Degaussing
Delete / format | Degaussing | Physical destruction | Software overwrite

Degaussing involves using a machine that produces a strong electromagnetic field to destroy all magnetically recorded data. This method of data destruction may have been effective in the past as a strong electromagnetic field was not needed to destroy data. However, modern hard drives use thicker shielding and require a much stronger electromagnetic field in order to ensure a complete erasure. There is no way to guarantee that a particular degassing machine will do a thorough job and therefore poses a security risk.

Different types of magnetic media require different magnetic field strength and there is a risk that an incomplete degauss might occur if the strength used is not strong enough. Degaussing machines also destroy other components of the hard drive making it difficult to verify the erasure process as the drives cannot be reused or tested. This significantly compromises data security and is not fully reliable. Degaussing machines are also expensive and care must be taken to prevent nearby equipment from being destroyed.


Advantages

  • Capable of destroying all the data on the hard drive (especially hard drives that require a weaker electromagnetic field)
  • Can be used to destroy data on a variety of magnetic media
  • Degaussing is a fast process
  • Purchasing a degaussing machine is usually a one time investment

Disadvantages

  • Modern hard drives use thicker shielding and require a much stronger electromagnetic field in order to destroy all the data
  • There is no way to guarantee that a particular degaussing machine is strong enough to destroy all the data on every hard drive
  • Hard drives have to be physically removed from the PC
  • Hard drives cannot be reused
  • Other components of the drive are also damaged making it difficult to verify the erasure process
  • Degaussing machines are expensive and special care must be taken to protect nearby equipment
  • Often involves using the services of a third party. Theft and uncontrolled handling can lead to data leaks
  • Degaussing does not provide reporting of the erasure process which is needed to prove regulatory compliance
  • Reduces the remarketing value of a PC
  • Can only be used on magnetic media