During their first year of work, the researchers learned that data could remain on diskettes that had been subjected to high heat, and had to abandon thermal destruction techniques because of the fire and harmful gases they generated. That left only magnetic techniques.
In developing techniques for complete erasure, the researchers first had to learn how different data storage drives operate, then assess the magnetic field levels necessary for complete erasure. To do that, they obtained a number of commercially-available micro-drives, cut the media into sections, subjected them to varying magnetic fields, and then tested the sections with the MFM.
"We had to understand how the data is laid out on the disk so we could know where to look for the patterns, and we had to do a lot of measurements to determine exactly what kind of magnetic field is needed to destroy all data," said Knotts. "We had to do a lot of destructive testing to determine that, and our lab is littered with the carcasses of dead hard drives to prove it."
Producing a magnetic field sufficient to destroy data patterns required the use of neodymium iron-boron magnets custom-designed for the project and special pole pieces made of esoteric cobalt alloys. The magnets, which weigh as much as 125 pounds, had to produce fields sufficient to penetrate metallic housings that surround some drives.
"We developed models for magnetic circuits that we could run through optimization codes to design the best shape to get the field that we needed," Knotts said. "It takes quite a magnetic field to get through the steel enclosures on some of the drives. We are producing magnetic fields comparable to those used in magnetic resonance imaging equipment, so these are not your ordinary refrigerator magnets."
Mechanically, the researchers faced challenges in reliably moving data storage devices through the magnetic fields. In some cases, aircraft crews would simply insert removable media into a motorized mechanism that pushes them past the magnets, while for other media, crews would have to twist a knob and pull drives out of their enclosures and through a magnetic field. To prevent accidental erasure, each technique requires several deliberate steps.
With success in erasing removable media and small hard drives, the researchers are moving onto a final phase of the project, which will involve large computer hard drives partially encased in thick steel caddies.
Beyond Department of Defense applications, the magnetic erasure techniques could have applications to the commercial world, where banks, human resource agencies and other organizations must ensure complete destruction of data in computer equipment being discarded.
Knotts admits he'll be a bit sad to see the project end.
"This was certainly an unusual project," he said. "It's not often that we get paid to crush equipment in presses, blow things up and set off fires in microwave ovens."
John Toon | EurekAlert!
Information integration and artificial intelligence for better diagnosis and therapy decisions
24.05.2017 | Fraunhofer MEVIS - Institut für Bildgestützte Medizin
World's thinnest hologram paves path to new 3-D world
18.05.2017 | RMIT University
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
26.05.2017 | Life Sciences
26.05.2017 | Life Sciences
26.05.2017 | Physics and Astronomy