How VaultPass works
A full walkthrough of client-side encryption, the dead man's switch, and exactly what data VaultPass holds vs. what stays on your device.
You enter your seed phrase
Your seed phrase is typed into the vault editor in your browser. It never leaves your device in plaintext.
A random vault key is generated
Your browser generates a fresh random 256-bit AES-256-GCM key via the Web Crypto CSPRNG. It is not derived from any password.
AES-256-GCM encrypts your vault
Your seed phrases and wallet instructions are encrypted in-browser using AES-256-GCM with a random 96-bit IV. GCM mode provides both encryption and authentication โ tampering is detectable.
The key is split into 3 shards
The random key is split via Shamir's Secret Sharing (2-of-3). Your owner shard stays on your device; the heir and sentinel shards are encrypted and uploaded. Any 2 shards reconstruct the key; 1 reveals nothing.
Prove it yourself โOnly ciphertext + encrypted shards are sent
The encrypted blob (ciphertext + IV + auth tag) and the encrypted heir/sentinel shards are uploaded. VaultPass stores them as opaque bytes and does not decrypt them in normal operation.
Dead man's switch monitors check-ins
Our server tracks only your check-in timestamps. If you miss your interval, a grace period and reminders begin. After the switch fires, your heir is notified.
Your heir reconstructs the vault
Your heir opens a one-time link; the heir and sentinel shards are released and combined in their browser to rebuild the key and decrypt the vault. No password required โ decryption happens entirely on their device.
- โEncrypted vault blob (ciphertext)
- โEncrypted heir + sentinel shards
- โIV / nonce (required, not secret)
- โHeir email address
- โCheck-in timestamps
- โSubscription status
- โYour plaintext seed phrases
- โYour owner shard
- โYour wallet addresses / private keys
- โThe reconstructed vault key
VaultPass stores your vault as ciphertext and holds the encrypted heir and sentinel shards. You hold your own shard, on your device. The vault is only rebuilt when shards are combined โ which happens automatically when the dead man's switch fires.
VaultPass is a conduit, not a custodian. We transport and store encrypted bytes. The cryptographic keys exist only in your mind and your heir's mind. Even a complete breach of our infrastructure exposes nothing recoverable without your master password.