Editing Data remanence (section)

{{Short description|Data that remains after deleting it}}
'''Data remanence''' is the residual representation of [[digital data]] that remains even after attempts have been made to remove or erase the data. This residue may result from data being left intact by a nominal [[file deletion]] operation, by reformatting of storage media that does not remove data previously written to the media, or through physical properties of the [[data storage device|storage media]] that allow previously written data to be recovered. Data remanence may make inadvertent disclosure of [[information sensitivity|sensitive information]] possible should the storage media be released into an uncontrolled environment (''e.g.'', thrown in the bin (trash) or lost). <!-- the significance of the concept depends on the existence of a third party -->

Various techniques have been developed to counter data remanence. These techniques are classified as [[#Clearing|clearing]], [[#Purging|purging/sanitizing]], or [[#Destruction|destruction]]. Specific methods include [[#Overwriting|overwriting]], [[#Degaussing|degaussing]], [[#Encryption|encryption]], and [[#Media destruction|media destruction]].

Effective application of countermeasures can be complicated by several factors, including media that are inaccessible, media that cannot effectively be erased, advanced storage systems that maintain histories of data throughout the data's life cycle, and persistence of data in memory that is typically considered volatile.

Several [[#Standards|standards]] exist for the secure removal of data and the elimination of data remanence.