What is Degaussing?
One of the first widely used methods for destroying data on hard drives was degaussing. The term sprang from the word gauss, a unit of magnetism, and the process was named for the 18th century German mathematician and physicist Carl Friedrich Gauss.
Degaussing literally translates into “removal of magnetic fields”, and it was originally used during WWII to reduce the magnetic fields of ships as they traveled across the ocean. Then in the 1950s – and well into the 1990s – a degaussing process was used to reduce static and correct distorted images on CRT (cathode ray tube) televisions and monitors.
Today, the term degaussing refers almost exclusively to the process of permanently destroying data stored on magnetic media devices. All hard drives, and most types of magnetic tape storage, can be degaussed, which is a highly effective way of permanently eradicating data.
How Degaussing Destroys Hard Drive Data
Every hard drive contains a round metal plate called a platter, and every platter contains millions or billions of tiny magnetic fields. Higher capacity drives actually contain multiple platters – all stacked one on top of another with enough space in between to let each platter spin independently.
But regardless of how many platters it contains, every hard drive is equipped with a read-write arm that delivers data onto the plates in binary form (a series of zeros and ones). Because the platters’ magnetic fields are oriented in a very specific pattern during the hard drive manufacturing process, degaussing essentially disorients the fields, and causes the data they contain to become unrecoverable.
While degaussing is a relatively simple method of securely erasing data from a hard drive, it’s also highly effective. The process doesn’t physically alter the drive in any way (not externally at least), but it does render it completely inoperable just the same. And that makes degaussing as effective as hard drive shredding – a process that physically breaks the drive and platter into small particles – when it comes to data destruction.
The Future of Degaussing
One distinct disadvantage that stands out when comparing degaussing with physical shredding is the amount of time it takes to accomplish the task. While a drive can be degaussed in 10 to 20 seconds in many cases, it takes at least that amount of time (if not longer) to load the drive into the degausser and remove it again. That means that, in a best-case scenario, only 2-3 hard drives can be degaussed every minute.
A hard drive shredder, on the other hand, allows 10-15 drives to be destroyed in less than 60 seconds – and even more than that in some cases! The other knock on degaussing is that there are no visual indications of whether or not data has been successfully destroyed. With shredding, the proof is in all the little bits coming out the back end.
Data storage is evolving as quickly as most other areas of technology, and the advent of SSDs (solid state drives) is threatening to make degaussing obsolete. Unlike hard drives, SSDs use integrated circuits to store data. And because there’s no magnetic element to this form of storage, degaussing has no effect on it. It’s probably safe to say that the degaussing process will soon be a thing of the past!