Best Practices for Destroying Hard Disk Drives: Shredding Versus Degaussing

intimus produces leading edge information security products for every medium, including computer hard disk drives (HDDs). Media shredding products form the foundation upon which intimus has built its reputation for the last fifty years.

intimus is a customer driven company that strives to provide the best products for each customer application. We understand our clients’ need for products capable of securely destroying hard drives containing sensitive data in a manner that satisfies their internal security requirments. The products offered by our competitors are insufficient for this purpose.

According to many in the information security field, including the US National Security Agency (NSA), shredding of HDDs is not the best method of destroying information contained in the drive. This is why the NSA, the world’s recognized leader in cyber security, requires that its Top Secret and above data residing on HDDs that are non-functional or obsolete be either degaussed or incinerated.

Incineration is typically not available to most government agencies and private firms due to the environmental concerns and expensive permits required to liquefy metal-based media. Degaussing is by far the most common method of sanitizing Top Secret data. To degauss an HDD, the drive is processed through a degausser that exposes it to a very high strength magnetic field, which erases the organized data and the underlying servo tracks of the hard disk platters.

Data on the disk platters is made up of data bits. Eight bits of data equals one byte. Data on HDDs is stored in bytes of data bits made up of binary numbers–bits read as a sequence of ones and zeroes. Each bit can be magnetically flipped in polarity between “-“ and “+”. A “-“ polarity value is seen by the read-write head of the HDD as a “0”. A “+” polarity particle is seen as a “1”. These bits are extremely small. To put their size in perspective, bits, at 10 nanometers in diameter, are half of the size of the smallest virus. The size of the data bits here is a critical concern when considering how to securely destroy an HDD.

Because hard disk data bits are half the size of the smallest virus–10,000 times smaller in diameter than a human hair–shredding hard disk platters into shards one inch (25mm ) in diameter does not securely destroy the data on the platers.

A good comparison would be spreading the Ebola virus all over a sheet of paper and then putting it in a paper shredder. The shredded pieces of paper with the Ebola virus on them are still just as dangerous as the complete sheet of paper, because the process does nothing to eliminate the virus.

On the other hand, degaussing eliminates and erases the microscopic particles that make up data. The bits are essentially vaporized leaving no trace behind. For non-working or obsolete HDDs and tape media, degaussing is the clear choice for sanitizing data and making it unrecoverable by any means. intimus offers degaussing equipment which complies with even the most challenging data security requirements.

Posted: December 2017