Researchers Find Technique To Quickly Erase Hard Drives

A team has crafted a new generation of superpowerful magnets, intended for use in military and other applications, that can penetrate hard disk enclosures to quickly erase magnetic media.
PORTLAND, Ore. — In 2001, an American spy plane collided in the air with a Chinese fighter and was forced to land on Chinese island. Since then, researchers have been looking for a way to quickly erase computer hard drives to deny access to sensitive intelligence data.

Scientists at the Georgia Institute of Technology (Atlanta), working with L-3 Communications Corp. (New York), said they have developed a technique for quickly erasing hard-disk drives. The team reports development of a prototype fast-erasure system to prevent sensitive information from reaching enemy eyes.

At the time of the U.S.-China incident, there was no way the U.S. crew could quickly erase hard drives on the surveillance aircraft before landing on Chinese soil. The Chinese eventually gained access to U.S. military secrets.

Erasing a hard drive usually takes hours using special procedures that repeatedly scramble information on a disk drive. Still, given unlimited resources and time, special magnetic snooping techniques can often recover at least some of the original information.

The researchers sought a method that not only securely erased information but also performed the erasure during emergency situations where minutes, not hours, were available.

The researchers concluded that permanent magnets are the best solution. Other methods, including burning disks with heat-generating thermite, crushing drives in presses, chemically destroying the media or frying them with microwaves all proved susceptible to sensitive, patient, recovery efforts.

Permanent magnets for erasing magnetic media have been available since the dawn of disk drives, but the team found that commercial systems were either magnetically too weak, too large and heavy or could not meet air-safety standards. Instead, the team crafted a new generation of super-powerful magnets to penetrate hard disk enclosures to quickly erase magnetic media. Special high-strength magnets as powerful as those in medical imaging equipment proved sufficient for permanently erasing all information on a disk drive in a single pass.

To create a magnetic field strong enough to penetrate the metal housing around a disk drive and erase the magnetic media inside, the researchers designed a neodymium iron-boron magnet with special pole pieces made of esoteric cobalt alloys. A motorized mechanism pushed disk drives past the magnets; a back up twist-knob allows operators to manually pull drives through the magnetic field.

The 125-pound prototype is being streamlined into a deployable version that is light enough for aircraft, operates independently of aircraft electrical systems, produces no noxious gases or flames and includes fail-safe procedures to prevent inadvertent erasures. The team verified that it was impossible to recover information from disk drives erased with the permanent magnets. They used a magnetic force microscope to map even the smallest magnetic domains on the surface of an erased disk drive to ensure that the patterns found there were completely random.

The team claimed the magnetic eraser could also be used for commercial applications like quickly erasing VHS tapes, floppy drives, data cassettes and hard drives.

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