Data Purge Methods for macOS Devices (Apple Silicon & Intel) Under NIST 800-88

Introduction

NIST SP 800-88r1 defines three sanitization levels: Clear, Purge, and Destroy. For enterprise Macs, Purge is the most common requirement when devices leave organizational control or are repurposed. This guide covers Apple Silicon (M1/M2/M3) and Intel Macs (with or without T2), offering scenarios based on device condition.

Why Purge Matters

• Clear: Logical overwrite; suitable for internal reuse.
• Purge: Makes data unrecoverable even with forensic tools.
• Destroy: Physical destruction; last resort for damaged or end-of-life devices.

Scenario 1: Apple Silicon Mac (M1/M2/M3) – Device Boots Normally

Recommended Method: Erase All Content and Settings (EACS)

• Why: Apple Silicon uses hardware encryption. EACS destroys encryption keys → cryptographic erase → NIST Purge.
• Steps:
  1. Backup data if needed.
  2. Go to System Settings → General → Transfer or Reset → Erase All Content and Settings.
  3. Confirm and let the process complete.
• Verification: Document the process; capture logs if using MDM.
• Optional: Use Jamf Pro’s EraseDevice command for remote wipe (requires Bootstrap Token escrow).

Scenario 2: Intel Mac with T2 Chip – Device Boots Normally

Recommended Method: Erase All Content and Settings (macOS 12+)

• Works similarly to Apple Silicon: cryptographic erase via T2 hardware.
• Steps: Same as Scenario 1.
• MDM Option: Jamf Pro → Wipe Computer (EraseDevice command).

Scenario 3: Intel Mac without T2 or Older macOS

Recommended Method: Secure Erase via Parted Magic or Certified Tool

• Why: No hardware encryption; must overwrite or sanitize SSD.
• Steps:
  1. Boot from Parted Magic USB.
  2. Use ATA Secure Erase or NVMe Sanitize.
  3. Verify with Disk Verifier.

Scenario 4: Device Does NOT Boot (Apple Silicon or Intel)

• Option A: Remove SSD (if removable) → sanitize using secure erase tools.
• Option B: If SSD soldered (Apple Silicon), physical destruction is required → shredding or pulverizing per NIST Destroy guidelines.

Scenario 5: Target Disk Mode

When to Use: Device boots but cannot run EACS (e.g., OS corruption, admin password unknown).

• Steps:
  1. Boot the problematic Mac into Target Disk Mode:
     • Intel: Hold T during startup.
     • Apple Silicon: Use Share Disk from macOS Recovery.
  2. Connect to a host Mac.
  3. Use the host Mac to:
     • Run diskutil secureErase (for spinning disks) or certified erasure tool for SSD.
     • Or use Blancco/BitRaser for full NIST-compliant purge.
  4. Verify completion and document logs.
• Notes: Ensure encryption keys are destroyed or overwrite is complete.

Compliance & Documentation

• Record:
  • Device serial number, method used, date/time.
  • Screenshots or Jamf logs or Disk Verifier logs - if possible

Comparison Table

Best Practices

• Always verify sanitization.
• Maintain logs or certificates.
• Align with organizational policy for NIST compliance.