Security Transparency

Exactly how Lockbox protects your data. No hand-waving. No "military-grade" nonsense. Just facts.

Encryption algorithms

AES-256-GCM

All data at rest. NIST-approved. Authenticated encryption prevents tampering.

PBKDF2-SHA256

Master password to key. 600,000 iterations via native C++ (OpenSSL). OWASP standard.

HKDF-SHA512

Derives separate keys for vault, sync, and sharing from one master key.

Per-Item Encryption

Every item is encrypted separately with AES-256-GCM under your vault key, each with its own random nonce and authentication tag.

Key hierarchy

Master Password
  ↓ PBKDF2-SHA256 (600,000 iterations, native)
Master Key
  ├─ HKDF → Vault Key → encrypts each item separately
  ├─ HKDF → Export Key → encrypts backup files
  └─ HKDF → Whisper Key → derives sharing keys

Cloud sync deliberately sits outside this hierarchy. Your master key cannot derive it, because every install has its own random PBKDF2 salt, so the same master password produces a different master key on each device. The sync key is derived separately from a sync passphrase you choose, which is why you enter that passphrase once per device.

What leaves your device

ActionData sentCan we read it?
Normal useNothingN/A
Whisper shareEncrypted ciphertext onlyNo. Key is in URL fragment.
Cloud sync (optional)Encrypted blobs to Lockbox servers, plus routing metadata (anonymous account ID, device ID, item IDs, change times)No. Encrypted on your device; we hold no keys.

What we cannot do

Even if compelled by a government, subpoena, or court order, we cannot:

This is not a policy decision. It is a mathematical impossibility. We do not have the keys.

Our security features

Every feature is built with security first. Here is exactly what protects your data.

AES-256-GCM Encryption

What it does: Every item in your vault is encrypted with AES-256-GCM, the same standard used by banks and governments. GCM mode provides authenticated encryption, meaning it both encrypts and verifies that data has not been tampered with.

Why it matters: Even if someone gains access to your device storage, they see only encrypted data. Without your master password, your vault is unreadable.

PBKDF2-SHA256 Key Derivation (600,000 iterations)

What it does: Your master password is transformed into an encryption key using 600,000 rounds of PBKDF2-SHA256. This runs via native C++ (OpenSSL/CommonCrypto) for consistent performance on both iOS and Android.

Why it matters: 600,000 iterations meets the OWASP 2023 standard. Each brute-force guess costs significant computation time, making password cracking impractical.

Per-Item Encryption

What it does: Each item in your vault is encrypted individually with AES-256-GCM, using a fresh random nonce per item. Your vault key is itself derived from your master password via PBKDF2-SHA256 (600,000 iterations) and HKDF-SHA512.

Why it matters: Items are stored and decrypted independently, so the app never needs to hold your whole vault in plaintext at once. Your keys never leave your device.

Runtime protection

FeatureDetail
ClipboardAuto-cleared after 10 seconds
Auto-lockLocks when app goes to background
Biometric unlockKey stored in the OS keychain (iOS Keychain / Android Keystore)
Dead Man's SwitchAuto-wipe after 7/14/30 days of inactivity
Rate limitingProgressive lockouts after 5/10/20 failed attempts

Open source cryptography

We use only proven, well-tested libraries (@noble/ciphers and @noble/hashes). No hand-rolled cryptography. These are widely audited, open-source libraries trusted by thousands of projects.

What about a security audit?

We have not yet completed a formal third-party security audit. We are transparent about this. We use only well-audited, open-source crypto libraries (@noble/ciphers and @noble/hashes). A formal audit will be funded from revenue and the results published here.

Contact

Found a vulnerability? Email security@lockboxnow.app

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