Install The Software

Installation and verification of the controller software.


Get the latest version of the SeedHammer software.

  • Download the disk image seedhammer-vX.Y.Z.img
  • Download the signature file seedhammer-vX.Y.Z.img.sig

...where vX.Y.Z is the most recent version number.

In addition download our public signing key.

  • This file should be downloaded only once and re-used for verification of future software versions.

All 3 files should be in the same directory:

all files should be in the same directory

Verify Image

Verify the software image signature.

  • Verify the seedhammer-vX.Y.Z.img with the ssh-keygen tool: $ ssh-keygen -Y verify -f -I -n seedhammer.img -s seedhammer-vX.Y.Z.img.sig < seedhammer-vX.Y.Z.img
  • The command should succeed with a message similar to: Good "seedhammer.img" signature for with ED25519 key SHA256:xqo5VI7m8vh8UHgceOt27dep1EZ7SyCFjJOogcQBrvw

For extra security build the software from source code. Instructions are in our GitHub README.

Write Image

Write seedhammer-vX.Y.Z.img to an empty or unused microSD card.

On Windows and macOS, use a tool like balenaEtcher.

On linux, use a tool like dd:

dd if=seedhammer-vx.y.z.img of=/dev/sdx conv=fdatasync bs=1M

Start The Controller

Never connect the controller to a computer, use a regular power adapter.

Test that the microSD card works by starting the controller.

  • Install the microSD card into a compatible controller (SeedSigner).
  • Power on the controller by plugging a micro-USB cable into the outermost port.
  • Remove the microSD card when the startup screen appears.

Power device


  • The controller should be powered on via the outermost USB port as the SeedHammer machine must use the middle port.

After starting the software, proceed to load a seed.