Secure Data Deletion

Secure Data Deletion

Deletion or overwriting is no longer a good enough solution to erase data from a computer

In October 2021 Wired magazine reported that Retro Collectors (buyers and sellers of older computers) were acquiring devices with confidential data intact.   These collectors are not actively seeking confidential data but documents exposed included high level minutes from within the British Medical Authority and patient details from a Wyoming Dermatologist. Even machines from the early 2000s such as the original MacBook are now realising enough capital to be worth selling to collectors rather than dumping.

All personal or corporate data should be removed from a computer before it is disposed of.  This would even be the case if the machine itself no longer functions.  Unfortunately as storage solutions evolve it has become more difficult to absolutely ensure that all data has been removed from them.  This is the flip side of improvements in data recovery options within computer software and hardware.

There are a range of data ‘deletion‘ operations available either from within the operating system, restoring to factory settings, the use of specialist software or the destruction of the component holding the data.  The existence of specialist data recovery firms is clear evidence of the lack of reliability of these methods.

The TV programme Breaking Bad (S05E01) portrayed the use of a powerful electromagnet to erase all data on a laptop.   Magnets are used to store computer data because once a charge is created by an magnetic field from an electromagnet some of the magnetic polarity remains when the power is disconnected.  If enough magnetic force can be applied to a Hard Disk Drive then the data within would probably be destroyed although the Breaking Bad scenario would be difficult to reproduce.  Hard Disk Drives store data on circular platters.  The best way to remove the data on them is to undo the drive, access the platters and physically damage them.

Many hard drives, especially on laptops are now Solid State Drives (SSD).  These still use magnetic force to store data but rely on transistors on chips within the drives for storage.  This system is even more tolerant to damage from magnetic force than HDDs.  The best way to erase data from SSDs is to take them apart and shatter their storage chips.

Although destroying drives is by far the optimal way to erase data the parts of the drive count as waste electrical and electronic equipment.  For a home user there would be no problem with taking the parts to the appropriate section of a local authority recycling site.  Larger businesses would need to work through an approved WEEE contractor.

If a storage device has been removed and destroyed it will reduce the value of the computer and make it harder to sell on.  Replacement drives for relatively recent machines are easily sourced so these could be passed on with new blank drives or the reduced value factored into any sales or removal cost.  For older computers replacement drives might not be available at a realistic cost due to changes in connection technology (SATA, IDE, maximum supported storage size). This takes us back to the Retro Collector marketplace and keeping the bulk of older computer devices out of the waste industry.