This project allows you to use various hardware security devices to operate GPG and SSH. Instead of keeping your key on your computer and decrypting it with a passphrase when you want to use it, the key is generated and stored on the device and never reaches your computer. Read more about the design here.

You can do things like sign your emails, git commits, and software packages, manage your passwords (with pass and gopass, among others), authenticate web tunnels and file transfers, and more.

See SatoshiLabs' blog posts about this feature:

• TREZOR Firmware 1.3.4 enables SSH login
• TREZOR Firmware 1.3.6 — GPG Signing, SSH Login Updates and Advanced Transaction Features for Segwit
• TREZOR Firmware 1.4.0 — GPG decryption support

Currently TREZOR One, TREZOR Model T, Keepkey, and Ledger Nano S are supported.

• Installation instructions are here

• SSH instructions and common use cases are here

  Note: If you're using Windows, see trezor-ssh-agent by Martin Lízner.

• GPG instructions and common use cases are here

• Instructions to configure a Trezor-style PIN entry program are here