Degaussing is the process of decreasing or eliminating a remnant magnetic field. Due to magnetic hysteresis, it is generally not possible to reduce a magnetic field completely to zero, so degaussing typically induces a very small “known” field referred to as bias. Degaussing was originally applied to reduce ships’ magnetic signatures during World War II. Degaussing is also used to reduce magnetic fields in cathode ray tube monitors and to destroy data held on magnetic storage.
Degaussing is not the only thing you should do to insure data security. While degaussing is the only safe method to remove data from a piece of technology, companies usually go one step further and pair their data erasure methods with crushing. CNet reported that once data is wiped, organizations can remove or destroy the platter on a hard drive to ensure complete certainty the information is unattainable. While most people believe that if the platter can’t spin, then the hard drive can’t be read—but data can actually still be recovered from the device. This is why degaussing beforehand is incredibly important.
After that, companies should consider using a product that effectively crushes the device or have some fun and do it on their own. Any method that will render it into tiny pieces is ideal. But, before taking a sledgehammer to media, make sure to erase the data. Even tiny pieces can be put together and information can be salvaged if not properly disposed of.
Degaussing Hard Drives
Hard drives and other electronic storage devices such as computer tapes store data within magnetic fields. Such storage mediums contain layers of magnetic material. By arranging the specific direction of these tiny magnetic materials, a drive can store millions of binary data bits. A hard drive retains this data only if the magnetic fields are kept in their precise order.
A degaussing machine subjects a hard drive to a high-intensity magnetic field, completely rearranging the entire magnetic structure of the drive. The degausser randomizes the patterns of magnetization by applying alternating fields of powerful magnetic amplitude. The end result is irrecoverable data.
Once a drive has been degaussed, it can no longer be used for storage.
Eight Important Facts about Degaussing
- Can data on a degaussed drive be recovered?
- Once a drive has been degaussed, it is impossible to retrieve the data.
- Can a degaussed disk be used after degaussing?
- A degaussed drive is inoperable in any system. The magnetic erasure rearranges the magnetic field to such an extent that standard read heads are unable to find a magnetic reference point for tracking.
- Does running an ordinary magnet over a hard drive accomplish degaussing?
- Standard magnets are not powerful enough to degauss a hard drive. Only an industrial degausser can guarantee the erasure of data.
- Can any degausser erase data?
- In order to be completely effective, a degausser should emit magnetic strength that is two or three times greater than the magnetic intensity of the hard drive. Some commercially-available degaussers are too weak to ensure that the data is erased. It is important to use an NSA-recommended degausser.
- Why is degaussing important?
- Degaussing is the first step in completely destroying data. Due to regulations such as HIPAA, the GLB-Act, and NSA requirements, destroying sensitive data is required by law.
- Does degaussing destroy other forms of tape storage (DLT, SDLT, 3480, AIT, etc.)?
- Degaussers emit such powerful magnetic fields that they can erase virtually any magnetic-based storage device.
- Can degaussing destroy data on a USB drive?
- No because USB memory devices operate on solid state memory, which does not depend on the same magnetic structure of hard drive or tape storage.
- Is degaussing the final step in data destruction?
- Although degaussing is a failsafe way of data erasure, the NSA recommends that media be physically destroyed / shredded after degaussing.
Who uses degaussing?
In today’s increasingly litigious world, the use of a degausser provides a safe and effective means of magnetic media data security for individuals, organizations, corporations and government agencies. Within the past several years, laws have been passed outlining stricter guidelines and greater penalties for data security, making it illegal for companies and organizations to carelessly or irresponsibly dispose of any critical or personal data. Such laws include the Health Insurance Portability and Accountability Act (HIPAA), Gramm-Leach-Bliley Act (GLBA), Fair and Accurate Credit Transactions Act (FACTA), Federal Information Security Management Act (FISMA), and the Sarbanes-Oxley Act.
Confidentiality & Risks of Data Leakage
For end-of-life data storage medium, a proper data erasure action is important before their disposal. Random disposal or insufficient data erasure may severely harm information confidentiality of organizations and companies and raise risks of data leakage.
Nowadays stories of high profile cases containing exposure of sensitive data are heard frequently. Improper data disclosure may result in different risks:
- Personal information goes to identity thefts
- Disclosure of business secrets to dumpster divers
- Time, effort and costs spent on explanation to customers
- Loss in consumer confidence
- Embarrassment in public
- Fine and penalty for violation of regulations
- Disclosure of national & military secrets
- Negative impact on environment
To protect information security, data must be completely destroyed before IT assets are disposed of or recycled. Corporations are obliged by law to ensure the security of sensitive information, otherwise they will face penalties or punishment for non-compliance.
Problems in Degaussing
If degaussing is done incorrectly, more problems can be generated than are solved. Traditional demagnetizing methods using surface AC demagnetizers or yokes will only affect a small area or surface spot, subsurface magnetism may still be left behind. As is often the case, this is not realized until after a machine is put back into operation and magnetic fields start to interact. These magnetic fields may strengthen, generating currents causing unforeseen damage. Therefore, if the removal of residual magnetism is skipped, or improperly done, the likeliness of problems will increase.