Dataoverwriting

Data overwriting is a process in which a part or all of an existing digital storage device, such as a hard disk drive or solid-state drive, is cleared and rewritten with new data. This can be performed intentionally, such as when a user prepares a storage device for reuse, or unintentionally, such as during a low-level format operation or as a result of a data corruption event.

Data overwriting can take place at various levels, including the logical and physical levels. Logical overwriting involves the deletion of data at the file system level, such as when a file or directory is deleted, while physical overwriting involves rewriting the underlying storage cells or sectors to securely erase the data.

Whole-disk overwriting involves rewriting the entire storage device with a specific pattern of values, such as zeros or ones, to prevent data recovery by security agencies or other malicious actors. This method of overwriting is used to securely erase data on storage devices before disposal or repurposing.

Data overwriting can be performed using specialized software and is often used in conjunction with secure file deletion methods, such as wiping algorithms or degaussing. The executed order of data overwriting depends on the specific device or operating system being used, such as in Windows, when files and folders are marked for deletions they get identifiers such as 'new' attributes, rather than fully removing them but blocking access.

Data recovery methods are ineffective against data that is sufficiently overwritten. It is essential to use secure overwriting techniques before discarding or reusing digital storage devices to prevent unauthorized access to sensitive information. In some jurisdictions, laws require the use of secure overwriting methods when disposing of data storage devices containing sensitive information.