Degaussing: Definition, Uses and its Working

Overview: Imagine you have a magic eraser that rubs out the pencil marks completely – That’s what degaussing is all about for computer data! In the prevailing age, data security has become an utmost priority for the people who work in organizations or run their businesses, especially since much of this sensitive data is stored in magnetic storage media. Here, degaussing helps by erasing information from the old computer disks so that no one can recover it. So, in this article, we will explore the definition of degaussing, how it works, its types, its impact on hard drives, and a secure alternative to degaussing for complying with laws and regulations.

Image: NSA CSS Approved Hard Disk Degausser

What is Degaussing a Hard Drive?

Degaussing is the process of reducing or eliminating unwanted magnetic fields from magnetic storage media like hard drives, magnetic tapes, and floppy disks. The process consists of disturbing the respective magnetic domains where data is stored, making it unreadable and untraceable. Thereby, completely destroying the hard drive.

Reference: Proton Data T-4 Hard Drive Degausser

The term ‘degaussing’ originates from a unit measuring magnetic flux density known as ‘Gauss’, named after mathematician Carl Friedrich Gauss. When you degauss a storage medium, the pieces of information (data) are scrambled or erased, rendering them inaccessible. Therefore, degaussing plays a great role in the secure disposal of sensitive or classified information.

Apart from these applications, Degaussing can be used to correct screen interference, for example, on CRT monitors. This restores the quality of the image by removing and neutralizing the magnetic distortions that would otherwise affect the display.

Do you know? Where is the magnetic property held in the hard drive?

Data kept inside a hard disk drive is stored in one or more spinning disks known as platters. Usually, these platters are covered using a magnetic substance such as a thin coating of magnetite (iron oxide) or any other equivalent substance. – This is where the magnetic property is held.

Video Tutorial on Degaussing: Meaning, Uses, Pros, and Cons

Process of Degaussing: How It Works

Reference: Infographics of Degaussing Working

Creating a New Magnetic Field: A degausser produces a stronger magnetic field, which is more than the object you are targeting.
Neutralizing the Magnetic Field: This new field disturbs and nullifies the already existing magnetic fields in the object, thus scrambling or erasing any stored information.
Gradual Reduction: Towards the end of this procedure, a degausser gradually keeps on reducing its magnetic field strength so that there is total neutralization of the target object’s magnetic field.

Types of Degausser

There are basically three types of degaussing devices, depending upon how they generate the magnetic field:

Coil Degausser: Gainfully utilized as it comprises a copper wire that has been coiled around a steel core for the purpose of generating a powerful electromagnetic field through varying currents. It serves to wipe out information on hard disc drives along with other storage devices.

Reference: Degaussing Wand Coil Degausser For CRT Tube Arcade Monitors

Capacitive Discharge Degausser: This is sometimes called a pulsed degausser, which works by storing and later releasing electric power to create a powerful electromagnetic pulse. Additionally, it gets rid of data on magnetic storage media by demagnetizing them.

Permanent Magnet Degausser: It employs the use of rare-earth magnets to generate exceedingly strong magnetic fields. This type is portable and generally used for field operations and is not as powerful as other types.

Reference: Magnetic Pulse Degausser

Types of Storage Media Where Degaussing is Done

Hard Disk Drives (HDDs) – Internal and external HDDs (e.g., Seagate, Western Digital), NAS HDDs, and old laptop drives (e.g., Toshiba, Hitachi).

Floppy Disks – 3.5-inch, 5.25-inch, and 8-inch disks for vintage computers like Commodore 64 and IBM PCs.

Magnetic Tape – Includes DAT, LTO (e.g., LTO-6, LTO-7), VHS, Reel-to-Reel, and Betacam.

Zip Disks – Iomega Zip 100MB, 250MB, and 750MB disks from the late ’90s.

Magnetic Cards/IDs – Cards with magnetic stripes (e.g., Visa, MasterCard), hotel key cards, and ID badges.

Backup Tapes – DLT, QIC, AIT, and Travan.

Storage Devices That Cannot Be Degaussed

SSDs – Internal (Samsung 860 EVO, Crucial MX500), External (SanDisk Extreme Portable), M.2 NVMe (WD Black SN850), Enterprise (Intel Optane).

Optical Media – CDs, DVDs, Blu-rays.

Flash Drives – Standard (Kingston, SanDisk), Encrypted (IronKey), High-capacity (SanDisk Ultra 1TB).

SD/MicroSD – Standard SD (SanDisk Extreme PRO), MicroSD (Samsung EVO Plus), High-speed (Sony SF-G Tough UHS-II).

Cell Phones, Tablets, iPads, Cloud Storage.

Application of Degaussing

It has a vast range of applications, especially in industries where data security has the highest level of importance. Here are some common use cases:

• Government and Military: It is necessary to securely destroy sensitive information stored on magnetic tapes or hard drives. Degaussing is one of the trusted means of destroying such information so that it cannot be referred back to.
• Financial Institutions: With financial institutions and banks, degaussing will erase sensitive bank records from magnetic storage devices.
• Corporate Sector: Before they dispose of them, large corporations frequently employ degaussing methods for safely erasing any data from their old hard discs.
• Media Industry: In the media and entertainment sector, degaussing is a way of deleting materials from magnetic tapes for further utilization.

Does Degaussing Destroy a Hard Drive?

Yes, degaussing serves to erase all your data but it also destroys hard disk drives so that they become unusable. Before discarding hard drives, people commonly use this technique to ensure complete data erasure. Always be sure to use this process, as this will destroy your whole hard drive and make it inoperable.

Advantages of Degaussing

Here are some advantages given below while doing this process:

• Data erasure from magnetic drives, floppies, and tapes is often considered a foolproof solution.
• It erases data from the hard drive permanently in order to erase data permanently.
• Degaussing is a quick method of destroying large volumes of drives.
• Degaussers are user-friendly and easy to operate even for non-technical staff.

Limitations of Using Degaussing Process

Let’s get familiar with specific shortcomings of degaussing while making any strategy plan for an organization:

• As it is a reversible process, the hard drive cannot be reused.
• Some degaussers need a lot of power, which may not be practical in all settings.
• You cannot apply this process to SSDs as they are ineffective and don’t use magnetic storage fields.
• Usually, degaussers are designed in such a way that they can destroy a single hard drive or a few units altogether, allowing no scalability.

Degaussing Versus Data Overwriting

Image Reference: Comparison of Degaussing Method vs Wiping Software

Final Takeaway

In this write-up, we have discussed what degaussing is, which is a strong method to erase data permanently from magnetic storage devices like hard drives, tapes, etc. Demagnetizing is the best option for final disposal, which makes data unrecoverable and also makes the hardware unusable. Then we got to know how it works, benefits, limitations, and ensuring its limits, which plays an important part for organizations that rely on protecting sensitive information.

Frequently Asked Questions

Q. What are the security measures needed when storing degaussed drives until disposal?

Ans. Considering the physical and cybersecurity considerations when storing degaussed but undisposed drives:

• Lock degaussed drives in controlled storage until disposal.
• Use barcodes and logs to account for each drive.
• Monitor storage areas with CCTV to deter tampering.

Q. Can You Use a Hard Drive after Degaussing?

Ans. Most probably, no. Once you degauss a hard disk, you cannot use it. Degaussing refers to a technique using a strong magnetic field to disrupt and randomize the magnetic domains on a storage device, for example, a hard drive or magnetic tape.