BUILD YOUR OWN
BITCOIN SIGNING DEVICE

using a raspberry pi zero (VERSION 1.3)

You can build an offline, air-gapped Bitcoin transaction signing device from off-the-shelf components for less than $50!

The fastest and easiest way to run the latest version of SeedSigner is to download our most recent release.

Want to maximize your signer’s trustlessness? Check out our manual build instructions to build from the source code.

The Orange Pill enclosure design is open source too! Print your own or mod the case design.

About SeedSigner

The goal of SeedSigner is to lower the cost and complexity of Bitcoin multi-signature wallet use. To accomplish this goal, SeedSigner offers anyone the opportunity to build a verifiably air-gapped, stateless Bitcoin signing device using inexpensive, publicly available hardware components (usually < $50). SeedSigner helps users save with Bitcoin by assisting with trustless private key generation and multi-signature wallet setup, and helps users transact with Bitcoin via a secure, air-gapped QR-exchange signing model.

Use SeedSigner to complete these tasks:

  • Calculate word 12/24 of a BIP39 seed phrase
  • Create a 24-word BIP39 seed phrase with 99 dice rolls
  • Create a 24-word BIP39 seed phrase by taking a digital photo
  • Temporarily store up to 3 seed phrases while device is powered
  • Guided interface to manually create a SeedQR for instant input
  • BIP39 passphrase / word 25 support
  • Native Segwit Multisig XPUB generation w/ QR display
  • Scan and parse transaction data from animated QR codes
  • Sign transactions & transfer XPUB data using animated QR codes
  • Live preview during photo-to-seed and QR scanning UX
  • Optimized seed word entry interface
  • Support for Bitcoin Mainnet & Testnet
  • Support for custom user-defined derivation paths
  • On-demand receive address verification
  • User-configurable QR code display density
  • Responsive, event-driven user interface

The key component in SeedSigner is a specific version of the Raspberry Pi Zero single board computer (version 1.3) that does not include WiFi or Bluetooth functionality; the absence of these modules ensures that your private keys never leave the device. Communication with wallet software is accomplished using a two-way QR code exchange process. Information about a proposed transaction is displayed by the wallet software on your computer’s screen, encoded in multiple QR codes, and you scan in the transaction information using SeedSigner’s built-in camera. Information about the proposed transaction is then displayed on the SeedSigner screen. Using cryptographic signatures, SeedSigner then proves that it has the correct private keys to authorize the transaction, and QR codes demonstrating that proof are displayed on SeedSigner’s screen. You then use your computers web-camera to input the QR codes generated by SeedSigner to authorize the transaction.

SeedSigner is built to be compatible with Specter-Desktop, Sparrow Wallet and BlueWallet Multisig Vaults.

Visit our SeedSigner Telegram community for support and feedback

SEEDSIGNER DEVELOPMENT FUND

Please consider making a donation to our development fund

It is jointly managed by 5 key stakeholders in the SeedSigner project and earmarked to support the work of our contributors!