SeedLock
SeedLock logo: a bird cage holding a seed

SeedLock

Open source and works only in offline mode.

Lock your seed phrase. Keep it anywhere.

// what it does

SeedLock turns a BIP39 recovery phrase into a small encrypted backup, protected by your password. Store it in the cloud, on a USB stick or in an e-mail: without the password it is useless.

Turn an old laptop into an air-gapped Bitcoin signing device, and keep your seed completely offline. No special hardware required: just an ordinary computer, a USB stick, and a true air-gap protected by cryptography.

Learn more
// command line

Backups from your terminal

Create, read and export backups with the command-line program, including a QR code of the backup that a phone can scan.

Passwords are stretched with Argon2id and the phrase is sealed with XChaCha20-Poly1305. Any change to the file is detected.

Argon2idXChaCha20-Poly1305100 bytes
Terminal

=== SeedLock 0.3.0: offline Bitcoin seed tool ===
It works only on a computer that is not connected to any network.

SEEDLOCK WORKS ONLY OFFLINE

This computer is connected to a network (through wlan0, wg0-mullvad). SeedLock does not work while a connection is possible: other programs could see your seed words or your password while they are on the screen or being typed.

Disconnect it: turn off Wi-Fi and unplug any network cable. Best of all, use a computer that is never connected.

Press Enter to check again, or type q to quit:

22:01
SeedLock
SEEDLOCK WORKS ONLY OFFLINE. Airplane mode is off. It is connected to a network (WIFI). Turn on airplane mode, and keep Wi-Fi, mobile data and Bluetooth off. SeedLock checks every second, and opens as soon as the phone is offline.

SeedLock cannot use the internet in any case: Android does not give it the permission to. It still does nothing while the phone is online, because other apps could then send away what is on the screen or typed; and if the phone goes online while SeedLock is open, it closes everything at once.

Check again

SeedLock 0.3.0, phone app preview.

// android app

Scan, name, restore

The phone app reads a backup from its QR code and suggests the name stored with it. Everything is checked against typos before any expensive work starts.

Get the Android apkCommand-line program