of zeros, ones or meaningless pseudorandom data onto all sectors of a hard disk drive.

[citation needed] Information technology assets commonly hold large volumes of confidential data.

These can inadvertently or intentionally make their way onto other media such as printers, USB, flash, Zip, Jaz, and REV drives.

Also, compromised networks and laptop theft and loss, as well as that of other portable media, are increasingly common sources of data breaches.

Physical destruction and degaussing destroy the digital media, requiring disposal and contributing to electronic waste while negatively impacting the carbon footprint of individuals and companies.

Because of this, many data erasure programs are provided in a bootable format, where you run off a live CD that has all of the necessary software to erase the disk.

[citation needed] Data erasure can be deployed over a network to target multiple PCs rather than having to erase each one sequentially.

In contrast with DOS-based overwriting programs that may not detect all network hardware, Linux-based data erasure software supports high-end server and storage area network (SAN) environments with hardware support for Serial ATA, Serial Attached SCSI (SAS) and Fibre Channel disks and remapped sectors.

Also, some standards require a method to verify that all the data have been removed from the entire hard drive and to view the overwrite pattern.

Complete data erasure should account for hidden areas, typically DCO, HPA and remapped sectors.

This provision was removed in a 2001 change to the manual and was never permitted for Top Secret media, but it is still listed as a technique by many providers of the data erasure software.

[13] Data erasure software should provide the user with a validation certificate indicating that the overwriting procedure was completed properly.

[27] This is not the case with modern hard drives: Even the possibility of recovering floppy disk data after overwrite is disputed.

Credit card numbers, private financial data, account information and records of online transactions can be accessed by most willing individuals.