OpenDLP: Cross-Machine Exfiltration Defense

1. Full Data Flow: Exfiltration Through Neutralization

Figure 1 — End-to-end data flow: SCP pull from target Mac, device mismatch detection, AES-256 encryption, plaintext destruction

3. Attack Scenario & Protected Data

An insider or compromised machine on the same network uses SCP to pull a sensitive file from a colleague's Mac. This simulates lateral movement, insider threat, and stolen credential scenarios.

Protected File Contents

=== CONFIDENTIAL TEST DATA ===
This file is protected by OpenDLP.
SSN: 123-45-6789
API Key: sk_test_EXAMPLE1234567890
Revenue: $4.2M
Credit Card: 4111-1111-1111-1111
Password: hunter2_supersecret
=== END CONFIDENTIAL ===

File Identity Tags (xattr)

com.transpansomware.device:  30436CB6-7241-5620-AAB8-7FCAB6C08D06
com.transpansomware.tracked: true
com.transpansomware.hash:    44af9f83c91f892f68de065d8d04edb2aa03ba1d8b0ad6ff41f1f4d487448a0a

scp [email protected]:/Users/akidob0t/opendlp_target/confidential.txt ./

5. Phase 2: Exfiltration Detection

OpenDLP's detection engine checks every file access against two criteria: device identity match (does the file belong on this machine?) and process authorization (is the accessing process sanctioned?). Both must pass for access to be authorized.

  File device tag:    30436CB6-7241-5620-AAB8-7FCAB6C08D06   ← Mac A
  Local device ID:    79DD1A3C-5734-5009-B2CB-AEF523F6FB39   ← Mac B

  [ERROR] [DEVICE_CHECK] Device mismatch!
  File device: 30436CB6..., Current: 79DD1A3C...

Tests 2b–2d: Unsanctioned Process Detection

{
  "timestamp": "2026-03-17T15:48:31-04:00",
  "level": "ERROR",
  "component": "EXFIL_DETECTED",
  "message": "ALERT: Device mismatch detected for confidential.txt"
}

{
  "timestamp": "2026-03-17T15:48:31-04:00",
  "level": "ERROR",
  "component": "EXFIL_ALERT",
  "process": "scp",
  "file": "confidential.txt",
  "reason": "device_mismatch"
}

7. Phase 4: Verification

Figure 4 — Complete test structure: 17 tests across 4 phases, all passing on real cross-machine test

Encryption alone is not enough — we must prove the output is genuinely unreadable. Phase 4 runs eight independent verification checks.

Plaintext Leakage Scan

Hash Verification

  Original hash:  44af9f83c91f892f68de065d8d04edb2aa03ba1d8b0ad6ff41f1f4d487448a0a
  Encrypted hash: 8271300c7f135ded069eae69885cdefb34b40fdb70c7fd56f32c1293dde1b288

PASS — Completely different SHA-256 hashes. File content fully transformed.

Entropy Analysis

  File size: 224 bytes
  Unique byte values: 154 / 256
  Minimum required (60% of file size): 134

PASS — 154 unique byte values (68.8% byte diversity). Consistent with proper AES encryption — a perfectly random 224-byte file would average ~155 unique bytes.

Wrong-Key Decryption

Forensic Evidence

{
  "iv": "1cc77229ded658c3...",
  "algorithm": "AES-256-CBC",
  "key_source": "entropy",
  "timestamp": 1773776912,
  "warning": "Key derived from
    unreproducible system entropy.
    Decryption is impossible."
}

{
  "local_device": "79DD1A3C...",
  "remote_device_tag": "30436CB6...",
  "process_entropy_sources": 633,
  "key_derivation": "SHA-256 of
    system entropy",
  "warning": "Key is unreproducible.
    File cannot be decrypted."
}

9. Defense Model: Traditional DLP vs OpenDLP

Figure 5 — Traditional DLP (block-and-hope) vs OpenDLP (detect-and-neutralize)

Attack Vectors Covered

11. Key Technologies

xattr -w com.transpansomware.device "30436CB6-7241-5620-AAB8-7FCAB6C08D06" confidential.txt

{
  "sanctioned_processes": ["git", "xcode", "vim", "nano", "code", "sublime_text"],
  "sanctioned_domains": ["github.com", "gitlab.com"]
}

13. Conclusion

On March 17, 2026, OpenDLP demonstrated real-world cross-machine data exfiltration defense between two physical macOS devices. A file containing Social Security numbers, API keys, credit card numbers, and passwords was pulled from a MacBook Pro to a MacBook Air via SCP — a standard lateral movement technique used in enterprise attacks.

OpenDLP detected the exfiltration through device identity mismatch, flagged the transfer process as unsanctioned, encrypted the stolen data with AES-256-CBC using an unreproducible entropy key, and permanently destroyed the plaintext. The encryption key was used once and immediately discarded.

The attacker was left with a 224-byte encrypted blob that can never be decrypted. No SSNs, no API keys, no passwords, no credit card numbers — just random-looking ciphertext and a metadata file that reads: "Key derived from unreproducible system entropy. Decryption is impossible."