Reasons to securely and permanently delete data
As we have discussed in this blog previously, there are several reasons why corporate and private computer users alike have to delete their stored data. For corporate, storing data beyond the data lifespan can cause unnecessary costs and in several cases, it is even mandatory to securely erase the data after a fixed time period. Additionally, when a firm wants to change their storage system or hard disks, the data on the old hardware requires proper deletion. This said, the reason for securely deleting data is obvious – but in what situations should one decide to use a degausser?
What does degaussing mean?
Hard disks and magnetic tapes use magnetic fields to store data on either the so called platters or on the tape. When degaussed, the magnetic fields are destroyed. Additionally, the degausser destroys all magnetic fields on the disks items, sectors and all data.
Different technologies used in degaussing
There are four main types of degausser technologies developed: The Conveyor Belt Degausser, the AC-Degausser, the Permanent-Magnet-Degausser and the Impulse-Degausser.
1. The Conveyor Belt Degausser
The Conveyor Belt Degausser works with an electromagnet underneath a conveyor belt. The devices are hovered over the electromagnet and the magnetic field will be destroyed and with it all of the data.
2. The AC-Degausser
The AC-Degausser looks like a scanner device with a glass surface, where the hardware – either a hard disk or a tape – will be placed on. As with the Conveyor Belt Degausser one strong electromagnet is directly placed underneath the middle of the glass plate. When degaussing, the user has to lay the disk or the tape directly over the glass and turn it several times.
3. The Permanent-Magnet-Degausser
This Hardware works with two rare natural magnets with high field strengths. The medium which is to be erased will be moved between the two magnets thus deleting all data. The magnets are “always on”.
4. The Impulse-Degausser
The Impulse-Degausser uses an electro-magnetic coil. Once started, it sends a high frequency electro-magnetic impulse – via built-in and fully loaded capacitors – through the coil, which destroys all data on the disk or tape. The medium to be erased is put inside the coil to cover all of the plates with the magnetic field. With this technology hardware degaussers can be built relatively small, easy to transport and are less energy consuming than the other technologies used.
5. The “mixed” Impulse/Permanent Magnet Degausser
This Technology uses both permanent built-in magnets to delete data and additionally sends an impulse through a coil to “finalize” the process.