W2QR

Basic, Advanced & Shamir Modes

W2QR offers three security levels. Choose the one that fits your needs. The encrypted data can come from any source (scan, upload, or Google Drive) — that choice is independent of the security mode.

Basic Mode — QR + Password

Basic mode encrypts your seed phrase with your password using honey encryption. The resulting QR code is your backup. To restore, you need the QR and your password — nothing else.

How it works: Your password goes through Argon2id (64 MB memory, 3 iterations), producing a key that is XOR-mixed with your mnemonic entropy. Every password produces a valid mnemonic — there is no way to tell which one is correct without checking the blockchain.

+ Simple — one password, one QR code
+ Works completely offline
+ No account or device registration needed
+ Compatible with all BIP-39 wallets
- If you forget your password, there is no recovery
- Security depends entirely on password strength

Advanced Mode — QR + Password + Authorization Factor

Advanced mode adds a 256-bit authorization secret (S) to the encryption. To unlock your wallet, you need your password plus one of three authorization methods:

Device / BiometricFace ID, fingerprint, or platform authenticator. S is bound to your device hardware via WebAuthn.
Google AccountSign in with Google to release S from the W2QR server. Google never receives your password or seed phrase.
Recovery CodeA printed code that can recover S offline. Store it with your QR as a paper backup.
+ Even if QR + password leak, the attacker still needs your device, Google Account, or Recovery Code
+ Forgot your password? Recover with any 2 of: Google Account, device, Recovery Code
+ Lost your QR? Restore encrypted data from Google Drive (data source only — does not unlock)
+ Honey encryption still active — wrong password + wrong S produces valid decoys
- Requires initial setup (register device or sign in with your Google Account)
- Device-bound credentials are lost if you reset the device without backup

Shamir Shares Mode — M-of-N Distributed Custody

Shamir Shares mode splits your mnemonic entropy into N shares using Shamir Secret Sharing, then honey-encrypts each share independently with its own password. Each share becomes a standalone QR code or encrypted text string.

Password modes: Choose one password for all shares (simpler) or individual passwords per share (stronger — ideal when different people hold different shares).

+ No single share reveals any information about the mnemonic
+ Works completely offline — no account, no server, no device enrollment
+ Each share is independently honey-encrypted (Argon2id + XOR)
+ Ideal for multi-party custody (family, team, inheritance)
- No password recovery — if you forget passwords, shares are unusable
- No cloud backup — you manage share storage yourself
- Must gather M shares physically to restore

When to use which?

ScenarioRecommended
Quick backup, comfortable with strong passwordsBasic
Long-term storage, high-value walletsAdvanced
Worried about forgetting the passwordAdvanced (disaster recovery)
No Google account, no biometric deviceBasic
Completely offline / air-gapped setupBasic
Multi-party custody (family, team, DAO)Shamir Shares
Geographically distributed backupsShamir Shares
Inheritance / dead man's switchShamir Shares

Can I upgrade later?

Yes. You can upgrade a Basic QR to Advanced at any time. Open your Basic QR, and W2QR will offer to upgrade it — generating a new Advanced QR with the same seed phrase. Your old Basic QR continues to work. You can also create Shamir Shares from an existing mnemonic at any time.

Disaster Recovery (Advanced only)

Advanced mode creates a recovery safety net using Shamir Secret Sharing. A recovery root (R) is split into 3 shares distributed across your Google Account (R1), your device (R2), and your Recovery Code (R3). Any 2 of the 3 can recover your wallet — even if you forget your password. Note: Shamir Shares mode does not include this recovery system — the shares themselves are the only backup.

Learn more about recovery →