Degaussing is a popular and effective method for erasing data from magnetic storage media. Many companies and organizations regularly use degaussing to permanently delete confidential information as an alternative to physically destroying o shredding a hard disk.
Degaussing only works on magnetic storage devices, so you wouldn’t use this technique to deal with solid-state drives (or SSDs). However, there are other newer hard drives, like HAMR and MAMR, where degaussing might be less effective. So, why does this happen, and is there an alternative?
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What Degaussing Is and How It Works:
Degaussing is a technique for permanent data destruction based on demagnetizing (or in some cases neutralizing) the magnetic field of certain storage media like tapes, floppy disks, and hard disk drives.
So, how does degaussing work, exactly? It helps to first understand the components of magnetic tapes. These are a fine metal iron oxide power, a film backing, and a binder. You can, in fact, think of magnetic media as a surface that is split into many tiny (we’re talking sub-micron) regions. These regions or magnetic domains are created using a writing head; the tape moves past it at a steady speed creating a magnetic field that alters the positioning of the powder on the tape’s surface.
The process of degaussing a hard drive can erase data by rearranging or randomizing the polarity or direction of these domains, removing the properties from the coatings, and eliminating any information stored in the media. This results in data destruction.
Different Types of Degaussers
There are three main types of degaussers used to delete the content of magnetic storage media. Some of the most popular options on the market are capacitive discharge degaussers (or pulse degaussers), coil degaussers, and permanent magnet degaussers. Let’s quickly look at each of them and how they work.
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- Capacitive discharge degaussers: These devices use a capacitor to store an electrical charge and create a high-frequency electromagnetic pulse to demagnetize the media and destroy the data.
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- Degaussing coils: Made of steel core and a copper wire wound on them, this secure data destruction method uses alternating current to generate an electromagnetic field with the same effect.
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- Permanent magnet degaussers: By using powerful, natural rare-earth magnets, these devices use a structured array to degauss magnetic data without requiring electric charges.
The type of degausser you will want to use to erase data will ultimately depend on the magnetic field’s strength you require to destroy the information. The field strength is typically measured in gauss or oersteds, and the same applies to tapes and hard drives and their coercivity or resistance to alterations (we will explain this better in the next section).
Can You Degauss Any Magnetic Media?
You can use the degaussing technique to eliminate data stored in hard disk drives (2.5 and 3.5 inches), magnetic tape drives (Digital Linear Tape or DLT, Linear Tape-Open or LTO, Quarter Inch Cartridge or QIC, Advanced Intelligent Tape or AIT, among others), and floppy disks (3 1⁄2-inch, 5 1⁄4-inch, and 8-inch).
Can You Use Your Drive After It’s Been Degaussed?
No. Once you’ve put a storage media device through a degaussing process, you won’t be able to use it again. This is because the method removes not just the stored data but also the start-up files required to boot up.
Are All Degaussers Equally Efficient?
The efficiency of a degausser actually depends on the strength of the magnetic field versus that of the magnetic media. Ideally, you will want the first to be two to three times stronger than the coercivity of the second. The more coercive the media, the more powerful your degaussing equipment must be.
Modern storage media that use advanced recording technologies to allow for storing more information have coercivities that are not just higher but also harder to determine. This means that you also require more powerful magnetic fields to alter them.
The Limitations of Degaussing Media
Degaussing can be very effective for the types of media mentioned above, but it’s important to understand there can be shortcomings when it comes to other drives. For instance:
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- Degaussers can only sanitize magnetic storage devices but will have no effect on solid-state drives, memory cards, or USB flash drives (all of which use solid-state drives).
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- Degaussers need specific magnetic forces to match the media’s coercivity, so you should always check the results to ensure things are working as expected.
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- Degaussing can have a slow turnaround as it requires significant time and manual effort. Therefore, it’s not a viable, scalable solution if you have to sanitize a lot of drives regularly.
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- Degaussers can be expensive due to their need for rare earth metals and physical construction. They can also become a high operational expense.
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- Degaussing a magnetic storage media will render it unusable, instantly turning into e-waste with no residual value. Thus, it’s a method best used for end-of-life media.
Additionally, degaussing might not work on heat-assisted magnetic recording (or HAMR) and microwave-assisted magnetic recording (or MAMR) hard drives. The first cannot be degaussed at this point, and there are questions regarding the efficiency of sanitizing MAMR drives, too. For these types of media, it’s recommended you instead incinerate or disintegrate them.
Conclusion
You should never rely only on degaussers to sanitize your storage media, as the technique only works if there’s a magnetic field to manipulate and you have the correct coercivities.
If you want to make sure you have proper data security for types of media, you should consider using products that can deal with the ever-changing technology and compliance demands. At Phiston, we work with machines that are capable of fully destroying any storage device to make confidential information unreadable and unrecoverable. Our range of products includes not just powerful and reliable degaussers but also HDD destroyers, SSD destroyers, and disintegrators. Request a quote today, and we’ll get back to you ASAP!
