Degaussing permanently erases data from magnetic storage media by exposing it to a powerful magnetic field that randomizes the magnetic alignment, making previously stored data unrecoverable. It is used for hard disk drives and magnetic tape at end of life or when sensitive media must be disposed of securely.
Degaussing does not work on solid-state drives, flash storage, or optical media because they do not store data magnetically. For SSDs, secure erasure requires cryptographic erasure or physical destruction. NIST guidelines for media sanitization must be followed for classified and sensitive data.
CISSP Relevance
Degaussing is covered in Domain 2 (Asset Security) under data destruction and media sanitization. CISSP candidates must understand appropriate sanitization methods for different media types and how sanitization choices must match the sensitivity of the data previously stored.
External reference: NIST SP 800-88 Guidelines for Media Sanitization
Related terms: Data Classification, Data Retention Policy