REAV

Glossary

Data sanitisation

Rendering the data on a storage device unrecoverable, by one of three methods with different levels of assurance.

Data sanitisation is the umbrella term for making stored data unrecoverable. The reference framework, NIST SP 800-88, splits it into three levels, and the difference between them is what a recovery attempt would have to be capable of.

Clear applies logical techniques such as overwriting to every user-addressable location. It defeats ordinary recovery software and is adequate for most reuse within a controlled environment. Purge applies stronger physical or logical techniques, cryptographic erase, block erase, that make recovery infeasible even with laboratory equipment. Destroy physically renders the media unusable, and is the only option when the media cannot be verified sanitised.

Choosing between them is a risk decision, not a technical preference: it depends on the sensitivity of the data and the type of media. The operational rule that follows is simple and often missed: a drive that fails verification at Clear or Purge must move to Destroy, and that outcome has to be documented as deliberately as a successful erasure.

Related terms

  • Erasure certificate The auditable record proving that all data on a specific device was destroyed, by a named method, at a known date.
  • ITAD The controlled process of retiring IT equipment so that data is destroyed, value is recovered and disposal is documented.
  • Chain of custody The unbroken, documented record of who held a device, when, and what was done to it, from collection to final disposition.
  • R2v3 The SERI certification standard for electronics reuse and recycling facilities, covering data security, environment, health and safety.

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