Category 1: Basic Overwrite (4 methods)
| Method | Passes | Pattern | NIST Level | Speed | Devices |
|---|---|---|---|---|---|
| Zero Fill | 1 | 0x00 written to all sectors | Clear | Fast | HDD/SSD/NVMe/USB |
| One Fill (0xFF) | 1 | 0xFF written to all sectors | Clear | Fast | HDD/SSD/NVMe/USB |
| Random Fill | 1 | Cryptographic random data (os.urandom) | Clear | Medium | HDD/SSD/NVMe/USB |
| Quick Format | 0 | Partition table erasure only (data sectors untouched) | None | Instant | HDD/SSD/NVMe/USB |
Category 2: International Standards (10 methods)
| Method | Passes | Pattern | NIST Level | Origin |
|---|---|---|---|---|
| NIST 800-88 Clear | 1 | 0x00 + mandatory read-back verification | Clear | USA (NIST) |
| NIST 800-88 Purge | 2 | Pass 1: Random; Pass 2: 0x00 | Purge | USA (NIST) |
| DoD 5220.22-M | 3 | Pass 1: 0x00 → Pass 2: 0xFF → Pass 3: Random | Purge | USA (DoD) |
| DoD 5220.22-M ECE | 7 | Extended 7-pass pattern (0x00, 0xFF, Random ×2, verify) | Purge | USA (DoD) |
| HMG IS5 Baseline | 1 | 0x00 + mandatory verification | Clear | UK (NCSC) |
| HMG IS5 Enhanced | 3 | Pass 1: 0x00 → Pass 2: 0xFF → Pass 3: Random + verify | Purge | UK (NCSC) |
| VSITR | 7 | Alternating 0x00/0xFF for 6 passes + Random final pass | Purge | Germany (BSI) |
| GOST R 50739-95 | 2 | Pass 1: 0x00 → Pass 2: Random | Clear | Russia (GOST) |
| Random 3-Pass | 3 | 3 independent cryptographic random passes | Purge | General |
| Gutmann | 35 | 4 random + 27 fixed patterns + 4 random (MFM/RLL encoding) | Purge | Academic |
Category 3: Hardware Commands (4 methods)
These methods use drive firmware commands for maximum speed and coverage, including remapped and overprovisioned sectors.
| Method | Interface | How It Works | NIST Level | Speed |
|---|---|---|---|---|
| ATA Secure Erase | SATA | Drive firmware internally overwrites all user data areas including reallocated sectors. Requires unfrozen state (automatic S3 sleep/wake cycle). | Purge | Seconds (SSD) to hours (HDD) |
| ATA Enhanced Secure Erase | SATA SSD | On encryption-capable SSDs, rotates the internal encryption key (cryptographic erase). Reaches all areas including overprovisioning. | Purge | Sub-second |
| NVMe Format (User Data Erase) | NVMe | NVMe Format NVM command with SES=1. Firmware-level format erasing all user data. | Purge | Seconds |
| NVMe Crypto Erase | NVMe | NVMe Format NVM command with SES=2. Rotates encryption key, instantly making all data unreadable. | Purge | Instant |
Category 4: Hybrid Methods (2 methods)
Defense-in-depth approach combining software overwrite with hardware commands.
| Method | Phases | Purpose | NIST Level |
|---|---|---|---|
| Zero Fill + ATA Secure Erase | Phase 1: Full zero overwrite Phase 2: ATA Secure Erase | Software overwrite for visible sectors + firmware erase for hidden/remapped areas | Purge |
| Zero Fill + ATA Enhanced SE | Phase 1: Full zero overwrite Phase 2: Enhanced Secure Erase (crypto key rotation) | Highest assurance for SATA SSDs | Purge |
Category 5: Mobile Device Methods (4 methods)
| Method | Platform | How It Works | NIST Level |
|---|---|---|---|
| Android Factory Reset | Android | ADB broadcast triggers OS factory reset. Wipes user data partition and cache. Pre-checks: battery >20%, USB debugging enabled. | Clear |
| Android Crypto Erase | Android (Knox) | Recovery wipe with cryptographic key destruction. Primarily for Samsung Knox-equipped devices. | Purge |
| iOS IPSW Restore (DFU) | iOS | idevicerestore --erase with official Apple IPSW firmware in DFU mode. Complete erase and OS reinstall. | Purge |
| iOS Manual Reset | iOS | Guided manual reset for locked devices. Settings > General > Reset > Erase All Content and Settings. | Purge |
Verification & Assurance Features
Post-Erasure Verification
Byte-by-byte read-back comparison for zero/fixed patterns. For random data, Shannon entropy verification (threshold: 7.9/8.0 bits) confirms proper randomization.
SMART Data Capture
Pre/post-erasure SMART attribute capture (24+ attributes). Health status, temperature, power-on hours, reallocated sectors. Stored in cloud with erasure log.
Bad Sector Handling
1MB block write → on failure subdivides to 4KB with 3 retries → skipped and logged. Final status: COMPLETE, COMPLETE_WITH_EXCEPTIONS, or FAILED.
Erasure Resume
Progress persisted to disk. On interruption (power loss, crash), resume from the last written offset for long-running wipe jobs.
PDF Certificate
NIST 800-88 compliance level, SHA-256 digital signature, QR verification code, OEM white-label branding support.
Real-Time Monitoring
3-second polling interval. Shows: percentage, current pass (e.g., "Pass 2/3"), speed (MB/s), ETA, elapsed time.
Frozen Drive Detection
Auto-detects SATA security frozen state. Triggers S3 sleep/wake cycle to unfreeze before hardware erase.
PII Scanner
Pre-erasure scan for personally identifiable information. Independent parallel thread, non-blocking.
Drive Benchmark
Read/write speed measurement before erasure. Results viewable in control dashboard.
Choosing the Right Method
| Scenario | Recommended Method | Why |
|---|---|---|
| Standard device reuse (HDD) | NIST Clear or Zero Fill | Fast single-pass, sufficient for non-classified data |
| SSD reuse (SATA) | ATA Enhanced Secure Erase | Sub-second, reaches all cells including overprovisioning |
| NVMe SSD reuse | NVMe Crypto Erase | Instant key rotation, most secure for NVMe |
| Regulated industry (healthcare/finance) | DoD 5220.22-M or NIST Purge | Multi-pass compliance with verification |
| Government/classified data | DoD 7-pass ECE or Gutmann | Maximum overwrite assurance |
| Maximum SSD assurance | Zero Fill + Enhanced SE (Hybrid) | Defense-in-depth: software + hardware |
| iPhone erasure | iOS IPSW Restore (DFU) | Complete OS reinstall via official firmware |
| Android bulk erasure | Android Factory Reset | Fast, parallelizable across 50 devices |
We can recommend the right method for your compliance, return, or reuse requirements.