In addition, degaussing can create irreversible damage to hard drives. It destroys the special servo control data on the drive, which is meant to be permanently embedded. Once the servo is damaged, the drive is unusable.
"Degaussing makes data unrecoverable, but it can damage certain media types so that they are no longer usable," Harkins says. "So if you're reusing [those media] this may not be the right method."
Once disks are rendered inoperable by degaussing, manufacturers may not be able to fix drives or honor replacement warranties and service contracts, Tero says.
There's also the issue of securing media during the process of degaussing. "If there are strict requirements that prevent exit of failed and decommissioned media from the data center, then the organization must assign physical space in the data center to secure the media and equipment for the disk eradication" process, Tero says.
The effectiveness of degaussing can depend on the density of drives, Harkins says. "We encountered that issue three or four years ago with hard drives in laptops," he says.
"Because of [technology] changes in hard drives and the size of them, we found that some of the degaussing capabilities [were] diminishing over time."
How effective the method is also depends on the people doing the degaussing. "If people make mistakes, then your control gets diminished," Harkins says. "Let's say the person responsible for degaussing drives was supposed to do it for 15 minutes, but they have to go to lunch so put it in for five minutes instead. You could have breakdowns like that." But he concedes that all three methods are susceptible to human error.
Organizations can physically destroy data in a number of ways, such as disk shredding, melting or any other method that renders physical storage media unusable and unreadable.
One of the biggest advantages of this method is that it provides the highest assurance of absolute destruction of the data. There's no likelihood that someone will be able to reconstruct or recover the data from a disk or drive that's been physically destroyed.
On the down side, physical destruction can be a costly way to get rid of data, given the high capital expenses involved.
"Physical destruction [is] an expensive and not a fiscally sustainable long-term strategy," Tero says. "The approach also contravenes an organization's green and sustainability programs."
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