SeedSigner+ Premium
This is the same SeedSigner+ I sell as the SeedSigner Plus, with the 3D printed shell replaced by a CNC machined aluminium case. Same 2.8 inch IPS screen, same DPAD, different body. SeedSigner is stateless. No private key is stored on the device, so there is nothing on it to steal. It reads your seed as a SeedQR, signs the transaction, and forgets everything the moment you unplug it. No wifi, no bluetooth, no battery, no storage. The aluminium does not make the signing any safer. It makes the device survive a drawer, a pocket and a few years of being handled.
Over dit product
Hardware
- CNC machined aluminium enclosure
- Raspberry Pi Zero 1.3, without wifi
- 2.8 inch IPS 240×320 display
- DPAD-knoppen
- ZeroCam mini camera
- USB-C power only port
- Spring loaded microSD extension
What is in the box
The signer, a USB-C power cable and a set of 25×25 SeedQR cards. No microSD card.
You supply the microSD card yourself. That is normal for a signing device, because the card is the firmware: whoever writes it decides what code runs on the machine that touches your seed. The SeedSigner project publishes its release image and asks you to flash and verify it yourself. A card I flashed for you is a card you would have to take my word for.
The cable is a different matter. It carries power and nothing else, so there is nothing on it to take on trust.
What it does
- Generate a BIP39 seed phrase from dice rolls or from the entropy in a photo
- Calculate the last word of a 12 or 24 word seed phrase
- BIP39 passphrase support
- Native segwit multisig xpub export as a QR code
- Scan, sign and return transactions as animated QR codes
- Verify a receive or change address on the device itself
- Derive BIP85 child seed phrases
- Bitcoin mainnet, testnet and regtest
How you use it
Nothing but power ever goes down the cable. Your wallet shows an unsigned transaction as a QR code, the SeedSigner reads it with the camera, you approve it on the screen, and it hands the signed transaction back as an animated QR code for your wallet to scan. The air gap is never crossed.
Because the device stores nothing, your backup is the only thing that matters. A Seedfan steel backup or a Titanium QR holds your seed in QR form, which is exactly what this device scans.
The software is the free and open source SeedSigner-project. The code is on GitHub, and you can build and flash the microSD card yourself rather than trust anyone else’s image.