Part of getting into bitcoin is taking self-custody of your funds; each day that you don’t, you’re taking a greater risk of an amount of bitcoin you might not be able to acquire again in the future. What I mean by this is today, you might be able to buy and hold 1 Bitcoin, but if you lose it due to an issue with your custody provider and try to buy it back once the price has run up, it might be out of the ballpark for you.
This is not some theoretical case; this is a painful reality that many in the past have faced, and many will continue to learn in the future. Self-custody is one of bitcoins’ primary features; being able to hold any amount of wealth with only a set of 24 words is a revolutionary action and one you should consider if you want to get the most out of your bitcoin experience.
Failure to do so could turn into a costly lesson.
Over the last ten years and countless horror stories later, we’ve seen several device manufacturers come into the bitcoin space to provide hardware signing devices, and there are some great pre-build options around.
But they are by no means the only solution in a bitcoiners’ arsenal.
Go free and open source
No device manufacturer has a monopoly over the market, you can choose to purchase their device due to the convenience and support they offer, or you can leverage the bitcoin FOSS ecosystem and build your own solutions.
SeedSigner is the new option for bitcoin holders and focuses on the emerging space of DIY bitcoin hardware wallets. It gives you the chance to experiment and get a greater feel for what a signing device is all about and certainly, does things differently compared to the other hardware wallets on the market.
The project was “born” on December 14, 2020, and has started to gain some serious traction within bitcoin circles.
What is SeedSigner?
SeedSigner is an open source project centred around a bitcoin signing device or as commonly referred to as a hardware wallet. SeedSigners software allows you to convert a few hardware items into a fully functioning bitcoin storage device.
The goal of SeedSigner is to offer people an alternative self-custody solution that lowers the cost and complexity of Bitcoin multi-signature wallet use. SeedSigner allows anyone to build a verifiably air-gapped, stateless Bitcoin signing device that helps users save with Bitcoin.
The SeedSigner device assists with bitcoin security by providing a trustless private key generation and multi-signature wallet setup and helps users transact with Bitcoin via a secure, air-gapped QR-exchange signing model.
Why use SeedSigner?
If you live in a country where hardware wallets need to be shipped far and wide and can take ages, don’t have much faith in your local delivery services, don’t trust resellers of hardware in your region, or simply want a low-cost device for yourself to give out. Then SeedSigner is a great option.
- It’s cheap to make (costing $50)
- It allows for QR communication between the device and the computer
- It is non-persistent
- It’s a bring-your-own-entropy (BYOE) device
- It is made of general-purpose hardware
What parts do I need?
If you want to start with SeedSigner, the first step would be to bag all the physical parts needed for assembly.
To build yours, you’ll need:
- Raspberry Pi Zero (no WiFi)
- SD card
- Waveshare 1.3-inch LCD
- AuviPal 5MP camera with OV5647 sensor
- MakerHawk ribbon cable
- GPIO Hammer Header (male)
- Four F-F M2.5 spacers (10 mm)
- Four M2.5 pan-head screws (6 mm)
- Four M2.5 pan-head screws (12 mm)
- 3D-printed case
- One joystick
- Three plastic buttons
Apart from 3D printing your own case, most of the parts are available on Amazon or at your local tech and gadget stores.
What can you do with a SeedSigner?
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 the 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
- Optimised 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
Tips when using SeedSigner
- Seedsigner is built for compatibility with Specter Desktop, Sparrow, and BlueWallet Vaults
- The device takes up to 60 seconds to boot before the menu appears, so please be patient!
- Always test your setup before transferring larger amounts of bitcoin (A protip would be to try using the bitcoin testnet first!)
- Taproot is not quite yet supported by SeedSigner devices, so you cannot generate those addresses or sign with them.
- Slightly rotating the screen clockwise or counter-clockwise should resolve lighting/glare issues
Enough talk, let’s get your hands DIY dirty
If you’d like a more detailed review of how SeedSigner devices work, check out this epic tutorial by BTC sessions.
If you prefer written guides, then check out this SeedSigner guide by Bitcoin Magazine
The device is perfect for someone who is a relative beginner and wants to learn how Bitcoin works under the hood. The project is very easy to put together, and because all of the steps in a transaction are broken up, you get to do them separately and manually — you get to look under the hood.
Follow the project
There you have it, a detailed breakdown of how to start building your signing device and keep your funds offline and secure. You could use this to create a low-cost wallet for yourself or give it out to friends and family. Get them involved in building their own security tools and get their hands dirty while learning all about bitcoin.
If you’d like to learn more about the project or want to try it, then check out the following resources.
Are you a bitcoin hodler?
Are you using bitcoin cold storage devices? Which device is your favourite? Do you have one you’d like us to cover? Let us know in the comments down below.
