Data Remanence Explained: Clear, Purge, Destroy (NIST SP 800-88)
When you delete a file, the data usually stays on the disk. In this video, I'll walk through data remanence and media sanitization: where leftover data hides, the three NIST sanitization methods, the techniques behind them, which method fits a hard drive, an SSD or cloud storage, and how to prove the job was done.
What you will learn
- What data remanence is, why delete removes only the pointer, and NIST SP 800-88 Rev. 2 (September 2025)
- Where data hides: slack space and SSD wear leveling
- The three NIST methods: clear, purge and destroy
- The main techniques: overwrite, degauss, cryptographic erase and disintegration
- Which method fits each medium: HDD, SSD and cloud storage
- Proof: verification and the certificate of sanitization
- Three tip ideas: multi-pass ≠ safer; degauss ≠ SSD; drilled ≠ destroyed